WorldWideScience

Sample records for enhances remediation efficiency

  1. Effect of heterogeneity on enhanced reductive dechlorination: Analysis of remediation efficiency and groundwater acidification

    Science.gov (United States)

    Brovelli, A.; Lacroix, E.; Robinson, C. E.; Gerhard, J.; Holliger, C.; Barry, D. A.

    2011-12-01

    Enhanced reductive dehalogenation is an attractive in situ treatment technology for chlorinated contaminants. The process includes two acid-forming microbial reactions: fermentation of an organic substrate resulting in short-chain fatty acids, and dehalogenation resulting in hydrochloric acid. The accumulation of acids and the resulting drop of groundwater pH are controlled by the mass and distribution of chlorinated solvents in the source zone, type of electron donor, alternative terminal electron acceptors available and presence of soil mineral phases able to buffer the pH (such as carbonates). Groundwater acidification may reduce or halt microbial activity, and thus dehalogenation, significantly increasing the time and costs required to remediate the aquifer. In previous work a detailed geochemical and groundwater flow simulator able to model the fermentation-dechlorination reactions and associated pH change was developed. The model accounts for the main processes influencing microbial activity and groundwater pH, including the groundwater composition, the electron donor used and soil mineral phase interactions. In this study, the model was applied to investigate how spatial variability occurring at the field scale affects dechlorination rates, groundwater pH and ultimately the remediation efficiency. Numerical simulations were conducted to examine the influence of heterogeneous hydraulic conductivity on the distribution of the injected, fermentable substrate and on the accumulation/dilution of the acidic products of reductive dehalogenation. The influence of the geometry of the DNAPL source zone was studied, as well as the spatial distribution of soil minerals. The results of this study showed that the heterogeneous distribution of the soil properties have a potentially large effect on the remediation efficiency. For examples, zones of high hydraulic conductivity can prevent the accumulation of acids and alleviate the problem of groundwater acidification. The

  2. Microemulsion-enhanced remediation of soils contaminated with organochlorine pesticides.

    Science.gov (United States)

    Zhang, Yanlin; Wong, Jonathan W C; Zhao, Zhenyong; Selvam, Ammaiyappan

    2011-12-01

    Soil contaminated by organic pollutants, especially chlorinated aromatic compounds such as DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), is an environmental concern because of the strong sorption of organochlorine pesticide onto the soil matrix and persistence in the environment. The remediation of organochlorine pesticide contaminated soils through microemulsion is an innovative technology to expedite this process. The remediation efficiency was evaluated by batch experiments through studying the desorption of DDT and hexachlorocyclohexane (y-HCH) and sorption of microemulsion composed of Triton X-100, 1-pentanol and linseed oil in the soil-surfactant-water suspension system. The reduction of desorption efficiency caused by the sorption loss of microemulsion components onto the soil could be corrected by the appropriate adjustment of C/S (Cosurfactant/Surfactant) and O/S (Oil/Surfactant) ratio. The C/S and O/S ratios of 1:2 and 3:20 were suitable to desorb DDT and gamma-HCH from the studied soils because of the lower sorption of Triton X-100 onto the soil. Inorganic salts added in microemulsion increased the pesticides desorption efficiency of pesticides and calcium chloride has a stronger ability to enhance the desorption of DDT than sodium chloride. From the remediation perspective, the balance of surfactant or cosurfactant sorbed to soil and desorption efficiency should be taken into consideration to enhance the remediation of soils contaminated by organochlorine pesticides.

  3. Enhanced electrokinetic remediation of lead-contaminated soil by complexing agents and approaching anodes.

    Science.gov (United States)

    Zhang, Tao; Zou, Hua; Ji, Minhui; Li, Xiaolin; Li, Liqiao; Tang, Tang

    2014-02-01

    Optimizing process parameters that affect the remediation time and power consumption can improve the treatment efficiency of the electrokinetic remediation as well as determine the cost of a remediation action. Lab-scale electrokinetic remediation of Pb-contaminated soils was investigated for the effect of complexant ethylenediaminetetraacetic acid (EDTA) and acetic acid and approaching anode on the removal efficiency of Pb. When EDTA was added to the catholyte, EDTA dissolved insoluble Pb in soils to form soluble Pb-EDTA complexes, increasing Pb mobility and accordingly removal efficiency. The removal efficiency was enhanced from 47.8 to 61.5 % when the EDTA concentration was increased from 0.1 to 0.2 M, showing that EDTA played an important role in remediation. And the migration rate of Pb was increased to 72.3 % when both EDTA and acetic acid were used in the catholyte. The "approaching anode electrokinetic remediation" process in the presence of both EDTA and acetic acid had a higher Pb-removal efficiency with an average efficiency of 83.8 %. The efficiency of electrokinetic remediation was closely related to Pb speciation. Exchangeable and carbonate-bounded Pb were likely the forms which could be removed. All results indicate that the approaching anode method in the presence of EDTA and acetic acid is an advisable choice for electrokinetic remediation of Pb-contaminated soil.

  4. Lead (II) removal from natural soils by enhanced electrokinetic remediation.

    Science.gov (United States)

    Altin, Ahmet; Degirmenci, Mustafa

    2005-01-20

    Electrokinetic remediation is a very effective method to remove metal from fine-grained soils having low adsorption and buffering capacity. However, remediation of soil having high alkali and adsorption capacity via the electrokinetic method is a very difficult process. Therefore, enhancement techniques are required for use in these soil types. In this study, the effect of the presence of minerals having high alkali and cation exchange capacity in natural soil polluted with lead (II) was investigated by means of the efficiency of electrokinetic remediation method. Natural soil samples containing clinoptilolite, gypsum and calcite minerals were used in experimental studies. Moreover, a sample containing kaolinite minerals was studied to compare with the results obtained from other samples. Best results for soils bearing alkali and high sorption capacity minerals were obtained upon addition of 3 mol AcH and application of 20 V constant potential after a remediation period of 220 h. In these test conditions, lead (II) removal efficiencies for these samples varied between 60% and 70% up to 0.55 normalized distance. Under the same conditions, removal efficiencies in kaolinite sample varied between 50% and 95% up to 0.9 normalized distance.

  5. Microwave thermal remediation of crude oil contaminated soil enhanced by carbon fiber.

    Science.gov (United States)

    Li, Dawei; Zhang, Yaobin; Quan, Xie; Zhao, Yazhi

    2009-01-01

    Thermal remediation of the soil contaminated with crude oil using microwave heating enhanced by carbon fiber (CF) was explored. The contaminated soil was treated with 2.45 GHz microwave, and CF was added to improve the conversion of microwave energy into thermal energy to heat the soil. During microwave heating, the oil contaminant was removed from the soil matrix and recovered by a condensation system of ice-salt bath. The experimental results indicated that CF could efficiently enhance the microwave heating of soil even with relatively low-dose. With 0.1 wt.% CF, the soil could be heated to approximately 700 degrees C within 4 min using 800 W of microwave irradiation. Correspondingly, the contaminated soil could be highly cleaned up in a short time. Investigation of oil recovery showed that, during the remediation process, oil contaminant in the soil could be efficiently recovered without causing significant secondary pollution.

  6. Sustainable Remediation for Enhanced NAPL Recovery from Groundwater

    Science.gov (United States)

    Javaher, M.

    2012-12-01

    Sustainable remediation relates to the achievement of balance between environmental, social, and economic elements throughout the remedial lifecycle. A significant contributor to this balance is the use of green and sustainable technologies which minimize environmental impacts, while maximizing social and economic benefits of remedial implementation. To this end, a patented mobile vapor energy generation (VEG) technology has been developed targeting variable applications, including onsite soil remediation for unrestricted reuse and enhanced non-aqueous phase liquid (NAPL) recover at the water table. At the core of the mobile VEG technology is a compact, high efficiency vapor generator, which utilizes recycled water and propane within an entirely enclosed system to generate steam as high as 1100°F. Operating within a fully enclosed system and capturing all heat that is generated within this portable system, the VEG technology eliminates all emissions to the atmosphere and yields an undetected carbon footprint with resulting carbon dioxide concentrations that are below ambient levels. Introduction of the steam to the subsurface via existing wells results in a desired change in the NAPL viscosity and the interfacial tension at the soil, water, NAPL interface; in turn, this results in mobilization and capture of the otherwise trapped, weathered NAPL. Approved by the California Air Resources Control Board (and underlying Air Quality Management Districts) and applied in California's San Joaquin Valley, in-well heating of NAPLs trapped at the water table using the VEG technology has proven as effective as electrical resistivity heating (ERH) in changing the viscosity of and mobilizing NAPLs in groundwater in support of recovery, but has achieved these results while minimizing the remedial carbon footprint by 90%, reducing energy use by 99%, and reducing remedial costs by more than 95%. NAPL recovery using VEG has also allowed for completion of source removal historically

  7. Citric-acid preacidification enhanced electrokinetic remediation for removal of chromium from chromium-residue-contaminated soil.

    Science.gov (United States)

    Meng, Fansheng; Xue, Hao; Wang, Yeyao; Zheng, Binghui; Wang, Juling

    2018-02-01

    Electrokinetic experiments were conducted on chromium-residue-contaminated soils collected from a chemical plant in China. Acidification-electrokinetic remediation technology was proposed in order to solve the problem of removing inefficient with ordinary electrokinetic. The results showed that electrokinetic remediation removal efficiency of chromium from chromium-contaminated soil was significantly enhanced with acidizing pretreatment. The total chromium [Cr(T)] and hexavalent chromium [Cr(VI)] removal rate of the group acidized by citric acid (0.9 mol/L) for 5 days was increased from 6.23% and 19.01% in the acid-free experiments to 26.97% and 77.66% in the acidification-treated experiments, respectively. In addition, part of chromium with the state of carbonate-combined will be converted into water-soluble state through acidification to improve the removal efficiency. Within the appropriate concentration range, the higher concentration of acid was, the more chromium was released. So the removal efficiency of chromium depended on the acid concentration. The citric acid is also a kind of complexing agent, which produced complexation with Cr that was released by the electrokinetic treatment and then enhanced the removal efficiency. The major speciation of chromium that was removed from soils by acidification-electrokinetics remediation was acid-soluble speciation, revivification speciation and oxidation speciation, which reduced biological availability of chromium.

  8. Selecting enhancing solutions for electrokinetic remediation of dredged sediments polluted with fuel.

    Science.gov (United States)

    Rozas, F; Castellote, M

    2015-03-15

    In this paper a procedure for selecting the enhancing solutions in electrokinetic remediation experiments is proposed. For this purpose, dredged marine sediment was contaminated with fuel, and a total of 22 different experimental conditions were tested, analysing the influence of different enhancing solutions by using three commercial non-ionic surfactants, one bio-surfactant, one chelating agent, and one weak acid. Characterisation, microelectrophoretic and electrokinetic remediation trials were carried out. The results are explained on the basis of the interactions between the fuel, the enhancing electrolytes and the matrix. For one specific system, the electrophoretic zeta potential, (ζ), of the contaminated matrix in the solution was found to be related to the electroosmotic averaged ζ in the experiment and not to the efficiency in the extraction. This later was correlated to a parameter accounting for both contributions, the contaminant and the enhancing solution, calculated on the basis of differences in the electrophoretic ζ in different conditions which has allowed to propose a methodology for selection of enhancing solutions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Enhancement Solution to Improve Remediation of Soil Contaminated with Lead by Electrical Field

    Directory of Open Access Journals (Sweden)

    Ayad Abd Al-hamza Faisal

    2015-11-01

    Full Text Available A laboratory investigation of six different tests were conducted on silty clay soil spiked with lead in concentrations of 1500 mg/kg. A constant DC voltage gradient of 1 V/cm was applied for all these tests with duration of 7 days remediation process for each test. Different purging solutions and addition configurations, i.e. injection wells, were investigated experimentally to enhance the removal of lead from Iraqi soil during electro-kinetic remediation process. The experimental results showed that the overall removal efficiency of lead for tests conducted with distilled water, 0.1 M acetic acid, 0.2 M EDTA and 1 M ammonium citrate as the purging solutions were equal to 18 %, 37 %, 42 %, and 29 %, respectively. However, introducing the injection wells as another enhancement technique into the tests used the same purging solutions mentioned above which have vital role in increasing the removal efficiency up to 59 %.

  10. Enhancement of in situ Remediation of Hydrocarbon Contaminated Soil

    Energy Technology Data Exchange (ETDEWEB)

    Palmroth, M.

    2006-07-01

    Approximately 750 000 sites of contaminated land exist across Europe. The harmful chemicals found in Finnish soils include heavy metals, oil products, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorophenols, and pesticides. Petroleum and petroleum products enter soil from ruptured oil pipelines, land disposal of refinery products, leaking storage tanks and through accidents. PAH contamination is caused by the spills of coal tar and creosote from coal gasification and wood treatment sites in addition to oil spills. Cleanup of soil by bioremediation is cheaper than by chemical and physical processes. However, the cleaning capacity of natural attenuation and in situ bioremediation is limited. The purpose of this thesis was to find feasible options to enhance in situ remediation of hydrocarbon contaminants. The aims were to increase the bioavailability of the contaminants and microbial activity at the subsurface in order to achieve higher contaminant removal efficiency than by intrinsic biodegradation alone. Enhancement of microbial activity and decrease of soil toxicity during remediation were estimated by using several biological assays. The performance of these assays was compared in order to find suitable indicators to follow the progress of remediation. Phytoremediation and chemical oxidation are promising in situ techniques to increase the degradation of hydrocarbons in soil. Phytoremediation is plant-enhanced decontamination of soil and water. Degradation of hydrocarbons is enhanced in the root zone by increased microbial activity and through the detoxifying enzymes of plants themselves. Chemical oxidation of contaminants by Fenton's reaction can produce degradation products which are more biodegradable than the parent compounds. Fenton's reaction and its modifications apply solutions of hydrogen peroxide and iron for the oxidation of organic chemicals. The cost of oxidation can be reduced by aiming at partial instead of full

  11. Low-concentration tailing and subsequent quicklime-enhanced remediation of volatile chlorinated hydrocarbon-contaminated soils by mechanical soil aeration.

    Science.gov (United States)

    Ma, Yan; Du, Xiaoming; Shi, Yi; Xu, Zhu; Fang, Jidun; Li, Zheng; Li, Fasheng

    2015-02-01

    Mechanical soil aeration has long been regarded as an effective ex-situ remediation technique and as suitable for remediation of large-scale sites contaminated by volatile organic compounds (VOCs) at low cost. However, it has been reported that the removal efficiency of VOCs from soil is relatively low in the late stages of remediation, in association with tailing. Tailing may extend the remediation time required; moreover, it typically results in the presence of contaminants residues at levels far exceeding regulations. In this context, the present study aimed to discuss the tailing that occurs during the process of remediation of soils contaminated artificially with volatile chlorinated hydrocarbons (VCHs) and to assess possible quicklime-enhanced removal mechanisms. The results revealed the following conclusions. First, temperature and aeration rate can be important controls on both the timing of appearance of tailing and the levels of residual contaminants. Furthermore, the addition of quicklime to soil during tailing can reduce the residual concentrations rapidly to below the remedial target values required for site remediation. Finally, mechanical soil aeration can be enhanced using quicklime, which can improve the volatilization of VCHs via increasing soil temperature, reducing soil moisture, and enhancing soil permeability. Our findings give a basic understanding to the elimination of the tailing in the application of mechanical soil aeration, particularly for VOCs-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Enhanced remediation of an oily sludge with saline water ...

    African Journals Online (AJOL)

    Enhanced remediation of an oily sludge with saline water. ... the remediation of an oily sludge, which was part of the waste stream from the improvement ... m3 of fresh water respectively while 'treatment' reactors C and D received ...

  13. Decontamination formulation with additive for enhanced mold remediation

    Science.gov (United States)

    Tucker, Mark D [Albuquerque, NM; Irvine, Kevin [Huntsville, AL; Berger, Paul [Rome, NY; Comstock, Robert [Bel Air, MD

    2010-02-16

    Decontamination formulations with an additive for enhancing mold remediation. The formulations include a solubilizing agent (e.g., a cationic surfactant), a reactive compound (e.g., hydrogen peroxide), a carbonate or bicarbonate salt, a water-soluble bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate), a mold remediation enhancer containing Fe or Mn, and water. The concentration of Fe.sup.2+ or Mn.sup.2+ ions in the aqueous mixture is in the range of about 0.0001% to about 0.001%. The enhanced formulations can be delivered, for example, as a foam, spray, liquid, fog, mist, or aerosol for neutralization of chemical compounds, and for killing certain biological compounds or agents and mold spores, on contaminated surfaces and materials.

  14. Multi-Objective Optimization of the Setup of a Surfactant-Enhanced DNAPL Remediation

    NARCIS (Netherlands)

    Schaerlaekens, J.; Carmeliet, J.; Feyen, J.

    2005-01-01

    Surfactant-enhanced aquifer remediation (SEAR) is widely considered a promising technique to remediate dense nonaqueous phase liquid (DNAPL) contaminations in-situ. The costs of a SEAR remediation are important and depend mostly on the setup of the remediation. Costs can be associated with the

  15. Enhanced tolerance and remediation of anthracene by transgenic tobacco plants expressing a fungal glutathione transferase gene

    International Nuclear Information System (INIS)

    Dixit, Prachy; Mukherjee, Prasun K.; Sherkhane, Pramod D.; Kale, Sharad P.; Eapen, Susan

    2011-01-01

    Highlights: → Transgenic plants expressing a TvGST gene were tested for tolerance, uptake and degradation of anthracene. → Transgenic plants were more tolerant to anthracene and take up more anthracene from soil and solutions compared to control plants. → Using in vitro T 1 seedlings, we showed that anthracene-a three fused benzene ring compound was phytodegraded to naphthalene derivatives, having two benzene rings. → This is the first time that a transgenic plant was shown to have the potential to phytodegrade anthracene. - Abstract: Plants can be used for remediation of polyaromatic hydrocarbons, which are known to be a major concern for human health. Metabolism of xenobiotic compounds in plants occurs in three phases and glutathione transferases (GST) mediate phase II of xenobiotic transformation. Plants, although have GSTs, they are not very efficient for degradation of exogenous recalcitrant xenobiotics including polyaromatic hydrocarbons. Hence, heterologous expression of efficient GSTs in plants may improve their remediation and degradation potential of xenobiotics. In the present study, we investigated the potential of transgenic tobacco plants expressing a Trichoderma virens GST for tolerance, remediation and degradation of anthracene-a recalcitrant polyaromatic hydrocarbon. Transgenic plants with fungal GST showed enhanced tolerance to anthracene compared to control plants. Remediation of 14 C uniformly labeled anthracene from solutions and soil by transgenic tobacco plants was higher compared to wild-type plants. Transgenic plants (T 0 and T 1 ) degraded anthracene to naphthalene derivatives, while no such degradation was observed in wild-type plants. The present work has shown that in planta expression of a fungal GST in tobacco imparted enhanced tolerance as well as higher remediation potential of anthracene compared to wild-type plants.

  16. Electrokinetic-Enhanced Remediation of Phenanthrene-Contaminated Soil Combined with Sphingomonas sp. GY2B and Biosurfactant.

    Science.gov (United States)

    Lin, Weijia; Guo, Chuling; Zhang, Hui; Liang, Xujun; Wei, Yanfu; Lu, Guining; Dang, Zhi

    2016-04-01

    Electrokinetic-microbial remediation (EMR) has emerged as a promising option for the removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils. The aim of this study was to enhance degradation of phenanthrene (Phe)-contaminated soils using EMR combined with biosurfactants. The electrokinetic (EK) remediation, combined with Phe-degrading Sphingomonas sp. GY2B, and biosurfactant obtained by fermentation of Pseudomonas sp. MZ01, degraded Phe in the soil with an efficiency of up to 65.1 % at the anode, 49.9 % at the cathode after 5 days of the treatment. The presence of biosurfactants, electricity, and a neutral electrolyte stimulated the growth of the degrading bacteria as shown by a rapid increase in microbial biomass with time. The electrical conductivity and pH changed little during the course of the treatment, which benefitted the growth of microorganisms and the remediation of Phe-contaminated soil. The EMR system with the addition of biosurfactant had the highest Phe removal, demonstrating the biosurfactant may enhance the bioavailability of Phe and the interaction with the microorganism. This study suggests that the EMR combined with biosurfactants can be used to enhance in situ bioremediation of PAH-contaminated soils.

  17. Enhanced tolerance and remediation of anthracene by transgenic tobacco plants expressing a fungal glutathione transferase gene

    Energy Technology Data Exchange (ETDEWEB)

    Dixit, Prachy; Mukherjee, Prasun K.; Sherkhane, Pramod D.; Kale, Sharad P. [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Eapen, Susan, E-mail: eapenhome@yahoo.com [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2011-08-15

    Highlights: {yields} Transgenic plants expressing a TvGST gene were tested for tolerance, uptake and degradation of anthracene. {yields} Transgenic plants were more tolerant to anthracene and take up more anthracene from soil and solutions compared to control plants. {yields} Using in vitro T{sub 1} seedlings, we showed that anthracene-a three fused benzene ring compound was phytodegraded to naphthalene derivatives, having two benzene rings. {yields} This is the first time that a transgenic plant was shown to have the potential to phytodegrade anthracene. - Abstract: Plants can be used for remediation of polyaromatic hydrocarbons, which are known to be a major concern for human health. Metabolism of xenobiotic compounds in plants occurs in three phases and glutathione transferases (GST) mediate phase II of xenobiotic transformation. Plants, although have GSTs, they are not very efficient for degradation of exogenous recalcitrant xenobiotics including polyaromatic hydrocarbons. Hence, heterologous expression of efficient GSTs in plants may improve their remediation and degradation potential of xenobiotics. In the present study, we investigated the potential of transgenic tobacco plants expressing a Trichoderma virens GST for tolerance, remediation and degradation of anthracene-a recalcitrant polyaromatic hydrocarbon. Transgenic plants with fungal GST showed enhanced tolerance to anthracene compared to control plants. Remediation of {sup 14}C uniformly labeled anthracene from solutions and soil by transgenic tobacco plants was higher compared to wild-type plants. Transgenic plants (T{sub 0} and T{sub 1}) degraded anthracene to naphthalene derivatives, while no such degradation was observed in wild-type plants. The present work has shown that in planta expression of a fungal GST in tobacco imparted enhanced tolerance as well as higher remediation potential of anthracene compared to wild-type plants.

  18. Correlation between DNAPL distribution area and dissolved concentration in surfactant enhanced aquifer remediation effluent: a two-dimensional flow cell study

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Bin; Li, Huiying; Du, Xiaoming; Zhong, Lirong; Yang, Bin; Du, Ping; Gu, Qingbao; Li, Fasheng

    2016-02-01

    During the process of surfactant enhanced aquifer remediation (SEAR), free phase dense non-aqueous phase liquid (DNAPL) may be mobilized and spread. The understanding of the impact of DNAPL spreading on the SEAR remediation is not sufficient with its positive effect infrequently mentioned. To evaluate the correlation between DNAPL spreading and remediation efficiency, a two-dimensional sandbox apparatus was used to simulate the migration and dissolution process of 1,2-DCA (1,2-dichloroethane) DNAPL in SEAR. Distribution area of DNAPL in the sandbox was determined by digital image analysis and correlated with effluent DNAPL concentration. The results showed that the effluent DNAPL concentration has significant positive linear correlation with the DNAPL distribution area, indicating the mobilization of DNAPL could improve remediation efficiency by enlarging total NAPL-water interfacial area for mass transfer. Meanwhile, the vertical migration of 1,2-DCA was limited within the boundary of aquifer in all experiments, implying that by manipulating injection parameters in SEAR, optimal remediation efficiency can be reached while the risk of DNAPL vertical migration is minimized. This study provides a convenient visible and quantitative method for the optimization of parameters for SEAR project, and an approach of rapid predicting the extent of DNAPL contaminant distribution based on the dissolved DNAPL concentration in the extraction well.

  19. Rheology enhancement for remediated PX6 melter feed

    International Nuclear Information System (INIS)

    Marek, J.C.; Eibling, R.E.

    1996-01-01

    This document is referenced in WSRC-TR-94-0556. This memorandum summarizes results of experimental work performed on the original IDMS PX6 melter feed, the remediated IDMS PX6 melter feed, and melter feeds produced in a laboratory simulation to duplicate the IDMS remediation as well as the experimental results on the caustic treatment to enhance the rheology. Characterization of the products of excess caustic addition and what steps to take if excess caustic is inadvertently added to the IDMS PX6 melter feed are also discussed

  20. Field-scale modeling of acidity production and remediation efficiency during in situ reductive dechlorination

    Science.gov (United States)

    Brovelli, A.; Robinson, C. E.; Barry, D. A.; Gerhard, J.

    2009-12-01

    Enhanced reductive dechlorination is a viable technology for in situ remediation of chlorinated solvent DNAPL source areas. Although in recent years increased understanding of this technology has led to more rapid dechlorination rates, complete dechlorination can be hindered by unfavorable conditions. Hydrochloric acid produced from dechlorination and organic acids generated from electron donor fermentation can lead to significant groundwater acidification. Adverse pH conditions can inhibit the activity of dehalogenating microorganisms and thus slow or stall the remediation process. The extent of acidification likely to occur at a contaminated site depends on a number of factors including (1) the extent of dechlorination, (2) the pH-sensitivity of dechlorinating bacteria, and (3) the geochemical composition of the soil and water, in particular the soil’s natural buffering capacity. The substantial mass of solvents available for dechlorination when treating DNAPL source zones means that these applications are particularly susceptible to acidification. In this study a reactive transport biogeochemical model was developed to investigate the chemical and physical parameters that control the build-up of acidity and subsequent remediation efficiency. The model accounts for the site water chemistry, mineral precipitation and dissolution kinetics, electron donor fermentation, gas phase formation, competing electron-accepting processes (e.g., sulfate and iron reduction) and the sensitivity of microbial processes to pH. Confidence in the model was achieved by simulating a well-documented field study, for which the 2-D field scale model was able to reproduce long-term variations of pH, and the concurrent build up of reaction products. Sensitivity analyses indicated the groundwater flow velocity is able to reduce acidity build-up when the rate of advection is comparable or larger than the rate of dechlorination. The extent of pH change is highly dependent on the presence of

  1. A multi-objective optimization framework for surfactant-enhanced remediation of DNAPL contaminations

    NARCIS (Netherlands)

    Schaerlaekens, J.; Mertens, J.; Van Linden, J.; Vermeiren, G.; Carmeliet, J.; Feyen, J.

    2006-01-01

    The occurrence of Dense Non-Aqueous Phase Liquid (DNAPL) contaminations in the subsurface is a threat for drinkwater resources in the western world. Surfactant-Enhanced Aquifer Remediation (SEAR) is widely considered as one of the most promising techniques to remediate DNAPL contaminations in-situ,

  2. Laboratory open-quotes proof of principleclose quotes investigation for the acoustically enhanced remediation technology

    International Nuclear Information System (INIS)

    Iovenitti, J.L.; Spencer, J.W.; Hill, D.G.

    1995-01-01

    This document describes a three phase program of Weiss Associates which investigates the systematics of using acoustic excitation fields (AEFs) to enhance the in-situ remediation of contaminated soil and ground water under both saturated and unsaturated conditions. The focus in this particular paper is a laboratory proof of principle investigation. The field deployment and engineering viability of acoustically enhanced remediation technology is also examined

  3. Drivers and applications of integrated clean-up technologies for surfactant-enhanced remediation of environments contaminated with polycyclic aromatic hydrocarbons (PAHs).

    Science.gov (United States)

    Liang, Xujun; Guo, Chuling; Liao, Changjun; Liu, Shasha; Wick, Lukas Y; Peng, Dan; Yi, Xiaoyun; Lu, Guining; Yin, Hua; Lin, Zhang; Dang, Zhi

    2017-06-01

    Surfactant-enhanced remediation (SER) is considered as a promising and efficient remediation approach. This review summarizes and discusses main drivers on the application of SER in removing polycyclic aromatic hydrocarbons (PAHs) from contaminated soil and water. The effect of PAH-PAH interactions on SER efficiency is, for the first time, illustrated in an SER review. Interactions between mixed PAHs could enhance, decrease, or have no impact on surfactants' solubilization power towards PAHs, thus affecting the optimal usage of surfactants for SER. Although SER can transfer PAHs from soil/non-aqueous phase liquids to the aqueous phase, the harmful impact of PAHs still exists. To decrease the level of PAHs in SER solutions, a series of SER-based integrated cleanup technologies have been developed including surfactant-enhanced bioremediation (SEBR), surfactant-enhanced phytoremediation (SEPR) and SER-advanced oxidation processes (SER-AOPs). In this review, the general considerations and corresponding applications of the integrated cleanup technologies are summarized and discussed. Compared with SER-AOPs, SEBR and SEPR need less operation cost, yet require more treatment time. To successfully achieve the field application of surfactant-based technologies, massive production of the cost-effective green surfactants (i.e. biosurfactants) and comprehensive evaluation of the drivers and the global cost of SER-based cleanup technologies need to be performed in the future. Copyright © 2017. Published by Elsevier Ltd.

  4. Ammonium citrate as enhancement for electrodialytic soil remediation and investigation of soil solution during the process

    DEFF Research Database (Denmark)

    Dias-Ferreira, Celia; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

    2015-01-01

    Seven electrodialytic experiments were conducted using ammonium citrate as enhancing agent to remediate copper and chromium-contaminated soil from a wood-preservation site. The purpose was to investigate the effect of current density (0.2, 1.0 and 1.5 mA cm−2), concentration of enhancing agent (0...... to remediate metal polluted soils at neutral to alkaline pH by choosing a good enhancement solution....

  5. Remediation of Cd(II)-contaminated soil via humin-enhanced electrokinetic technology.

    Science.gov (United States)

    Ding, Ling; Lv, Wenying; Yao, Kun; Li, Liming; Wang, Mengmeng; Liu, Guoguang

    2017-02-01

    Humin is the component of humic substances that is recalcitrant to extraction by either strong bases or strong acids, which contains a variety of functional groups that may combine with heavy metal ions. The present study employed humin as an adsorbent to investigate the efficacy of a remediation strategy under the effects of humin-enhanced electrokinetics. Because the cations gravitate toward cathode and anions are transferred to anode, humin was placed in close proximity to the cathode in the form of a package. The humin was taken out after the experiments to determine whether a target pollutant (cadmium) might be completely removed from soil. Acetic acid-sodium acetate was selected as the electrolyte for these experiments, which was circulated between the two electrode chambers via a peristaltic pump, in order to control the pH of the soil. The results indicated that when the remediation duration was extended to 240 h, the removal of acid extractable Cd(II) could be up to 43.86% efficiency, and the adsorption of the heavy metal within the humin was 86.15 mg/kg. Further, the recycling of the electrolyte exhibited a good control of the pH of the soil. When comparing the pH of the soil with the circulating electrolyte during remediation, in contrast to when it was not being recycled, the pH of the soil at the anode increased from 3.89 to 5.63, whereas the soil at the cathode decreased from 8.06 to 7.10. This indicated that the electrolyte recycling had the capacity to stabilize the pH of the soil.

  6. DEMONSTRATION BULLETIN STEAM ENHANCED REMEDIATION STEAM TECH ENVIRONMENTAL SERVICES, INC.

    Science.gov (United States)

    Steam Enhanced Remediation is a process in which steam is injected into the subsurface to recover volatile and semivolatile organic contaminants. It has been applied successfully to recover contaminants from soil and aquifers and at a fractured granite site. This SITE demonstra...

  7. Electrokinetic Enhanced Permanganate Delivery for Low Permeability Soil Remediation

    Science.gov (United States)

    Chowdhury, A. I.; Gerhard, J.; Reynolds, D. A.; Sleep, B. E.; O'Carroll, D. M.

    2016-12-01

    Contaminant mass sequestered in low permeability zones (LPZ) in the subsurface has become a significant concern due to back diffusion of contaminants, leading to contaminant rebound following treatment of the high permeability strata. In-situ remediation technologies such as in-situ chemical oxidation (ISCO) are promising, however, successful delivery of oxidants into silts and clays remains a challenge. Electrokinetics (EK) has been proposed as a technique that can overcome this challenge by delivering oxidants into low permeability soils. This study demonstrates the ability of EK to facilitate permanganate delivery into silt for treatment of trichloroethene (TCE). A two-dimensional sandbox was packed with alternate vertical layers of coarse sand and silt contaminated with high concentrations of aqueous phase TCE. Nine experiments were conducted to compare EK-enhanced in-situ chemical oxidation (EK-ISCO) to ISCO alone or EK alone. Frequent groundwater sampling at multiple locations combined with image analysis provided detailed mapping of TCE, permanganate, and manganese dioxide mass distributions. EK-ISCO successfully delivered the permanganate throughout the silt cross-section while ISCO without EK resulted in permanganate delivery only to the edges of the silt layer. EK-ISCO resulted in a 4.4 order-of-magnitude (OoM) reduction in TCE concentrations in the coarse sand compared to a 3.5 OoM reduction for ISCO alone. This study suggests that electrokinetics coupled with ISCO can achieve enhanced remediation of lower permeability strata, where remediation technologies for successful contaminant mass removal would otherwise be limited.

  8. Enhanced electrokinetic remediation of fluorine-contaminated soil by applying an ammonia continuous circulation system

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Shufa; Zhou, Ming; Zhang, Shuangyan [Henan University of Science and Technology, Luoyang (China)

    2016-02-15

    The objective of this research was to investigate the effects of ammonia continuous circulation enhanced electrokinetic remediation of fluorine contaminated soil and to analyze its influence on soil pH after remediation. An experimental study was carried out in self-made electrokinetic apparatus. The voltage gradient was set at 1.0V/cm and ammonia water with different concentrations was used as electrolyte which circulated in series. Comparative studies were made by using deionized water as electrolyte which circulated separately in one experiment and continuously in another. According to the experiment the continuous circulation of ammonia water increased the current value during the remediation process and maintained current through the soil cell stabler, which not only increased fluorine migration but also reduced energy consumption. Among the given ammonia concentrations (0, 0.01, 0.1 and 0.2mol/L) the removal rate increased with ammonia concentration. 0.2mol/L had the highest current (26.8mA), and the removal rate amounted up to 57.3%. By using ammonia circulation enhanced electrokinetic technology, the difference between pH values of cathode soil and anode soil became smaller. Ammonia continuous circulation enhanced electrokinetics can effectively remediate fluorine contaminated soil and the residual ammonia in the soil can also improve soil fertility.

  9. Phytoextraction of arsenic-contaminated soil with Pteris vittata in Henan Province, China: comprehensive evaluation of remediation efficiency correcting for atmospheric depositions.

    Science.gov (United States)

    Lei, Mei; Wan, Xiaoming; Guo, Guanghui; Yang, Junxing; Chen, Tongbin

    2018-01-01

    Research on the appropriate method for evaluating phytoremediation efficiency is limited. A 2-year field experiment was conducted to investigate phytoremediation efficiency using the hyperaccumulator Pteris vittata on an arsenic (As)-contaminated site. The remediation efficiency was evaluated through the removal rate of As in soils and extraction rate of heavy metals in plants. After 2 years of remediation, the concentration of total As in soils decreased from 16.27 mg kg -1 in 2012 to 14.58 mg kg -1 in 2014. The total remediation efficiency of As was 10.39% in terms of the removal rate of heavy metals calculated for soils, whereas the remediation efficiency calculated from As uptake by P. vittata was 16.09%. Such a discrepancy aroused further consideration on the potential input of As. A large amount of As was brought in by atmospheric emissions, which possibly biased the calculation of remediation efficiency. In fact, considering also the atmospheric depositions of As, the corrected removal rate of As from soil was 16.57%. Therefore, the results of this work suggest that (i) when evaluating the phytoextraction efficiency, the whole input and output cycle of the element of interest in the targeted ecosystem must be considered, and (ii) P. vittata has the potential to be used to remediate As-contaminated soils in Henan Province, China.

  10. Comparative study of remediation of Cr(VI)-contaminated soil using electrokinetics combined with bioremediation.

    Science.gov (United States)

    He, Jiaying; He, Chiquan; Chen, Xueping; Liang, Xia; Huang, Tongli; Yang, Xuecheng; Shang, Hai

    2018-06-01

    The purpose of this research is to design a new bioremediation-electrokinetic (Bio-EK) remediation process to increase treatment efficiency of chromium contamination in soil. Upon residual chromium analysis, it is shown that traditional electrokinetic-PRB system (control) does not have high efficiency (80.26%) to remove Cr(VI). Bio-electrokinetics of exogenous add with reduction bacteria Microbacterium sp. Y2 and electrokinetics can enhance treatment efficiency Cr(VI) to 90.67% after 8 days' remediation. To optimize the overall performance, integrated bio-electrokinetics were designed by synergy with 200 g humic substances (HS) into the systems. According to our results, Cr(VI) (98.33%) was effectively removed via electrokinetics. Moreover, bacteria and humic substances are natural, sustainable, and economical enhancement agents. The research results indicated that the use of integrated bio-electrokinetics is an effective method to remediate chromium-contaminated soils.

  11. Remediation of Nitrobenzene Contaminated Soil by Combining Surfactant Enhanced Soil Washing and Effluent Oxidation with Persulfate

    Science.gov (United States)

    Yan, Jingchun; Gao, Weiguo; Qian, Linbo; Han, Lu; Chen, Yun; Chen, Mengfang

    2015-01-01

    The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•−, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil. PMID:26266532

  12. A remediation performance model for enhanced metabolic reductive dechlorination of chloroethenes in fractured clay till

    Science.gov (United States)

    Manoli, Gabriele; Chambon, Julie C.; Bjerg, Poul L.; Scheutz, Charlotte; Binning, Philip J.; Broholm, Mette M.

    2012-04-01

    A numerical model of metabolic reductive dechlorination is used to describe the performance of enhanced bioremediation in fractured clay till. The model is developed to simulate field observations of a full scale bioremediation scheme in a fractured clay till and thereby to assess remediation efficiency and timeframe. A relatively simple approach is used to link the fermentation of the electron donor soybean oil to the sequential dechlorination of trichloroethene (TCE) while considering redox conditions and the heterogeneous clay till system (clay till matrix, fractures and sand stringers). The model is tested on lab batch experiments and applied to describe sediment core samples from a TCE-contaminated site. Model simulations compare favorably to field observations and demonstrate that dechlorination may be limited to narrow bioactive zones in the clay matrix around fractures and sand stringers. Field scale simulations show that the injected donor is expected to be depleted after 5 years, and that without donor re-injection contaminant rebound will occur in the high permeability zones and the mass removal will stall at 18%. Long remediation timeframes, if dechlorination is limited to narrow bioactive zones, and the need for additional donor injections to maintain dechlorination activity may limit the efficiency of ERD in low-permeability media. Future work should address the dynamics of the bioactive zones, which is essential to understand for predictions of long term mass removal.

  13. Cost studies of thermally enhanced in situ soil remediation technologies

    International Nuclear Information System (INIS)

    Bremser, J.; Booth, S.R.

    1996-05-01

    This report describes five thermally enhanced technologies that may be used to remediate contaminated soil and water resources. The standard methods of treating these contaminated areas are Soil Vapor Extraction (SVE), Excavate ampersand Treat (E ampersand T), and Pump ampersand Treat (P ampersand T). Depending on the conditions at a given site, one or more of these conventional alternatives may be employed; however, several new thermally enhanced technologies for soil decontamination are emerging. These technologies are still in demonstration programs which generally are showing great success at achieving the expected remediation results. The cost savings reported in this work assume that the technologies will ultimately perform as anticipated by their developers in a normal environmental restoration work environment. The five technologies analyzed in this report are Low Frequency Heating (LF or Ohmic, both 3 and 6 phase AC), Dynamic Underground Stripping (DUS), Radio Frequency Heating (RF), Radio Frequency Heating using Dipole Antennae (RFD), and Thermally Enhanced Vapor Extraction System (TEVES). In all of these technologies the introduction of heat to the formation raises vapor pressures accelerating contaminant evaporation rates and increases soil permeability raising diffusion rates of contaminants. The physical process enhancements resulting from temperature elevations permit a greater percentage of volatile organic compound (VOC) or semi- volatile organic compound (SVOC) contaminants to be driven out of the soils for treatment or capture in a much shorter time period. This report presents the results of cost-comparative studies between these new thermally enhanced technologies and the conventional technologies, as applied to five specific scenarios

  14. In-situ treatment of hydrocarbons contamination through enhanced bio-remediation and two phase extraction system

    International Nuclear Information System (INIS)

    Aglietto, I.; Brunero Bronzin, M.

    2005-01-01

    analytical data. After the study of all data acquired during investigations we could select the proper technologies for site remediation but to define correctly all project data we had to implement several laboratory tests to analyse bio-remediation processes, a series of pilot test for two phase extraction and bio-venting and a pilot test to select the best product for the release of oxygen into groundwater. The collection of the necessary parameters for the implementation of full-scale treatment was carried out throughout a period of several months, both with periodical measurements and sampling and with fixed monitoring probes, in order to record the aquifer changes related to contaminant concentrations, geochemical data, etc. At the end of all the tests we proceeded first with implementation of two phase extraction system through a double line of extraction wells that cover the extension of the area interested by the presence of free phase of LNAPL. The use of this technology instead of other more common system for free product recovery, is due to the fact that two phase extraction system results in an efficient recover of LNAPL and in a low extraction of groundwater that means lower treatment costs. Another important characteristic of this technology is that while extracting oil from the water table it extracts also soil gas from subsoil enhancing hydrocarbons bio-remediation through microbial activity. The second step after the complete recover of free product was to proceed with remediation of subsoil. Bio-remediation processes, enhanced by two phase extraction application, were increased with implementation of a bio-venting system made up of two horizontal wells installed along contaminated area. The injection of air through these wells supply oxygen to subsoil providing necessary aerobic conditions for degradation of hydrocarbon compounds. The results of laboratory tests showed that it would be suitable, to further stimulate microbial activity, to supply micro

  15. Ammonium citrate as enhancement for electrodialytic soil remediation and investigation of soil solution during the process.

    Science.gov (United States)

    Dias-Ferreira, Celia; Kirkelund, Gunvor M; Ottosen, Lisbeth M

    2015-01-01

    Seven electrodialytic experiments were conducted using ammonium citrate as enhancing agent to remediate copper and chromium-contaminated soil from a wood-preservation site. The purpose was to investigate the effect of current density (0.2, 1.0 and 1.5 mA cm(-2)), concentration of enhancing agent (0.25, 0.5 and 1.0 M) and remediation times (21, 42 and 117 d) for the removal of Cu and Cr from a calcareous soil. To gain insight on metal behavior, soil solution was periodically collected using suction cups. It was seen that current densities higher than 1.0 mA cm(-2) did not increase removal and thus using too high current densities can be a waste of energy. Desorption rate is important and both remediation time and ammonium citrate concentration are relevant parameters. It was possible to collect soil solution samples following an adaptation of the experimental set-up to ensure continuous supply of ammonium citrate to the soil in order to keep it saturated during the remediation. Monitoring soil solution gives valuable information on the evolution of remediation and helps deciding when the soil is remediated. Final concentrations in the soil ranged from 220 to 360 mg Cu kg(-1) (removals: 78-86%) and 440-590 mg Cr kg(-1) (removals: 35-51%), being within the 500 mg kg(-1) limit for a clean soil only for Cu. While further optimization is still required for Cr, the removal percentages are the highest achieved so far, for a real Cu and Cr-contaminated, calcareous soil. The results highlight EDR potential to remediate metal polluted soils at neutral to alkaline pH by choosing a good enhancement solution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Remediation of soils combining soil vapor extraction and bioremediation: benzene.

    Science.gov (United States)

    Soares, António Alves; Albergaria, José Tomás; Domingues, Valentina Fernandes; Alvim-Ferraz, Maria da Conceição M; Delerue-Matos, Cristina

    2010-08-01

    This work reports the study of the combination of soil vapor extraction (SVE) with bioremediation (BR) to remediate soils contaminated with benzene. Soils contaminated with benzene with different water and natural organic matter contents were studied. The main goals were: (i) evaluate the performance of SVE regarding the remediation time and the process efficiency; (ii) study the combination of both technologies in order to identify the best option capable to achieve the legal clean up goals; and (iii) evaluate the influence of soil water content (SWC) and natural organic matter (NOM) on SVE and BR. The remediation experiments performed in soils contaminated with benzene allowed concluding that: (i) SVE presented (a) efficiencies above 92% for sandy soils and above 78% for humic soils; (b) and remediation times from 2 to 45 h, depending on the soil; (ii) BR showed to be an efficient technology to complement SVE; (iii) (a) SWC showed minimum impact on SVE when high airflow rates were used and led to higher remediation times for lower flow rates; (b) NOM as source of microorganisms and nutrients enhanced BR but hindered the SVE due the limitation on the mass transfer of benzene from the soil to the gas phase. (c) 2010 Elsevier Ltd. All rights reserved.

  17. Electrokinetically Enhanced Delivery for ERD Remediation of Chlorinated Ethenes in a Fractured Limestone Aquifer

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Hyldegaard, Bente Højlund; With Nedergaard, Lærke

    causing very long remediation timeframes. Electrokinetics (EK) offers some unique transport processes, which can potentially overcome the diffusion limitations in the matrix. A novel technology combines ERD and EK for enhanced delivery. The combined technology (EK-BIO) has shown promising results in clay....... Experimental work on EK-BIO in limestone was conducted in a laboratory setup with limestone cores. EK was demonstrated to be promising in establishing enhanced contact between the donor lactate, bacteria, and cis-DCE within the limestone matrix. Complete dechlorination is expected to take place in the matrix......, since back diffusion limitations in the limestone matrix are overcome. This is essential for the overall time perspective of a remediation in limestone aquifers....

  18. Remediation mechanisms of mercapto-grafted palygorskite for cadmium pollutant in paddy soil.

    Science.gov (United States)

    Liang, Xuefeng; Qin, Xu; Huang, Qingqing; Huang, Rong; Yin, Xiuling; Cai, Yanming; Wang, Lin; Sun, Yuebing; Xu, Yingming

    2017-10-01

    The immobilization agent was the key factor that determined the success of remediation of heavy metal polluted soil. In this study, mercapto-grafted palygorskite (MP) as a novel and efficient immobilization agent was utilized for the remediation of Cd-polluted paddy soil in pot trials, and the remediation mechanisms were investigated in the aspect of soil chemistry and plant physiology with different rice cultivars as model plants. Mercapto-grafted palygorskite at applied doses of 0.1-0.3% could reduce Cd contents of brown rice and straws of different cultivars significantly. Both reduced DTPA-extractable Cd contents in rhizosphere and non-rhizosphere soil and decreasing Cd contents in iron plaques on rice root surfaces confirmed that MP was an efficient immobilization agent for Cd pollutant in paddy soil. In the aspect of soil chemistry, the pH values of rhizosphere and non-rhizosphere soils had no statistical changes in the MP treatment groups, but their zeta potentials decreased obviously, indicating that MP could enhance the fixation or sorption of Cd on soil compositions. In the aspect of antioxidant system, MP could increase POD activity of rice roots significantly to alleviate the stress of Cd to roots, and resulted in the decrease of T-AOC, SOD, and CAT activities of rice roots of the selected cultivars. MP had no inhabitation or enhancement effects on TSH of rice roots but enhance the contents of MTs and NPT to binding Cd to complete detoxification process. MP as a novel and efficient immobilization agent could complete the remediation effects through soil chemistry and plant physiological mechanisms.

  19. Remediation planning and risk assessment support through data fusion technology

    International Nuclear Information System (INIS)

    1996-01-01

    Coleman Research's Data Fusion Modeling (DFM) services gives one the ability to use large geophysical and hydrological data sets, which include direct and indirect measurements, to obtain a unified mathematical model of the geology and hydrology at one's site. Coleman Research (CRC) has adapted highly stable and efficient statistical inversion techniques, developed over the past 20 years, to provide a 3D site model with quantified uncertainty based on state-of-the-art modeling codes. This site model supports risk assessment and remediation planning with enhanced numerical accuracy for tradeoff studies of alternate remediation strategies. Further, DFM supports real time model updates during remediation and site investigation

  20. Phyto remediation of PAH contaminated soil

    International Nuclear Information System (INIS)

    Petruzzelli, G.; Pedron, F.; Barbafieri, M.; Cervelli, St.; Vigna Guidi, G.

    2005-01-01

    Phyto-remediation may enhance degradation of organic compounds promoting an adequate substrate for microbial growth. The aim of this work was to evaluate the efficiency of two plant species, Lupinus albus and Zea mais, in the bio-remediation of a PAH contaminated soil. This soil has been collected in a contaminated industrial area in Italy characterized by PAH concentrations up to 16000 mg/Kg. Microcosms experiments were carried out by planting Lupinus albus and Zea mais in the polluted soil; controls without plants were run separately. Growing period lasted by three months. Plants favoured PAH biodegradation by percentages of 32% with Lupinus albus and 22% with Zea mais, with respect to non vegetated microcosms. (authors)

  1. Engineering Behavior and Characteristics of Water-Soluble Polymers: Implication on Soil Remediation and Enhanced Oil Recovery

    Directory of Open Access Journals (Sweden)

    Shuang Cindy Cao

    2016-02-01

    Full Text Available Biopolymers have shown a great effect in enhanced oil recovery because of the improvement of water-flood performance by mobility control, as well as having been considered for oil contaminated-soil remediation thanks to their mobility control and water-flood performance. This study focused on the wettability analysis of biopolymers such as chitosan (85% deacetylated power, PEO (polyethylene oxide, Xanthan (xanthan gum, SA (Alginic Acid Sodium Salt, and PAA (polyacrylic acid, including the measurements of contact angles, interfacial tension, and viscosity. Furthermore, a micromodel study was conducted to explore pore-scale displacement phenomena during biopolymer injection into the pores. The contact angles of biopolymer solutions are higher on silica surfaces submerged in decane than at atmospheric conditions. While interfacial tensions of the biopolymer solutions have a relatively small range of 25 to 39 mN/m, the viscosities of biopolymer solutions have a wide range, 0.002 to 0.4 Pa·s, that dramatically affect both the capillary number and viscosity number. Both contact angles and interfacial tension have effects on the capillary entry pressure that increases along with an applied effective stress by overburden pressure in sediments. Additionally, a high injection rate of biopolymer solutions into the pores illustrates a high level of displacement ratio. Thus, oil-contaminated soil remediation and enhanced oil recovery should be operated in cost-efficient ways considering the injection rates and capillary entry pressure.

  2. Cylindrical Electrolyser Enhanced Electrokinetic Remediation of Municipal Solid Waste Incineration Fly Ashes

    Science.gov (United States)

    Huang, Tao; Zhou, Lulu; Tao, Junjun; Liu, Longfei

    2018-01-01

    The paper discusses enhancement and efficiency of removing spiked heavy metal (HM) contaminants from the municipal solid waste incineration (MSWI) fly ashes in the cylindrical electrolyser device. The characterization parameters of the electrolyte solution pH, electric current, electrical conductivity, voltage gradient were discussed after the experiment. The chemical speciation of HMs was analysed between the original samples and remediated ones by BCR sequential extraction. The detoxification efficiencies of Zn, Pb, Cu and Cd in the column-uniform device were compared with that in the traditional rectangular apparatus. The pH value changed smoothly with small amplitude of oscillation in general in cathode and anode compartments except the initial break. The electrical current rapidly increased on the first day of the experiment and steadily declined after that and the electrical conductivity presented a clear rising trend. The residual partition of detoxified samples were obviously lifted which was much higher than the analysis data of the raw materials. The pH and the electrical conductivity in sample region were distributed more uniformly and the blind area was effectively eliminated in the electrolytic cells which was indirectly validated by the contrastive detoxification result of the spiked HMs between the rectangular and cylindrical devices.

  3. Bioavailability enhanced rhizosphere remediation of petroleum hydrocarbon contaminated soil

    International Nuclear Information System (INIS)

    Marchenko, A.; Vorobyov, A.; Zharikov, G.; Ermolenko, Z.; Dyadishchev, N.; Borovick, R.; Sokolov, M.; Ortega-Calvo, J.J.

    2005-01-01

    Aliphatic, aromatic and polycyclic aromatic oil hydrocarbons are structurally complicated man-caused pollutants that are constantly brought into biosphere. Oil production in Russia, so as all over the world, is connected with pollution of biotopes, ecosystems and agro-landscapes. Presently large funds are allocated either for oil leak prevention or for discharged oil gathering. At the same time, in spite of large necessity in technologies for efficient reconstruction of soil bio-productivity, reliable regional systems of their remediation in situ have not been developed yet. One such method is rhizosphere remediation, a biotechnology, based on the functioning of plant-microbial complexes. Little is known about bioavailability in phyto-remediation systems. Specific bioavailability-promoting mechanisms, operating in soil with hydrocarbon-degrading populations, may be responsible for increased rates of pollutant transformation (increased bacterial adherence to the pollutants, production of bio-surfactants by bacteria or by plants, possible role of chemotaxis). In the course of work collection of 42 chemo-tactically active bio-surfactant producing strain-degraders of petroleum hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) was created. Two representative strains were selected for detailed chemotaxis studies with PAHs (naphthalene, phenanthrene, anthracene, and pyrene), bacterial lipopolysaccharide and root exudates from seven different plants. These strains are produce the bio-surfactants (rhamno-lipid). The chemotactic response was quantified with a capillary and densitometric chemotaxis assay. Surface tension of cultural liquid was measured after cultivation of strains in the presence of hexadecane or phenanthrene with the use of a ring tensiometer. Before measuring of surface tension microbial cells were collected from liquid culture by centrifugation. Total petroleum Hydrocarbons (TPH) in soil were analyzed by infra-red spectroscopy method. PAHs

  4. Bioavailability enhanced rhizosphere remediation of petroleum hydrocarbon contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Marchenko, A.; Vorobyov, A.; Zharikov, G.; Ermolenko, Z.; Dyadishchev, N.; Borovick, R.; Sokolov, M. [Research Centre for Toxicology and Hygienic Regulation of Biopreparations, Moscow region (Russian Federation); Ortega-Calvo, J.J. [Instituto de Recursos Naturales y Agrobiologia, CSIC, Sevilla (Spain)

    2005-07-01

    Aliphatic, aromatic and polycyclic aromatic oil hydrocarbons are structurally complicated man-caused pollutants that are constantly brought into biosphere. Oil production in Russia, so as all over the world, is connected with pollution of biotopes, ecosystems and agro-landscapes. Presently large funds are allocated either for oil leak prevention or for discharged oil gathering. At the same time, in spite of large necessity in technologies for efficient reconstruction of soil bio-productivity, reliable regional systems of their remediation in situ have not been developed yet. One such method is rhizosphere remediation, a biotechnology, based on the functioning of plant-microbial complexes. Little is known about bioavailability in phyto-remediation systems. Specific bioavailability-promoting mechanisms, operating in soil with hydrocarbon-degrading populations, may be responsible for increased rates of pollutant transformation (increased bacterial adherence to the pollutants, production of bio-surfactants by bacteria or by plants, possible role of chemotaxis). In the course of work collection of 42 chemo-tactically active bio-surfactant producing strain-degraders of petroleum hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) was created. Two representative strains were selected for detailed chemotaxis studies with PAHs (naphthalene, phenanthrene, anthracene, and pyrene), bacterial lipopolysaccharide and root exudates from seven different plants. These strains are produce the bio-surfactants (rhamno-lipid). The chemotactic response was quantified with a capillary and densitometric chemotaxis assay. Surface tension of cultural liquid was measured after cultivation of strains in the presence of hexadecane or phenanthrene with the use of a ring tensiometer. Before measuring of surface tension microbial cells were collected from liquid culture by centrifugation. Total petroleum Hydrocarbons (TPH) in soil were analyzed by infra-red spectroscopy method. PAHs

  5. Assessment of the effectiveness of onsite exsitu remediation by enhanced natural attenuation in the Niger Delta region, Nigeria.

    Science.gov (United States)

    Okparanma, Reuben N; Azuazu, Ikeabiama; Ayotamuno, Josiah M

    2017-12-15

    This study was conducted to quantify and rank the effectiveness of onsite exsitu remediation by enhanced natural attenuation using soil quality index. The investigation was conducted at three oil spill sites in the Niger Delta (5.317°N, 6.467°E), Nigeria with a predominance of Oxisols. Baseline assessment and a two-step post-remediation monitoring of the sites were conducted. Target contaminants including total petroleum hydrocarbon (TPH) and BTEX (benzene, toluene, ethylbenzene, and xylene) were analyzed by gas chromatography-mass spectrometry. Results of the baseline assessment showed that TPH concentrations across the study sites averaged between 5113 and 7640 mg/kg at 0- to 1-m depth, which was higher than the local regulatory value of 5000 mg/kg. The soil quality index across the sites ranged between 68 and 45, suggesting medium to high potential ecological health risks with medium to high priority for remediation. BTEX concentrations followed a similar trend. However, after remediation TPH degraded rapidly initially and then slowly but asymptotically during the post-remediation monitoring period. Then, soil quality index across the study sites ranged between 100 and 58, indicating very low to medium potential ecological health risks. This demonstrates the effectiveness of onsite exsitu remediation by enhanced natural attenuation as a remediation strategy for petroleum-contaminated soils, which holds great promise for the Niger Delta province. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Integrated enhanced bioremediation and vacuum extraction for remediation of a hydrocarbon release in response to oscillating hydrologic conditions 'Traverse Co-Bio-Vac'

    International Nuclear Information System (INIS)

    Korreck, W.M.; Armstrong, J.M.; Douglass, R.H.

    1992-01-01

    The use of enhanced in-situ biological treatment and vacuum extraction has been demonstrated to be successful in the remediation of ground water and soil contaminated with hydrocarbons. Seasonal fluctuations in the ground water causes the zone of contamination to be in the either saturated or unsaturated zone of the aquifer. In order to address these conditions, an integrated engineering design approach is being taken for the full scale remediation of an aviation of an aviation gasoline spill at the US Coast Guard Air Station at Traverse City, Township, Michigan. Enhanced aerobic biodegradation will be utilized during the periods of high water table whereby most of the contaminated interval is saturated. Carbon treated water will be utilized from the existing ground water plume. Oxygen will be injected via an oxygen generator to saturate the process stream prior to discharge to the aquifer. During low water table conditions, the same infrastructure will be utilized as a modified vacuum extraction system. The same injection wells used during the high water table would then be used during the low table condition as vapor extraction wells. The vapors will be routed to an above-ground catalytic incinerator for compound destruction. This integrated approach, entitled 'Traverse Co-Bio-Vac,' should reduce the capital costs of installing a full scale remedial system as well allowing the system to operate efficiently depending on water table conditions. The system is expected to be constructed in 1992

  7. Pulse current enhanced electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Sun, Tian R.; Ottosen, Lisbeth M.; Jensen, Pernille E.

    2012-01-01

    Energy consumption is an important factor influencing the cost of electrodialytic soil remediation (EDR). It has been indicated that the pulse current (in low frequency range) could decrease the energy consumption during EDR. This work is focused on the comparison of energy saving effect at diffe......Energy consumption is an important factor influencing the cost of electrodialytic soil remediation (EDR). It has been indicated that the pulse current (in low frequency range) could decrease the energy consumption during EDR. This work is focused on the comparison of energy saving effect...

  8. Electrokinetic remediation of heavy metals contaminated kaolin by a CNT-covered polyethylene terephthalate yarn cathode

    International Nuclear Information System (INIS)

    Yuan, Lizhu; Li, Haiyan; Xu, Xingjian; Zhang, Jing; Wang, Nana; Yu, Hongwen

    2016-01-01

    In the current study, carbon nanotube (CNT) covered polyethylene terephthalate yarns (PET-CNT) electrode has been investigated as a novel cathode material for the electrokinetic (EK) remediation of multi-metals (Cd, Cu, Ni, Pb, Zn) contaminated kaolin. The results of scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) showed that CNT was successfully covered on the surface of PET. The results obtained from EK process showed that PET-CNT as a cathode obviously elevated electric current and electro-osmotic flow (EOF), significantly decreased kaolin pH, and enhanced heavy metals removal efficiencies. The removal efficiencies of Cd, Cu, Ni, Pb, and Zn in PET-CNT treatment were 89.7%, 63.6%, 90.7%, 19.2%, and 88.7%, respectively. In comparison with the Pt/Ti and graphite treatments, the removal efficiencies of Cd, Ni, and Zn were improved at least about 30%, Cu and Pb were improved at least 16.6% and 6.9%, respectively. Our results demonstrated the PET-CNT was a good alternative cathode material for enhancing efficiency of EK remediation.

  9. A remediation performance model for enhanced metabolic reductive dechlorination of chloroethenes in fractured clay till

    DEFF Research Database (Denmark)

    Manoli, Gabriele; Chambon, Julie C.; Bjerg, Poul L.

    2012-01-01

    A numerical model of metabolic reductive dechlorination is used to describe the performance of enhanced bioremediation in fractured clay till. The model is developed to simulate field observations of a full scale bioremediation scheme in a fractured clay till and thereby to assess remediation...

  10. STEAM ENHANCED REMEDIATION RESEARCH FOR DNAPL IN FRACTURED ROCK, LORING AIR FORCE BASE, LIMESTONE, MAINE

    Science.gov (United States)

    This report details a research project on Steam Enhanced Remediation (SER) for the recovery of volatile organic compounds from fractured limestone that was carried out at the Quarry at the former Loring Air Force Base in Limestone, Maine. This project was carried out by USEPA, Ma...

  11. Washing enhanced electrokinetic remediation for removal cadmium from real contaminated soil

    International Nuclear Information System (INIS)

    Giannis, Apostolos; Gidarakos, Evangelos

    2005-01-01

    The main objective of this study is to evaluate the combination of electrokinetic remediation and soil washing technology in order to remove cadmium from contaminated soil. This paper presents the results of an experimental research undertaken to evaluate different washing and purging solutions to enhance the removal of cadmium from a real contaminated soil during electrokinetic remediation. Two different experimental modules were applied in the laboratory. Soil was saturated with tap water, while acetic and hydrochloric acids, as well as ethylenediaminetetraacetic acid (EDTA) were used as purging solutions in the first module. Results show that there was a decrease of cadmium concentration near anode, but a significant increase in the middle of the cell, due to the increasing pH. Citric, nitric and acetic acids were used for soil washing and purging solutions in the second module. In this case, an 85% reduction of cadmium concentration was achieved. Therefore, results indicate that soil pH and washing solutions are the most important factors in governing the dissolution and/or desorption of Cd in a soil system under electrical fields

  12. In-situ treatment of a mixed hydrocarbon plume through a permeable reactive barrier and enhanced bio-remediation

    International Nuclear Information System (INIS)

    Aglietto, I.; Bretti, L.L.

    2005-01-01

    Groundwater is frequently polluted with mixtures of contaminants that are amenable to different types of remediation. One example is the combination of petroleum hydrocarbons (mostly BTEX) and chlorinated solvents (chlorinated ethenes and propanes), as it occurs in the groundwater beneath the industrial site that is the objective of the present case study. The site is located in Italy near a main river (Arno), which is supposed to be the final recipient of the contamination and where a possible exposure might take place. The aim of the treatment is the plume containment within the site boundaries in order to avoid further migration of the contaminants towards the river. The design of the remediation system was based on an extensive site characterization that included - but was not limited to - the following information: geological and geochemical, microbiological and hydrological data, together with analytical data (i.e. contaminant concentrations). Pilot tests were also implemented in order to collect the necessary parameters for the full-scale treatment design and calibration. The site was contaminated by a mixed plume of more than 30 different contaminants, ranging from BTEX, to MTBE, to PAH, to chlorinated solvents. The concentration peaks were in the order of 1-100 mg/l for each contaminant. Petroleum hydrocarbons are quickly degradable through oxidative mechanisms (especially aerobic biodegradation), whereas fully-chlorinated compounds are only degradable via reductive pathways. A mixed plume of both types of contaminants therefore requires a combined approach with the application of different treatment technologies. The remediation strategy elaborated combines a permeable reactive barrier (PRB) in a funnel and gate configuration for the down-gradient plume containment, with the enhanced bio-remediation of the contaminants for the control of the plume boundaries and for the abatement of the concentration peaks. Pilot tests were carried out in order to assess

  13. Effects of different remediation treatments on crude oil contaminated saline soil.

    Science.gov (United States)

    Gao, Yong-Chao; Guo, Shu-Hai; Wang, Jia-Ning; Li, Dan; Wang, Hui; Zeng, De-Hui

    2014-12-01

    Remediation of the petroleum contaminated soil is essential to maintain the sustainable development of soil ecosystem. Bioremediation using microorganisms and plants is a promising method for the degradation of crude oil contaminants. The effects of different remediation treatments, including nitrogen addition, Suaeda salsa planting, and arbuscular mycorrhiza (AM) fungi inoculation individually or combined, on crude oil contaminated saline soil were assessed using a microcosm experiment. The results showed that different remediation treatments significantly affected the physicochemical properties, oil contaminant degradation and bacterial community structure of the oil contaminated saline soil. Nitrogen addition stimulated the degradation of total petroleum hydrocarbon significantly at the initial 30d of remediation. Coupling of different remediation techniques was more effective in degrading crude oil contaminants. Applications of nitrogen, AM fungi and their combination enhanced the phytoremediation efficiency of S. salsa significantly. The main bacterial community composition in the crude oil contaminated saline soil shifted with the remediation processes. γ-Proteobacteria, β-Proteobacteria, and Actinobacteria were the pioneer oil-degraders at the initial stage, and Firmicutes were considered to be able to degrade the recalcitrant components at the later stage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Heavy Metal Phytoremediation: Microbial Indicators of Soil Health for the Assessment of Remediation Efficiency

    Science.gov (United States)

    Epelde, Lur; Ma Becerril, José; Alkorta, Itziar; Garbisu, Carlos

    Phytoremediation is an effective, non-intrusive, inexpensive, aesthetically pleasing, socially accepted, promising phytotechnology for the remediation of polluted soils. The objective of any soil remediation process must be not only to remove the contaminant(s) from the soil but, most importantly, to restore the continued capacity of the soil to perform or function according to its potential (i.e., to recover soil health). Hence, indicators of soil health are needed to properly assess the efficiency of a phytoremediation process. Biological indicators of soil health, especially those related to the size, activity and diversity of the soil microbial communities, are becoming increasingly used, due to their sensitivity and capacity to provide information that integrates many environmental factors. In particular, microbial indicators of soil health are valid tools to evaluate the success of metal phytoremediation procedures such as phytoextraction and phytostabilization processes.

  15. Genealogy Remediated

    DEFF Research Database (Denmark)

    Marselis, Randi

    2007-01-01

    Genealogical websites are becoming an increasingly popular genre on the Web. This chapter will examine how remediation is used creatively in the construction of family history. While remediation of different kinds of old memory materials is essential in genealogy, digital technology opens new...... possibilities. Genealogists use their private websites to negotiate family identity and hereby create a sense of belonging in an increasingly complex society. Digital technologies enhance the possibilities of coorporation between genealogists. Therefore, the websites are also used to present archival...

  16. Electrokinetic-enhanced bioaugmentation for remediation of chlorinated solvents contaminated clay

    International Nuclear Information System (INIS)

    Mao, Xuhui; Wang, James; Ciblak, Ali; Cox, Evan E.; Riis, Charlotte; Terkelsen, Mads; Gent, David B.; Alshawabkeh, Akram N.

    2012-01-01

    Highlights: ► Simultaneous delivery of electron donors and bacteria into low permeability clays. ► Bacteria injection, growth and consequent transformation of contaminants are viable. ► EK injection is more effective than advection-based injection for clay soil. ► Electroosmosis appears to be the driving mechanism for bacteria injection. ► Both EK transport and biodegradation contribute the removal of VOCs in clay. - Abstract: Successful bioremediation of contaminated soils is controlled by the ability to deliver bioremediation additives, such as bacteria and/or nutrients, to the contaminated zone. Because hydraulic advection is not practical for delivery in clays, electrokinetic (EK) injection is an alternative for efficient and uniform delivery of bioremediation additive into low-permeability soil and heterogeneous deposits. EK-enhanced bioaugmentation for remediation of clays contaminated with chlorinated solvents is evaluated. Dehalococcoides (Dhc) bacterial strain and lactate ions are uniformly injected in contaminated clay and complete dechlorination of chlorinated ethene is observed in laboratory experiments. The injected bacteria can survive, grow, and promote effective dechlorination under EK conditions and after EK application. The distribution of Dhc within the clay suggests that electrokinetic transport of Dhc is primarily driven by electroosmosis. In addition to biodegradation due to bioaugmentation of Dhc, an EK-driven transport of chlorinated ethenes is observed in the clay, which accelerates cleanup of chlorinated ethenes from the anode side. Compared with conventional advection-based delivery, EK injection is significantly more effective for establishing microbial reductive dechlorination capacity in low-permeability soils.

  17. Improving the Efficiency of 3-D Hydrogeological Mixers: Dilution Enhancement Via Coupled Engineering-Induced Transient Flows and Spatial Heterogeneity

    Science.gov (United States)

    Di Dato, Mariaines; de Barros, Felipe P. J.; Fiori, Aldo; Bellin, Alberto

    2018-03-01

    Natural attenuation and in situ oxidation are commonly considered as low-cost alternatives to ex situ remediation. The efficiency of such remediation techniques is hindered by difficulties in obtaining good dilution and mixing of the contaminant, in particular if the plume deformation is physically constrained by an array of wells, which serves as a containment system. In that case, dilution may be enhanced by inducing an engineered sequence of injections and extractions from such pumping system, which also works as a hydraulic barrier. This way, the aquifer acts as a natural mixer, in a manner similar to the industrialized engineered mixers. Improving the efficiency of hydrogeological mixers is a challenging task, owing to the need to use a 3-D setup while relieving the computational burden. Analytical solutions, though approximated, are a suitable and efficient tool to seek the optimum solution among all possible flow configurations. Here we develop a novel physically based model to demonstrate how the combined spatiotemporal fluctuations of the water fluxes control solute trajectories and residence time distributions and therefore, the effectiveness of contaminant plume dilution and mixing. Our results show how external forcing configurations are capable of inducing distinct time-varying groundwater flow patterns which will yield different solute dilution rates.

  18. Foam-Delivery of Remedial Amendments for Enhanced Vadose Zone Metals and Radionuclides Remediation

    International Nuclear Information System (INIS)

    Zhong, L.; Szecsody, J.E.; Dresel, P.E.; Zhang, Z.F.; Qafoku, N.P.

    2009-01-01

    The remediation of metals and radionuclides contamination, such as Cr(VI), Tc-99, and Sr-90 in the U.S. DOE Hanford Site vadose zone is a critical need. Water-based remedial amendments delivery to the deep vadose zone is facing significant technical challenges. Water-based delivery will easily leach out the highly mobile pollutants therefore contaminate the underlying aquifer. Preferential flow of the amendment-laden solution in the vadose zone due to the formation heterogeneity is difficult to overcome, resulting in bypassing of the less permeable zones. Foam has unique transport properties in the vadose zone that enable mitigation on the mobilization of mobile contaminants and enhance the sweeping over heterogeneous systems. Calcium polysulfide (CPS) is a remedial amendment that can be used to reduce and immobilize hexavalent chromium [Cr(VI)] and other redox-sensitive radionuclides/metals in the vadose zone. The delivery of CPS to the vadose zone using foam and the immobilization of Cr(VI) via reduction by the foam-delivered CPS was investigated in this study. Batch tests were conducted to select the foam-generating CPS-surfactant solutions, to determine the solution foamability and the reducing potential of CPS-containing foams, and to study the influence of foam quality, surfactant concentration, and CPS concentration on foam stability. Column experiments were performed to test the foam delivery of CPS to sediments under conditions similar to field vadose zone, to study the foam transport and interaction with sediments, and to determine the extent of Cr(VI) immobilization using this novel delivery approach. CPS-containing foams with high reducing potential were prepared based on the batch tests. Sediment reduction by foam-delivered CPS was observed in the column studies. Significant mobilization of Cr(VI) from sediments occurred when CPS was delivered in aqueous solution. The Cr(VI) mobilization was minimized when CPS was delivered by foams, resulting in

  19. Natural Remediation at Savannah River Site

    International Nuclear Information System (INIS)

    Lewis, C. M.; Van Pelt, R.

    2002-01-01

    Natural remediation is a general term that includes any technology or strategy that takes advantage of natural processes to remediate a contaminated media to a condition that is protective of human health and the environment. Natural remediation techniques are often passive and minimally disruptive to the environment. They are generally implemented in conjunction with traditional remedial solutions for source control (i.e., capping, stabilization, removal, soil vapor extraction, etc.). Natural remediation techniques being employed at Savannah River Site (SRS) include enhanced bio-remediation, monitored natural attenuation, and phytoremediation. Enhanced bio-remediation involves making nutrients available and conditions favorable for microbial growth. With proper precautions and feeding, the naturally existing microbes flourish and consume the contaminants. Case studies of enhanced bio-remediation include surface soils contaminated with PCBs and pesticides, and Volatile Organic Compound (VOC) contamination in both the vadose zone and groundwater. Monitored natural attenuation (MNA) has been selected as the preferred alternative for groundwater clean up at several SRS waste units. Successful implementation of MNA has been based on demonstration that sources have been controlled, groundwater modeling that indicates that plumes will not expand or reach surface water discharge points at levels that exceed regulatory limits, and continued monitoring. Phytoremediation is being successfully utilized at several SRS waste units. Phytoremediation involves using plants and vegetation to uptake, break down, or manage contaminants in groundwater or soils. Case studies at SRS include managing groundwater plumes of tritium and VOCs with pine trees that are native to the area. Significant decreases in tritium discharge to a site stream have been realized in one phytoremediation project. Studies of other vegetation types, methods of application, and other target contaminants are

  20. In-situ treatment of a mixed hydrocarbon plume through enhanced bio-remediation and a PRB system

    International Nuclear Information System (INIS)

    Aglietto, I.; Bargoni, G.; Bretti, L.L.

    2005-01-01

    (especially aerobic biodegradation), whereas fully-chlorinated compounds are only biodegradable via reductive pathways. Therefore, a mixed plume of both types of contaminants requires a combined approach with the application of different treatment technologies. The remediation strategy elaborated combines an enhanced bio-remediation of the hot spots with a permeable reactive barrier (PRB) in a funnel and gate configuration for the down-gradient plume containment. Pilot tests were carried out in order to assess the efficiency and feasibility of such technologies in the site of interest. The enhanced bio-remediation is going to be carried out by means of injections of hydrogen release compounds (HRC) and oxygen release compounds (ORC) for the biodegradation of chlorinated solvents and petroleum hydrocarbons respectively. A pilot test was conducted to determine the degradation rates of the different contaminants. The pilot test was monitored with a periodic sampling and analysis of the groundwater and with a continuous monitoring of the physical-chemical parameters (temperature, pH, conductivity, redox potential and dissolved oxygen) in the monitoring wells placed immediately down-gradient of the injection points. The tests showed the possibility to use the enhanced bio-remediation with the double aim to reduce the hot spot concentrations, in order to lower the contaminant load on the PRB, and to control the lateral spreading of the plume in the side regions. Permeable reactive barriers are passive groundwater treatment systems that are able to decontaminate groundwater as it flows through a permeable treatment medium under natural gradients. The main advantage of this technology over ex-situ and other in-situ groundwater remediation approaches is the reduced operation- and maintenance costs. For the permeable reactive barrier, a funnel and gate configuration was selected. This system uses low permeability materials (funnel) to direct groundwater towards a permeable treatment

  1. In-situ treatment of a mixed hydrocarbon plume through enhanced bio-remediation and a PRB system

    Energy Technology Data Exchange (ETDEWEB)

    Aglietto, I.; Bargoni, G.; Bretti, L.L. [Studio aglietto s.r.l. (Italy)

    2005-07-01

    (especially aerobic biodegradation), whereas fully-chlorinated compounds are only biodegradable via reductive pathways. Therefore, a mixed plume of both types of contaminants requires a combined approach with the application of different treatment technologies. The remediation strategy elaborated combines an enhanced bio-remediation of the hot spots with a permeable reactive barrier (PRB) in a funnel and gate configuration for the down-gradient plume containment. Pilot tests were carried out in order to assess the efficiency and feasibility of such technologies in the site of interest. The enhanced bio-remediation is going to be carried out by means of injections of hydrogen release compounds (HRC) and oxygen release compounds (ORC) for the biodegradation of chlorinated solvents and petroleum hydrocarbons respectively. A pilot test was conducted to determine the degradation rates of the different contaminants. The pilot test was monitored with a periodic sampling and analysis of the groundwater and with a continuous monitoring of the physical-chemical parameters (temperature, pH, conductivity, redox potential and dissolved oxygen) in the monitoring wells placed immediately down-gradient of the injection points. The tests showed the possibility to use the enhanced bio-remediation with the double aim to reduce the hot spot concentrations, in order to lower the contaminant load on the PRB, and to control the lateral spreading of the plume in the side regions. Permeable reactive barriers are passive groundwater treatment systems that are able to decontaminate groundwater as it flows through a permeable treatment medium under natural gradients. The main advantage of this technology over ex-situ and other in-situ groundwater remediation approaches is the reduced operation- and maintenance costs. For the permeable reactive barrier, a funnel and gate configuration was selected. This system uses low permeability materials (funnel) to direct groundwater towards a permeable treatment

  2. Remediation of PAH-contaminated soil using Achromobacter sp

    International Nuclear Information System (INIS)

    Cutright, T.J.; Lee, S.

    1994-01-01

    Several technologies have the potential to effectively remediate soil contaminated with polycyclic aromatic hydrocarbons (PAHs): solvent extraction, coal-oil agloflotation, supercritical extraction, and bioremediation. Due to the cost effectiveness and in-situ treatment capabilities of bioremediation, studies were conducted to determine the efficiency of Achromobacter sp. to remediate an industrial contaminated soil sample. Specifically, the use of three different mineral salt solutions in conjunction with the Achromobacter sp. was investigated. The molecular identification of the contaminants and their respective levels after remediation were determined using a Hewlett-Packard 1050 HPLC. Preliminary results show a 92% remediation for the use of two of the mineral salt solutions after 20 days' treatment. After 8 weeks, the remediation efficiency reached 99%. Bioremediation was also critically compared to the other potential remediation technologies

  3. Enhancing Neuroplasticity to Augment Cognitive Remediation in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Carol Jahshan

    2017-09-01

    Full Text Available There is a burgeoning need for innovative treatment strategies to improve the cognitive deficits in schizophrenia. Cognitive remediation (CR is effective at the group level, but the variability in treatment response is large. Given that CR may depend on intact neuroplasticity to produce cognitive gains, it is reasonable to combine it with strategies that harness patients’ neuroplastic potential. In this review, we discuss two non-pharmacological approaches that can enhance neuroplasticity and possibly augment the effects of CR in schizophrenia: physical exercise and transcranial direct current stimulation (tDCS. Substantial body of evidence supports the beneficial effect of physical exercise on cognition, and a handful of studies in schizophrenia have shown that physical exercise in conjunction with CR has a larger impact on cognition than CR alone. Physical exercise is thought to stimulate neuroplasticity through the regulation of central growth factors, and current evidence points to brain-derived neurotrophic factor as the potential underlying mechanism through which physical exercise might enhance the effectiveness of CR. tDCS has emerged as a potential tool for cognitive enhancement and seems to affect the cellular mechanisms involved in long-term potentiation (LTP. A few reports have demonstrated the feasibility of integrating tDCS with CR in schizophrenia, but there are insufficient data to determine if this multimodal approach leads to incremental performance gain in patients. Larger randomized controlled trials are necessary to understand the mechanisms of the combined tDCS–CR intervention. Future research should take advantage of new developments in neuroplasticity paradigms to examine the effects of these interventions on LTP.

  4. Improved surfactants formulation for remediation of oil sludge recovery

    International Nuclear Information System (INIS)

    Syed Hakimi Sakuma Syed Ahmad; Shahidan Radiman

    2000-01-01

    Surfactant enhanced remediation based on mobilisation of the residual NAPLs (oil sludge) which is radioactive depends on the tendency of the surfactants to lower interfacial tension. Mobilisation has greater potential than solubilisation to increase the rate of remediation. Optimised surfactants formulation was determined with concentration of Aqua 2000 and D Bond of 1% wt respectively, sodium chloride concentration of 2 gmL -1 and addition of 3% wt butanol as cosolvent. The formulation was of benefit not only able to decrease further the interfacial tension of aqueous solution containing oil emulsion, but also to make possible to be more mobile and destruction of mixed liquid crystals that formed. Formation of liquid crystals can hinders significantly recovery efficiency of aqueous solution containing oil emulsion in field remediation work. In a 100 litres soil column experiment conducted containing oil emulsion in field sludge soil and using the surfactants formulation for flushing, miniemulsion formed sizes maintained at average size between 125 nm and 280 nm before and after remediation. Total oil and grease concentration removed from the soil were significant due to the decreased in oil emulsion sizes, increase mobility and solubility. (Author)

  5. Optimum Remediation Conditions of Vertical Electrokinetic-Flushing Equipment to Decontaminate a Radioactive Soil

    International Nuclear Information System (INIS)

    Kim, Gye Nam; Yang, Byeong IL; Moon, Jei Kwon; Lee, Kune Woo

    2009-01-01

    Vertical electrokintic-flushing remediation equipment was developed for the remediation of a radioactive soil near nuclear facilities. An optimum reagent was selected to decontaminate the radioactive soil near nuclear facilities with the developed vertical electrokintic-flushing remediation equipment, and the optimum remediation conditions were established to obtain a higher remediation efficiency. Namely, acetic acid was selected as an optimum reagent due to its higher remediation efficiency. When the electrokinetic remediation and the electrokinetic-flushing remediation results were compared, the removal efficiency of 4.6% and the soil waste solution volume of 1.5 times were increased in the electrokinetic remediation. When the potential gradient within an electrokinetic soil cell was increased by two times (4.0 V/cm), the removal efficiencies of Co 2+ and Cs + were increased by about 4.3%( Co 2+ : 98.9%, Cs + : 96.7%). Also, when the reagent concentration was increased from 0.01 M to 0.05 M, the removal efficiency of Co 2+ was increased but that of Cs + was decreased. Therefore, the optimum remediation conditions were that the acetic concentration was 0.01 M ∼ 0.05 M, the potential gradient was 4 V/cm, the injection of reagent 2.4 ml/g, and the remediation period was 20 days.

  6. Impact of carbonate on the efficiency of heavy metal removal from kaolinite soil by the electrokinetic soil remediation method

    Energy Technology Data Exchange (ETDEWEB)

    Ouhadi, V.R., E-mail: vahidouhadi@yahoo.ca [Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Yong, R.N. [RNY Geoenvironmental Research, North Saanich (Canada); Shariatmadari, N. [Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Saeidijam, S.; Goodarzi, A.R.; Safari-Zanjani, M. [Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

    2010-01-15

    While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of 'calcite or carbonate' (CaCO{sub 3}) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.

  7. Impact of carbonate on the efficiency of heavy metal removal from kaolinite soil by the electrokinetic soil remediation method

    International Nuclear Information System (INIS)

    Ouhadi, V.R.; Yong, R.N.; Shariatmadari, N.; Saeidijam, S.; Goodarzi, A.R.; Safari-Zanjani, M.

    2010-01-01

    While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of 'calcite or carbonate' (CaCO 3 ) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.

  8. Nanocomposite Electrospun Nanofiber Membranes for Environmental Remediation.

    Science.gov (United States)

    Homaeigohar, Shahin; Elbahri, Mady

    2014-02-10

    Rapid worldwide industrialization and population growth is going to lead to an extensive environmental pollution. Therefore, so many people are currently suffering from the water shortage induced by the respective pollution, as well as poor air quality and a huge fund is wasted in the world each year due to the relevant problems. Environmental remediation necessitates implementation of novel materials and technologies, which are cost and energy efficient. Nanomaterials, with their unique chemical and physical properties, are an optimum solution. Accordingly, there is a strong motivation in seeking nano-based approaches for alleviation of environmental problems in an energy efficient, thereby, inexpensive manner. Thanks to a high porosity and surface area presenting an extraordinary permeability (thereby an energy efficiency) and selectivity, respectively, nanofibrous membranes are a desirable candidate. Their functionality and applicability is even promoted when adopting a nanocomposite strategy. In this case, specific nanofillers, such as metal oxides, carbon nanotubes, precious metals, and smart biological agents, are incorporated either during electrospinning or in the post-processing. Moreover, to meet operational requirements, e.g., to enhance mechanical stability, decrease of pressure drop, etc. , nanofibrous membranes are backed by a microfibrous non-woven forming a hybrid membrane. The novel generation of nanocomposite/hybrid nanofibrous membranes can perform extraordinarily well in environmental remediation and control. This reality justifies authoring of this review paper.

  9. Nanocomposite Electrospun Nanofiber Membranes for Environmental Remediation

    Directory of Open Access Journals (Sweden)

    Shahin Homaeigohar

    2014-02-01

    Full Text Available Rapid worldwide industrialization and population growth is going to lead to an extensive environmental pollution. Therefore, so many people are currently suffering from the water shortage induced by the respective pollution, as well as poor air quality and a huge fund is wasted in the world each year due to the relevant problems. Environmental remediation necessitates implementation of novel materials and technologies, which are cost and energy efficient. Nanomaterials, with their unique chemical and physical properties, are an optimum solution. Accordingly, there is a strong motivation in seeking nano-based approaches for alleviation of environmental problems in an energy efficient, thereby, inexpensive manner. Thanks to a high porosity and surface area presenting an extraordinary permeability (thereby an energy efficiency and selectivity, respectively, nanofibrous membranes are a desirable candidate. Their functionality and applicability is even promoted when adopting a nanocomposite strategy. In this case, specific nanofillers, such as metal oxides, carbon nanotubes, precious metals, and smart biological agents, are incorporated either during electrospinning or in the post-processing. Moreover, to meet operational requirements, e.g., to enhance mechanical stability, decrease of pressure drop, etc., nanofibrous membranes are backed by a microfibrous non-woven forming a hybrid membrane. The novel generation of nanocomposite/hybrid nanofibrous membranes can perform extraordinarily well in environmental remediation and control. This reality justifies authoring of this review paper.

  10. POTENTIAL ENHANCEMENTS TO NATURAL ATTENUATION: LINES OF INQUIRY SUPPORTING ENHANCED PASSIVE REMEDIATION OF CHLORINATED SOLVENTS

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, K; Tom Early, T; Michael Heitkamp, M; Brian02 Looney, B; David Major, D; Brian Riha, B; Jody Waugh, J; Gary Wein, G

    2004-06-18

    The Department of Energy (DOE) is sponsoring an initiative to facilitate efficient, effective and responsible use of Monitored Natural Attenuation (MNA) and Enhanced Passive Remediation (EPR) for chlorinated solvents. This Office of Environmental Management (EM) ''Alternative Project,'' focuses on providing scientific and policy support for MNA/EPR. A broadly representative working group of scientists supports the project along with partnerships with regulatory organizations such as the Interstate Technology and Regulatory Council and the U.S. Environmental Protection Agency (EPA). The initial product of the technical working group was a summary report that articulated the conceptual approach and central scientific tenants of the project, and that identified a prioritized listing of technical targets for field research. This report documented the process in which: (1) scientific ground rules were developed, (2) lines of inquiry were identified and then critically evaluated, (3) promising applied research topics were highlighted in the various lines of inquiry, and (4) these were discussed and prioritized. The summary report will serve as a resource to guide management and decision-making throughout the period of the subject MNA/EPR Alternative Project. To support and more fully document the information presented in the summary report, we are publishing a series of supplemental documents that present the full texts from the technical analyses within the various lines of inquiry (see listing). The following report - documenting our evaluation of the state of the science of the characterization and monitoring process and tools-- is one of those supplemental documents.

  11. Remediation of contaminated soils by biotechnology with nanomaterials: bio-behavior, applications, and perspectives.

    Science.gov (United States)

    Gong, Xiaomin; Huang, Danlian; Liu, Yunguo; Peng, Zhiwei; Zeng, Guangming; Xu, Piao; Cheng, Min; Wang, Rongzhong; Wan, Jia

    2018-05-01

    Soil contamination caused by heavy metals and organic pollutants has drawn world-wide concern. Biotechnology has been applied for many years to the decontamination of soils polluted with organic and inorganic contaminants, and novel nanomaterials (NMs) has attracted much concern due to their high capacity for the removal/stabilization/degradation of pollutants. Recently, developing advanced biotechnology with NMs for the remediation of contaminated soils has become a hot research topic. Some researchers found that bioremediation efficiency of contaminated soils was enhanced by the addition of NMs, while others demonstrated that the toxicity of NMs to the organism negatively influenced the repair capacity of polluted soils. This paper reviews the application of biotechnology and NMs in soil remediation, and further provides a critical view of the effects of NMs on the phytoremediation and micro-remediation of contaminated soils. This review also discusses the future research needs for the combined application of biotechnology and NMs in soil remediation.

  12. Microbial metabolism and community structure in response to bioelectrochemically enhanced remediation of petroleum hydrocarbon-contaminated soil.

    Science.gov (United States)

    Lu, Lu; Huggins, Tyler; Jin, Song; Zuo, Yi; Ren, Zhiyong Jason

    2014-04-01

    This study demonstrates that electrodes in a bioelectrochemical system (BES) can potentially serve as a nonexhaustible electron acceptor for in situ bioremediation of hydrocarbon contaminated soil. The deployment of BES not only eliminates aeration or supplement of electron acceptors as in contemporary bioremediation but also significantly shortens the remediation period and produces sustainable electricity. More interestingly, the study reveals that microbial metabolism and community structure distinctively respond to the bioelectrochemically enhanced remediation. Tubular BESs with carbon cloth anode (CCA) or biochar anode (BCA) were inserted into raw water saturated soils containing petroleum hydrocarbons for enhancing in situ remediation. Results show that total petroleum hydrocarbon (TPH) removal rate almost doubled in soils close to the anode (63.5-78.7%) than that in the open circuit positive controls (37.6-43.4%) during a period of 64 days. The maximum current density from the BESs ranged from 73 to 86 mA/m(2). Comprehensive microbial and chemical characterizations and statistical analyses show that the residual TPH has a strongly positive correlation with hydrocarbon-degrading microorganisms (HDM) numbers, dehydrogenase activity, and lipase activity and a negative correlation with soil pH, conductivity, and catalase activity. Distinctive microbial communities were identified at the anode, in soil with electrodes, and soil without electrodes. Uncommon electrochemically active bacteria capable of hydrocarbon degradation such as Comamonas testosteroni, Pseudomonas putida, and Ochrobactrum anthropi were selectively enriched on the anode, while hydrocarbon oxidizing bacteria were dominant in soil samples. Results from genus or phylum level characterizations well agree with the data from cluster analysis. Data from this study suggests that a unique constitution of microbial communities may play a key role in BES enhancement of petroleum hydrocarbons

  13. Spectral induced polarization for monitoring electrokinetic remediation processes

    Science.gov (United States)

    Masi, Matteo; Losito, Gabriella

    2015-12-01

    Electrokinetic remediation is an emerging technology for extracting heavy metals from contaminated soils and sediments. This method uses a direct or alternating electric field to induce the transport of contaminants toward the electrodes. The electric field also produces pH variations, sorption/desorption and precipitation/dissolution of species in the porous medium during remediation. Since heavy metal mobility is pH-dependent, the accurate control of pH inside the material is required in order to enhance the removal efficiency. The common approach for monitoring the remediation process both in laboratory and in the field is the chemical analysis of samples collected from discrete locations. The purpose of this study is the evaluation of Spectral Induced Polarization as an alternative method for monitoring geochemical changes in the contaminated mass during remediation. The advantage of this technique applied to field-scale is to offer higher resolution mapping of the remediation site and lower cost compared to the conventional sampling procedure. We carried out laboratory-scale electrokinetic remediation experiments on fine-grained marine sediments contaminated by heavy metal and we made Spectral Induced Polarization measurements before and after each treatment. Measurements were done in the frequency range 10- 3-103 Hz. By the deconvolution of the spectra using the Debye Decomposition method we obtained the mean relaxation time and total chargeability. The main finding of this work is that a linear relationship exists between the local total chargeability and pH, with good agreement. The observed behaviour of chargeability is interpreted as a direct consequence of the alteration of the zeta potential of the sediment particles due to pH changes. Such relationship has a significant value for the interpretation of induced polarization data, allowing the use of this technique for monitoring electrokinetic remediation at field-scale.

  14. Thermal soil remediation

    International Nuclear Information System (INIS)

    Nelson, D.

    1999-01-01

    The environmental properties and business aspects of thermal soil remediation are described. Thermal soil remediation is considered as being the best option in cleaning contaminated soil for reuse. The thermal desorption process can remove hydrocarbons such as gasoline, kerosene and crude oil, from contaminated soil. Nelson Environmental Remediation (NER) Ltd. uses a mobile thermal desorption unit (TDU) with high temperature capabilities. NER has successfully applied the technology to target heavy end hydrocarbon removal from Alberta's gumbo clay in all seasons. The TDU consist of a feed system, a counter flow rotary drum kiln, a baghouse particulate removal system, and a secondary combustion chamber known as an afterburner. The technology has proven to be cost effective and more efficient than bioremediation and landfarming

  15. Cost-efficient remediation of an upstream oilfield battery site

    Energy Technology Data Exchange (ETDEWEB)

    Siebert, L.D. [Imperial Oil Resources Canada, Calgary, AB (Canada); Bedard, G.; Pouliot, M.; Soucy, F.; Faucher, C.; Corbin, R. [Biogenie Inc., Quebec City, PQ (Canada)

    2003-07-01

    The soil at an oilfield battery site, located 18 kilometres (km) northwest of Devon, Alberta has been contaminated with crude oil and salt, following years of operation. Surrounding the site is flat farmland intended for future agricultural production. A remedial program aimed at complying with Tier I criteria of the Alberta Soil and Water Quality Guidelines for Hydrocarbons at Upstream Oil and Gas Facilities (ASWQG) of Alberta Environment, was developed and implemented. Characterization of the site was carried out in 1997 to delineate a salt plume, followed by a second sampling campaign in 1999, which all together revealed three impacted areas. A supplementary characterization was performed in 2001 by Biogenie in an effort to better determine the nature and level of petroleum contamination and more accurately evaluate the volume of contaminated soil. A three-dimensional Visualization software integrating a Kriging geostatistical model was used for this purpose. The results indicated that an estimated 8,800 cubic metres of contaminated soil would need to be excavated and treated. The next phase involved an evaluation of the various remedial options, which was accomplished using a biotreatability study. The remediation program selected involved the excavation of the contaminated soil and segregation of source material, the ex-situ Biopile treatment of the source material to meet Class II landfill criteria, and the ex-situ Biopile treatment of the contaminated soil followed by its use as backfill on site. The biotreatability study proved to be a strategic tool in the remediation effort. 1 tab., 2 figs.

  16. Optimizing the Environmental Performance of In Situ Thermal Remediation Technologies Using Life Cycle Assessment

    DEFF Research Database (Denmark)

    Lemming, Gitte; Nielsen, Steffen G.; Weber, Klaus

    2013-01-01

    In situ thermal remediation technologies provide efficient and reliable cleanup of contaminated soil and groundwater, but at a high cost of environmental impacts and resource depletion due to the large amounts of energy and materials consumed. This study provides a detailed investigation of four...... in situ thermal remediation technologies (steam enhanced extraction, thermal conduction heating, electrical resistance heating, and radio frequency heating) in order to (1) compare the life-cycle environmental impacts and resource consumption associated with each thermal technology, and (2) identify...... improvements is a 10 to 21% decrease in environmental impacts and an 8 to 20% decrease in resource depletion depending on the thermal remediation technology considered. The energy consumption was found to be the main contributor to most types of environmental impacts; this will, however, depend...

  17. Eisenia fetida avoidance behavior as a tool for assessing the efficiency of remediation of Pb, Zn and Cd polluted soil

    International Nuclear Information System (INIS)

    Udovic, Metka; Lestan, Domen

    2010-01-01

    Remediation by means of soil leaching with ethylenediaminetetraacetic acid (EDTA) is capable of extracting the most labile soil fractions, leaving the residual metals in biologically non-available forms. We evaluated the feasibility of the standardized earthworm (Eisenia fetida) avoidance test for assessing the efficiency of soil remediation of Pb, Zn and Cd polluted soil. Chemical extraction tests (six-step sequential extraction, toxicity characteristic leaching procedure, physiologically based extraction test, diethylenediaminepentaacetic acid extraction) indicated that the mobility, oral bioaccessibility and phytoavailability of Pb, Zn and Cd were consistently reduced. However, the avoidance test showed no significant avoidance of polluted soil in favor of that which had been remediated. Pb, Zn and Cd accumulation in E. fetida mirrored the decreasing pattern of metal potential bioavailability gained by leaching the soil with increasing EDTA concentrations. The calculated bioaccumulation factors indicated the possibility of underestimating the metal bioavailability in soil using chemical extraction tests. - Tests with indicator organisms should be used for a more meaningful and holistic assessment of metal biological availability in polluted and remediated soil.

  18. Eisenia fetida avoidance behavior as a tool for assessing the efficiency of remediation of Pb, Zn and Cd polluted soil

    Energy Technology Data Exchange (ETDEWEB)

    Udovic, Metka [Centre for Soil and Environmental Science, Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, Sl-1000 Ljubljana (Slovenia); Lestan, Domen, E-mail: domen.lestan@bf.uni-lj.s [Centre for Soil and Environmental Science, Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, Sl-1000 Ljubljana (Slovenia)

    2010-08-15

    Remediation by means of soil leaching with ethylenediaminetetraacetic acid (EDTA) is capable of extracting the most labile soil fractions, leaving the residual metals in biologically non-available forms. We evaluated the feasibility of the standardized earthworm (Eisenia fetida) avoidance test for assessing the efficiency of soil remediation of Pb, Zn and Cd polluted soil. Chemical extraction tests (six-step sequential extraction, toxicity characteristic leaching procedure, physiologically based extraction test, diethylenediaminepentaacetic acid extraction) indicated that the mobility, oral bioaccessibility and phytoavailability of Pb, Zn and Cd were consistently reduced. However, the avoidance test showed no significant avoidance of polluted soil in favor of that which had been remediated. Pb, Zn and Cd accumulation in E. fetida mirrored the decreasing pattern of metal potential bioavailability gained by leaching the soil with increasing EDTA concentrations. The calculated bioaccumulation factors indicated the possibility of underestimating the metal bioavailability in soil using chemical extraction tests. - Tests with indicator organisms should be used for a more meaningful and holistic assessment of metal biological availability in polluted and remediated soil.

  19. Electrodialytic remediation of suspended mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, Adrian; Pino, Denisse

    2008-01-01

    This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. A newly designed remediation cell, where the solids were kept in suspension by airflow, was tested. The results show that electric current could remove copper from suspended tailings...... efficiency from 1% to 80% compared to experiments with no stirring but with the same operational conditions. This showed the crucial importance of having the solids in suspension and not settled during the remediation....

  20. Efficient visible-light photocatalytic and enhanced photocorrosion inhibition of Ag2WO4 decorated MoS2 nanosheets

    Science.gov (United States)

    Thangavel, Sakthivel; Thangavel, Srinivas; Raghavan, Nivea; Alagu, Raja; Venugopal, Gunasekaran

    2017-11-01

    The use of two-dimensional nanomaterials as co-catalysts in the photodegradation of toxic compounds using light irradiation is an attractive ecofriendly process. In this study, we prepared a novel MoS2/Ag2WO4 nanohybrid via a one-step hydrothermal approach and the photocatalytic properties were investigated by the degradation of methyl-orange under stimulated irradiation. The nanohybrid exhibits enhanced efficiency in dye degradation compared to the bare Ag2WO4 nanorods; the same has been evidently confirmed with UV-visible spectra and total organic carbon removal analysis. The pseudo-first order rate constant of the nanohybrid is nearly 1.8 fold higher than that of the bare Ag2WO4 nanorods. With the aid of classical radical quenching and photoluminescence spectral analysis, a reasonable mechanism has been derived for the addition of MoS2 to nanohybrids to enhance the photocatalytic efficiency. MoS2 prevents photocorrosion of Ag2WO4 and also diminishes the number of photogenerated electron-hole recombination. Our findings could provide new insights in understanding the mechanism of the MoS2/Ag2WO4 nanohybrid as an efficient photocatalyst suitable for waste-water treatment and remedial applications.

  1. LCA of Soil and Groundwater Remediation

    DEFF Research Database (Denmark)

    Søndergaard, Gitte Lemming; Owsianiak, Mikolaj

    2018-01-01

    Today, there is increasing interest in applying LCA to support decision-makers in contaminated site management. In this chapter, we introduce remediation technologies and associated environmental impacts, present an overview of literature findings on LCA applied to remediation technologies...... and present methodological issues to consider when conducting LCAs within the area. Within the field of contaminated site remediation , a terminology distinguishing three types of environmental impacts: primary, secondary and tertiary, is often applied. Primary impacts are the site-related impacts due...... and efficiency of remediation, which are important for assessment or primary impacts; (ii) robust assessment of primary impacts using site-specific fate and exposure models; (iii) weighting of primary and secondary (or tertiary) impacts to evaluate trade-offs between life cycle impacts from remediation...

  2. Phyto-remediation of contaminated soils

    International Nuclear Information System (INIS)

    Chagvardieff, P.

    2014-01-01

    Some plants can be selected for their capacity to extract radionuclides from the soil, on the contrary other plants can be chosen for being able to produce food grade products in a contaminated environment. Modern genetic methods can be used to enhance these abilities and turn some plants into an efficient means in the managing of contaminated areas. The DEMETERRES project that gathers different research organisations like CEA, IRSN and INRA and industrial partners like AREVA and VEOLIA aims at developing innovative bio-technologies like phyto-extraction and environment friendly physico-chemical technologies for the remediation of contaminated soils. This project was launched in 2013 on a 5-year scheme and is expected to lead to industrial applications. (A.C.)

  3. Heterogeneous photocatalysis for air and water treatment: Fundamental needs for quantum efficiency enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Ollis, D.F. [North Carolina State Univ., Raleigh, NC (United States)

    1996-09-01

    In the remediation industries, a useful treatment technology must be {open_quotes}general, robust, and cheap{close_quotes}. Among oxidation processes, heterogeneous photocatalysis is now broadly demonstrated to destroy common water and air contaminants. The potential process uses of highly stable titania, long lived lamps (one year), and room temperature operation, indicating a simple and robust process. We are left to address the third criterion: Can photocatalysis be {open_quotes}cheap{close_quotes}? In both liquid phase and gas phase treatment and purification by photocatalysis, it is established that the primary barrier to commercialization is often cost. Cost in return is dominated by the efficiency with which solar or lamp photons are harvested for productive light, and subsequent dark, reactions. This paper therefore defines fundamental needs in photocatalysis for pollution control in terms of activities which could lead to quantum efficiency enhancement. We first recall three related definitions. The quantum yield (QY) is the ratio of molecules of reactant converted per photon absorbed, a fundamental quantity. A less fundamental, but more easily measured variable is the quantum efficiency (QE), the ratio of molecules converted per photon entering the reactor. A third variable is the energy required per order of magnitude pollutant reduction, or EEO, a definition which provides for easy energy cost comparisons among different technologies. Each measure cited here reflects the photon, and thus the electrical, cost of this photochemistry.

  4. The effect of CO2 on the plasma remediation of NxOy

    Science.gov (United States)

    Gentile, Ann C.; Kushner, Mark J.

    1996-04-01

    Plasma remediation is being investigated for the removal of oxides of nitrogen (NxOy) from atmospheric pressure gas streams. In previous works we have investigated the plasma remediation of NxOy from N2/O2/H2O mixtures using repetitively pulsed dielectric barrier discharges. As combustion effluents contain large percentages of CO2, in this paper we discuss the consequences of CO2 in the gas mixture on the efficiency of remediation and on the end products. We find that there is a small increase in the efficiency of total NxOy remediation (molecules/eV) with increasing CO2 fraction, however the efficiency of NO remediation alone generally decreases with increasing CO2. This differential is more pronounced at low energy deposition per pulse. More remediation occurs through the reduction channel with increasing CO2 while less NO2 and HNOx are produced through the oxidation channel. CO is produced by electron impact of CO2 though negligible amounts of cyanides are generated.

  5. Application of ozone micro-nano-bubbles to groundwater remediation.

    Science.gov (United States)

    Hu, Liming; Xia, Zhiran

    2018-01-15

    Ozone is widely used for water treatment because of its strong oxidation ability. However, the efficiency of ozone in groundwater remediation is limited because of its relatively low solubility and rapid decomposition in the aqueous phase. Methods for increasing the stability of ozone within the subsurface are drawing increasing attention. Micro-nano-bubbles (MNBs), with diameters ranging from tens of nanometres to tens of micrometres, present rapid mass transfer rates, persist for a relatively long time in water, and transport with groundwater flow, which significantly improve gas concentration and provide a continuous gas supply. Therefore, MNBs show a considerable potential for application in groundwater remediation. In this study, the characteristics of ozone MNBs were examined, including their size distribution, bubble quantity, and zeta potential. The mass transfer rate of ozone MNBs was experimentally investigated. Ozone MNBs were then used to treat organics-contaminated water, and they showed remarkable cleanup efficiency. Column tests were also conducted to study the efficiency of ozone MNBs for organics-contaminated groundwater remediation. Based on the laboratory tests, field monitoring was conducted on a trichloroethylene (TCE)-contaminated site. The results showed that ozone MNBs can greatly improve remediation efficiency and represent an innovative technology for in situ remediation of organics-contaminated groundwater. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  6. Interactive computer-enhanced remote viewing system

    Energy Technology Data Exchange (ETDEWEB)

    Tourtellott, J.A.; Wagner, J.F. [Mechanical Technology Incorporated, Latham, NY (United States)

    1995-10-01

    Remediation activities such as decontamination and decommissioning (D&D) typically involve materials and activities hazardous to humans. Robots are an attractive way to conduct such remediation, but for efficiency they need a good three-dimensional (3-D) computer model of the task space where they are to function. This model can be created from engineering plans and architectural drawings and from empirical data gathered by various sensors at the site. The model is used to plan robotic tasks and verify that selected paths are clear of obstacles. This report describes the development of an Interactive Computer-Enhanced Remote Viewing System (ICERVS), a software system to provide a reliable geometric description of a robotic task space, and enable robotic remediation to be conducted more effectively and more economically.

  7. Electrodialytic Remediation of Soil Fines (<63μm) in Suspension

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Ottosen, Lisbeth M.; Ferreira, Célia

    2007-01-01

    Current treatment of the remaining soil fines from soil wash is onerous and expensive, and therefore, in this work, we investigated the feasibility of electrodialytic remediation (EDR) as an alternative treatment. The study focuses on EDR efficiency as a function of current strength, liquid......-exchange membrane increased the pH, and this resulted in decreased remediation efficiency. It was shown that complete remediation of the soil-fines is possible, with the majority of the Pb being transported into the catholyte and precipitated at the cathode. Based on the results it is recommended that EDR...

  8. Evaluation of design factors for a cascade aerator to enhance the efficiency of an oxidation pond for ferruginous mine drainage.

    Science.gov (United States)

    Oh, Chamteut; Ji, Sangwoo; Cheong, Youngwook; Yim, Giljae; Hong, Ji-Hye

    2016-10-01

    This research focused on the optimum design of a cascade aerator to enhance the efficiency of an oxidation pond in a passive treatment system for remediating ferruginous mine drainage. For this purpose, various aeration experiments with aerators of different drop heights (0-4 m) and formations (types A and B) were executed on mine drainage. Type A simply drops the mine drainage into the oxidation pond while type B sprays the mine drainage and retains it for 8 min in each step. The efficiency enhancement of the oxidation pond was strongly dependent on the increase in pH and DO of the mine drainage discharged into the pond. The water quality improved with the increase in drop height but especially showed better effect with type B. The reasons for this result were attributed to the increase of contact surface and retention time of the mine drainage. The cascade aerator, therefore, should be designed to be as high as possible with the assistance of spraying form and retention time of the mine drainage to maximize the efficiency of the oxidation pond. These effects could be evaluated by calculating required areas of the oxidation pond for 95% of Fe(2+) oxidation.

  9. Integrating GIS and GPS in environmental remediation oversight

    International Nuclear Information System (INIS)

    Kaletsky, K.; Earle, J.R.; Schneider, T.A.

    1996-01-01

    This paper presents findings on Ohio EPA Office of Federal Facilities Oversight's (OFFO) use of GIS and GPS for environmental remediation oversight at the U.S. Department of Energy's (DOE) Fernald Site. The Fernald site is a former uranium metal production facility within DOE's nuclear weapons complex. Significant uranium contamination of soil and groundwater is being remediated under state and federal regulations. OFFO uses GIS/GPS to enhance environmental monitoring and remediation oversight. These technologies are utilized within OFFO's environmental monitoring program for sample location and parameter selection, data interpretation and presentation. GPS is used to integrate sample data into OFFO's GIS and for permanently linking precise and accurate geographic data to samples and waste units. It is important to identify contamination geographically as all visual references (e.g., buildings, infrastructure) will be removed during remediation. Availability of the GIS allows OFFO to perform independent analysis and review of DOE contractor generated data, models, maps, and designs. This ability helps alleviate concerns associated with open-quotes black boxclose quotes models and data interpretation. OFFO's independent analysis has increased regulatory confidence and the efficiency of design reviews. GIS/GPS technology allows OFFO to record and present complex data in a visual format aiding in stakeholder education and awareness. Presented are OFFO's achievements within the aforementioned activities and some reasons learned in implementing the GIS/GPS program. OFFO's two years of GIS/GPS development have resulted in numerous lessons learned and ideas for increasing effectiveness through the use of GIS/GPS

  10. Policy and Strategies for Environmental Remediation

    International Nuclear Information System (INIS)

    2015-01-01

    In the environmental remediation of a given site, concerned and interested parties have diverse and often conflicting interests with regard to remediation goals, the time frames involved, reuse of the site, the efforts necessary and cost allocation. An environmental remediation policy is essential for establishing the core values on which remediation is to be based. It incorporates a set of principles to ensure the safe and efficient management of remediation situations. Policy is mainly established by the national government and may become codified in the national legislative system. An environmental remediation strategy sets out the means for satisfying the principles and requirements of the national policy. It is normally established by the relevant remediation implementer or by the government in the case of legacy sites. Thus, the national policy may be elaborated in several different strategies. To ensure the safe, technically optimal and cost effective management of remediation situations, countries are advised to formulate an appropriate policy and strategies. Situations involving remediation include remediation of legacy sites (sites where past activities were not stringently regulated or adequately supervised), remediation after emergencies (nuclear and radiological) and remediation after planned ongoing operation and decommissioning. The environmental policy involves the principles of justification, optimization of protection, protection of future generations and the environment, efficiency in the use of resources, and transparent interaction with stakeholders. A typical policy will also take into account the national legal framework and institutional structure and applicable international conventions while providing for the allocation of responsibilities and resources, in addition to safety and security objectives and public information and participation in the decision making process. The strategy reflects and elaborates the goals and requirements set

  11. Electrodialytic remediation of soil polluted with heavy metals

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Ottosen, Lisbeth M.; Hansen, Lene

    1999-01-01

    In this paper, the importance of some parameters for the efficiency of electrodialytic soil remediation are evaluated. The parameters investigated are pH, the limiting current density and the adding of desorbing agents to the soil. Three parameters are found to be of greatest importance. Results...... show that the electrodialytic soil remediation can be optimized by understanding and adjusting of these parameters. For scaling up of the remediation method these parameters are of crucial importance....

  12. X-231A demonstration of in-situ remediation of DNAPL compounds in low permeability media by soil fracturing with thermally enhanced mass recovery or reactive barrier destruction

    International Nuclear Information System (INIS)

    Siegrist, R.L.; Slack, W.W.; Houk, T.C.

    1998-03-01

    The overall goal of the program of activities is to demonstrate robust and cost-effective technologies for in situ remediation of DNAPL compounds in low permeability media (LPM), including adaptations and enhancements of conventional technologies to achieve improved performance for DNAPLs in LPM. The technologies sought should be potential for application at simple, small sites (e.g., gasoline underground storage tanks) as well as at complex, larger sites (e.g., DOE land treatment units). The technologies involved in the X-231A demonstration at Portsmouth Gaseous Diffusion Plant (PORTS) utilized subsurface manipulation of the LPM through soil fracturing with thermally enhanced mass recovery or horizontal barrier in place destruction. To enable field evaluation of these approaches, a set of four test cells was established at the X-231A land treatment unit at the DOE PORTS plant in August 1996 and a series of demonstration field activities occurred through December 1997. The principal objectives of the PORTS X-231A demonstration were to: determine and compare the operational features of hydraulic fractures as an enabling technology for steam and hot air enhanced soil vapor extraction and mass recovery, in situ interception and reductive destruction by zero valent iron, and in situ interception and oxidative destruction by potassium permanganate; determine the interaction of the delivered agents with the LPM matrix adjacent to the fracture and within the fractured zone and assess the beneficial modifications to the transport and/or reaction properties of the LPM deposit; and determine the remediation efficiency achieved by each of the technology strategies

  13. Interactive computer-enhanced remote viewing system

    International Nuclear Information System (INIS)

    Tourtellott, J.A.; Wagner, J.F.

    1995-01-01

    Remediation activities such as decontamination and decommissioning (D ampersand D) typically involve materials and activities hazardous to humans. Robots are an attractive way to conduct such remediation, but for efficiency they need a good three-dimensional (3-D) computer model of the task space where they are to function. This model can be created from engineering plans and architectural drawings and from empirical data gathered by various sensors at the site. The model is used to plan robotic tasks and verify that selected paths are clear of obstacles. This report describes the development of an Interactive Computer-Enhanced Remote Viewing System (ICERVS), a software system to provide a reliable geometric description of a robotic task space, and enable robotic remediation to be conducted more effectively and more economically

  14. Electroluminescence Efficiency Enhancement using Metal Nanoparticles

    National Research Council Canada - National Science Library

    Soref, Richard A; Khurgin, J. B; Sun, G

    2008-01-01

    We apply the "effective mode volume" theory to evaluate enhancement of the electroluminescence efficiency of semiconductor emitters placed in the vicinity of isolated metal nanoparticles and their arrays...

  15. Overview: Microbial amendment of remediated soils for effective recycling

    Directory of Open Access Journals (Sweden)

    Kim Soo-Bin

    2017-01-01

    Full Text Available In recent years, various methods are being considered with appropriate amendments, not with conventional reclamation to recycle deteriorated soils after remediation as agricultural addition, backfilling and construction materials etc. Among these amendments, microbial amendments with effective microorganism(EMs are known to improve soil qualities such as fertility, strength and toxicity to be recycled into possible utilizations. This study indicates the possibility of recycling the remediated soils by using these EMs most efficiently. Soil samples will be collected from contaminated sites with either heavy metals or petroleum and will be remediated by bench-scale soil washing and thermal desorption. And then the remediated soils will be treated with easily obtainable inocula, substrates (culture media near our life and they are compared with commercial EM products in terms of the cost and efficiency. Also, after treating with a number of mixing ratios, soil properties of (1 fresh, (2 contaminated, (3 remediated (4 amended soils will be evaluated based on soil quality indicators depending on demands and the optimal mixing ratios which are effective than commercial EM products will be determined. The ratio derived from pre-tests could be applied on the remediated soils with pilot-scale in order to assess suitability for recycling and characterize correlation between soil properties and microbial amendments regarding contaminants and remediation, and furthermore for modelling. In conclusion, application of the established models on recycling remediated soils may help to dispose the remediated soils in future, including environmental and ecological values as well as economical values.

  16. Improved stability and enhanced efficiency to degrade chlorimuron-ethyl by the entrapment of esterase SulE in cross-linked poly (γ-glutamic acid)/gelatin hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liqiang [State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang (China); University of Chinese Academy of Sciences, Beijing (China); Li, Xinyu; Li, Xu; Su, Zhencheng; Zhang, Chenggang; Xu, MingKai [State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang (China); Zhang, Huiwen, E-mail: hwzhang@iae.ac.cn [State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang (China)

    2015-04-28

    Highlights: • Esterase SulE was entrapped in a three-dimensional network of CPE. • CPE-SulE obviously improved thermostability, pH stability and reusability. • CPE-SulE displayed obviously enhanced efficiency in degrading chlorimuron-ethyl. • The three-dimensional network and kinetic parameters of CPE-SulE were analysed. • CPE-SulE possesses the great potential to remediate chlorimuron-ethyl contaminated in situ. - Abstract: Free enzymes often undergo some problems such as easy deactivation, low stability, and less recycling in biodegradation processes, especially in soil condition. A novel esterase SulE, which is responsible for primary degradation of a wide range of sulfonylurea herbicides by methyl or ethyl ester de-esterification, was expressed by strain Hansschlegelia sp. CHL1 and entrapped for the first time in an environment-friendly, biocompatible and biodegradable cross-linked poly (γ-glutamic acid)/gelatin hydrogel (CPE). The activity and stability of CPE-SulE were compared with free SulE under varying pH and temperature condition by measuring chlorimuron-ethyl residue. Meanwhile, the three-dimensional network of CPE-SulE was verified by scanning electron microscopy (SEM). The results showed that CPE-SulE obviously improved thermostability, pH stability and reusability compared with free SulE. Furthermore, CPE-SulE enhanced degrading efficiency of chlorimuron-ethyl in both soil and water system, especially in acid environment. The characteristics of CPE-SulE suggested the great potential to remediate chlorimuron-ethyl contaminated soils in situ.

  17. Improved stability and enhanced efficiency to degrade chlorimuron-ethyl by the entrapment of esterase SulE in cross-linked poly (γ-glutamic acid)/gelatin hydrogel

    International Nuclear Information System (INIS)

    Yang, Liqiang; Li, Xinyu; Li, Xu; Su, Zhencheng; Zhang, Chenggang; Xu, MingKai; Zhang, Huiwen

    2015-01-01

    Highlights: • Esterase SulE was entrapped in a three-dimensional network of CPE. • CPE-SulE obviously improved thermostability, pH stability and reusability. • CPE-SulE displayed obviously enhanced efficiency in degrading chlorimuron-ethyl. • The three-dimensional network and kinetic parameters of CPE-SulE were analysed. • CPE-SulE possesses the great potential to remediate chlorimuron-ethyl contaminated in situ. - Abstract: Free enzymes often undergo some problems such as easy deactivation, low stability, and less recycling in biodegradation processes, especially in soil condition. A novel esterase SulE, which is responsible for primary degradation of a wide range of sulfonylurea herbicides by methyl or ethyl ester de-esterification, was expressed by strain Hansschlegelia sp. CHL1 and entrapped for the first time in an environment-friendly, biocompatible and biodegradable cross-linked poly (γ-glutamic acid)/gelatin hydrogel (CPE). The activity and stability of CPE-SulE were compared with free SulE under varying pH and temperature condition by measuring chlorimuron-ethyl residue. Meanwhile, the three-dimensional network of CPE-SulE was verified by scanning electron microscopy (SEM). The results showed that CPE-SulE obviously improved thermostability, pH stability and reusability compared with free SulE. Furthermore, CPE-SulE enhanced degrading efficiency of chlorimuron-ethyl in both soil and water system, especially in acid environment. The characteristics of CPE-SulE suggested the great potential to remediate chlorimuron-ethyl contaminated soils in situ

  18. Phyto-enhanced remediation of soil co-contaminated with lead and diesel fuel using biowaste and Dracaena reflexa: A laboratory study.

    Science.gov (United States)

    Dadrasnia, Arezoo; Pariatamby, Agamuthu

    2016-03-01

    In phytoremediation of co-contaminated soil, the simultaneous and efficient remediation of multiple pollutants is a major challenge rather than the removal of pollutants. A laboratory-scale experiment was conducted to investigate the effect of 5% addition of each of three different organic waste amendments (tea leaves, soy cake, and potato skin) to enhance the phytoaccumulation of lead (60 mg kg(-1)) and diesel fuel (25,000 mg kg(-1)) in co-contaminated soil by Dracaena reflexa Lam for a period of 180 day. The highest rate of oil degradation was recorded in co-contaminated soil planted with D. reflexa and amended with soy cake (75%), followed by potato skin (52.8%) and tea leaves (50.6%). Although plants did not accumulate hydrocarbon from the contaminated soil, significant bioaccumulation of lead in the roots and stems of D. reflexa was observed. At the end of 180 days, 16.7 and 9.8 mg kg(-1) of lead in the stems and roots of D. reflexa were recorded, respectively, for the treatment with tea leaves. These findings demonstrate the potential of organic waste amendments in enhancing phytoremediation of oil and bioaccumulation of lead. © The Author(s) 2015.

  19. Enhanced removal of petroleum hydrocarbons using a bioelectrochemical remediation system with pre-cultured anodes

    International Nuclear Information System (INIS)

    Venkidusamy, Krishnaveni; Megharaj, Mallavarapu; Marzorati, Massimo; Lockington, Robin; Naidu, Ravi

    2016-01-01

    Bioelectrochemical remediation (BER) systems such as microbial fuel cells (MFCs) have recently emerged as a green technology for the effective remediation of petroleum hydrocarbon contaminants (PH) coupled with simultaneous energy recovery. Recent research has shown that biofilms previously enriched for substrate degrading bacteria resulted in excellent performance in terms of substrate removal and electricity generation but the effects on hydrocarbon contaminant degradation were not examined. Here we investigate the differences between enriched biofilm anodes and freshly inoculated new anodes in diesel fed single chamber mediatorless microbial fuel cells (DMFC) using various techniques for the enhancement of PH contaminant remediation with concomitant electricity generation. An anodophilic microbial consortium previously selected for over a year through continuous culturing with a diesel concentration of about 800 mg l"−"1 and which now showed complete removal of this concentration of diesel within 30 days was compared to that of a freshly inoculated new anode MFC (showing 83.4% removal of diesel) with a simultaneous power generation of 90.81 mW/m"2 and 15.04 mW/m"2 respectively. The behaviour of pre-cultured anodes at a higher concentration of PH (8000 mg l"−"1) was also investigated. Scanning electron microscopy observation revealed a thick biofilm covering the pre-cultured anodic electrode but not the anode from the freshly inoculated MFC. High resolution imaging showed the presence of thin 60 nm diametre pilus-like projections emanating from the cells. Anodic microbial community profiling confirmed that the selection for diesel degrading exoelectrogenic bacteria had occurred. Identification of a biodegradative gene (alkB) provided strong evidence of the catabolic pathway used for diesel degradation in the DMFCs.

  20. Enhanced removal of petroleum hydrocarbons using a bioelectrochemical remediation system with pre-cultured anodes

    Energy Technology Data Exchange (ETDEWEB)

    Venkidusamy, Krishnaveni [Centre for Environmental Risk Assessment and Remediation (CERAR), University of South (Australia); CRC for Contamination Assessment and Remediation of the Environment (CRCCARE), Mawson Lakes, SA5095 (Australia); Megharaj, Mallavarapu, E-mail: megh.mallavarapu@newcastle.edu.au [Centre for Environmental Risk Assessment and Remediation (CERAR), University of South (Australia); CRC for Contamination Assessment and Remediation of the Environment (CRCCARE), Mawson Lakes, SA5095 (Australia); Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308 (Australia); Marzorati, Massimo [Laboratory for Microbial Ecology and Technology (LabMET), Gent University, 9000 Gent (Belgium); Lockington, Robin [Centre for Environmental Risk Assessment and Remediation (CERAR), University of South (Australia); CRC for Contamination Assessment and Remediation of the Environment (CRCCARE), Mawson Lakes, SA5095 (Australia); Naidu, Ravi [Centre for Environmental Risk Assessment and Remediation (CERAR), University of South (Australia); CRC for Contamination Assessment and Remediation of the Environment (CRCCARE), Mawson Lakes, SA5095 (Australia); Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308 (Australia)

    2016-01-01

    Bioelectrochemical remediation (BER) systems such as microbial fuel cells (MFCs) have recently emerged as a green technology for the effective remediation of petroleum hydrocarbon contaminants (PH) coupled with simultaneous energy recovery. Recent research has shown that biofilms previously enriched for substrate degrading bacteria resulted in excellent performance in terms of substrate removal and electricity generation but the effects on hydrocarbon contaminant degradation were not examined. Here we investigate the differences between enriched biofilm anodes and freshly inoculated new anodes in diesel fed single chamber mediatorless microbial fuel cells (DMFC) using various techniques for the enhancement of PH contaminant remediation with concomitant electricity generation. An anodophilic microbial consortium previously selected for over a year through continuous culturing with a diesel concentration of about 800 mg l{sup −1} and which now showed complete removal of this concentration of diesel within 30 days was compared to that of a freshly inoculated new anode MFC (showing 83.4% removal of diesel) with a simultaneous power generation of 90.81 mW/m{sup 2} and 15.04 mW/m{sup 2} respectively. The behaviour of pre-cultured anodes at a higher concentration of PH (8000 mg l{sup −1}) was also investigated. Scanning electron microscopy observation revealed a thick biofilm covering the pre-cultured anodic electrode but not the anode from the freshly inoculated MFC. High resolution imaging showed the presence of thin 60 nm diametre pilus-like projections emanating from the cells. Anodic microbial community profiling confirmed that the selection for diesel degrading exoelectrogenic bacteria had occurred. Identification of a biodegradative gene (alkB) provided strong evidence of the catabolic pathway used for diesel degradation in the DMFCs.

  1. The benefits from environmental remediation

    International Nuclear Information System (INIS)

    Falck, W.E.

    2002-01-01

    Environmental remediation projects inevitably take place against a backdrop of overall social goals and values. These goals can include, for example, full employment, preservation of the cultural, economic and archaeological resources, traditional patterns of land use, spiritual values, quality of life factors, biological diversity, environmental and socio-economic sustainability, protection of public health. Different countries will have different priorities, linked to the overall set of societal goals and the availability of resources, including funding, man-power and skills. These issues are embedded within both a national and local socio-cultural context, and will shape the way in which the remediation process is structured in any one country. The context will shape both the overall objectives of a remediation activity within the framework of competing societal goals, as well as generate constraints on the decision making process. Hence, the overall benefit of a remediation project is determined by its overall efficiency and effectiveness within the given legal, institutional, and governance framework, under the prevailing socio-economic boundary conditions, and balancing technology performance and risk reduction with fixed or limited budgetary resources, and is not simply the result of the technical remediation operation itself. (author)

  2. The nanotoxicology of a newly developed zero-valent iron nanomaterial for groundwater remediation and its remediation efficiency assessment combined with in vitro bioassays for detection of dioxin-like environmental pollutants

    OpenAIRE

    Schiwy, Andreas Herbert

    2016-01-01

    The assessment of chemicals and new compounds is an important task of ecotoxicology. In this thesis a newly developed zero-valent iron material for nanoremediation of groundwater contaminations was investigated and in vitro bioassays for high throughput screening were developed. These two elements of the thesis were combined to assess the remediation efficiency of the nanomaterial on the groundwater contaminant acridine. The developed in vitro bioassays were evaluated for quantification of th...

  3. Biological technologies for the remediation of co-contaminated soil.

    Science.gov (United States)

    Ye, Shujing; Zeng, Guangming; Wu, Haipeng; Zhang, Chang; Dai, Juan; Liang, Jie; Yu, Jiangfang; Ren, Xiaoya; Yi, Huan; Cheng, Min; Zhang, Chen

    2017-12-01

    Compound contamination in soil, caused by unreasonable waste disposal, has attracted increasing attention on a global scale, particularly since multiple heavy metals and/or organic pollutants are entering natural ecosystem through human activities, causing an enormous threat. The remediation of co-contaminated soil is more complicated and difficult than that of single contamination, due to the disparate remediation pathways utilized for different types of pollutants. Several modern remediation technologies have been developed for the treatment of co-contaminated soil. Biological remediation technologies, as the eco-friendly methods, have received widespread concern due to soil improvement besides remediation. This review summarizes the application of biological technologies, which contains microbial technologies (function microbial remediation and composting or compost addition), biochar, phytoremediation technologies, genetic engineering technologies and biochemical technologies, for the remediation of co-contaminated soil with heavy metals and organic pollutants. Mechanisms of these technologies and their remediation efficiencies are also reviewed. Based on this study, this review also identifies the future research required in this field.

  4. COFFEE - Coherent Optical System Field Trial for Spectral Efficiency Enhancement

    DEFF Research Database (Denmark)

    Imran, Muhammad; Fresi, Francesco; Rommel, Simon

    2016-01-01

    The scope, aims, and contributions of the COFFEE project for spectral efficiency enhancement and market exposure are presented.......The scope, aims, and contributions of the COFFEE project for spectral efficiency enhancement and market exposure are presented....

  5. Enhanced counting efficiency of Cerenkov radiation from bismuth-210

    International Nuclear Information System (INIS)

    Peck, G.A.; Smith, J.D.

    1998-01-01

    This paper describes the measurement of 210 Bi by Cerenkov counting in a commercial liquid scintillation counter. The counting efficiency in water is 0.17 counts per second per Becquerel (17%). When the enhancers Triton X-100 (15% v/v) and sodium salicylate (1% m/v) are added to the solution the counting efficiency for 210 Bi increases from 17% to 75%. The 210 Po daughter of 210 Bi causes interference of 0.85 counts per second per Becquerel in the presence of the enhancers but not in water. When 210 Bi and 210 Po are present in secular equilibrium the total counting efficiency is 160%. When 210 Bi and 210 Po are not in secular equilibrium the 210 Po can be removed immediately before counting by plating onto silver foil. The use of the enhancers gives a substantial increase in counting efficiency compared to counting in water. Compared with solutions used in liquid scintillation counting the enhancer solution is inexpensive and can be disposed of without environmental hazard. (author)

  6. EDTA and HCl leaching of calcareous and acidic soils polluted with potentially toxic metals: remediation efficiency and soil impact.

    Science.gov (United States)

    Udovic, Metka; Lestan, Domen

    2012-07-01

    The environmental risk of potentially toxic metals (PTMs) in soil can be diminished by their removal. Among the available remediation techniques, soil leaching with various solutions is one of the most effective but data about the impact on soil chemical and biological properties are still scarce. We studied the effect of two common leaching agents, hydrochloric acid (HCl) and a chelating agent (EDTA) on Pb, Zn, Cd removal and accessibility and on physico-chemical and biological properties in one calcareous, pH neutral soil and one non-calcareous acidic soil. EDTA was a more efficient leachant compared to HCl: up to 133-times lower chelant concentration was needed for the same percentage (35%) of Pb removal. EDTA and HCl concentrations with similar PTM removal efficiency decreased PTM accessibility in both soils but had different impacts on soil properties. As expected, HCl significantly dissolved carbonates from calcareous soil, while EDTA leaching increased the pH of the acidic soil. Enzyme activity assays showed that leaching with HCl had a distinctly negative impact on soil microbial and enzyme activity, while leaching with EDTA had less impact. Our results emphasize the importance of considering the ecological impact of remediation processes on soil in addition to the capacity for PTM removal. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Potential Electrokinetic Remediation Technologies of Laboratory Scale into Field Application- Methodology Overview

    Science.gov (United States)

    Ayuni Suied, Anis; Tajudin, Saiful Azhar Ahmad; Nizam Zakaria, Muhammad; Madun, Aziman

    2018-04-01

    Heavy metal in soil possesses high contribution towards soil contamination which causes to unbalance ecosystem. There are many ways and procedures to make the electrokinetic remediation (EKR) method to be efficient, effective, and potential as a low cost soil treatment. Electrode compartment for electrolyte is expected to treat the contaminated soil through electromigration and enhance metal ions movement. The electrokinetic is applicable for many approaches such as electrokinetic remediation (EKR), electrokinetic stabilization (EKS), electrokinetic bioremediation and many more. This paper presents a critical review on comparison of laboratory scale between EKR, EKS and EK bioremediation treatment by removing the heavy metal contaminants. It is expected to propose one framework of contaminated soil mapping. Electrical Resistivity Method (ERM) is one of famous indirect geophysical tools for surface mapping and subsurface profiling. Hence, ERM is used to mapping the migration of heavy metal ions by electrokinetic.

  8. Efficiency enhancement of InGaN amber MQWs using nanopillar structures

    KAUST Repository

    Ou, Yiyu

    2017-09-09

    We have investigated the use of nanopillar structures on high indium content InGaN amber multiple quantum well (MQW) samples to enhance the emission efficiency. A significant emission enhancement was observed which can be attributed to the enhancement of internal quantum efficiency and light extraction efficiency. The size-dependent strain relaxation effect was characterized by photoluminescence, Raman spectroscopy and time-resolved photoluminescence measurements. In addition, the light extraction efficiency of different MQW samples was studied by finite-different time-domain simulations. Compared to the as-grown sample, the nanopillar amber MQW sample with a diameter of 300 nm has demonstrated an emission enhancement by a factor of 23.8.

  9. Efficiency enhancement of InGaN amber MQWs using nanopillar structures

    KAUST Repository

    Ou, Yiyu; Iida, Daisuke; Liu, Jin; Wu, Kaiyu; Ohkawa, Kazuhiro; Boisen, Anja; Petersen, Paul Michael; Ou, Haiyan

    2017-01-01

    We have investigated the use of nanopillar structures on high indium content InGaN amber multiple quantum well (MQW) samples to enhance the emission efficiency. A significant emission enhancement was observed which can be attributed to the enhancement of internal quantum efficiency and light extraction efficiency. The size-dependent strain relaxation effect was characterized by photoluminescence, Raman spectroscopy and time-resolved photoluminescence measurements. In addition, the light extraction efficiency of different MQW samples was studied by finite-different time-domain simulations. Compared to the as-grown sample, the nanopillar amber MQW sample with a diameter of 300 nm has demonstrated an emission enhancement by a factor of 23.8.

  10. Remediation of BTEX contaminated groundwater: best technology assessment between pump&treat and bioremediation by oxygen injection

    Directory of Open Access Journals (Sweden)

    Daniele Baldi

    2012-06-01

    Full Text Available The presence of benzene, toluene, ethylbenzene and xylene (BTEX dissolved in the groundwater and migrated from a light non-aqueous phase liquid (LNAPL source in an alluvial aquifer required a remedial action to be taken by the responsible party as established by the Italian regulation (Legislative Decree 152/06 and subsequent amendments. For such purpose, field investigations were conducted on site in order to define the site conceptual model and to identify the appropriate remediation technology to be applied. The remediation design was developed by means of a flow and reactive transport mathematical model, applied to saturated media, using the numerical codes MODFLOW and RT3D. Groundwater field observations showed evidence of occurring BTEX biodegradation processes by bacteria naturally present in the aquifer. Since such specific bacterial activity would be significantly enhanced by the injection of free oxygen in the aquifer, the performance of traditional pump and treat systems (P&T was assessed and compared with cost/efficiency of reactive oxygen bio-barrier technology (OD. The results showed a clear advantage in terms of cost/efficiency with the application of the OD. This presents an overall cost of about 30% of the P&T installation and maintenance, and it reaches remedial target in a shorter timeframe. Moreover, the system is also applicable as a bioremediation technology in case of Environmental Emergency Measures (MISE. The site examined is part of an industrial plant located in Central Italy.

  11. Thermal remediation alters soil properties - a review.

    Science.gov (United States)

    O'Brien, Peter L; DeSutter, Thomas M; Casey, Francis X M; Khan, Eakalak; Wick, Abbey F

    2018-01-15

    Contaminated soils pose a risk to human and ecological health, and thermal remediation is an efficient and reliable way to reduce soil contaminant concentration in a range of situations. A primary benefit of thermal treatment is the speed at which remediation can occur, allowing the return of treated soils to a desired land use as quickly as possible. However, this treatment also alters many soil properties that affect the capacity of the soil to function. While extensive research addresses contaminant reduction, the range and magnitude of effects to soil properties have not been explored. Understanding the effects of thermal remediation on soil properties is vital to successful reclamation, as drastic effects may preclude certain post-treatment land uses. This review highlights thermal remediation studies that have quantified alterations to soil properties, and it supplements that information with laboratory heating studies to further elucidate the effects of thermal treatment of soil. Notably, both heating temperature and heating time affect i) soil organic matter; ii) soil texture and mineralogy; iii) soil pH; iv) plant available nutrients and heavy metals; v) soil biological communities; and iv) the ability of the soil to sustain vegetation. Broadly, increasing either temperature or time results in greater contaminant reduction efficiency, but it also causes more severe impacts to soil characteristics. Thus, project managers must balance the need for contaminant reduction with the deterioration of soil function for each specific remediation project. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Maximizing Operational Efficiencies in Waste Management on the Hanford Plateau Remediation Contract in a Down-turned Market - 13484

    Energy Technology Data Exchange (ETDEWEB)

    Simiele, Connie J.; Blackford, L. Ty [CH2M HILL Plateau Remediation Contract - CHPRC (United States); West, Lori D. [East Tennessee Materials and Energy Corporation - M and EC (United States)

    2013-07-01

    Recent changes in DOE priorities and funding have pressed DOE and its contractors to look for innovative methods to sustain critical operations at sites across the Complex. At the Hanford Site, DOE Richland Operations and its prime contractor, CH2M Hill Plateau Remediation Company (CHPRC), have completed in-depth assessments of the Plateau Remediation Contract (PRC) operations that compared available funding to mission and operational objectives in an effort to maintain requisite safety and compliance margins while realizing cost savings that meet funding profiles. These assessments included confirmation of current baseline activities, identification of potential efficiencies, barriers to implementation, and potential increased risks associated with implementation. Six operating PRC waste management facilities were evaluated against three possible end-states: complete facility closure, maintaining base operations, and performing minimum safe surveillance and maintenance activities. The costs to completely close evaluated facilities were determined to be prohibitively high and this end-state was quickly dropped from consideration. A summary of the analysis of remaining options by facility, efficiencies identified, impact to risk profiles, and expected cost savings is provided in Table I. The expected cost savings are a result of: - right-sizing and cross-training work crews to address maintenance activities across facilities; - combining and sequencing 'like-moded' operational processes; - cross-cutting emergency planning and preparedness staffing; - resource redistribution and optimization; - reducing areas requiring routine surveillance and inspection. For the efficiencies identified, there are corresponding increases in risk, including a loss of breadth and depth of available resources; lengthened response time to emergent issues; inability to invest in opportunities for improvement (OFIs); potential single-point failures or non-compliancies due to

  13. Maximizing Operational Efficiencies in Waste Management on the Hanford Plateau Remediation Contract in a Down-turned Market - 13484

    International Nuclear Information System (INIS)

    Simiele, Connie J.; Blackford, L. Ty; West, Lori D.

    2013-01-01

    Recent changes in DOE priorities and funding have pressed DOE and its contractors to look for innovative methods to sustain critical operations at sites across the Complex. At the Hanford Site, DOE Richland Operations and its prime contractor, CH2M Hill Plateau Remediation Company (CHPRC), have completed in-depth assessments of the Plateau Remediation Contract (PRC) operations that compared available funding to mission and operational objectives in an effort to maintain requisite safety and compliance margins while realizing cost savings that meet funding profiles. These assessments included confirmation of current baseline activities, identification of potential efficiencies, barriers to implementation, and potential increased risks associated with implementation. Six operating PRC waste management facilities were evaluated against three possible end-states: complete facility closure, maintaining base operations, and performing minimum safe surveillance and maintenance activities. The costs to completely close evaluated facilities were determined to be prohibitively high and this end-state was quickly dropped from consideration. A summary of the analysis of remaining options by facility, efficiencies identified, impact to risk profiles, and expected cost savings is provided in Table I. The expected cost savings are a result of: - right-sizing and cross-training work crews to address maintenance activities across facilities; - combining and sequencing 'like-moded' operational processes; - cross-cutting emergency planning and preparedness staffing; - resource redistribution and optimization; - reducing areas requiring routine surveillance and inspection. For the efficiencies identified, there are corresponding increases in risk, including a loss of breadth and depth of available resources; lengthened response time to emergent issues; inability to invest in opportunities for improvement (OFIs); potential single-point failures or non-compliancies due to resource

  14. Efficiency enhancement of InGaN amber MQWs using nanopillar structures

    Directory of Open Access Journals (Sweden)

    Ou Yiyu

    2018-01-01

    Full Text Available We have investigated the use of nanopillar structures on high indium content InGaN amber multiple quantum well (MQW samples to enhance the emission efficiency. A significant emission enhancement was observed which can be attributed to the enhancement of internal quantum efficiency and light extraction efficiency. The size-dependent strain relaxation effect was characterized by photoluminescence, Raman spectroscopy and time-resolved photoluminescence measurements. In addition, the light extraction efficiency of different MQW samples was studied by finite-different time-domain simulations. Compared to the as-grown sample, the nanopillar amber MQW sample with a diameter of 300 nm has demonstrated an emission enhancement by a factor of 23.8.

  15. Efficiency enhancement of InGaN amber MQWs using nanopillar structures

    DEFF Research Database (Denmark)

    Ou, Yiyu; Iida, Daisuke; Liu, Jin

    2018-01-01

    We have investigated the use of nanopillar structures on high indium content InGaN amber multiple quantum well (MQW) samples to enhance the emission efficiency. A significant emission enhancement was observed which can be attributed to the enhancement of internal quantum efficiency and light extr...

  16. 78 FR 13294 - Enhanced Prudential Standards and Early Remediation Requirements for Foreign Banking...

    Science.gov (United States)

    2013-02-27

    ... Prudential Standards and Early Remediation Requirements for Foreign Banking Organizations and Foreign Nonbank... 166 of the Act for foreign banking organizations and foreign nonbank financial companies supervised by... Prudential Standards and Early Remediation Requirements for Foreign Banking Organizations and Foreign Nonbank...

  17. Hydrogeological site investigation for the efficient remediation of uranium mining sites -- an integrated approach

    International Nuclear Information System (INIS)

    Biehler, D.; Jaquet, O.; Croise, J.; Lavanchy, J.-M.

    2002-01-01

    The currently practised remediation of former uranium mines in Eastern Germany involves the flooding of underground and open pit mines, and the stabilization of waste rock dumps and tailings ponds, e.g. by dewatering, covering, improving dams, cleaning effluents. This article presents examples demonstrating that the remediation concepts developed and implemented have failed their targets, resulting in uncontrolled flow behaviour and migration of contaminated water, leading to increased costs and additional threats to the environment. A generic series of steps for an improved remediation management with respect to financial efforts and environmental safety are proposed in terms of an integrated approach. (author)

  18. Electrodialytic soil remediation enhanced by low frequency pulse current

    DEFF Research Database (Denmark)

    Sun, Tian R.; Ottosen, Lisbeth M.; Mortensen, John

    2013-01-01

    The effect of low frequency pulse current on decreasing the polarization and energy consumption during the process of electrodialytic soil remediation was investigated in the present work. The results indicated that the transportation of cations through the cation exchange membrane was the rate...

  19. Risk assessment and remedial policy evaluation using predictive modeling

    International Nuclear Information System (INIS)

    Linkov, L.; Schell, W.R.

    1996-01-01

    As a result of nuclear industry operation and accidents, large areas of natural ecosystems have been contaminated by radionuclides and toxic metals. Extensive societal pressure has been exerted to decrease the radiation dose to the population and to the environment. Thus, in making abatement and remediation policy decisions, not only economic costs but also human and environmental risk assessments are desired. This paper introduces a general framework for risk assessment and remedial policy evaluation using predictive modeling. Ecological risk assessment requires evaluation of the radionuclide distribution in ecosystems. The FORESTPATH model is used for predicting the radionuclide fate in forest compartments after deposition as well as for evaluating the efficiency of remedial policies. Time of intervention and radionuclide deposition profile was predicted as being crucial for the remediation efficiency. Risk assessment conducted for a critical group of forest users in Belarus shows that consumption of forest products (berries and mushrooms) leads to about 0.004% risk of a fatal cancer annually. Cost-benefit analysis for forest cleanup suggests that complete removal of organic layer is too expensive for application in Belarus and a better methodology is required. In conclusion, FORESTPATH modeling framework could have wide applications in environmental remediation of radionuclides and toxic metals as well as in dose reconstruction and, risk-assessment

  20. Remediation of electronic waste polluted soil using a combination of persulfate oxidation and chemical washing.

    Science.gov (United States)

    Chen, Fu; Luo, Zhanbin; Liu, Gangjun; Yang, Yongjun; Zhang, Shaoliang; Ma, Jing

    2017-12-15

    Laboratory experiments were conducted to investigate the efficiency of a simultaneous chemical extraction and oxidation for removing persistent organic pollutants (POPs) and toxic metals from an actual soil polluted by the recycling activity of electronic waste. Various chemicals, including hydroxypropyl-β-cyclodextrin (HPCD), citric acid (CA) and sodium persulfate (SP) were applied synchronously with Fe 2+ activated oxidation to enhance the co-removal of both types of pollutants. It is found that the addition of HPCD can enhance POPs removal through solubilization of POPs and iron chelation; while the CA-chelated Fe 2+ activation process is effective for extracting metals and degrading residual POPs. Under the optimized reagent conditions, 69.4% Cu, 78.1% Pb, 74.6% Ni, 97.1% polychlorinated biphenyls, 93.8% polycyclic aromatic hydrocarbons, and 96.4% polybrominated diphenylethers were removed after the sequential application of SP-HPCD-Fe 2+ and SP-CA-Fe 2+ processes with a duration of 180 and 240 min, respectively. A high dehalogenation efficiency (84.8% bromine and 86.2% chlorine) is observed, suggesting the low accumulation of halogen-containing organic intermediates. The remediated soil can satisfy the national soil quality standard of China. Collectively, co-contaminated soil can be remediated with reasonable time and capital costs through simultaneous application of persulfate oxidation and chemical extraction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Surfactant flushing remediation of o-dichlorobenzene and p-dichlorobenzene contaminated soil.

    Science.gov (United States)

    Pei, Guangpeng; Zhu, Yuen; Cai, Xiatong; Shi, Weiyu; Li, Hua

    2017-10-01

    Surfactant-enhanced remediation is used to treat dichlorobenzene (DCB) contaminated soil. In this study, soil column experiments were conducted to investigate the removal efficiencies of o-dichlorobenzene (o-DCB) and p-dichlorobenzene (p-DCB) from contaminated soil using micellar solutions of biosurfactants (saponin, alkyl polyglycoside) compare to a chemically synthetic surfactant (Tween 80). Leachate was collected and analyzed for o-DCB and p-DCB content. In addition, soil was analyzed to explore the effect of surfactants on soil enzyme activities. Results showed that the removal efficiency of o-DCB and p-DCB was highest for saponin followed by alkyl polyglycoside and Tween 80. The maximum o-DCB and p-DCB removal efficiencies of 76.34% and 80.43%, respectively, were achieved with 4 g L -1 saponin solution. However, an opposite result was observed in the cumulative mass of o-DCB and p-DCB in leachate. The cumulative extent of o-DCB and p-DCB removal by the biosurfactants saponin and alkyl polyglycoside was lower than that of the chemically synthetic surfactant Tween 80 in leachate. Soil was also analyzed to explore the effect of surfactants on soil enzyme activities. The results indicated that surfactants were potentially effective in facilitating soil enzyme activities. Thus, it was confirmed that the biosurfactants saponin and alkyl polyglycoside could be used for remediation of o-DCB and p-DCB contaminated soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Sand amendment enhances bioelectrochemical remediation of petroleum hydrocarbon contaminated soil.

    Science.gov (United States)

    Li, Xiaojing; Wang, Xin; Ren, Zhiyong Jason; Zhang, Yueyong; Li, Nan; Zhou, Qixing

    2015-12-01

    Bioelectrochemical system is an emerging technology for the remediation of soils contaminated by petroleum hydrocarbons. However, performance of such systems can be limited by the inefficient mass transport in soil. Here we report a new method of sand amendment, which significantly increases both oxygen and proton transports, resulting to increased soil porosity (from 44.5% to 51.3%), decreased Ohmic resistance (by 46%), and increased charge output (from 2.5 to 3.5Cg(-1)soil). The degradation rates of petroleum hydrocarbons increased by up to 268% in 135d. The degradation of n-alkanes and polycyclic aromatic hydrocarbons with high molecular weight was accelerated, and denaturing gradient gel electrophoresis showed that the microbial community close to the air-cathode was substantially stimulated by the induced current, especially the hydrocarbon degrading bacteria Alcanivorax. The bioelectrochemical stimulation imposed a selective pressure on the microbial community of anodes, including that far from the cathode. These results suggested that sand amendment can be an effective approach for soil conditioning that will enhances the bioelectrochemical removal of hydrocarbons in contaminated soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Use of Historical Pump-and-Treat Data to Enhance Site Characterization and Remediation Performance Assessment.

    Science.gov (United States)

    Brusseau, Mark L

    2013-10-01

    Groundwater withdrawal and contaminant concentration data are routinely collected for pump-and-treat operations conducted at hazardous waste sites. These data sets can be mined to produce a wealth of information to support enhanced site characterization, optimization of remedial system operations, and improved decision making regarding long-term site management and closure. Methods that may be used to analyze and interpret pump-and-treat data to produce such assessments are presented, along with a brief illustration of their application to a site. The results presented herein illustrate that comprehensive analysis of pump-and-treat data is a powerful, cost-effective method for providing higher-resolution, value-added characterization of contaminated sites.

  4. Efficiency of modified chemical remediation techniques for soil contaminated by organochlorine pesticides

    Science.gov (United States)

    Correa-Torres, S. N.; Kopytko, M.; Avila, S.

    2016-07-01

    This study reports the optimization of innovation chemical techniques in order to improve the remediation of soils contaminated with organochloride pesticides. The techniques used for remediation were dehalogenation and chemical oxidation in soil contaminated by pesticides. These techniques were applied sequentially and combined to evaluate the design optimize the concentration and contact time variables. The soil of this study was collect in cotton crop zone in Agustin Codazzi municipality, Colombia, and its physical properties was measure. The modified dehalogenation technique of EPA was applied on the contaminated soil by adding Sodium Bicarbonate solution at different concentrations and rates during 4, 7 and 14 days, subsequently oxidation technique was implemented by applying a solution of KMnO4 at different concentration and reaction times. Organochlorine were detected by Gas Chromatography analysis coupled Mass Spectrometry and its removals were between 85.4- 90.0% of compounds such as 4, 4’-DDT, 4,4’-DDD, 4,4-DDE, trans-Clordane y Endrin. These results demonstrate that the technique of dehalogenation with oxidation chemistry can be used for remediation soils contaminated by organochloride pesticides.

  5. Optimization of Remediation Conditions using Vadose Zone Monitoring Technology

    Science.gov (United States)

    Dahan, O.; Mandelbaum, R.; Ronen, Z.

    2010-12-01

    Success of in-situ bio-remediation of the vadose zone depends mainly on the ability to change and control hydrological, physical and chemical conditions of subsurface. These manipulations enables the development of specific, indigenous, pollutants degrading bacteria or set the environmental conditions for seeded bacteria. As such, the remediation efficiency is dependent on the ability to implement optimal hydraulic and chemical conditions in deep sections of the vadose zone. Enhanced bioremediation of the vadose zone is achieved under field conditions through infiltration of water enriched with chemical additives. Yet, water percolation and solute transport in unsaturated conditions is a complex process and application of water with specific chemical conditions near land surface dose not necessarily result in promoting of desired chemical and hydraulic conditions in deeper sections of the vadose zone. A newly developed vadose-zone monitoring system (VMS) allows continuous monitoring of the hydrological and chemical properties of the percolating water along deep sections of the vadose zone. Implementation of the VMS at sites that undergoes active remediation provides real time information on the chemical and hydrological conditions in the vadose zone as the remediation process progresses. Manipulating subsurface conditions for optimal biodegradation of hydrocarbons is demonstrated through enhanced bio-remediation of the vadose zone at a site that has been contaminated with gasoline products in Tel Aviv. The vadose zone at the site is composed of 6 m clay layer overlying a sandy formation extending to the water table at depth of 20 m bls. The upper 5 m of contaminated soil were removed for ex-situ treatment, and the remaining 15 m vadose zone is treated in-situ through enhanced bioremedaition. Underground drip irrigation system was installed below the surface on the bottom of the excavation. Oxygen and nutrients releasing powder (EHCO, Adventus) was spread below the

  6. Plasma remediation of trichloroethylene in silent discharge plasmas

    International Nuclear Information System (INIS)

    Evans, D.; Rosocha, L.A.; Anderson, G.K.; Coogan, J.J.; Kushner, M.J.

    1993-01-01

    Plasma destruction of toxins, and volatile organic compounds in particular, from gas streams is receiving increased attention as an energy efficient means to remediate those compounds. In this regard, remediation of trichloroethylene (TCE) in silent discharge plasmas has been experimentally and theoretically investigated. We found that TCE can be removed from Ar/O 2 gas streams at atmospheric pressure with an energy efficiency of 15--20 ppm/(mJ/cm 3 ), or 2--3 kW h kg -1 . The majority of the Cl from TCE is converted to HCl, Cl 2 , and COCl 2 , which can be removed from the gas stream by a water bubbler. The destruction efficiency of TCE is smaller in humid mixtures compared to dry mixtures due to interception of reactive intermediates by OH radicals

  7. Microbial fuel cell driving electrokinetic remediation of toxic metal contaminated soils.

    Science.gov (United States)

    Habibul, Nuzahat; Hu, Yi; Sheng, Guo-Ping

    2016-11-15

    An investigation of the feasibility of in-situ electrokinetic remediation for toxic metal contaminated soil driven by microbial fuel cell (MFC) is presented. Results revealed that the weak electricity generated from MFC could power the electrokinetic remediation effectively. The metal removal efficiency and its influence on soil physiological properties were also investigated. With the electricity generated through the oxidation of organics in soils by microorganisms, the metals in the soils would mitigate from the anode to the cathode. The concentrations of Cd and Pb in the soils increased gradually through the anode to the cathode regions after remediation. After about 143days and 108 days' operation, the removal efficiencies of 31.0% and 44.1% for Cd and Pb at the anode region could be achieved, respectively. Soil properties such as pH and soil conductivity were also significantly redistributed from the anode to the cathode regions. The study shows that the MFC driving electrokinetic remediation technology is cost-effective and environmental friendly, with a promising application in soil remediation. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by Autochthonous Willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River

    International Nuclear Information System (INIS)

    Li Jiahua; Sun Yuanyuan; Yin Ying; Ji Rong; Wu Jichun; Wang Xiaorong; Guo Hongyan

    2010-01-01

    In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L -1 medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L -1 medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate = 68/39 and 53.5/53.5, respectively) reached 0.71 mg d -1 pot -1 for the duration of Day 5-8 and 0.59 mg d -1 pot -1 for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River.

  9. Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by autochthonous willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River.

    Science.gov (United States)

    Li, Jiahua; Sun, Yuanyuan; Yin, Ying; Ji, Rong; Wu, Jichun; Wang, Xiaorong; Guo, Hongyan

    2010-09-15

    In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L(-1) medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L(-1) medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate=68/39 and 53.5/53.5, respectively) reached 0.71 mg d(-1) pot(-1) for the duration of Day 5-8 and 0.59 mg d(-1) pot(-1) for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River. Copyright 2010 Elsevier B.V. All rights

  10. International experience in tailings pond remediation

    Energy Technology Data Exchange (ETDEWEB)

    MacG. Robertson, A. [Robertson GeoConsultants Ltd., Vancouver (Canada)

    2001-07-01

    Tailings pond remediation is required primarily on mine closure. While mining is an ancient industry, requirement for mine facility remediation is a comparatively new development. Requirement for remediation has come about partly as a result of mans awareness of the environmental impacts of mining and his desire to minimize this, partly, as a result of the ever-increasing scale and production rates of tailings generation and the resulting increased environmental impacts and safety risks. The paper starts with a review of the evolution of mans intolerance of environmental impacts from tailings production and the assignment of liability to remediate such impacts. Many of the tailings ponds currently undergoing remediation were designed and constructed using methods and technology that would be considered inappropriate for new impoundments being designed and developed today. The paper reviews the history of tailings impoundment design and construction practice and the resulting inherent deficiencies that must be remediated. Current practices and future trends in tailings pond remediation are reviewed. The evolution of regulatory requirements is not only in terms of technical and safety criteria, but also in terms of financial and political risk. Perhaps the most substantive driver of risk management is today the requirement for corporate governance at mining company board level and oversight of new project development in the underdeveloped countries by the large financial institutions responsible for funding projects. Embarrassment in the public eye and punishment in the stock markets for poor environmental and safety performance is driving the need for efficient and effective risk management of potential impacts and the remediation to avoid these. A basis for practical risk management is described. (orig.)

  11. International experience in tailings pond remediation

    International Nuclear Information System (INIS)

    Robertson, A.MacG.

    2001-01-01

    Tailings pond remediation is required primarily on mine closure. While mining is an ancient industry, requirement for mine facility remediation is a comparatively new development. Requirement for remediation has come about partly as a result of mans awareness of the environmental impacts of mining and his desire to minimize this, partly, as a result of the ever-increasing scale and production rates of tailings generation and the resulting increased environmental impacts and safety risks. The paper starts with a review of the evolution of mans intolerance of environmental impacts from tailings production and the assignment of liability to remediate such impacts. Many of the tailings ponds currently undergoing remediation were designed and constructed using methods and technology that would be considered inappropriate for new impoundments being designed and developed today. The paper reviews the history of tailings impoundment design and construction practice and the resulting inherent deficiencies that must be remediated. Current practices and future trends in tailings pond remediation are reviewed. The evolution of regulatory requirements is not only in terms of technical and safety criteria, but also in terms of financial and political risk. Perhaps the most substantive driver of risk management is today the requirement for corporate governance at mining company board level and oversight of new project development in the underdeveloped countries by the large financial institutions responsible for funding projects. Embarrassment in the public eye and punishment in the stock markets for poor environmental and safety performance is driving the need for efficient and effective risk management of potential impacts and the remediation to avoid these. A basis for practical risk management is described. (orig.)

  12. To fail is human: remediating remediation in medical education.

    Science.gov (United States)

    Kalet, Adina; Chou, Calvin L; Ellaway, Rachel H

    2017-12-01

    Remediating failing medical learners has traditionally been a craft activity responding to individual learner and remediator circumstances. Although there have been moves towards more systematic approaches to remediation (at least at the institutional level), these changes have tended to focus on due process and defensibility rather than on educational principles. As remediation practice evolves, there is a growing need for common theoretical and systems-based perspectives to guide this work. This paper steps back from the practicalities of remediation practice to take a critical systems perspective on remediation in contemporary medical education. In doing so, the authors acknowledge the complex interactions between institutional, professional, and societal forces that are both facilitators of and barriers to effective remediation practices. The authors propose a model that situates remediation within the contexts of society as a whole, the medical profession, and medical education institutions. They also outline a number of recommendations to constructively align remediation principles and practices, support a continuum of remediation practices, destigmatize remediation, and develop institutional communities of practice in remediation. Medical educators must embrace a responsible and accountable systems-level approach to remediation if they are to meet their obligations to provide a safe and effective physician workforce.

  13. Geotechnical behaviour of low-permeability soils in surfactant-enhanced electrokinetic remediation.

    Science.gov (United States)

    López-Vizcaíno, Rubén; Navarro, Vicente; Alonso, Juan; Yustres, Ángel; Cañizares, Pablo; Rodrigo, Manuel A; Sáez, Cristina

    2016-01-01

    Electrokinetic processes provide the basis of a range of very interesting techniques for the remediation of polluted soils. These techniques consist of the application of a current field in the soil that develops different transport mechanisms capable of mobilizing several types of pollutants. However, the use of these techniques could generate nondesirable effects related to the geomechanical behavior of the soil, reducing the effectiveness of the processes. In the case of the remediation of polluted soils with plasticity index higher than 35, an excessive shrinkage can be observed in remediation test. For this reason, the continued evaporation that takes place in the sample top can lead to the development of cracks, distorting the electrokinetic transport regime, and consequently, the development of the operation. On the other hand, when analyzing silty soils, in the surroundings of injection surfactant wells, high seepages can be generated that give rise to the development of piping processes. In this article methods are described to allow a reduction, or to even eliminate, both problems.

  14. Lectin enhancement of the lipofection efficiency in human lung carcinoma cells.

    Science.gov (United States)

    Yanagihara, K; Cheng, P W

    1999-10-18

    Poor transfection efficiency of human lung carcinoma cells by lipofection begs further development of more efficient gene delivery strategies. The purpose of this study was to determine whether lectins can improve the lipofection efficiency in lung carcinoma cells. A549, Calu3, and H292 cells grown to 90% confluence were transfected for 18 h with a plasmid DNA containing a beta-galactosidase reporter gene (pCMVlacZ) using lipofectin plus a lectin as the vector. Ten different lectins, which exhibit a wide range of carbohydrate-binding specificities, were examined for their abilities to enhance the efficiency of lipofection. The transfected cells were assessed for transfection efficiency by beta-galactosidase activity (units/microg protein) and % blue cells following X-Gal stain. Lipofectin supplemented with Griffonia simplicifolia-I (GS-I) yields largest enhancement of the lipofection efficiency in A549 and Calu3 cells (5.3- and 28-fold, respectively). Maackia amurensis gives the largest enhancement (6.5-fold) of lipofection efficiency in H292 cells. The transfection efficiency correlates with the amounts of DNA delivered to the nucleus. Binding of FITC-labeled GS-I and the enhancement of the lipofection efficiency by GS-I were inhibited by alpha-methyl-D-galactopyranoside, indicating an alpha-galactoside-mediated gene transfer to lung carcinoma cells. We conclude that lectin-facilitated lipofection is an efficient gene delivery strategy. Employment of cell type-specific lectins may allow for efficient cell type-specific gene targeting.

  15. Experimental Investigation of Phenanthrene Pollutant Removal Efficiency for Contaminated Sandy Soil by Enhanced Soil Washing

    Directory of Open Access Journals (Sweden)

    Saif salah Alquzweeni

    2016-12-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are environmental concerns that must be removed to acceptable level. This research assesses two agents (Na2EDTA and SDS to remediate contaminated sandy soil, spiked with 500mg/kg phenanthrene. Five sets of experiments (batch are applied to investigate the optimal of five influencing factors on soil remediation: Na2EDTA-SDS concentration, liquid/Solid ratio, stirring speed, pH value of flushing solution and mixing time. The results of batch experiments showed that SDS has high phenanthrene removal efficiency (90%, while Na2EDTA shows no phenanthrene removal. pH has no effect on phenanthrene removal. To study the influence of flow rates on the removal efficiency of contaminants, two column tests with hydraulic gradient of 0.2 and 1.2 conducted by SDS solution. The results illustrate that high phenanthrene removal from soil obtained by 1.2 hydraulic gradient condition. The SDS flushing solution removed approximately 69% and 81% of phenanthrene from soil under low and high hydraulic gradients, respectively. It was concluded that phenanthrene removal depend on surfactant micelles formation. Overall, the study showed that soil flushing removal efficiency for contaminants depends on the flushing agents selectivity and affinity to the contaminants and the condition of hydraulic gradient.

  16. Use of surfactants for the remediation of contaminated soils: a review.

    Science.gov (United States)

    Mao, Xuhui; Jiang, Rui; Xiao, Wei; Yu, Jiaguo

    2015-03-21

    Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Chance-constrained multi-objective optimization of groundwater remediation design at DNAPLs-contaminated sites using a multi-algorithm genetically adaptive method

    Science.gov (United States)

    Ouyang, Qi; Lu, Wenxi; Hou, Zeyu; Zhang, Yu; Li, Shuai; Luo, Jiannan

    2017-05-01

    In this paper, a multi-algorithm genetically adaptive multi-objective (AMALGAM) method is proposed as a multi-objective optimization solver. It was implemented in the multi-objective optimization of a groundwater remediation design at sites contaminated by dense non-aqueous phase liquids. In this study, there were two objectives: minimization of the total remediation cost, and minimization of the remediation time. A non-dominated sorting genetic algorithm II (NSGA-II) was adopted to compare with the proposed method. For efficiency, the time-consuming surfactant-enhanced aquifer remediation simulation model was replaced by a surrogate model constructed by a multi-gene genetic programming (MGGP) technique. Similarly, two other surrogate modeling methods-support vector regression (SVR) and Kriging (KRG)-were employed to make comparisons with MGGP. In addition, the surrogate-modeling uncertainty was incorporated in the optimization model by chance-constrained programming (CCP). The results showed that, for the problem considered in this study, (1) the solutions obtained by AMALGAM incurred less remediation cost and required less time than those of NSGA-II, indicating that AMALGAM outperformed NSGA-II. It was additionally shown that (2) the MGGP surrogate model was more accurate than SVR and KRG; and (3) the remediation cost and time increased with the confidence level, which can enable decision makers to make a suitable choice by considering the given budget, remediation time, and reliability.

  18. Remediation of sandy soils contaminated with hydrocarbons and halogenated hydrocarbons by soil vapour extraction.

    Science.gov (United States)

    Albergaria, José Tomás; Alvim-Ferraz, Maria da Conceição M; Delerue-Matos, Cristina

    2012-08-15

    This paper presents the study of the remediation of sandy soils containing six of the most common contaminants (benzene, toluene, ethylbenzene, xylene, trichloroethylene and perchloroethylene) using soil vapour extraction (SVE). The influence of soil water content on the process efficiency was evaluated considering the soil type and the contaminant. For artificially contaminated soils with negligible clay contents and natural organic matter it was concluded that: (i) all the remediation processes presented efficiencies above 92%; (ii) an increase of the soil water content led to a more time-consuming remediation; (iii) longer remediation periods were observed for contaminants with lower vapour pressures and lower water solubilities due to mass transfer limitations. Based on these results an easy and relatively fast procedure was developed for the prediction of the remediation times of real soils; 83% of the remediation times were predicted with relative deviations below 14%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Use of surfactants for the remediation of contaminated soils: A review

    International Nuclear Information System (INIS)

    Mao, Xuhui; Jiang, Rui; Xiao, Wei; Yu, Jiaguo

    2015-01-01

    Highlights: • The recent advances in use of surfactant for soil remediation are reviewed. • The mechanisms of surfactant-based soil remediation are discussed. • A review on the application of different types of surfactants is made. • The future research direction of surfactant-based technologies is suggested. - Abstract: Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation

  20. Use of surfactants for the remediation of contaminated soils: A review

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Xuhui, E-mail: clab@whu.edu.cn [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Jiang, Rui; Xiao, Wei [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Yu, Jiaguo, E-mail: jiaguoyu@yahoo.com [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

    2015-03-21

    Highlights: • The recent advances in use of surfactant for soil remediation are reviewed. • The mechanisms of surfactant-based soil remediation are discussed. • A review on the application of different types of surfactants is made. • The future research direction of surfactant-based technologies is suggested. - Abstract: Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation.

  1. Ability of salt marsh plants for TBT remediation in sediments.

    Science.gov (United States)

    Carvalho, Pedro N; Basto, M Clara P; Silva, Manuela F G M; Machado, Ana; Bordalo, A A; Vasconcelos, M Teresa S D

    2010-07-01

    detected in nonvegetated sediment, whereas MBT was quantified in most samples. This work demonstrated that H. portulacoides has potentiality to be used for enhancing TBT remediation in sediments from salted areas. The results observed in situ for S. maritima or S. fruticosa suggested that these two salt marsh plants also favored TBT remediation. Therefore, the application of halophytes in technologies for TBT remediation in sediments seems to be efficient both in situ and ex situ, cost effective, and nondestructive, despite the fact that they have been rarely used for this purpose so far.

  2. Remedial action planning for Trench 1

    International Nuclear Information System (INIS)

    Primrose, A.; Sproles, W.; Burmeister, M.; Wagner, R.; Law, J.; Greengard, T.; Castaneda, N.

    1998-01-01

    The accelerated action to remove the depleted uranium chips and associated soils and wastes from Trench 1 at the Rocky Flats Environmental Technology Site (RFETS) will begin in June 1998. To ensure that the remedial action is conducted safely, a rigorous and disciplined planning process was followed that incorporates the principles of Integrated Safety Management and Enhanced Work Planning. Critical to the success of the planning was early involvement of project staff (salaried and hourly) and associated technical support groups and disciplines. Feedback was and will continue to be solicited, and lessons learned incorporated to ensure the safe remediation of this site

  3. Remediation of Deep Vadose Zone Radionuclide and Metal Contamination: Status and Issues

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P. Evan; Truex, Michael J.; Cantrell, Keri

    2008-12-30

    This report documents the results of a PNNL literature review to report on the state of maturity of deep vadose zone remediation technologies for metal contaminants including some radionuclides. Its recommendations feed into decisionmakers need for scientific information and cost-effective in situ remediation technlogies needed under DOE's Environmental Management initiative Enhanced Remediation Methods: Scientific & Technical Basis for In Stu Treatment Systems for Metals and Radionuclides.

  4. Ligand-enhanced electrokinetic remediation of metal-contaminated marine sediments with high acid buffering capacity.

    Science.gov (United States)

    Masi, Matteo; Iannelli, Renato; Losito, Gabriella

    2016-06-01

    The suitability of electrokinetic remediation for removing heavy metals from dredged marine sediments with high acid buffering capacity was investigated. Laboratory-scale electrokinetic remediation experiments were carried out by applying two different voltage gradients to the sediment (0.5 and 0.8 V/cm) while circulating water or two different chelating agents at the electrode compartments. Tap water, 0.1 M citric acid and 0.1 M ethylenediaminetetraacetic acid (EDTA) solutions were used respectively. The investigated metals were Zn, Pb, V, Ni and Cu. In the unenhanced experiment, the acid front could not propagate due to the high acid buffering capacity of the sediments; the production of OH(-) ions at the cathode resulted in a high-pH environment causing the precipitation of CaCO3 and metal hydroxides. The use of citric acid prevented the formation of precipitates, but solubilisation and mobilisation of metal species were not sufficiently achieved. Metal removal was relevant when EDTA was used as the conditioning agent, and the electric potential was raised up to 0.8 V/cm. EDTA led to the formation of negatively charged complexes with metals which migrated towards the anode compartment by electromigration. This result shows that metal removal from sediments with high acid buffering capacity may be achieved by enhancing the electrokinetic process by EDTA addition when the acidification of the medium is not economically and/or environmentally sustainable.

  5. Radiochemical methods to enhance efficiency of α-spectral measurements

    International Nuclear Information System (INIS)

    Silkina, G.P.; Artem'ev, O.I.

    2001-01-01

    The paper describes possible ways to improve a plutonium radiochemical separation technique developed in the Khlopin Radium Institute and modify it to account for the site-specific features of samples from the former Semipalatinsk test site (STS) and enhance the alpha spectrometry efficiency.The paper describes possible ways to improve a plutonium radiochemical separation technique developed in the Khlopin Radium Institute and modify it to account for the site-specific features of samples from the former Semipalatinsk test site (STS) and enhance the alpha spectrometry efficiency. (author)

  6. Optimization of remediation strategies using vadose zone monitoring systems

    Science.gov (United States)

    Dahan, Ofer

    2016-04-01

    In-situ bio-remediation of the vadose zone depends mainly on the ability to change the subsurface hydrological, physical and chemical conditions in order to enable development of specific, indigenous, pollutants degrading bacteria. As such the remediation efficiency is much dependent on the ability to implement optimal hydraulic and chemical conditions in deep sections of the vadose zone. These conditions are usually determined in laboratory experiments where parameters such as the chemical composition of the soil water solution, redox potential and water content of the sediment are fully controlled. Usually, implementation of desired optimal degradation conditions in deep vadose zone at full scale field setups is achieved through infiltration of water enriched with chemical additives on the land surface. It is assumed that deep percolation into the vadose zone would create chemical conditions that promote biodegradation of specific compounds. However, application of water with specific chemical conditions near land surface dose not necessarily results in promoting of desired chemical and hydraulic conditions in deep sections of the vadose zone. A vadose-zone monitoring system (VMS) that was recently developed allows continuous monitoring of the hydrological and chemical properties of deep sections of the unsaturated zone. The VMS includes flexible time-domain reflectometry (FTDR) probes which allow continuous monitoring of the temporal variation of the vadose zone water content, and vadose-zone sampling ports (VSPs) which are designed to allow frequent sampling of the sediment pore-water and gas at multiple depths. Implementation of the vadose zone monitoring system in sites that undergoes active remediation provides real time information on the actual chemical and hydrological conditions in the vadose zone as the remediation process progresses. Up-to-date the system has been successfully implemented in several studies on water flow and contaminant transport in

  7. Applications of Ecological Engineering Remedies for Uranium Processing Sites, USA

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, William [Navarro Research and Engineering

    2016-05-23

    The U.S. Department of Energy (USDOE) is responsible for remediation of environmental contamination and long-term stewardship of sites associated with the legacy of nuclear weapons production during the Cold War in the United States. Protection of human health and the environment will be required for hundreds or even thousands of years at many legacy sites. USDOE continually evaluates and applies advances in science and technology to improve the effectiveness and sustainability of surface and groundwater remedies (USDOE 2011). This paper is a synopsis of ecological engineering applications that USDOE is evaluating to assess the effectiveness of remedies at former uranium processing sites in the southwestern United States. Ecological engineering remedies are predicated on the concept that natural ecological processes at legacy sites, once understood, can be beneficially enhanced or manipulated. Advances in tools for characterizing key processes and for monitoring remedy performance are demonstrating potential. We present test cases for four ecological engineering remedies that may be candidates for international applications.

  8. Remediation of sites with dispersed radioactive contamination

    International Nuclear Information System (INIS)

    2004-01-01

    To respond to the needs of Member States, the IAEA launched an environmental remediation project to deal with the problems of radioactive contamination worldwide. The IAEA environmental remediation project includes an IAEA Coordinated Research Project, as well as the participation of IAEA experts in concrete remediation projects when requested by individual Member States. The IAEA has prepared several documents dedicated to particular technical or conceptual areas, including documents on the characterization of contaminated sites, technical and non-technical factors relevant to the selection of a preferred remediation strategy and technique, overview of applicable techniques for environmental remediation,, options for the cleanup of contaminated groundwater and planning and management issues. In addition, a number of other IAEA publications dealing with related aspects have been compiled under different IAEA projects; these include TECDOCs on the remediation of uranium mill tailings, the decontamination of buildings and roads and the characterization of decommissioned sites. Detailed procedures for the planning and implementation of remedial measures have been developed over the past decade or so. A critical element is the characterization of the contamination and of the various environmental compartments in which it is found, in order to be able to evaluate the applicability of remediation techniques. The chemical or mineralogical form of the contaminant will critically influence the efficiency of the remediation technique chosen. Careful delineation of the contamination will ensure that only those areas or volumes of material that are actually contaminated are treated. This, in turn, reduces the amount of any secondary waste generated. The application of a remediation technique requires holistic studies examining the technical feasibility of the proposed measures, including analyses of their impact. Consequently, input from various scientific and engineering

  9. Study on 3D surfactant assisted electrokinetic remediation of 1,2,4-trichlorobenzene in low permeability soil

    Science.gov (United States)

    Qiao, W.; Ye, S.; Wu, J.

    2014-12-01

    Electrickinetic(EK) is a promising remediation technology because of its capability to remediate soils with low permeability. It has been used for heavy metals and organic pollutant(OPs) contaminated soils. As the most OPs are poor solubility and strong sorption capacity, combined EK technology is usually used, for example, EK combined with surfactants. Numerous combined EK tests are done in one-dimension(1D) column, however, it is proved that there is a big gap between 1D tests and field application. The objectives of this study are to investigate the remediation efficiency and EK behavior of 1,2,4-trichlorobenzene(1,2,4-TCB) contaminated clay enhanced by surfactants in a three-dimension reactor with 28cm length×15cm width×16cm height. 1,2,4-TCB was one of the main contaminants at a field site in Nanjing, China, where the polluted soils are clay. Soil filled in EK cell was divided into six layers in depth, and each layer was divided into six parts in length and three parts in width. There were 108 specimens in total which realized 3D monitoring the effects of EK. Triton X-100(Exp1) and Tween80(Exp2) dissolved in NaCO3/NaHCO3 buffer respectively, were used as the anode purging solution. The distributions of soil pH and water content showed that the buffer was sufficient to neutralize H+ produced at anode and the direction of electroosmotic flow(EOF) remained constant. Exp2 generated a higher EOF than Exp1, but remediation efficiencies were not satisfactory so far. The concentration of 1,2,4-TCB in soil reached a peak and nadir in the normalized distances of 0.75 and 0.9 from cathode after 5 days, respectively. The 1,2,4-TCB concentration in the peak was almost twice as much as the initial concentration. It suggested that 1,2,4-TCB was desorbed from soil by surfactants and was transported from anode to cathode by EOF, which proved the capability of EK with surfactants to move 1,2,4-TCB in clay. The concentration of 1,2,4-TCB in the normalized distances of 0

  10. An analysis on remediation characteristics of soils contaminated with Co for in-situ application

    International Nuclear Information System (INIS)

    Kim, K. N.; Won, H. J.; Kweun, H. S.; Shon, J. S.; Oh, W. J.

    1999-01-01

    The solvent flushing apparatus for in-situ soil remediation was designed. After the soil around nuclear facilities was sampled and compulsorily contaminated by Co solution, the remediation characteristics by solvent flushing were analyzed. Meanwhile, the nonequilibrium sorption code was developed for modelling of the soil remediation by solvent flushing, and input parameters needed for modelling were measured by laboratory experiment. Experimental results are as follows: The soil around nuclear facilities belongs to Silt Loam including a lot of silt and sand. When water was used as a solvent, the higher was the hydraulic conductivity, the higher the efficiency of soil remediation was. The values calculated by the nonequilibrium sorption code agreed with experimental values more exactly than the values calculated by the equilibrium sorption code. When citric acid was used as a solvent, the soil remediation efficiency by citric acid showed 1.65 times that by water

  11. Biological optimization systems for enhancing photosynthetic efficiency and methods of use

    Science.gov (United States)

    Hunt, Ryan W.; Chinnasamy, Senthil; Das, Keshav C.; de Mattos, Erico Rolim

    2012-11-06

    Biological optimization systems for enhancing photosynthetic efficiency and methods of use. Specifically, methods for enhancing photosynthetic efficiency including applying pulsed light to a photosynthetic organism, using a chlorophyll fluorescence feedback control system to determine one or more photosynthetic efficiency parameters, and adjusting one or more of the photosynthetic efficiency parameters to drive the photosynthesis by the delivery of an amount of light to optimize light absorption of the photosynthetic organism while providing enough dark time between light pulses to prevent oversaturation of the chlorophyll reaction centers are disclosed.

  12. Part 2: A field study of enhanced remediation of Toluene in the vadose zone using a nutrient solution

    Science.gov (United States)

    Tindall, J.A.; Weeks, E.P.; Friedel, M.

    2005-01-01

    The objective of this study was to test the effectiveness of a nitrate-rich nutrient solution and hydrogen peroxide (H2O2) to enhance in-situ microbial remediation of toluene in the unsaturated zone. Three sand-filled plots were tested in three phases (each phase lasting approximately 2 weeks). During the control phase, toluene was applied uniformly via sprinkler irrigation. Passive remediation was allowed to occur during this phase. A modified Hoagland nutrient solution, concentrated in 150 L of water, was tested during the second phase. The final phase involved addition of 230 moles of H2O2 in 150 L of water to increase the available oxygen needed for aerobic biodegradation. During the first phase, measured toluene concentrations in soil gas were reduced from 120 ppm to 25 ppm in 14 days. After the addition of nutrients during the second phase, concentrations were reduced from 90 ppm to about 8 ppm within 14 days, and for the third phase (H 2O2), toluene concentrations were about 1 ppm after only 5 days. Initial results suggest that this method could be an effective means of remediating a contaminated site, directly after a BTEX spill, without the intrusiveness and high cost of other abatement technologies such as bioventing or soil-vapor extraction. However, further tests need to be completed to determine the effect of each of the BTEX components. ?? Springer 2005.

  13. Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by Autochthonous Willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River

    Energy Technology Data Exchange (ETDEWEB)

    Li Jiahua [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Sun Yuanyuan [State Key Laboratory of Pollution Control and Resource Reuse, Department of Hydrosciences, Nanjing University, Nanjing 210093 (China); Yin Ying; Ji Rong [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Wu Jichun [State Key Laboratory of Pollution Control and Resource Reuse, Department of Hydrosciences, Nanjing University, Nanjing 210093 (China); Wang Xiaorong [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Guo Hongyan, E-mail: hyguo@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

    2010-09-15

    In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L{sup -1} medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L{sup -1} medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate = 68/39 and 53.5/53.5, respectively) reached 0.71 mg d{sup -1}pot{sup -1} for the duration of Day 5-8 and 0.59 mg d{sup -1}pot{sup -1} for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River.

  14. IPCS: An integrated process control system for enhanced in-situ bioremediation

    International Nuclear Information System (INIS)

    Huang, Y.F.; Wang, G.Q.; Huang, G.H.; Xiao, H.N.; Chakma, A.

    2008-01-01

    To date, there has been little or no research related to process control of subsurface remediation systems. In this study, a framework to develop an integrated process control system for improving remediation efficiencies and reducing operating costs was proposed based on physical and numerical models, stepwise cluster analysis, non-linear optimization and artificial neural networks. Process control for enhanced in-situ bioremediation was accomplished through incorporating the developed forecasters and optimizers with methods of genetic algorithm and neural networks modeling. Application of the proposed approach to a bioremediation process in a pilot-scale system indicated that it was effective in dynamic optimization and real-time process control of the sophisticated bioremediation systems. - A framework of process control system was developed to improve in-situ bioremediation efficiencies and reducing operating costs

  15. Measurement systems in the area of land remediation and soil segregation activities

    International Nuclear Information System (INIS)

    Simon, Gerold G.; Sokcic-Kostic, Marina; Auler, Ingolf; Eickelpasch, Ludger; Betts, Jonathan

    2007-01-01

    Available in abstract form only. Full text of publication follows: The remediation of radioactively contaminated land is a small but growing sector in the area of decommissioning of nuclear facilities. This also includes the material from buildings after demolition. Contamination comprises in general alpha and beta activities and emission of alpha, beta and gamma radiation. The measurement is in practice restricted to the measurement of gamma emission, because of the high penetration of material by gamma rays. All isotopes, which do not emit gammas are estimated on the basis of given relation between alpha and beta emitters without gamma radiation and emitters with gamma radiation. This method is called 'key nuclide method'. Whilst many studies have been completed, others still continue in the processing of large volumes of concrete, steel and soil. An important conclusion from these and similar research programs is that a significant proportion of the waste contains only low concentrations of radioactive nuclides. Therefore, much of the material from the remediation can be considered for 'free release'. It was often not possible to attain adequate specific information on these materials, so a measurement system is needed for their classification and characterization. NUKEM Technologies has practical experience in characterising and remediating of nuclear sites. Recently, it has pioneered the use of innovative in-situ and ex-situ characterisation and waste segregation technologies, which enhance the efficiency of remedial actions and provide assurance to customers, regulators and the public that all significant contamination has been removed and sites can be used for new purposes. (authors)

  16. Chance-constrained multi-objective optimization of groundwater remediation design at DNAPLs-contaminated sites using a multi-algorithm genetically adaptive method.

    Science.gov (United States)

    Ouyang, Qi; Lu, Wenxi; Hou, Zeyu; Zhang, Yu; Li, Shuai; Luo, Jiannan

    2017-05-01

    In this paper, a multi-algorithm genetically adaptive multi-objective (AMALGAM) method is proposed as a multi-objective optimization solver. It was implemented in the multi-objective optimization of a groundwater remediation design at sites contaminated by dense non-aqueous phase liquids. In this study, there were two objectives: minimization of the total remediation cost, and minimization of the remediation time. A non-dominated sorting genetic algorithm II (NSGA-II) was adopted to compare with the proposed method. For efficiency, the time-consuming surfactant-enhanced aquifer remediation simulation model was replaced by a surrogate model constructed by a multi-gene genetic programming (MGGP) technique. Similarly, two other surrogate modeling methods-support vector regression (SVR) and Kriging (KRG)-were employed to make comparisons with MGGP. In addition, the surrogate-modeling uncertainty was incorporated in the optimization model by chance-constrained programming (CCP). The results showed that, for the problem considered in this study, (1) the solutions obtained by AMALGAM incurred less remediation cost and required less time than those of NSGA-II, indicating that AMALGAM outperformed NSGA-II. It was additionally shown that (2) the MGGP surrogate model was more accurate than SVR and KRG; and (3) the remediation cost and time increased with the confidence level, which can enable decision makers to make a suitable choice by considering the given budget, remediation time, and reliability. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. 300-FF-1 remedial design report/remedial action work plan

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, F.W.

    1997-02-01

    The 300 Area has been divided into three operable units 300-FF-1, 300-FF-2, and 300-FF-5 all of which are in various stages of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) process. The 300-FF-1 Operable Unit, the subject of this report, includes liquid waste disposal sites, landfills, and a burial ground. This Remedial Design Report/Remedial Action Work Plan (RDR/RAWP) provides a summary description of each waste site included in the 300-FF-1 Operable Unit, the basis for remedial actions to be taken, and the remedial action approach and management process for implementing these actions. The remedial action approach and management sections provide a description of the remedial action process description, the project schedule, the project team, required planning documentation, the remedial action change process, the process for verifying attainment of the remedial action goals, and the required CERCLA and RCRA closeout documentation. Appendix A provides additional details on each waste site. In addition to remediation of the waste sites, waste generated during the remedial investigation/feasibility study portions of the project will also be disposed at the Environmental Restoration Disposal Facility (ERDF). Appendix B provides a summary of the modeling performed in the 300-FF-1 Phase 3 FS and a description of the modeling effort to be used to show attainment of the remedial action goals. Appendix C provides the sampling and analysis plan (SAP) for all sampling and field-screening activities performed during remediation and for verification of attainment with the remedial action goals. Appendix D provides the public involvement plan, prepared to ensure information is provided to the public during remedial design and remedial action processes.

  18. 300-FF-1 remedial design report/remedial action work plan

    International Nuclear Information System (INIS)

    Gustafson, F.W.

    1997-02-01

    The 300 Area has been divided into three operable units 300-FF-1, 300-FF-2, and 300-FF-5 all of which are in various stages of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) process. The 300-FF-1 Operable Unit, the subject of this report, includes liquid waste disposal sites, landfills, and a burial ground. This Remedial Design Report/Remedial Action Work Plan (RDR/RAWP) provides a summary description of each waste site included in the 300-FF-1 Operable Unit, the basis for remedial actions to be taken, and the remedial action approach and management process for implementing these actions. The remedial action approach and management sections provide a description of the remedial action process description, the project schedule, the project team, required planning documentation, the remedial action change process, the process for verifying attainment of the remedial action goals, and the required CERCLA and RCRA closeout documentation. Appendix A provides additional details on each waste site. In addition to remediation of the waste sites, waste generated during the remedial investigation/feasibility study portions of the project will also be disposed at the Environmental Restoration Disposal Facility (ERDF). Appendix B provides a summary of the modeling performed in the 300-FF-1 Phase 3 FS and a description of the modeling effort to be used to show attainment of the remedial action goals. Appendix C provides the sampling and analysis plan (SAP) for all sampling and field-screening activities performed during remediation and for verification of attainment with the remedial action goals. Appendix D provides the public involvement plan, prepared to ensure information is provided to the public during remedial design and remedial action processes

  19. Aerodynamic Efficiency Enhancements for Air Vehicles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The need for aerodynamics-based efficiency enhancements for air vehicles is presented. Concepts are presented for morphing aircraft, to enable the aircraft to...

  20. A novel phytoremediation technology shown to remediate petroleum hydrocarbons from soils in situ

    Energy Technology Data Exchange (ETDEWEB)

    Huang, X.D.; Yu, X.M.; Gerhardt, K.; Glick, B.; Greenberg, B [Waterloo Environmental Biotechnology Inc., Hamilton, ON (Canada); Waterloo Univ., ON (Canada). Dept. of Biology

    2009-04-01

    This article described a newly developed, advanced microbe-enhanced phytoremediation system that can be used to remediate lands polluted by hydrocarbons, salts and metals. The technology uses 3 complementary processes to achieve effective remediation of strongly bound persistent organic pollutants (POPs) from soil. The remediation process involves physical soil treatment, photochemical photooxidation, microbial remediation and growth of plants treated with plant growth promoting rhizobacteria (PGPR). The PGPR-enhanced phytoremediation system (PEPS) alleviates plant stress and increases biodegradation activities, thereby accelerating plant growth in the presence of POPs or poor soils. The PEPS has been used successfully to remove petroleum hydrocarbons (PHCs) from impacted soils in situ at several sites across Canada. Studies have shown that the PHCs are degraded in the rhizosphere. This article also presented a summary of the work conducted at 3 sites in Alberta. It took only 2 years to remediate the 3 sites to levels required for site closure under Alberta Tier 1 guidelines. It was concluded that PEPS is equally effective for total PHC and Fraction 3 CCME hydrocarbons. 1 tab., 3 figs.

  1. Electrodialytic remediation of copper mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, A.; Ottpsen, Lisbeth M.

    2005-01-01

    electrodialytic remediation experiments on copper mine tailings. The results show that electric current could remove copper from watery tailing if the potential gradient was higher than 2V/cm during 21 days. With addition of sulphuric acid, the process was enhanced because the pH decreased to around 4...

  2. Field Test of Enhanced Remedial Amendment Delivery Using a Shear-Thinning Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Vermeul, Vincent R.; Adamson, David; Oostrom, Martinus; Zhong, Lirong; Mackley, Rob D.; Fritz, Brad G.; Horner, Jacob A.; Johnson, Timothy C.; Thomle, Jonathan N.; Newcomer, Darrell R.; Johnson, Christian D.; Rysz, Michal; Wietsma, Thomas W.; Newell, Charles J.

    2015-03-01

    Heterogeneity of hydraulic properties in aquifers may lead to contaminants residing in lower-permeability zones where it is difficult to deliver remediation amendments using conventional injection processes. The focus of this effort is to examine use of a shear-thinning fluid (STF) to improve the uniformity of remedial amendment distribution within a heterogeneous aquifer. Previous studies have demonstrated the significant potential of STFs for improving remedial amendment delivery in heterogeneous aquifers, but quantitative evaluation of these improvements from field applications are lacking. A field-scale test was conducted that compares data from successive injection of a tracer in water followed by injection of a tracer in a STF to evaluate the impact of the STF on tracer distribution uniformity in the presence of permeability contrasts within the targeted injection zone. Data from tracer breakthrough at multiple depth-discrete monitoring intervals and electrical resistivity tomography showed that inclusion of STF in the injection solution slowed movement in high-permeability pathways, improved delivery of amendment to low-permeability materials, and resulted in better uniformity in injected fluid distribution within the targeted treatment zone.

  3. Aerodynamic Efficiency Enhancements for Air Vehicles, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The need for aerodynamics-based efficiency enhancements for air vehicles is presented. The results of the Phase I investigation of concepts for morphing aircraft are...

  4. Electrodialytic remediation of polychlorinated biphenyls contaminated soil with iron nanoparticles and two different surfactants

    DEFF Research Database (Denmark)

    Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.

    2014-01-01

    Polychlorinated biphenyls (PCB) are persistent organic pollutants (POP) that strongly adsorb in soils and sediments. There is a need to develop new and cost-effective solutions for the remediation of PCB contaminated soils. The suspended electrodialytic remediation combined with zero valent iron......ZVI showed encouraging tendencies and a base is thus formed for further optimization towards a new method for remediation of PCB polluted soils....... nanoparticles (nZVI) could be a competitive alternative to the commonly adapted solutions of incineration or landfilling. Surfactants can enhance the PCB desorption, dechlorination, and the contaminated soil cleanup. In this work, two different surfactants (saponin and Tween 80) were tested to enhance PCB...

  5. Screening of groundwater remedial alternatives for brownfield sites: a comprehensive method integrated MCDA with numerical simulation.

    Science.gov (United States)

    Li, Wei; Zhang, Min; Wang, Mingyu; Han, Zhantao; Liu, Jiankai; Chen, Zhezhou; Liu, Bo; Yan, Yan; Liu, Zhu

    2018-06-01

    Brownfield sites pollution and remediation is an urgent environmental issue worldwide. The screening and assessment of remedial alternatives is especially complex owing to its multiple criteria that involves technique, economy, and policy. To help the decision-makers selecting the remedial alternatives efficiently, the criteria framework conducted by the U.S. EPA is improved and a comprehensive method that integrates multiple criteria decision analysis (MCDA) with numerical simulation is conducted in this paper. The criteria framework is modified and classified into three categories: qualitative, semi-quantitative, and quantitative criteria, MCDA method, AHP-PROMETHEE (analytical hierarchy process-preference ranking organization method for enrichment evaluation) is used to determine the priority ranking of the remedial alternatives and the solute transport simulation is conducted to assess the remedial efficiency. A case study was present to demonstrate the screening method in a brownfield site in Cangzhou, northern China. The results show that the systematic method provides a reliable way to quantify the priority of the remedial alternatives.

  6. [Cognitive remediation and cognitive assistive technologies in schizophrenia].

    Science.gov (United States)

    Sablier, J; Stip, E; Franck, N

    2009-04-01

    Cognitive impairments are a core feature in schizophrenia. They impact several cognitive abilities but most importantly attention, memory and executive functions, consequently leading to great difficulties in everyday life. Most schizophrenia patients need assurance and require assistance and help from care workers, family members and friends. Family members taking care of a patient have additional daily work burden, and suffer psychological anguish and anxiety. Therefore, improving cognitive functions in schizophrenia patients is essential for the well-being of patients and their relatives. Reducing these deficits may decrease the economic burden to the health care system through lower numbers of hospital admissions and shorter hospitalisation periods, for example. Cognitive rehabilitation was developed to address the limited benefits of conventional treatments on cognitive deficits through the use of assistive technology as a means of enhancing memory and executive skills in schizophrenia patients. To provide clinicians with comprehensive knowledge on cognitive trainings, programs of remediation, and cognitive assistive technologies. Literature review. A search in the electronic databases (PubMed, EMBASE, Index Medicus) for recent articles in the last 10 years related to cognitive remediation published in any language using the words: cognitive and remediation or rehabilitation and schizophrenia, and a search for chapters in psychiatry and rehabilitation textbooks. We found 392 articles and 112 review paper mainly in English. First, we identified cognitive remediation programs that were beneficial to schizophrenia patients. Programs available in French (IPT, RECOS, and RehaCom) and others (CET, NET, CRT, NEAR, APT and CAT) were identified. In addition, since memory and executive function impairments could be present in people without schizophrenia, we reviewed inventories of cognitive assistive technologies proven to enhance cognitive skills in other populations

  7. Remediation of Contaminated Soils by Solvent Flushing

    NARCIS (Netherlands)

    Augustijn, Dionysius C.M.; Jessup, Ron E.; Rao, P. Suresh C.; Wood, A. Lynn

    1994-01-01

    Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, and increases the

  8. Monitored Natural Attenuation as a Remediation Strategy for Nuclear Power Plant Applications

    Science.gov (United States)

    Kim, K.; Bushart, S.

    2009-12-01

    A NRC Information Notice (IN 2006-13) was produced to inform holders of nuclear operating licenses “of the occurrence of radioactive contamination of ground water at multiple facilities due to undetected leakage from facility structures, systems, or components (SSCs) that contain or transport radioactive fluids” so that they could consider actions, as appropriate, to avoid similar problems. To reinforce their commitment to environmental stewardship the nuclear energy industry has committed to improving management of situations that have the potential to lead to the inadvertent release of radioactive fluids. This Industry Groundwater Protection Initiative, finalized in June 2007 as [NEI 07-07], calls for implementation and improvement of on-site groundwater monitoring programs and enhanced communications with stakeholders and regulators about situations related to inadvertent releases. EPRI developed its Groundwater Protection Program to provide the nuclear energy industry with the technical support needed to implement the Industry Groundwater Initiative. An objective of the EPRI Groundwater Protection Program is to provide the nuclear industry with technically sound guidance for implementing and enhancing on-site groundwater monitoring programs. EPRI, in collaboration with the EPRI Groundwater Protection Committee of utility members, developed the EPRI Groundwater Protection Guidelines for Nuclear Power Plants (EPRI Report 1015118, November 2007), which provides site-specific guidance for implementing a technically sound groundwater monitoring program. The guidance applies a graded approach for nuclear plants to tailor a technically effective and cost efficient groundwater monitoring program to the site’s hydrogeology and risk for groundwater contamination. As part of the Groundwater Protection Program, EPRI is also investigating innovative remediation technologies for addressing low-level radioactive contamination in soils and groundwater at nuclear power

  9. Enhanced bioremediation as a cost effective approach following thermally enhanced soil vapour extraction for sites requiring remediation of chlorinated solvents - 16296

    International Nuclear Information System (INIS)

    Kozlowska, Anna-Maria; Kahlon, Manjit S.; Langford, Steve R.; Williams, Haydn G.

    2009-01-01

    Thermally enhanced bioremediation can be a more cost-effective alternative to full scale in-situ thermal treatment especially for sites contaminated with chlorinated solvents, where reductive dechlorination is or might be a dominant biological step. The effect of Thermally Enhanced Soil Vapour Extraction (TESVE) on indigenous microbial communities and the potential for subsequent biological polishing of chlorinated solvents was investigated in field trials at the Western Storage Area (WSA) - RSRL (formerly United Kingdom Atomic Energy Authority - UKAEA) Oxfordshire, UK. The WSA site had been contaminated with various chemicals including mineral oil, chloroform, trichloroethane (TCA), carbon tetrachloride and tetrachloroethene (PCE). The contamination had affected the unsaturated zone, groundwater in the chalk aquifer and was a continuing source of groundwater contamination below the WSA. During TESVE the target treatment zone was heated to above the boiling point of water increasing the degree of volatilization of contaminants of concern (CoC), which were mobilised and extracted in the vapour phase. A significant reduction of concentrations of chlorinated solvent in the unsaturated zone was achieved by the full-scale application of TESVE - In Situ Thermal Desorption (ISTD) technology. The rock mass temperature within target treatment zone remained in the range of 35 deg. - 44 deg. C, 6 months after cessation of heating. The concentration of chlorinated ethenes and other CoC were found to be significantly lower adjacent to the thermal treatment area and 1 to 2 orders of magnitude lower within the thermal treatment zone. Samples were collected within and outside the thermal treatment zone using BioTraps R (passive, in- situ microbial samplers) from which the numbers of specific bacteria were measured using quantitative polymerase chain reaction (qPCR) methods of analysis. High populations of reductive de-chlorinators such as Dechalococcoides spp. and Dehalobacter spp

  10. Biofilm formation and microbial community analysis of the simulated river bioreactor for contaminated source water remediation.

    Science.gov (United States)

    Xu, Xiang-Yang; Feng, Li-Juan; Zhu, Liang; Xu, Jing; Ding, Wei; Qi, Han-Ying

    2012-06-01

    The start-up pattern of biofilm remediation system affects the biofilm characteristics and operating performances. The objective of this study was to evaluate the performances of the contaminated source water remediation systems with different start-up patterns in view of the pollutants removal performances and microbial community succession. The operating performances of four lab-scale simulated river biofilm reactors were examined which employed different start-up methods (natural enrichment and artificial enhancement via discharging sediment with influent velocity gradient increase) and different bio-fillers (Elastic filler and AquaMats® ecobase). At the same time, the microbial communities of the bioreactors in different phases were analyzed by polymerase chain reaction, denaturing gradient gel electrophoresis, and sequencing. The pollutants removal performances became stable in the four reactors after 2 months' operation, with ammonia nitrogen and permanganate index (COD(Mn)) removal efficiencies of 84.41-94.21% and 69.66-76.60%, respectively. The biomass of mature biofilm was higher in the bioreactors by artificial enhancement than that by natural enrichment. Microbial community analysis indicated that elastic filler could enrich mature biofilm faster than AquaMats®. The heterotrophic bacteria diversity of biofilm decreased by artificial enhancement, which favored the ammonia-oxidizing bacteria (AOB) developing on the bio-fillers. Furthermore, Nitrosomonas- and Nitrosospira-like AOB coexisted in the biofilm, and Pseudomonas sp., Sphaerotilus sp., Janthinobacterium sp., Corynebacterium aurimucosum were dominant in the oligotrophic niche. Artificial enhancement via the combination of sediment discharging and influent velocity gradient increasing could enhance the biofilm formation and autotrophic AOB enrichment in oligotrophic niche.

  11. Enhanced efficiency of internal combustion engines by employing spinning gas.

    Science.gov (United States)

    Geyko, V I; Fisch, N J

    2014-08-01

    The efficiency of the internal combustion engine might be enhanced by employing spinning gas. A gas spinning at near sonic velocities has an effectively higher heat capacity, which allows practical fuel cycles, which are far from the Carnot efficiency, to approach more closely the Carnot efficiency. A remarkable gain in fuel efficiency is shown to be theoretically possible for the Otto and Diesel cycles. The use of a flywheel, in principle, could produce even greater increases in efficiency.

  12. Remediation of petroleum contaminated soils through bioventing in cold regions

    International Nuclear Information System (INIS)

    Brar, G.S.; Currier, P.M.; Reynolds, C.M.; Millhouse, J.B.

    1994-01-01

    Petroleum contaminated soils are found in many remote sites in Alaska where releases from bulk storage of fuel oil for heat and power generation have occurred. Bioventing, a process in which petroleum degradation by indigenous aerobic bacteria is enhanced by supplying oxygen and nutrients, may be a viable treatment technique for soils at remote sites if limitations due to low temperatures can be overcome. The objectives of this study were to: (1) test a design for ex-situ bioventing in cold regions, (2) evaluate biodegradation rates at low temperatures, and (3) determine the effects of applied nutrients on low-temperature biodegradation. Two aerated biopit remediation cells were constructed to treat previously excavated soils at Eareckson Air Force Station, Shemya, Alaska. Experimental treatments consisted of a fertilized pile (FP) and a nonfertilized pile (NFP). Hourly soil and air temperature data at 4 depths were recorded at 4 locations in each biopit. During 148 days of remediation, mean temperature ranged from -3 to 6 C for air at 100 cm. above the piles. The mean concentrations of TPH and DRO decreased from an initial 1,304 and 982 mg/kg of 139 and 82 mg/kg, respectively, with the FP, and 422 and 294 mg/kg with the NFP in 115 days. Cumulative degradation rates of TPH and DRO are significantly (P 2 = 0.94 for TPH. 0.93 for DRO). Pit bioventing technology was shown to be efficient, fast, and cost-effective in cold regions where temperature during winter months is a major constraint for the remediation of contaminated soils

  13. Integrated approach to hazardous and radioactive waste remediation

    International Nuclear Information System (INIS)

    Hyde, R.A.; Reece, W.J.

    1994-01-01

    The US Department of Energy Office of Technology Development is supporting the demonstration, and evaluation of a suite of waste retrieval technologies. An integration of leading-edge technologies with commercially available baseline technologies will form a comprehensive system for effective and efficient remediation of buried waste throughout the complex of DOE nuclear facilities. This paper discusses the complexity of systems integration, addressing organizational and engineering aspects of integration as well as the impact of human operators, and the importance of using integrated systems in remediating buried hazardous and radioactive waste

  14. Soil remediation via bioventing, vapor extraction and transition regime between vapor extraction and bioventing

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2014-01-01

    Conclusion: Comparison of the BV, SVE and AIBV technologies indicated that all of those technologies are efficient for remediation of unsaturated zone, but after specific remediation time frames, only AIBV able to support guide line values and protect ground waters.

  15. Risk-based economic decision analysis of remediation options at a PCE-contaminated site

    DEFF Research Database (Denmark)

    Lemming, Gitte; Friis-Hansen, P.; Bjerg, Poul Løgstrup

    2010-01-01

    by the remediation activities. More attention is increasingly being given to these secondary environmental impacts when evaluating remediation options. This paper presents a methodology for an integrated economic decision analysis which combines assessments of remediation costs, health risk costs and potential...... at a downstream groundwater well. Potential environmental impacts on the local, regional and global scales due to the site remediation activities are evaluated using life cycle assessments (LCA). The potential impacts on health and environment are converted to monetary units using a simplified cost model. A case......Remediation methods for contaminated sites cover a wide range of technical solutions with different remedial efficiencies and costs. Additionally, they may vary in their secondary impacts on the environment i.e. the potential impacts generated due to emissions and resource use caused...

  16. Remediation of TCE-contaminated groundwater using nanocatalyst and bacteria.

    Science.gov (United States)

    Kang, Ser Ku; Seo, Hyunhee; Sun, Eunyoung; Kim, Inseon; Roh, Yul

    2011-08-01

    The objective of this study was to develop and evaluate the remediation of trichloroethene (TCE)-contaminated groundwater using both a nanocatalyst (bio-Zn-magnetite) and bacterium (similar to Clostridium quinii) in anoxic environments. Of the 7 nanocatalysts tested, bio-Zn-magnetite showed the highest TCE dechlorination efficiency, with an average of ca. 90% within 8 days in a batch experiment. The column tests confirmed that the application of bio-Zn-magnetite in combination with the bacterium achieved high degradation efficiency (ca. 90%) of TCE within 5 days compared to the nanocatalyst only, which degraded only 30% of the TCE. These results suggest that the application of a nanocatalyst and the bacterium have potential for the remediation of TCE-contaminated groundwater in subsurface environments.

  17. Documenting clinical performance problems among medical students: feedback for learner remediation and curriculum enhancement

    Directory of Open Access Journals (Sweden)

    Brian E. Mavis

    2013-07-01

    Full Text Available Introduction: We operationalized the taxonomy developed by Hauer and colleagues describing common clinical performance problems. Faculty raters pilot tested the resulting worksheet by observing recordings of problematic simulated clinical encounters involving third-year medical students. This approach provided a framework for structured feedback to guide learner improvement and curricular enhancement. Methods: Eighty-two problematic clinical encounters from M3 students who failed their clinical competency examination were independently rated by paired clinical faculty members to identify common problems related to the medical interview, physical examination, and professionalism. Results: Eleven out of 26 target performance problems were present in 25% or more encounters. Overall, 37% had unsatisfactory medical interviews, with ‘inadequate history to rule out other diagnoses’ most prevalent (60%. Seventy percent failed because of physical examination deficiencies, with missing elements (69% and inadequate data gathering (69% most common. One-third of the students did not introduce themselves to their patients. Among students failing based on standardized patient (SP ratings, 93% also failed to demonstrate competency based on the faculty ratings. Conclusions: Our review form allowed clinical faculty to validate pass/fail decisions based on standardized patient ratings. Detailed information about performance problems contributes to learner feedback and curricular enhancement to guide remediation planning and faculty development.

  18. Thermal conductivity engineering in width-modulated silicon nanowires and thermoelectric efficiency enhancement

    Science.gov (United States)

    Zianni, Xanthippi

    2018-03-01

    Width-modulated nanowires have been proposed as efficient thermoelectric materials. Here, the electron and phonon transport properties and the thermoelectric efficiency are discussed for dimensions above the quantum confinement regime. The thermal conductivity decreases dramatically in the presence of thin constrictions due to their ballistic thermal resistance. It shows a scaling behavior upon the width-modulation rate that allows for thermal conductivity engineering. The electron conductivity also decreases due to enhanced boundary scattering by the constrictions. The effect of boundary scattering is weaker for electrons than for phonons and the overall thermoelectric efficiency is enhanced. A ZT enhancement by a factor of 20-30 is predicted for width-modulated nanowires compared to bulk silicon. Our findings indicate that width-modulated nanostructures are promising for developing silicon nanostructures with high thermoelectric efficiency.

  19. Carbon dioxide efficiency of terrestrial enhanced weathering.

    Science.gov (United States)

    Moosdorf, Nils; Renforth, Phil; Hartmann, Jens

    2014-05-06

    Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimistic scenarios. The results show that the choice of source rocks and material comminution technique dominate the CO2 efficiency of enhanced weathering. CO2 emissions from transport amount to on average 0.5-3% of potentially sequestered CO2. The emissions of material mining and application are negligible. After accounting for all emissions, 0.5-1.0 t CO2 can be sequestered on average per tonne of rock, translating into a unit cost from 1.6 to 9.9 GJ per tonne CO2 sequestered by enhanced weathering. However, to control or reduce atmospheric CO2 concentrations substantially with enhanced weathering would require very large amounts of rock. Before enhanced weathering could be applied on large scales, more research is needed to assess weathering rates, potential side effects, social acceptability, and mechanisms of governance.

  20. Mathematical Modelling of Bacterial Populations in Bio-remediation Processes

    Science.gov (United States)

    Vasiliadou, Ioanna A.; Vayenas, Dimitris V.; Chrysikopoulos, Constantinos V.

    2011-09-01

    An understanding of bacterial behaviour concerns many field applications, such as the enhancement of water, wastewater and subsurface bio-remediation, the prevention of environmental pollution and the protection of human health. Numerous microorganisms have been identified to be able to degrade chemical pollutants, thus, a variety of bacteria are known that can be used in bio-remediation processes. In this study the development of mathematical models capable of describing bacterial behaviour considered in bio-augmentation plans, such as bacterial growth, consumption of nutrients, removal of pollutants, bacterial transport and attachment in porous media, is presented. The mathematical models may be used as a guide in designing and assessing the conditions under which areas contaminated with pollutants can be better remediated.

  1. ICT applications enhancing energy efficiency

    Directory of Open Access Journals (Sweden)

    A. G. Matani

    2016-06-01

    Full Text Available Computers, laptops and mobile devices – information technology (IT accounts for 2% of human greenhouse gas emissions worldwide, as evidenced in a study by Global Action Plan, a UK based environmental organization. This figure can be reduced if the green segment, or Green IT, continues to grow. Energy can also be saved through cloud computing, namely the principle of outsourcing the programs and functions of one’s own computer to service providers over the internet. This also means sharing storage capacity with others. This paper highlights the impact of information technology applications towards enhancing energy efficiency of the systems.

  2. 2-D model for electrokinetic remediation

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Maroto, J.M.; Garcia Delgado, R.A.; Gomez Lahoz, C.; Garcia Herruzo, F. [Dept. de Ingenieria Quimica, Univ. de Malaga (Spain); Vereda Alonso, C. [Dept. de Ingenieria Quimica, Univ. de Malaga (Spain)]|[Inst. for Geologi and Geoteknik, Danmarks Tekniske Univ., Lyngby (Denmark)

    2001-07-01

    A simple two-dimensional numerical model is presented in this work. In this case, the model is used to examine the enhanced method of the electrokinetic remediation technique in a 2-D arrangement. Nevertheless the model with minor changes can also be used to study the effect of the electrode configuration in the performance of this technique. (orig.)

  3. Recent Developments for Remediating Acidic Mine Waters Using Sulfidogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Ivan Nancucheo

    2017-01-01

    Full Text Available Acidic mine drainage (AMD is regarded as a pollutant and considered as potential source of valuable metals. With diminishing metal resources and ever-increasing demand on industry, recovering AMD metals is a sustainable initiative, despite facing major challenges. AMD refers to effluents draining from abandoned mines and mine wastes usually highly acidic that contain a variety of dissolved metals (Fe, Mn, Cu, Ni, and Zn in much greater concentration than what is found in natural water bodies. There are numerous remediation treatments including chemical (lime treatment or biological methods (aerobic wetlands and compost bioreactors used for metal precipitation and removal from AMD. However, controlled biomineralization and selective recovering of metals using sulfidogenic bacteria are advantageous, reducing costs and environmental risks of sludge disposal. The increased understanding of the microbiology of acid-tolerant sulfidogenic bacteria will lead to the development of novel approaches to AMD treatment. We present and discuss several important recent approaches using low sulfidogenic bioreactors to both remediate and selectively recover metal sulfides from AMD. This work also highlights the efficiency and drawbacks of these types of treatments for metal recovery and points to future research for enhancing the use of novel acidophilic and acid-tolerant sulfidogenic microorganisms in AMD treatment.

  4. Enhancing crystalline silicon solar cell efficiency with SixGe1-x layers

    Science.gov (United States)

    Ali, Adnan; Cheow, S. L.; Azhari, A. W.; Sopian, K.; Zaidi, Saleem H.

    Crystalline silicon (c-Si) solar cell represents a cost effective, environment-friendly, and proven renewable energy resource. Industrially manufacturing of c-Si solar has now matured in terms of efficiency and cost. Continuing cost-effective efficiency enhancement requires transition towards thinner wafers in near term and thin-films in the long term. Successful implementation of either of these alternatives must address intrinsic optical absorption limitation of Si. Bandgap engineering through integration with SixGe1-x layers offers an attractive, inexpensive option. With the help of PC1D software, role of SixGe1-x layers in conventional c-Si solar cells has been intensively investigated in both wafer and thin film configurations by varying Ge concentration, thickness, and placement. In wafer configuration, increase in Ge concentration leads to enhanced absorption through bandgap broadening with an efficiency enhancement of 8% for Ge concentrations of less than 20%. At higher Ge concentrations, despite enhanced optical absorption, efficiency is reduced due to substantial lowering of open-circuit voltage. In 5-25-μm thickness, thin-film solar cell configurations, efficiency gain in excess of 30% is achievable. Therefore, SixGe1-x based thin-film solar cells with an order of magnitude reduction in costly Si material are ideally-suited both in terms of high efficiency and cost. Recent research has demonstrated significant improvement in epitaxially grown SixGe1-x layers on nanostructured Si substrates, thereby enhancing potential of this approach for next generation of c-Si based photovoltaics.

  5. The Role of Motivation in Cognitive Remediation for People with Schizophrenia.

    Science.gov (United States)

    Saperstein, Alice M; Medalia, Alice

    2016-01-01

    Motivation impairment is an often prominent component of schizophrenia symptomatology that impacts treatment engagement and reduces the functional benefit from psychosocial interventions. Intrinsic motivation in particular has been shown to be impaired in schizophrenia. Nowhere is the role of intrinsic motivation impairment more evident than in cognitive remediation for schizophrenia. This chapter describes the theoretical determinants of motivation to learn and illustrates how those determinants have been translated into therapeutic techniques that enhance intrinsic motivation in a clinical context. We review the extant research that indicates how motivation enhancing techniques yield treatment-related improvements within cognitive remediation therapy and, more broadly, in other behavioral skills-based interventions for schizophrenia.

  6. Efficient 3M PBS enhancing miniature projection optics

    Science.gov (United States)

    Yun, Zhisheng; Nevitt, Timothy; Willett, Stephen; Mortenson, Dave; Le, John; McDowell, Erin; Kent, Susan; Wong, Timothy; Beniot, Gilles J.; Ouderkirk, Andrew

    2016-09-01

    Over the past decade, 3M has developed a number of mobile projectors, with a goal towards providing the world's smallest, most efficient projection systems. Compact size and efficiency are required characteristics for projection systems used in mobile devices and more lately, in augmented reality systems. In this paper we summarize the main generations of 3M light engine optical designs. We present the optical architectures of four light engines, including the rationale behind the illumination designs and the projection systems. In particular, we describe various configurations relating to the 3M polarizing beam splitter (PBS) which is key to enhanced efficiency of the miniature projection systems.

  7. Carbon Nanotube Based Groundwater Remediation: The Case of Trichloroethylene

    Directory of Open Access Journals (Sweden)

    Kshitij C. Jha

    2016-07-01

    Full Text Available Adsorption of chlorinated organic contaminants (COCs on carbon nanotubes (CNTs has been gaining ground as a remedial platform for groundwater treatment. Applications depend on our mechanistic understanding of COC adsorption on CNTs. This paper lays out the nature of competing interactions at play in hybrid, membrane, and pure CNT based systems and presents results with the perspective of existing gaps in design strategies. First, current remediation approaches to trichloroethylene (TCE, the most ubiquitous of the COCs, is presented along with examination of forces contributing to adsorption of analogous contaminants at the molecular level. Second, we present results on TCE adsorption and remediation on pure and hybrid CNT systems with a stress on the specific nature of substrate and molecular architecture that would contribute to competitive adsorption. The delineation of intermolecular interactions that contribute to efficient remediation is needed for custom, scalable field design of purification systems for a wide range of contaminants.

  8. Carbon Nanotube Based Groundwater Remediation: The Case of Trichloroethylene.

    Science.gov (United States)

    Jha, Kshitij C; Liu, Zhuonan; Vijwani, Hema; Nadagouda, Mallikarjuna; Mukhopadhyay, Sharmila M; Tsige, Mesfin

    2016-07-21

    Adsorption of chlorinated organic contaminants (COCs) on carbon nanotubes (CNTs) has been gaining ground as a remedial platform for groundwater treatment. Applications depend on our mechanistic understanding of COC adsorption on CNTs. This paper lays out the nature of competing interactions at play in hybrid, membrane, and pure CNT based systems and presents results with the perspective of existing gaps in design strategies. First, current remediation approaches to trichloroethylene (TCE), the most ubiquitous of the COCs, is presented along with examination of forces contributing to adsorption of analogous contaminants at the molecular level. Second, we present results on TCE adsorption and remediation on pure and hybrid CNT systems with a stress on the specific nature of substrate and molecular architecture that would contribute to competitive adsorption. The delineation of intermolecular interactions that contribute to efficient remediation is needed for custom, scalable field design of purification systems for a wide range of contaminants.

  9. Green Remediation Best Management Practices: Implementing In Situ Thermal Technologies

    Science.gov (United States)

    Over recent years, the use of in situ thermal technologies such as electrical resistance heating, thermal conductive heating, and steam enhanced extraction to remediate contaminated sites has notably increased.

  10. Surfactant-enhanced electrokinetic remediation of soil contaminated with hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.W.; Park, J.Y.; Lee, H.H.; Cho, H.J. [Dept. of Chemical Engineering, Korea Advanced Inst. of Science and Technology, Taejon (Korea)

    2001-07-01

    Removal of hydrophobic organic contaminants (HOCs) using electrokinetic method was studied in a model system. Kaolinite and phenanthrene were selected as the model clay soil and representative HOC. Three different types of surfactants, APG (alkyl polyglucoside), Brij30 (polyoxyethylene 4 lauryl ether), and SDS (sodium dodecyl sulfate), were used to enhance the solubility of HOCs. Electrokinetic (EK) column experiments were performed using water, surfactant solution, and acetate buffer solution under a constant current condition. Voltage and flow through the soil system were interpreted with time. Electrolyte pH at the anode and cathode compartments was observed for operation time. Removal efficiency of phenanthrene was examined after the end of EK operation during 2, 4, and 6 weeks. (orig.)

  11. Spectral efficiency enhancement with interference cancellation for wireless relay network

    DEFF Research Database (Denmark)

    Yomo, Hiroyuki; De Carvalho, Elisabeth

    The introduction of relaying into wireless communication system for coverage enhancement can cause severe decrease of spectral efficiency due to the requirement on extra radio resource. In this paper, we propose a method to increase spectral efficiency in such a wireless relay network by employing...... an interference cancellation technique. We focus on a typical scenario of relaying in a cellular system, where a mobile station (MS) requires the help of a relay station (RS) to communicate with the base station (BS). In such a case, interference cancellation can be used to achieve a small reuse distance...... of identical radio resource. We analyze a simple scenario with BS, single RS, and 2 MSs, and show that the proposed method has significant potential to enhance spectral efficiency in wireless relay networks....

  12. Novel sorbents for environmental remediation

    Science.gov (United States)

    Manariotis, Ioannis D.; Karapanagioti, Hrissi K.; Werner, David

    2014-05-01

    Nowadays, one of the major environmental problems is the pollution of aquatic systems and soil by persistent pollutants. Persistent pollutants have been found widespread in sediments, surface waters, and drinking water supplies. The removal of pollutants can be accomplished prior to their discharge to receiving bodies or by immobilizing them onto soil. Sorption is the most commonly applied process, and activated carbons have been widely used. Rapid progress in nanotechnology and a new focus on biomass-based instead of non-renewable starting materials have produced a wide range of novel engineered sorbents including biosorbents, biochars, carbon-based nanoparticles, bio-nano hybrid materials, and iron-impregnated activated carbons. Sorbent materials have been used in environmental remediation processes and especially in agricultural soil, sediments and contaminated soil, water treatment, and industrial wastewater treatment. Furthermore, sorbents may enhance the synergistic action of other processes, such as volatilization and biodegradation. Novel sorbents have been employed for the removal or immobilization of persistent pollutants such as and include heavy metals (As, Cr, Cu, Pb, Cd, and Hg), halogenated organic compounds, endocrine disrupting chemicals, metalloids and non-metallic elements, and other organic pollutants. The development and evaluation of novel sorbents requires a multidisciplinary approach encompassing environmental, nanotechnology, physical, analytical, and surface chemistry. The necessary evaluations encompass not only the efficiency of these materials to remove pollutants from surface waters and groundwater, industrial wastewater, polluted soils and sediments, etc., but also the potential side-effects of their environmental applications. The aim of this work is to present the results of the use of biochar and impregnated carbon sorbents for the removal of organic pollutants and metals. Furthermore, the new findings from the forthcoming session

  13. Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

    Science.gov (United States)

    Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

    2017-04-01

    Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Construction of vesicle CdSe nano-semiconductors photocatalysts with improved photocatalytic activity: Enhanced photo induced carriers separation efficiency and mechanism insight.

    Science.gov (United States)

    Wen, Jiangsu; Ma, Changchang; Huo, Pengwei; Liu, Xinlin; Wei, Maobin; Liu, Yang; Yao, Xin; Ma, Zhongfei; Yan, Yongsheng

    2017-10-01

    Visible-light-driven photocatalysis as a green technology has attracted a lot of attention due to its potential applications in environmental remediation. Vesicle CdSe nano-semiconductor photocatalyst are successfully prepared by a gas template method and characterized by a variety of methods. The vesicle CdSe nano-semiconductors display enhanced photocatalytic performance for the degradation of tetracycline hydrochloride, the photodegradation rate of 78.824% was achieved by vesicle CdSe, which exhibited an increase of 31.779% compared to granular CdSe. Such an exceptional photocatalytic capability can be attributed to the unique structure of the vesicle CdSe nano-semiconductor with enhanced light absorption ability and excellent carrier transport capability. Meanwhile, the large surface area of the vesicle CdSe nano-semiconductor can increase the contact probability between catalyst and target and provide more surface-active centers. The photocatalytic mechanisms are analyzed by active species quenching. It indicates that h + and O 2 - are the main active species which play a major role in catalyzing environmental toxic pollutants. Simultaneously, the vesicle CdSe nano-semiconductor had high efficiency and stability. Copyright © 2017. Published by Elsevier B.V.

  15. Remediation mechanisms for Cd-contaminated soil using natural sepiolite at the field scale.

    Science.gov (United States)

    Yin, Xiuling; Xu, Yingming; Huang, Rong; Huang, Qingqing; Xie, Zhonglei; Cai, Yanming; Liang, Xuefeng

    2017-12-13

    Remediation of heavy metal polluted agricultural soil is essential for human health and ecological safety and remediation mechanisms at the microscopic level are vital for their large-scale utilization. In this study, natural sepiolite was employed as an immobilization agent for in situ field-scale remediation of Cd-contaminated paddy soil and the remediation mechanisms were investigated in terms of soil chemistry and plant physiology. Natural sepiolite had a significant immobilization effect for bioavailable Cd contents in paddy soil, and consequently could lower the Cd concentrations of brown rice, husk, straw, and roots of rice plants by 54.7-73.7%, 44.0-62.5%, 26.5-67.2%, and 36.7-46.7%, respectively. Regarding soil chemistry, natural sepiolite increased the soil pH values and shifted the zeta potentials of soil particles to be more negative, enhancing the fixation or sorption of Cd on soil particles, and resulted in the reduction of HCl and DTPA extractable Cd concentrations in paddy soil. Natural sepiolite neither enhanced nor inhibited iron plaques on the rice root surface, but did change the chemical environments of Fe and S in rice root. Natural sepiolite improved the activities of antioxidant enzymes and enhanced the total antioxidant capacity to alleviate the stress of Cd. It also promotes the synthesis of GSH and NPT to complete the detoxification. In general, the remediation mechanisms of natural sepiolite for the Cd pollutant in paddy soil could be summarized as the collective effects of soil chemistry and plant physiology.

  16. Remediation techniques for heavy metal-contaminated soils: Principles and applicability.

    Science.gov (United States)

    Liu, Lianwen; Li, Wei; Song, Weiping; Guo, Mingxin

    2018-08-15

    Globally there are over 20millionha of land contaminated by the heavy metal(loid)s As, Cd, Cr, Hg, Pb, Co, Cu, Ni, Zn, and Se, with the present soil concentrations higher than the geo-baseline or regulatory levels. In-situ and ex-situ remediation techniques have been developed to rectify the heavy metal-contaminated sites, including surface capping, encapsulation, landfilling, soil flushing, soil washing, electrokinetic extraction, stabilization, solidification, vitrification, phytoremediation, and bioremediation. These remediation techniques employ containment, extraction/removal, and immobilization mechanisms to reduce the contamination effects through physical, chemical, biological, electrical, and thermal remedy processes. These techniques demonstrate specific advantages, disadvantages, and applicability. In general, in-situ soil remediation is more cost-effective than ex-situ treatment, and contaminant removal/extraction is more favorable than immobilization and containment. Among the available soil remediation techniques, electrokinetic extraction, chemical stabilization, and phytoremediation are at the development stage, while the others have been practiced at full, field scales. Comprehensive assessment indicates that chemical stabilization serves as a temporary soil remediation technique, phytoremediation needs improvement in efficiency, surface capping and landfilling are applicable to small, serious-contamination sites, while solidification and vitrification are the last remediation option. The cost and duration of soil remediation are technique-dependent and site-specific, up to $500ton -1 soil (or $1500m -3 soil or $100m -2 land) and 15years. Treatability studies are crucial to selecting feasible techniques for a soil remediation project, with considerations of the type and degree of contamination, remediation goals, site characteristics, cost effectiveness, implementation time, and public acceptability. Copyright © 2018 Elsevier B.V. All rights

  17. Green Chemistry and Engineering Opportunity Assessment (GC&EOA) to US Army. A Case Study in Sustainable Remediation

    Science.gov (United States)

    2009-11-30

    transport of airborne contaminants and dust o Use heavy equipment efficiently (e.g. diesel emission reduction plan) o Maximize use of machinery equipped...remediation) Design for Energy Efficiency Favor low-energy technologies ( bioremediation , phytoremediation) where possible and effective; Use...Selection of a Remediation Scenario for a Diesel - Contaminated Site Using LCA. International Journal of Life Cycle Assessment 12(4), 239-251

  18. Efficient OCT Image Enhancement Based on Collaborative Shock Filtering.

    Science.gov (United States)

    Liu, Guohua; Wang, Ziyu; Mu, Guoying; Li, Peijin

    2018-01-01

    Efficient enhancement of noisy optical coherence tomography (OCT) images is a key task for interpreting them correctly. In this paper, to better enhance details and layered structures of a human retina image, we propose a collaborative shock filtering for OCT image denoising and enhancement. Noisy OCT image is first denoised by a collaborative filtering method with new similarity measure, and then the denoised image is sharpened by a shock-type filtering for edge and detail enhancement. For dim OCT images, in order to improve image contrast for the detection of tiny lesions, a gamma transformation is first used to enhance the images within proper gray levels. The proposed method integrating image smoothing and sharpening simultaneously obtains better visual results in experiments.

  19. Microbial Fuel Cells for Organic-Contaminated Soil Remedial Applications

    NARCIS (Netherlands)

    Li, Xiaojing; Wang, Xin; Weng, Liping; Zhou, Qixing; Li, Yongtao

    2017-01-01

    Efficient noninvasive techniques are desired for repairing organic-contaminated soils. Bioelectrochemical technology, especially microbial fuel cells (MFCs), has been widely used to promote a polluted environmental remediation approach, and applications include wastewater, sludge, sediment, and

  20. Enhancing Bioremediation of Oil-contaminated Soils by Controlling Nutrient Transport using Dual Characteristics of Soil Pore Structure

    Science.gov (United States)

    Mori, Y.; Suetsugu, A.; Matsumoto, Y.; Fujihara, A.; Suyama, K.; Miyamoto, T.

    2012-12-01

    Soil structure is heterogeneous with cracks or macropores allowing bypass flow, which may lead to applied chemicals avoiding interaction with soil particles or the contaminated area. We investigated the bioremediation efficiency of oil-contaminated soils by applying suction at the bottom of soil columns during bioremediation. Unsaturated flow conditions were investigated so as to avoid bypass flow and achieve sufficient dispersion of chemicals in the soil column. The boundary conditions at the bottom of the soil columns were 0 kPa and -3 kPa, and were applied to a volcanic ash soil with and without macropores. Unsaturated flow was achieved with -3 kPa and an injection rate of 1/10 of the saturated hydraulic conductivity. The resultant biological activities of the effluent increased dramatically in the unsaturated flow with macropores condition. Unsaturated conditions prevented bypass flow and allowed dispersion of the injected nutrients. Unsaturated flow achieved 60-80% of saturation, which enhanced biological activity in the soil column. Remediation results were better for unsaturated conditions because of higher biological activity. Moreover, unsaturated flow with macropores achieved uniform remediation efficiency from upper through lower positions in the column. Finally, taking the applied solution volume into consideration, unsaturated flow with -3 kPa achieved 10 times higher efficiency when compared with conventional saturated flow application. These results suggest that effective use of nutrients or remediation chemicals is possible by avoiding bypass flow and enhancing biological activity using relatively simple and inexpensive techniques.

  1. Gradient remediability in linear distributed parabolic systems ...

    African Journals Online (AJOL)

    The aim of this paper is the introduction of a new concept that concerned the analysis of a large class of distributed parabolic systems. It is the general concept of gradient remediability. More precisely, we study with respect to the gradient observation, the existence of an input operator (gradient efficient actuators) ensuring ...

  2. Use of cation selective membrane and acid addition for PH control in two-dimensional electrokinetic remediation of copper

    Energy Technology Data Exchange (ETDEWEB)

    Chan, M.S.M.; Lynch, R.J. [Cambridge Univ., Engineering Dept. (United Kingdom); Ilett, D.J. [AEA Technology, Harwell, Oxfordshire (United Kingdom)

    2001-07-01

    The feasibility of using a combination of a cation selective membrane and acid addition for pH control in electrokinetic remediation to toxic and heavy metals from low-permeability soil has been investigated. The high pH generated during the remediation process, as a result of surplus OH{sup -} ions, may cause metal ions to precipitate as hydroxides at or near the cathodes. This region of high pH is known to be associated with high electrical resistance, which limits the remediation efficiency by inhibiting current flow through the soil. One way to control pH is by adding acid to neutralize the OH{sup -} ions. However, preliminary work showed that addition of acid to the cathodic region was not effective in preventing the spread of the alkaline zone from cathodes toward anodes. Precipitates were formed before metal ions reached the cathodic region. Therefore, another method of pH control was investigated, using a cation selective membrane to enhance the electrokinetic process. The membrane was placed in front of the cathodes to contain the OH{sup -} ions generated, and confine the precipitates of metal hydroxide to a small cathodic region. The clean-up of a contaminated site was modelled in a rectangular tank, using silt as the low permeability soul and copper to simulate the contamination. The objective was to redistribute the contaminant so as to concentrate it into a small area. Three experiments were performed with the following methods of pH control: (1) acid addition, (2) use of a cation selective membrane and (3) a combination of acid addition and a cation selective membrane. Using the combined approach, it was found that 75% of the target clean-up section (bounded by the cation selective membrane and the anodes) had more than 40% of the initial copper removed. The general efficiency of remediation increased in the following order. (orig.)

  3. Electrochemical soil remediation - accelerated soil weathering?

    Energy Technology Data Exchange (ETDEWEB)

    Ottosen, L.M.; Villumsen, A.; Hansen, H.K.; Jensen, P.E.; Pedersen, A.J. [Dept. of Civil Engineering, Technical Univ. of Denmark, Lyngby (Denmark); Ribeiro, A.B. [Dept. of Environmental Sciences and Engineering, New Univ. of Lisbon, Monte da Caparica (Portugal)

    2001-07-01

    In electrochemical soil remediation systems, where enhancement solutions and complexing agents are not used, a developing acidic front is mobilizing the heavy metals and the electric current is removing the mobilized elements from the soil. The hypotheses investigated in this paper is whether this process may be comparable to the chemical soil weathering that occurs in the environment due to the acidic rain, where the mobilized elements are removed from the soil by the penetrating water. Even through the weathering process is highly accelerated in the electrochemical cell. This paper shows results from electrodialytic remediation experiments performed with four different Danish heavy metal polluted soils. The main emphasis is laid on the relation between the developing acidic front and electromigration of Cu, Zn, Mn, Mg, Fe and Ca. (orig.)

  4. Remediation of heavy metal contaminated soils by using Solanum nigrum: A review.

    Science.gov (United States)

    Rehman, Muhammad Zia Ur; Rizwan, Muhammad; Ali, Shafaqat; Ok, Yong Sik; Ishaque, Wajid; Saifullah; Nawaz, Muhammad Farrakh; Akmal, Fatima; Waqar, Maqsooda

    2017-09-01

    Heavy metals are among the major environmental pollutants and the accumulation of these metals in soils is of great concern in agricultural production due to the toxic effects on crop growth and food quality. Phytoremediation is a promising technique which is being considered as an alternative and low-cost technology for the remediation of metal-contaminated soils. Solanum nigrum is widely studied for the remediation of heavy metal-contaminated soils owing to its ability for metal uptake and tolerance. S. nigrum can tolerate excess amount of certain metals through different mechanism including enhancing the activities of antioxidant enzymes and metal deposition in non-active parts of the plant. An overview of heavy metal uptake and tolerance in S. nigrum is given. Both endophytic and soil microorganisms can play a role in enhancing metal tolerance in S. nigrum. Additionally, optimization of soil management practices and exogenous application of amendments can also be used to enhance metal uptake and tolerance in this plant. The main objective of the present review is to highlight and discuss the recent progresses in using S. nigrum for remediation of metal contaminated soils. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Design requirements for ERD and ISCO: How close and how fast to achieve an effective remediation?

    DEFF Research Database (Denmark)

    Chambon, Julie Claire Claudia; Lemming, Gitte; Manoli, Gabriele

    2011-01-01

    Clayey tills contaminated with chlorinated solvents are a threat to groundwater and are difficult to remediate. Full scale Enhanced Reductive Dechlorination (ERD) and In-Situ Chemical Oxidation (ISCO) are promising remediation technologies for such sites, but the delivery of reactants...

  6. Bystander cells enhance NK cytotoxic efficiency by reducing search time.

    Science.gov (United States)

    Zhou, Xiao; Zhao, Renping; Schwarz, Karsten; Mangeat, Matthieu; Schwarz, Eva C; Hamed, Mohamed; Bogeski, Ivan; Helms, Volkhard; Rieger, Heiko; Qu, Bin

    2017-03-13

    Natural killer (NK) cells play a central role during innate immune responses by eliminating pathogen-infected or tumorigenic cells. In the microenvironment, NK cells encounter not only target cells but also other cell types including non-target bystander cells. The impact of bystander cells on NK killing efficiency is, however, still elusive. In this study we show that the presence of bystander cells, such as P815, monocytes or HUVEC, enhances NK killing efficiency. With bystander cells present, the velocity and persistence of NK cells were increased, whereas the degranulation of lytic granules remained unchanged. Bystander cell-derived H 2 O 2 was found to mediate the acceleration of NK cell migration. Using mathematical diffusion models, we confirm that local acceleration of NK cells in the vicinity of bystander cells reduces their search time to locate target cells. In addition, we found that integrin β chains (β1, β2 and β7) on NK cells are required for bystander-enhanced NK migration persistence. In conclusion, we show that acceleration of NK cell migration in the vicinity of H 2 O 2 -producing bystander cells reduces target cell search time and enhances NK killing efficiency.

  7. Potential and drawbacks of EDDS-enhanced phytoextraction of copper from contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Komarek, Michael, E-mail: komarek@af.czu.c [Department of Agro-Environmental Chemistry and Plant Nutrition, Czech University of Life Sciences Prague, Kamycka 129, 165 21 Prague 6 (Czech Republic); Vanek, Ales [Department of Soil Science and Soil Protection, Czech University of Life Sciences Prague, Kamycka 129, 165 21 Prague 6 (Czech Republic); Mrnka, Libor; Sudova, Radka [Department of Mycorrhizal Symbioses, Institute of Botany, Academy of Sciences of the Czech Republic, Lesni 322, 252 43 Pruhonice (Czech Republic); Szakova, Jirina [Department of Agro-Environmental Chemistry and Plant Nutrition, Czech University of Life Sciences Prague, Kamycka 129, 165 21 Prague 6 (Czech Republic); Tejnecky, Vaclav [Department of Soil Science and Soil Protection, Czech University of Life Sciences Prague, Kamycka 129, 165 21 Prague 6 (Czech Republic); Chrastny, Vladislav [Czech Geological Survey, Geologicka 6, 152 00 Prague 5 (Czech Republic); Faculty of Science, University of South Bohemia, Branisovska 31, 370 05 Ceske Budejovice (Czech Republic)

    2010-07-15

    Incubation and pot experiments using poplar (Populus nigra L. cv. Wolterson) were performed in order to evaluate the questionable efficiency of EDDS-enhanced phytoextraction of Cu from contaminated soils. Despite the promising conditions of the experiment (low contamination of soils with a single metal with a high affinity for EDDS, metal tolerant poplar species capable of producing high biomass yields, root colonization by mycorrhizal fungi), the phytoextraction efficiency was not sufficient. The EDDS concentrations used in this study (3 and 6 mmol kg{sup -1}) enhanced the mobility (up to a 100-fold increase) and plant uptake of Cu (up to a 65-fold increase). However, despite EDDS degradation and the competition of Fe and Al for the chelant, Cu leaching cannot be omitted during the process. Due to the low efficiency, further research should be focused on other environment-friendly methods of soil remediation. - Research focused on EDDS-enhanced phytoextraction of metals from contaminated soils has probably reached a dead-end.

  8. Potential and drawbacks of EDDS-enhanced phytoextraction of copper from contaminated soils

    International Nuclear Information System (INIS)

    Komarek, Michael; Vanek, Ales; Mrnka, Libor; Sudova, Radka; Szakova, Jirina; Tejnecky, Vaclav; Chrastny, Vladislav

    2010-01-01

    Incubation and pot experiments using poplar (Populus nigra L. cv. Wolterson) were performed in order to evaluate the questionable efficiency of EDDS-enhanced phytoextraction of Cu from contaminated soils. Despite the promising conditions of the experiment (low contamination of soils with a single metal with a high affinity for EDDS, metal tolerant poplar species capable of producing high biomass yields, root colonization by mycorrhizal fungi), the phytoextraction efficiency was not sufficient. The EDDS concentrations used in this study (3 and 6 mmol kg -1 ) enhanced the mobility (up to a 100-fold increase) and plant uptake of Cu (up to a 65-fold increase). However, despite EDDS degradation and the competition of Fe and Al for the chelant, Cu leaching cannot be omitted during the process. Due to the low efficiency, further research should be focused on other environment-friendly methods of soil remediation. - Research focused on EDDS-enhanced phytoextraction of metals from contaminated soils has probably reached a dead-end.

  9. Anisotropic metamaterial for efficiency enhancement of mid-range wireless power transfer under coil misalignment

    International Nuclear Information System (INIS)

    Ranaweera, A L A K; Moscoso, Carlos Arriola; Lee, Jong-Wook

    2015-01-01

    In a wireless power transfer (WPT) system, misalignment between transmitter and receiver coils is one of the key factors affecting efficiency. Recently, metamaterials have shown great potential to enhance electromagnetic propagation in various environments. In this work, we apply a metamaterial to enhance the WPT in a more general environment where misalignment is considered. Using an anisotropic metamaterial, we obtain a significant efficiency enhancement. Therefore, we propose that the metamaterial is an effective means to mitigate the decreased efficiency caused by misalignment. In addition, we investigate the effect of coil misalignment on the threshold distance beyond which the metamaterial enhances the performance of WPT. (paper)

  10. Remediation of lead contaminated soil by biochar-supported nano-hydroxyapatite.

    Science.gov (United States)

    Yang, Zhangmei; Fang, Zhanqiang; Zheng, Liuchun; Cheng, Wen; Tsang, Pokeung Eric; Fang, Jianzhang; Zhao, Dongye

    2016-10-01

    In this study, a high efficiency and low cost biochar-supported nano-hydroxyapatite (nHAP@BC) material was used in the remediation of lead (Pb)-contaminated soil. The remediation effect of nHAP@BC on Pb-contaminated soil was evaluated through batch experiments. The stability, bioaccessibility of Pb in the soil and the change in soil characteristics are discussed. Furthermore, the effects of the amendments on the growth of cabbage mustard seedlings and the accumulation of Pb were studied. The results showed that the immobilization rates of Pb in the soil were 71.9% and 56.8%, respectively, after a 28 day remediation using 8% nHAP and nHAP@BC materials, and the unit immobilization amount of nHAP@BC was 5.6 times that of nHAP, indicating that nHAP@BC can greatly reduce the cost of remediation of Pb in soil. After the nHAP@BC remediation, the residual fraction Pb increased by 61.4%, which greatly reduced the bioaccessibility of Pb in the soil. Moreover, nHAP@BC could effectively reduce the accumulation of Pb in plants by 31.4%. Overall, nHAP@BC can effectively remediate Pb-contaminated soil and accelerate the recovery of soil fertility. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Materials That Enhance Efficiency and Radiation Resistance of Solar Cells

    Science.gov (United States)

    Sun, Xiadong; Wang, Haorong

    2012-01-01

    A thin layer (approximately 10 microns) of a novel "transparent" fluorescent material is applied to existing solar cells or modules to effectively block and convert UV light, or other lower solar response waveband of solar radiation, to visible or IR light that can be more efficiently used by solar cells for additional photocurrent. Meanwhile, the layer of fluorescent coating material remains fully "transparent" to the visible and IR waveband of solar radiation, resulting in a net gain of solar cell efficiency. This innovation alters the effective solar spectral power distribution to which an existing cell gets exposed, and matches the maximum photovoltaic (PV) response of existing cells. By shifting a low PV response waveband (e.g., UV) of solar radiation to a high PV response waveband (e.g. Vis-Near IR) with novel fluorescent materials that are transparent to other solar-cell sensitive wavebands, electrical output from solar cells will be enhanced. This approach enhances the efficiency of solar cells by converting UV and high-energy particles in space that would otherwise be wasted to visible/IR light. This innovation is a generic technique that can be readily implemented to significantly increase efficiencies of both space and terrestrial solar cells, without incurring much cost, thus bringing a broad base of economical, social, and environmental benefits. The key to this approach is that the "fluorescent" material must be very efficient, and cannot block or attenuate the "desirable" and unconverted" waveband of solar radiation (e.g. Vis-NIR) from reaching the cells. Some nano-phosphors and novel organometallic complex materials have been identified that enhance the energy efficiency on some state-of-the-art commercial silicon and thin-film-based solar cells by over 6%.

  12. Using quartz sand to enhance the removal efficiency of M. aeruginosa by inorganic coagulant and achieve satisfactory settling efficiency.

    Science.gov (United States)

    Pei, Haiyan; Jin, Yan; Xu, Hangzhou; Ma, Chunxia; Sun, Jiongming; Li, Hongmin

    2017-10-19

    In this study, low-cost and non-polluting quartz sand was respectively mixed with AlCl 3 , FeCl 3 and PAFC to synergistically remove Microcystis aeruginosa. Results showed that quartz sand could markedly increase the algae removal efficiency and decrease the coagulant doses. The increase of removal efficiency with AlCl 3 and FeCl 3 was only due to the enhancement of floc density by the quartz sand. However, the removal efficiency with PAFC was increased not only by the enhanced floc density, but also by the enlarged floc size. Flocs from 50 mg/L sand addition were larger than that with other sand doses, which was on account of the appropriate enhancement of collision efficiency at this dose. After coagulation, the extracellular organic matter (EOM) and microcystins (MCs) in system with quartz sand was remarkably reduced. That's because quartz sand can enhance the coagulation so as to improve capping the EOM and MCs in flocs during coagulation process. Owing to 200 mg/L quartz sand could damage the cell's membrane during coagulation proces, algal cells in the system lysed two days earlier than with 50 mg/L sand during flocs storage. In addition, cells with PAFC incurred relatively moderate cellular oxidative damage and could remain intact for longer time.

  13. Efficiency enhancement of liquid crystal projection displays using light recycle technology

    Science.gov (United States)

    Wang, Y.

    2002-01-01

    A new technology developed at JPL using low absorption color filters with polarization and color recycle system, is able to enhance efficiency of a single panel liquid crytal display (LCD) projector to the same efficiency of a 3 panel LCD projector.

  14. Remediation of uranium impacted sediments in a watercourse

    Energy Technology Data Exchange (ETDEWEB)

    Shephard, Eugene; Walter, Nelson; Downey, Heath [AMEC, Inc., Portland, Maine (United States); Collopy, Peter [AMEC, Inc., San Diego, California (United States); Conant, John [ABB, Inc., Windsor, Connecticut (United States)

    2013-07-01

    In 2009, remediation was initiated for a non-operational fuel cycle facility previously used for government contract work located in Windsor, Connecticut, USA. Radiological contaminants consisted primarily of high enriched uranium (HEU). Other radionuclides encountered in relatively minor amounts in certain areas of the clean-up included Co-60, Cs- 137, Ra-226, Th-232 and low enriched uranium (LEU).Between 2009 and the spring of 2011, remediation efforts were focused on demolition of contaminated buildings and removal of contaminated soil. In the late spring of 2011, the last phase of remediation commenced involving the removal of contaminated sediments from portions of a 1,200 meter long gaining stream. Planning and preparation for remediation of the stream began in 2009 with submittal of permit applications to undertake construction activities in a wetland area. The permitting process was lengthy and involved securing permits from multiple agencies. However, early and frequent communication with stakeholders played an integral role in efficiently obtaining the permit approvals. Frequent communication with stakeholders throughout the planning and remediation process also proved to be a key factor in timely completion of the project. The remediation of the stream involved the use of temporary bladder berms to divert surface water flow, water diversion piping, a sediment vacuum removal system, excavation of sediments using small front-end loaders, sediment dewatering, and waste packaging, transportation and disposal. Many safeguards were employed to protect several species of concern in the work area, water management during project activities, challenges encountered during the project, methods of Final Status Survey, and stream restoration. (authors)

  15. ZnO-graphene quantum dots heterojunctions for natural sunlight-driven photocatalytic environmental remediation

    Science.gov (United States)

    Kumar, Suneel; Dhiman, Ankita; Sudhagar, Pitchaimuthu; Krishnan, Venkata

    2018-07-01

    In this work, we report the formation of heterojunctions comprising of graphene quantum dots (GQD) decorated ZnO nanorods (NR) and its use as efficient photocatalysts for environmental remediation. The heterojunctions has been designed to be active both in the UV and visible light regions and anticipated utilize the maximum part of the solar light spectrum. In this view, we examined the photocatalytic performance of our heterojunctions towards the degradation of colored pollutant (methylene blue (MB) dye) and a colorless pollutant (carbendazim (CZ) fungicide) under sunlight irradiation. Compared to bare photocatalyst ZnO and GQD, the heterojunction with 2 wt% of GQD (ZGQD2) showed the best photocatalytic activity by effectively degrading (about 95%) of organic pollutants (MB and CZ) from water within a short span of 70 min. The superior photocatalytic activity of these ZnO-GQD heterojunctions could be attributed to efficient charge carrier separation lead suppressed recombination rate at photocatalyst interfaces. In addition to the enhanced light absorption from UV to visible region, the high specific surface area of ZGQD2 heterojunction (353.447 m2 g-1) also imparts strong adsorption capacity for pollutants over catalyst surface, resulting in high photoactivity. Based on the obtained results, band gap alignment at ZnO-GQD heterojunction and active species trapping experiments, a plausible mechanism is proposed for photocatalytic reaction. The excellent photostability and recyclability of the ZnO-GQD heterojunctions fostering as promising photocatalyst candidate for environmental remediation applications.

  16. Enhancing Efficiency of Perovskite Solar Cells via Surface Passivation with Graphene Oxide Interlayer.

    Science.gov (United States)

    Li, Hao; Tao, Leiming; Huang, Feihong; Sun, Qiang; Zhao, Xiaojuan; Han, Junbo; Shen, Yan; Wang, Mingkui

    2017-11-08

    Perovskite solar cells have been demonstrated as promising low-cost and highly efficient next-generation solar cells. Enhancing V OC by minimization the interfacial recombination kinetics can further improve device performance. In this work, we for the first time reported on surface passivation of perovskite layers with chemical modified graphene oxides, which act as efficient interlayer to reduce interfacial recombination and enhance hole extraction as well. Our modeling points out that the passivation effect mainly comes from the interaction between functional group (4-fluorophenyl) and under-coordinated Pb ions. The resulting perovskite solar cells achieved high efficient power conversion efficiency of 18.75% with enhanced high open circuit V OC of 1.11 V. Ultrafast spectroscopy, photovoltage/photocurrent transient decay, and electronic impedance spectroscopy characterizations reveal the effective passivation effect and the energy loss mechanism. This work sheds light on the importance of interfacial engineering on the surface of perovskite layers and provides possible ways to improve device efficiency.

  17. Limited applicability of cost-effectiveness and cost-benefit analyses for the optimization of radon remedial measures

    International Nuclear Information System (INIS)

    Jiránek, Martin; Rovenská, Kateřina

    2010-01-01

    Ways of using different decision-aiding techniques for optimizing and evaluating radon remedial measures have been studied on a large set of data obtained from the remediation of 32 houses that had an original indoor radon concentration level above 1,000 Bq/m 3 (around 0.2 % of all dwellings in the Czech Republic have a radon concentration higher than 1,000 Bq/ m 3 ). Detailed information about radon concentrations before and after remediation, type and extent of remedial measures and installation and operation costs were used as the input parameters for a comparison of costs and for determining the efficiencies, for a cost-benefit analysis and a cost-effectiveness analysis, in order to find out whether these criteria and techniques provide sufficient and relevant information for the improvement and optimization of remediation. The study has delivered quite new results. It is confirmed that the installation costs of remedial measures do not depend on the original level of indoor radon concentration, but on the technical state of the building. In addition, the study reveals that the efficiency of remediation does not depend on the installation costs. Each of the studied remedial measures will on an average save 0.3 lives and gain 4.3 years of life. On one hand, the general decision-aiding techniques - cost-benefit analysis and cost-effectiveness analysis - lead to the conclusion that the remedial measures reducing the indoor radon concentration from values above 1,000 Bq/m 3 to values below the action level of 400 Bq/m 3 are always acceptable and reasonable. On the other hand, these analytical techniques can neither help the designer to choose the proper remedial measure nor provide information resulting in improved remediation. (author)

  18. Design requirements for ERD in diffusion-dominated media: how do injection interval, bioactive zones and reaction kinetics affect remediation performance?

    Science.gov (United States)

    Chambon, J.; Lemming, G.; Manoli, G.; Broholm, M. M.; Bjerg, P.; Binning, P. J.

    2011-12-01

    Enhanced Reductive Dechlorination (ERD) has been successfully used in high permeability media, such as sand aquifers, and is considered to be a promising technology for low permeability settings. Pilot and full-scale applications of ERD at several sites in Denmark have shown that the main challenge is to get contact between the injected bacteria and electron donor and the contaminants trapped in the low-permeability matrix. Sampling of intact cores from the low-permeability matrix has shown that the bioactive zones (where degradation occurs) are limited in the matrix, due to the slow diffusion transport processes, and this affects the timeframes for the remediation. Due to the limited ERD applications and the complex transport and reactive processes occurring in low-permeability media, design guidelines are currently not available for ERD in such settings, and remediation performance assessments are limited. The objective of this study is to combine existing knowledge from several sites with numerical modeling to assess the effect of the injection interval, development of bioactive zones and reaction kinetics on the remediation efficiency for ERD in diffusion-dominated media. A numerical model is developed to simulate ERD at a contaminated site, where the source area (mainly TCE) is located in a clayey till with fractures and interbedded sand lenses. Such contaminated sites are common in North America and Europe. Hydro-geological characterization provided information on geological heterogeneities and hydraulic parameters, which are relevant for clay till sites in general. The numerical model couples flow and transport in the fracture network and low-permeability matrix. Sequential degradation of TCE to ethene is modeled using Monod kinetics, and the kinetic parameters are obtained from laboratory experiments. The influence of the reaction kinetics on remediation efficiency is assessed by varying the biomass concentration of the specific degraders. The injected

  19. Ability of salt marsh plants for TBT remediation in sediments

    OpenAIRE

    Carvalho, P. N.; Basto, M. C.; Moreira da Silva, M.; Machado, A.; Bordalo, A.; Vasconcelos, M. T.

    2010-01-01

    The capability of Halimione portulacoides, Spartina maritima, and Sarcocornia fruticosa (halophytes very commonly found in salt marshes from Mediterranean areas) for enhancing remediation of tributyltin (TBT) from estuarine sediments was investigated, using different experimental conditions.

  20. Program summary for the Office of Remedial Action and Waste Technology

    International Nuclear Information System (INIS)

    1989-10-01

    The US Department of Energy is the lead Federal agency responsible for planning and implementing the programs that ensure safe and efficient management of nuclear wastes from both civilian and defense activities. Within the Department, three offices share this responsibility: the Office of Remedial Action and Waste Technology, the Office of Civilian Radioactive Waste Management, and the Office of Defense Waste and Transportation Management. This document summarizes the programs managed by the Office of Remedial Action and Waste Technology

  1. Sequential Application of Soil Vapor Extraction and Bioremediation Processes for the Remediation of Ethylbenzene-Contaminated Soils

    DEFF Research Database (Denmark)

    Soares, António Carlos Alves; Pinho, Maria Teresa; Albergaria, José Tomás

    2012-01-01

    Soil vapor extraction (SVE) is an efficient, well-known and widely applied soil remediation technology. However, under certain conditions it cannot achieve the defined cleanup goals, requiring further treatment, for example, through bioremediation (BR). The sequential application of these technol......Soil vapor extraction (SVE) is an efficient, well-known and widely applied soil remediation technology. However, under certain conditions it cannot achieve the defined cleanup goals, requiring further treatment, for example, through bioremediation (BR). The sequential application...

  2. Internal quantum efficiency enhancement of GaInN/GaN quantum-well structures using Ag nanoparticles

    DEFF Research Database (Denmark)

    Iida, Daisuke; Fadil, Ahmed; Chen, Yuntian

    2015-01-01

    We report internal quantum efficiency enhancement of thin p-GaN green quantumwell structure using self-assembled Ag nanoparticles. Temperature dependent photoluminescence measurements are conducted to determine the internal quantum efficiency. The impact of excitation power density on the enhance......We report internal quantum efficiency enhancement of thin p-GaN green quantumwell structure using self-assembled Ag nanoparticles. Temperature dependent photoluminescence measurements are conducted to determine the internal quantum efficiency. The impact of excitation power density...

  3. Removal of heavy metals from contaminated soil by electrodialytic remediation enhanced with organic acids.

    Science.gov (United States)

    Merdoud, Ouarda; Cameselle, Claudio; Boulakradeche, Mohamed Oualid; Akretche, Djamal Eddine

    2016-11-09

    The soil from an industrial area in Algeria was contaminated with Cr (8370 mg kg -1 ), Ni (1135 mg kg -1 ) and zinc (1200 mg kg -1 ). The electrodialytic remediation of this soil was studied using citric acid and EDTA as facilitating agents. 0.1 M citric acid or EDTA was added directly to the soil before it was introduced in an electrodialytic cell in an attempt to enhance the heavy metal solubility in the interstitial fluid. The more acidic pH in the soil when citric acid was used as the facilitating agent was not enough to mobilize and remove the metals from the soil. Only 7.2% of Ni and 6.7% of Zn were removed from the soil in the test with citric acid. The best results were found with EDTA, which was able to solubilize and complex Zn and Ni forming negatively charged complexes that were transported and accumulated in the anolyte. Complete removal was observed for Ni and Zn in the electrodialytic treatment with EDTA. Minor amounts of Cr were removed with both EDTA and citric acid.

  4. Enhancement in Photoelectrochemical Efficiency by Fabrication of BiVO4@MWCNT Nanocomposites

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2011-01-01

    Full Text Available An enormous enhancement in the photo-to-current conversion efficiency over the nanocomposite material composed by BiVO4 on the surface of MWCNTs, with respect to electrode of pure BiVO4, was observed. The heterojunction formed between MWCNTs and nano-BiVO4 is beneficial for the separation of photogenerated electrons and holes, resulting in more electrons that are able to transport efficiently to the surface and therefore enhance the photoefficiency.

  5. Kinetics as a tool to assess the immobilization of soil trace metals by binding phase amendments for in situ remediation purposes

    International Nuclear Information System (INIS)

    Varrault, Gilles; Bermond, Alain

    2011-01-01

    Highlights: → Assessment of the efficiency of soil remediation method by binding phase amendment. → Use of a kinetic fractionation method to assess trace metal mobility in amended soils. → Vernadite amendments are effective for lead and cadmium remediation. → IHA amendments are only effective for copper remediation. → Advantages of kinetic fractionation vs. extraction schemes performed at equilibrium. - Abstract: Many soil remediation techniques consist in decreasing the mobility of trace metals by means of adding trace metal binding phases. For this study, whose aim is to assess the efficiency of soil remediation method by binding phase amendment, a kinetic fractionation method that provides the labile and slowly labile trace metal amounts in soil has been introduced. Manganese oxides (vernadite) and insolubilized humic acids (IHA) have been used as binding phases for the remediation of four heavily polluted soils. Vernadite amendments are effective for lead and cadmium remediation, whereas IHA amendments are only effective for copper remediation. In most cases, the labile metal fractions decrease dramatically in amended soils (up to 50%); on the other hand, the amounts of total extracted metal near the point of thermodynamic equilibrium often show no significant difference between the amended soil and the control soil. These results highlight the utility of kinetic fractionation in assessing the efficiency of soil remediation techniques and, more generally, in evaluating trace metal mobility in soils and its potential advantages compared to extraction schemes performed under equilibrium conditions. In the future, this kinetic method could be considerably simplified so as to consume much less time allowing its routine use.

  6. Solar One demolition and remediation

    International Nuclear Information System (INIS)

    Wallace, G.L.

    1995-01-01

    Solar One was designed to demonstrate the feasibility of generating electrical energy from solar power using a central receiver concept. An array of heliostats focused sunlight onto a central receiver, which superheated water to produce steam. Although Solar One was successful, the oil-based Thermal Storage System (TSS), used to store heat energy for power generation at night, was not efficient. When the TSS was demolished for the installation of a more efficient molten salt system, a major effort was made to salvage or recycle all of its equipment and materials. During TSS demolition, approximately 7 tons of aluminum shielding and 205 tons of steel were salvaged as scrap metal; 200 tons of concrete was used for erosion protection along the Mohave River banks; 150,000 gallons of oil was recycled and 100 tons of equipment was salvaged for use at other facilities. During remediation, approximately 9,000 tons of oil contaminated sand, gravel and soil was recycled into approximately 10,000 tons of asphalt concrete and used to pave a nearby 5-acre parking lot at Barstow College. This not only reduced project remediation costs, but also met environmental requirements and provided a much needed community service. Of the estimated 11,864 tons of equipment and material from the TSS, less than 1% was disposed of at a landfill

  7. Groundwater re-injection at Fernald: Its role in accelerating the aquifer remedy

    International Nuclear Information System (INIS)

    Broberg, Kenneth A.; Janke, Robert

    2000-01-01

    A successful field-scale demonstration of the use of groundwater re-injection at the Fernald Environmental Management Project (FEMP) was recently completed, bringing the U.S. Department of Energy one step closer to achieving an accelerated site remediation. The demonstration marks the end of a several-year effort to evaluate (a) whether re-injection could be conducted efficiently at Fernald and (b) whether the approved aquifer remedy at Fernald would benefit from incorporating re-injection

  8. Effect of increased groundwater viscosity on the remedial performance of surfactant-enhanced air sparging

    Science.gov (United States)

    Choi, Jae-Kyeong; Kim, Heonki; Kwon, Hobin; Annable, Michael D.

    2018-03-01

    The effect of groundwater viscosity control on the performance of surfactant-enhanced air sparging (SEAS) was investigated using 1- and 2-dimensional (1-D and 2-D) bench-scale physical models. The viscosity of groundwater was controlled by a thickener, sodium carboxymethylcellulose (SCMC), while an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), was used to control the surface tension of groundwater. When resident DI water was displaced with a SCMC solution (500 mg/L), a SDBS solution (200 mg/L), and a solution with both SCMC (500 mg/L) and SDBS (200 mg/L), the air saturation for sand-packed columns achieved by air sparging increased by 9.5%, 128%, and 154%, respectively, (compared to that of the DI water-saturated column). When the resident water contained SCMC, the minimum air pressure necessary for air sparging processes increased, which is considered to be responsible for the increased air saturation. The extent of the sparging influence zone achieved during the air sparging process using the 2-D model was also affected by viscosity control. Larger sparging influence zones (de-saturated zone due to air injection) were observed for the air sparging processes using the 2-D model initially saturated with high-viscosity solutions, than those without a thickener in the aqueous solution. The enhanced air saturations using SCMC for the 1-D air sparging experiment improved the degradative performance of gaseous oxidation agent (ozone) during air sparging, as measured by the disappearance of fluorescence (fluorescein sodium salt). Based on the experimental evidence generated in this study, the addition of a thickener in the aqueous solution prior to air sparging increased the degree of air saturation and the sparging influence zone, and enhanced the remedial potential of SEAS for contaminated aquifers.

  9. Interactive computer-enhanced remote viewing system

    International Nuclear Information System (INIS)

    Tourtellott, J.A.; Wagner, J.F.

    1995-01-01

    Remediation activities such as decontamination and decommissioning (D ampersand D) typically involve materials and activities hazardous to humans. Robots are an attractive way to conduct such remediation, but for efficiency they need a good three-dimensional (3-D) computer model of the task space where they are to function. This model can be created from engineering plans and architectural drawings and from empirical data gathered by various sensors at the site. The model is used to plan robotic tasks and verify that selected paths am clear of obstacles. This need for a task space model is most pronounced in the remediation of obsolete production facilities and underground storage tanks. Production facilities at many sites contain compact process machinery and systems that were used to produce weapons grade material. For many such systems, a complex maze of pipes (with potentially dangerous contents) must be removed, and this represents a significant D ampersand D challenge. In an analogous way, the underground storage tanks at sites such as Hanford represent a challenge because of their limited entry and the tumbled profusion of in-tank hardware. In response to this need, the Interactive Computer-Enhanced Remote Viewing System (ICERVS) is being designed as a software system to: (1) Provide a reliable geometric description of a robotic task space, and (2) Enable robotic remediation to be conducted more effectively and more economically than with available techniques. A system such as ICERVS is needed because of the problems discussed below

  10. Slow-light-enhanced energy efficiency for graphene microheaters on silicon photonic crystal waveguides

    Science.gov (United States)

    Yan, Siqi; Zhu, Xiaolong; Frandsen, Lars Hagedorn; Xiao, Sanshui; Mortensen, N. Asger; Dong, Jianji; Ding, Yunhong

    2017-01-01

    Slow light has been widely utilized to obtain enhanced nonlinearities, enhanced spontaneous emissions and increased phase shifts owing to its ability to promote light–matter interactions. By incorporating a graphene on a slow-light silicon photonic crystal waveguide, here we experimentally demonstrate an energy-efficient graphene microheater with a tuning efficiency of 1.07 nmmW−1 and power consumption per free spectral range of 3.99 mW. The rise and decay times (10–90%) are only 750 and 525 ns, which, to the best of our knowledge, are the fastest reported response times for microheaters in silicon photonics. The corresponding figure of merit of the device is 2.543 nW s, one order of magnitude better than results reported in previous studies. The influence of the length and shape of the graphene heater to the tuning efficiency is further investigated, providing valuable guidelines for enhancing the tuning efficiency of the graphene microheater. PMID:28181531

  11. Fast-track remediation case study: Southern California refined fuel distributor

    International Nuclear Information System (INIS)

    Bubier, T.W.; Felix, P.R.

    1993-01-01

    Successful environmental remediation projects have three requirements in common: (1) an adequate data base that defines the extent and severity of the problem; (2) a detailed understanding of the actual performance of the remediation technologies being considered; and (3) good communication with the regulatory agencies to assure them that the health and safety of the community and workers will not be jeopardized. In a fast-track remediation project, these requirements are key issues in the critical path. The case study involves soil and groundwater remediation of a 16-acre bulk fuel storage and distribution facility. The facility was in operation for approximately 75 years and contained 20 large aboveground tanks with a total capacity in excess of 20 million gallons. Activities at the facility included receipt, storage, and distribution of refined fuel products, such as kerosene, gasoline, diesel, and bunker fuel. A harbor-widening project was undertaken to increase the level of safety for larger ships when passing through the port. Because of the critical need for harbor-widening, the environmental cleanup needed to be completed as quickly as possible. The following steps were taken during the fast-track remediation case study to meet the above-listed requirements: (1) New Data Quality Objectives (DQOs) were identified for the project; (2) Potentially applicable remedial technologies were evaluated and tested; and (3) An agency task force was developed to enhance communication with the regulatory agencies. This paper discusses these steps and presents examples of how each step was implemented during the remediation case study

  12. Enhanced bioleaching efficiency of metals from E-wastes driven by biochar

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuhua; Zheng, Yue; Yan, Weifu; Chen, Lixiang [CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Dummi Mahadevan, Gurumurthy [CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China); Zhao, Feng, E-mail: fzhao@iue.ac.cn [CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China)

    2016-12-15

    Electronic wastes (E-wastes) contain a huge amount of valuable metals that are worth recovering. Bioleaching has attracted widespread attention as an environment-friendly and low-cost technology for the recycling of E-wastes. To avoid the disadvantages of being time-consuming or having a relatively low efficiency, biochar with redox activity was used to enhance bioleaching efficiency of metals from a basic E-waste (i.e., printed circuit boards in this study). The role of biochar was examined through three basic processes: Carbon-mediated, Sulfur-mediated and Iron-mediated bioleaching pathways. Although no obvious enhancement of bioleaching performance was observed in the C-mediated and S-mediated systems, Fe-mediated bioleaching was significantly promoted by the participation of biochar, and its leaching time was decreased by one-third compared with that of a biochar-free system. By mapping the dynamic concentration of Fe(II) and Cu(II), biochar was proved to facilitate the redox action between Fe(II) to Fe(III), which resulted in effective leaching of Cu. Two dominant functional species consisting of Alicyclobacillus spp. and Sulfobacillus spp. may cooperate in the Fe-mediated bioleaching system, and the ratio of these two species was regulated by biochar for enhancing the efficiency of bioleaching. Hence, this work provides a method to improve bioleaching efficiency with low-cost solid redox media.

  13. Enhanced bioleaching efficiency of metals from E-wastes driven by biochar

    International Nuclear Information System (INIS)

    Wang, Shuhua; Zheng, Yue; Yan, Weifu; Chen, Lixiang; Dummi Mahadevan, Gurumurthy; Zhao, Feng

    2016-01-01

    Electronic wastes (E-wastes) contain a huge amount of valuable metals that are worth recovering. Bioleaching has attracted widespread attention as an environment-friendly and low-cost technology for the recycling of E-wastes. To avoid the disadvantages of being time-consuming or having a relatively low efficiency, biochar with redox activity was used to enhance bioleaching efficiency of metals from a basic E-waste (i.e., printed circuit boards in this study). The role of biochar was examined through three basic processes: Carbon-mediated, Sulfur-mediated and Iron-mediated bioleaching pathways. Although no obvious enhancement of bioleaching performance was observed in the C-mediated and S-mediated systems, Fe-mediated bioleaching was significantly promoted by the participation of biochar, and its leaching time was decreased by one-third compared with that of a biochar-free system. By mapping the dynamic concentration of Fe(II) and Cu(II), biochar was proved to facilitate the redox action between Fe(II) to Fe(III), which resulted in effective leaching of Cu. Two dominant functional species consisting of Alicyclobacillus spp. and Sulfobacillus spp. may cooperate in the Fe-mediated bioleaching system, and the ratio of these two species was regulated by biochar for enhancing the efficiency of bioleaching. Hence, this work provides a method to improve bioleaching efficiency with low-cost solid redox media.

  14. Enhanced bioleaching efficiency of metals from E-wastes driven by biochar.

    Science.gov (United States)

    Wang, Shuhua; Zheng, Yue; Yan, Weifu; Chen, Lixiang; Dummi Mahadevan, Gurumurthy; Zhao, Feng

    2016-12-15

    Electronic wastes (E-wastes) contain a huge amount of valuable metals that are worth recovering. Bioleaching has attracted widespread attention as an environment-friendly and low-cost technology for the recycling of E-wastes. To avoid the disadvantages of being time-consuming or having a relatively low efficiency, biochar with redox activity was used to enhance bioleaching efficiency of metals from a basic E-waste (i.e., printed circuit boards in this study). The role of biochar was examined through three basic processes: Carbon-mediated, Sulfur-mediated and Iron-mediated bioleaching pathways. Although no obvious enhancement of bioleaching performance was observed in the C-mediated and S-mediated systems, Fe-mediated bioleaching was significantly promoted by the participation of biochar, and its leaching time was decreased by one-third compared with that of a biochar-free system. By mapping the dynamic concentration of Fe(II) and Cu(II), biochar was proved to facilitate the redox action between Fe(II) to Fe(III), which resulted in effective leaching of Cu. Two dominant functional species consisting of Alicyclobacillus spp. and Sulfobacillus spp. may cooperate in the Fe-mediated bioleaching system, and the ratio of these two species was regulated by biochar for enhancing the efficiency of bioleaching. Hence, this work provides a method to improve bioleaching efficiency with low-cost solid redox media. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Bio-electrochemical remediation of real field petroleum sludge as an electron donor with simultaneous power generation facilitates biotransformation of PAH: effect of substrate concentration.

    Science.gov (United States)

    Chandrasekhar, K; Venkata Mohan, S

    2012-04-01

    Remediation of real-field petroleum sludge was studied under self-induced electrogenic microenvironment with the function of variable organic loads (OLs) in bio-electrochemical treatment (BET) systems. Operation under various OLs documented marked influence on both electrogenic activity and remediation efficiency. Both total petroleum hydrocarbons (TPH) and its aromatic fraction documented higher removal with OL4 operation followed by OL3, OL2, OL1 and control. Self-induced biopotential and associated multiple bio-electrocatalytic reactions during BET operation facilitated biotransformation of higher ring aromatics (5-6) to lower ring aromatic (2-3) compounds. Asphaltenes and NSO fractions showed negligible removal during BET operation. Higher electrogenic activity was recorded at OL1 (343mV; 53.11mW/m(2), 100Ω) compared to other three OLs operation. Bioaugmentation to anodic microflora with anaerobic culture documented enhanced electrogenic activity at OL4 operation. Voltammetric profiles, Tafel analysis and VFA generation were in agreement with the observed power generation and degradation efficiency. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Elemental composition study of heavy metal (Ni, Cu, Zn) in riverbank soil by electrokinetic-assisted phyto remediation using XRF and SEM/EDX

    International Nuclear Information System (INIS)

    Suhailly Jamari; Zaidi Embong; Zaidi Embong; Ismail Bakar

    2013-01-01

    Full-text: Electrokinetic (EK)-assisted phyto remediation is one of the methods that have a big potential in enhancing the ability of plant uptake in soils remediation process. This research was conducted to investigate the difference in elemental composition concentration of riverbank soil and the change of pH between pre- and post-phyto remediation under the following condition: 1) control or as-receive sample; 2) Dieffenbachia spp plant with EK system (a pair of EK electrodes connected to a direct current (DC) power supply). After the electrodes were connected to a magnitude of 6 V/ cm -1 electric field for 4 hours/ day, the soil and plant samples were analyzed using and X-ray Fluorescence Spectrometer (XRF) and Scanning Electron Microscope/ Energy Dispersive X-ray Spectroscopy (SEM/ EDX). The SEM/EDX analysis showed that concentration of elemental composition (Ni, Cu and Zn) in post-phyto remediation plant powder samples had increase while elemental concentrations in the post-hydrotreatment soil samples were decreased. XRF analysis presented a variation in soil elemental composition concentration from anode to cathode where the concentration near anode region increased while decreased near the cathode region. A significant changes in soil pH were obtained where the soil pH increase in cathode region while decrease in anode region. The results reveal that the assistance of EK in phyto remediation process has increase the efficiency of plant uptake. (author)

  17. Electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Karlsmose, Bodil; Ottosen, Lisbeth M.; Hansen, Lene

    1999-01-01

    The paper gives an overview of how heavy metals can be found in the soil and the theory of electrodialytic remediation. Basically electrodialytic remediation works by passing electric current through the soil, and the heavy metals in ionic form will carry some of the current. Ion-exchange membranes...... prevents the protons and the hydroxides ions from the electrode processes to enter the soil. The heavy metals are collected in a concentration compartment, which is separated from the soil by ion-exchange membranes. Examples from remediation experiments are shown, and it is demonstrated that it is possible...... to remediate soil polluted with heavy metals be this method. When adding desorbing agents or complexing agents, chosing the right current density, electrolyte and membranes, the proces can be optimised for a given remediation situation. Also electroosmosis is influencing the system, and if extra water...

  18. Biosurfactant-enhanced soil bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Kosaric, N.; Lu, G.; Velikonja, J. [Univ. of Western Ontario, London, Ontario (Canada)

    1995-12-01

    Bioremediation of soil contaminated with organic chemicals is a viable alternative method for clean-up and remedy of hazardous waste sites. The final objective in this approach is to convert the parent toxicant into a readily biodegradable product which is harmless to human health and/or the environment. Biodegradation of hydrocarbons in soil can also efficiently be enhanced by addition or in-situ production of biosufactants. It was generally observed that the degradation time was shortened and particularly the adaptation time for the microbes. More data from our laboratories showed that chlorinated aromatic compounds, such as 2,4-dichlorophenol, a herbicide Metolachlor, as well as naphthalene are degraded faster and more completely when selected biosurfactants are added to the soil. More recent data demonstrated an enhanced biodegradation of heavy hydrocarbons in petrochemical sludges, and in contaminated oil when biosurfactants were present or were added prior to the biodegradation process.

  19. Minimizing the Health Risks from Hydrocarbon Contaminated Soils by Using Electric Field-Based Treatment for Soil Remediation

    Directory of Open Access Journals (Sweden)

    Irina Aura Istrate

    2018-01-01

    Full Text Available The present work addresses the assessment of human health risk from soil contaminated with total petroleum hydrocarbons (TPHs due to crude oil pollution, with a particular focus on the polycyclic aromatic hydrocarbon (PAH group of carcinogenic and toxic substances. Given that the measured risk for human health exceeded the accepted level, the study considered an electrochemical remediation method. The laboratory-scale experiments were conducted by using an electric field-based treatment as a possible solution for the remediation of contaminated soil. After 20 days of treatment, while the voltage applied was 15 V (specific voltage of 1 V/cm, the hydrocarbon content was significantly reduced. The parameters measured to determine the overall remediation efficiency were pH, redox potential, ionic strength, soil characteristics, voltage gradient, and zeta potential. The remediation degree observed during the experiments was around 50% for TPHs and 46% for PAHs. The applied remediation method resulted in significant removal efficiency of the tested contaminants from the soil. Consequently, the human health risk assessment for the new degree of contaminants in the soil was achieved. This data demonstrated to what extent the application of the remediation applied technology ensured an acceptable risk under the same exposure conditions for the industrial workers.

  20. Soil and ground-water remediation techniques

    International Nuclear Information System (INIS)

    Beck, P.

    1996-01-01

    Urban areas typically contain numerous sites underlain by soils or ground waters which are contaminated to levels that exceed clean-up guidelines and are hazardous to public health. Contamination most commonly results from the disposal, careless use and spillage of chemicals, or the historic importation of contaminated fill onto properties undergoing redevelopment. Contaminants of concern in soil and ground water include: inorganic chemicals such as heavy metals; radioactive metals; salt and inorganic pesticides, and a range of organic chemicals included within petroleum fuels, coal tar products, PCB oils, chlorinated solvents, and pesticides. Dealing with contaminated sites is a major problem affecting all urban areas and a wide range of different remedial technologies are available. This chapter reviews the more commonly used methods for ground-water and soil remediation, paying particular regard to efficiency and applicability of specific treatments to different site conditions. (author). 43 refs., 1 tab., 27 figs

  1. Objective Assessment of General Surgery Residents Followed by Remediation.

    Science.gov (United States)

    Gas, Becca L; Buckarma, EeeLN H; Mohan, Monali; Pandian, T K; Farley, David R

    Surgical training programs often lack objective assessment strategies. Complicated scheduling characteristics frequently make it difficult for surgical residents to undergo formal assessment; actually having the time and opportunity to remediate poor performance is an even greater problem. We developed a novel methodology of assessment for residents and created an efficient remediation system using a combination of simulation, online learning, and self-assessment options. Postgraduate year (PGY) 2 to 5 general surgery (GS) residents were tested in a 5 station, objective structured clinical examination style event called the Surgical X-Games. Stations were 15 minutes in length and tested both surgical knowledge and technical skills. Stations were scored on a scale of 1 to 5 (1 = Fail, 2 = Mediocre, 3 = Pass, 4 = Good, and 5 = Stellar). Station scores ≤ 2 were considered subpar and required remediation to a score ≥ 4. Five remediation sessions allowed residents the opportunity to practice the stations with staff surgeons. Videos of each skill or test of knowledge with clear instructions on how to perform at a stellar level were offered. Trainees also had the opportunity to checkout take-home task trainers to practice specific skills. Residents requiring remediation were then tested again in-person or sent in self-made videos of their performance. Academic medical center. PGY2, 3, 4, and 5 GS residents at Mayo Clinic in Rochester, MN. A total of, 35 residents participated in the Surgical X-Games in the spring of 2015. Among all, 31 (89%) had scores that were deemed subpar on at least 1 station. Overall, 18 (58%) residents attempted remediation. All 18 (100%) achieved a score ≥ 4 on the respective stations during a makeup attempt. Overall X-Games scores and those of PGY2s, 3s, and 4s were higher after remediation (p remediation. Despite difficulties with training logistics and busy resident schedules, it is feasible to objectively assess most GS trainees and

  2. Efficiency of biodegradable EDDS, NTA and APAM on enhancing the phytoextraction of cadmium by Siegesbeckia orientalis L. grown in Cd-contaminated soils.

    Science.gov (United States)

    Lan, Jichuan; Zhang, Shirong; Lin, Haichuan; Li, Ting; Xu, Xiaoxun; Li, Yun; Jia, Yongxia; Gong, Guoshu

    2013-05-01

    Chelant assisted phytoextraction has been proposed to enhance the efficiency of remediation. This study evaluated the effects of biodegradable ethylene diamine tetraacetate (EDDS), nitrilotriacetic (NTA) and anionic polyacrylamide (APAM) on the tolerance and uptake of Siegesbeckia orientalis L. at 10 and 100 mg kg(-1) Cd-contaminated soils. On the 80th and 90th days of transplanting, pots were treated with EDDS and NTA at 0 (control), 1 and 2 mmol kg(-1) soils, and APAM at 0 (control), 0.07 and 0.14 g kg(-1). Generally, the root and shoot biomass of S. orientalis in all treatments reduced not significantly compared with the control, and the activities of peroxidase and catalase in leaves generally increased by the application of chelants (P<0.05). The concentrations of Cd in the shoots were increased significantly by addition of all chelants. As a result, the Cd accumulation of S. orientalis under treatments with higher dosages of the three chelants on the 80th day were 1.40-2.10-fold and 1.12-1.25-fold compared to control at 10 and 100 mg kg(-1) Cd, respectively. Under the addition of 2 mmol kg(-1) NTA on the 80th day, the highest metal extraction ratio reached 1.2% and 0.4% at 10 and 100 mg kg(-1) Cd soils, respectively. Therefore, the applications of EDDS, NTA and APAM may provide more efficient choices in chemical-enhanced phytoextraction. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Remediation of TCE-contaminated groundwater using acid/BOF slag enhanced chemical oxidation.

    Science.gov (United States)

    Tsai, T T; Kao, C M; Wang, J Y

    2011-04-01

    The objective of this study was to evaluate the potential of applying acid/H(2)O(2)/basic oxygen furnace slag (BOF slag) and acid/S(2)O(8)(2-)/BOF slag systems to enhance the chemical oxidation of trichloroethylene (TCE)-contaminated groundwater. Results from the bench-scale study indicate that TCE oxidation via the Fenton-like oxidation process can be enhanced with the addition of BOF slag at low pH (pH=2-5.2) and neutral (pH=7.1) conditions. Because the BOF slag has iron abundant properties (14% of FeO and 6% of Fe(2)O(3)), it can be sustainably reused for the supplement of iron minerals during the Fenton-like or persulfate oxidation processes. Results indicate that higher TCE removal efficiency (84%) was obtained with the addition of inorganic acid for the activation of Fenton-like reaction compared with the experiments with organic acids addition (with efficiency of 10-15% lower) (BOF slag=10gL(-1); initial pH=5.2). This could be due to the fact that organic acids would compete with TCE for available oxidants. Results also indicate that the pH value had a linear correlation with the observed first-order decay constant of TCE, and thus, lower pH caused a higher TCE oxidation rate. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. The impact of abandoned coal gasification plants on groundwater and remediation strategies

    International Nuclear Information System (INIS)

    Werner, P.; Stieber, M.

    1997-01-01

    Areas of abandoned coal gasification-, cokeovenplants and town gasworks normally contain hazardous contaminants as there are among others PAHs, cyanides, mono aromatic compounds and phenols. Therefore a strong impact on the groundwater can be expected. In the thousands of sites existing in Germany a complete remediation is almost impossible. Combustion is the only safe way to eliminate the contaminants by mineralization; but is to expensive and not applicable for the large amount of soil to be treated. Soil washing and bio-remediation is limited by the composition of the contaminants on the one side and by the soil structure on the other. Therefore the success of the mentioned remediation techniques is normally weak and only in some selected cases efficient enough. A combination of different methods according the site characteristics might help to increase the efficiency. On the other hand it it obvious, that there are natural barriers integrated between the contaminants and the groundwater as there are e.g solubility adsorbability and biodegradability of the hazardous compounds and the distance to the groundwater. Recently developed methods for downstream groundwater remediation are presented and discussed for the application in gas work contaminations. Those so called 'passive systems' are said to be very economic and might help to prevent further distribution of the contaminants into the environment. (au)

  5. The use of chelating agents in the remediation of metal-contaminated soils: A review

    Energy Technology Data Exchange (ETDEWEB)

    Lestan, Domen [Agronomy Department, Centre for Soil and Environmental Science, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana (Slovenia); Luo Chunling [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)], E-mail: cexdli@polyu.edu.hk

    2008-05-15

    This paper reviews current remediation technologies that use chelating agents for the mobilization and removal of potentially toxic metals from contaminated soils. These processes can be done in situ as enhanced phytoextraction, chelant enhanced electrokinetic extraction and soil flushing, or ex situ as the extraction of soil slurry and soil heap/column leaching. Current proposals on how to treat and recycle waste washing solutions after soil is washed are discussed. The major controlling factors in phytoextraction and possible strategies for reducing the leaching of metals associated with the application of chelants are also reviewed. Finally, the possible impact of abiotic and biotic soil factors on the toxicity of metals left after the washing of soil and enhanced phytoextraction are briefly addressed. - The use of synthetic chelants for soil washing and enhanced phytoextraction by plants has been well studied for the remediation of metal-contaminated soils in the last two decades.

  6. The use of chelating agents in the remediation of metal-contaminated soils: A review

    International Nuclear Information System (INIS)

    Lestan, Domen; Luo Chunling; Li Xiangdong

    2008-01-01

    This paper reviews current remediation technologies that use chelating agents for the mobilization and removal of potentially toxic metals from contaminated soils. These processes can be done in situ as enhanced phytoextraction, chelant enhanced electrokinetic extraction and soil flushing, or ex situ as the extraction of soil slurry and soil heap/column leaching. Current proposals on how to treat and recycle waste washing solutions after soil is washed are discussed. The major controlling factors in phytoextraction and possible strategies for reducing the leaching of metals associated with the application of chelants are also reviewed. Finally, the possible impact of abiotic and biotic soil factors on the toxicity of metals left after the washing of soil and enhanced phytoextraction are briefly addressed. - The use of synthetic chelants for soil washing and enhanced phytoextraction by plants has been well studied for the remediation of metal-contaminated soils in the last two decades

  7. Remediation technology needs and applied R ampersand D initiatives

    International Nuclear Information System (INIS)

    Lien, S.C.T.; Levine, R.S.; Devgun, J.S.; Beskid, N.J.; Erickson, M.D.; Webster, S.L.

    1991-01-01

    The US Department of Energy (DOE) recently consolidated its environmental restoration and waste management activities. Within that new organization, DOE has committed to support Research, Development, Demonstration, Testing and Evaluation (RDDT ampersand E) activities with the following objectives: rapidly advance beyond currently available restoration and waste management technologies; provide solutions to key technical issues that will improve effectiveness, efficiency, and safety; and enhance DOE's ability to meet its 30-year compliance and cleanup goals. Four general categories have been identified where R ampersand D (and DT ampersand E) efforts need to be focused: waste minimization technologies, site characterization and assessment methods, waste treatment technologies, and remediation technologies with emphasis on in-situ methods. The DOE has already supported a number of R ampersand D activities in these areas and plans to continue that support in the future. For technology development, the DOE is committed to forming cooperative partnerships and eliciting broad participation from qualified organizations who can contribute to RDDT ampersand E activities. The new technologies resulting from these R ampersand D initiatives will enhance DOE's ability to meet its 30-year cleanup goal reduce risk, and provide significant cost savings over existing technologies. Even modest investments in these emerging technologies now can be expected to generate a high rate of return

  8. Remediation technology needs and applied R ampersand D initiatives

    International Nuclear Information System (INIS)

    Lien, S.C.T.; Levine, R.S.; Webster, S.L.

    1991-01-01

    The US Department of Energy (DOE) recently consolidated its environmental restoration and waste management activities. Within that new organization, DOE has committed to support Research, Development, Demonstration, Testing and, Evaluation (RDDT ampersand E) activities with the following objectives: rapidly advance beyond currently available technologies; provide solutions to key technical issues that will improve effectiveness, efficiency, and safety; and enhance DOE's ability to meet its 30-year compliance and cleanup goals. Four general categories have been identified where R ampersand D (and DT ampersand E) efforts need to be focused. These include: waste minimization technologies, site characterization and assessment methods, waste treatment technologies, and remediation technologies with emphasis on in-situ methods. The DOE has already supported a number of R ampersand D activities in these areas and plans to continue that support in the future. For technology development, the DOE is committed to forming cooperative partnerships and eliciting broad participation from qualified organizations who can contribute to RDDT ampersand E activities. The new technologies resulting from these R ampersand D initiatives will enhance DOE's ability to meet its 30-year cleanup goal, reduce environmental risk, and provide significant cost savings over existing technologies. Even modest investments in these emerging technologies now can be expected to generate a high rate of return. 3 refs., 2 tabs

  9. Some aspects of remediation of contaminated soils

    Science.gov (United States)

    Bech, Jaume; Korobova, Elena; Abreu, Manuela; Bini, Claudio; Chon, Hyo-Taek; Pérez-Sirvent, Carmen; Roca, Núria

    2014-05-01

    Soils are essential components of the environment, a limited precious and fragile resource, the quality of which should be preserved. The concentration, chemical form and distribution of potential harmful elements in soils depends on parent rocks, weathering, soil type and soil use. However, their concentration can be altered by mismanagement of industrial and mining activities, energy generation, traffic increase, overuse of agrochemicals, sewage sludge and waste disposal, causing contamination, environmental problems and health concerns. Heavy metals, some metalloids and radionuclides are persistent in the environment. This persistence hampers the cost/efficiency of remediation technologies. The choice of the most appropriate soil remediation techniques depends of many factors and essentially of the specific site. This contribution aims to offer an overview of the main remediation methods in contaminated soils. There are two main groups of technologies: the first group dealing with containment and confinement, minimizing their toxicity, mobility and bioavailability. Containment measures include covering, sealing, encapsulation and immobilization and stabilization. The second group, remediation with decontamination, is based on the remotion, clean up and/or destruction of contaminants. This group includes mechanical procedures, physical separations, chemical technologies such as soil washing with leaching or precipitation of harmful elements, soil flushing, thermal treatments and electrokinetic technologies. There are also two approaches of biological nature: bioremediation and phytoremediation. Case studies from Chile, Ecuador, Italy, Korea, Peru, Portugal, Russia and Spain, will be discussed in accordance with the time available.

  10. Potential enhancements to addressing programmatic risk in the tank waste remediation system (TWRS) program

    International Nuclear Information System (INIS)

    Brothers, A.; Fassbender, L.; Bilyard, G.; Levine, L.

    1996-04-01

    Pacific Northwest National Laboratory (PNNL) conducted a Tank Waste Remediation System (TWRS) Risk Management methodology development task. The objective of this task was to develop risk management methodology focused on (1) the use of programmatic risk information in making TWRS architecture selection decisions and (2) the identification/evaluation/selection of TWRS risk-handling actions. Methods for incorporating programmatic risk/uncertainty estimates into trade studies are provided for engineers/analysts. Methods for identifying, evaluating, and selecting risk-handling actions are provided for managers. The guidance provided in this report is designed to help decision-makers make difficult judgments. Current approaches to architecture selection decisions and identification/evaluation/selection of risk-handling actions are summarized. Three categories of sources of programmatic risk (parametric, external, and organizational) are examined. Multiple analytical approaches are presented to enhance the current alternative generation and analysis (AGA) and risk-handling procedures. Appendix A describes some commercially available risk management software tools and Appendix B provides a brief introduction to quantification of risk attitudes. The report provides three levels of analysis for enhancing the AGA Procedure: (1) qualitative discussion coupled with estimated uncertainty ranges for scores in the alternatives-by-criteria matrix; (2) formal elicitation of probability distributions for the alternative scores; and (3) a formal, more structured, comprehensive risk analysis. A framework is also presented for using the AGA programmatic risk analysis results in making better decisions. The report also presents two levels of analysis for evaluation and selection of risk-handling actions: (1) qualitative analysis and judgmental rankings of alternative actions, and (2) Simple Multi-Attribute Rating Technique (SMART)

  11. Environmental Remediation Data Management Tools

    International Nuclear Information System (INIS)

    Wierowski, J. V.; Henry, L. G.; Dooley, D. A.

    2002-01-01

    Computer software tools for data management can improve site characterization, planning and execution of remediation projects. This paper discusses the use of two such products that have primarily been used within the nuclear power industry to enhance the capabilities of radiation protection department operations. Advances in digital imaging, web application development and programming technologies have made development of these tools possible. The Interactive Visual Tour System (IVTS) allows the user to easily create and maintain a comprehensive catalog containing digital pictures of the remediation site. Pictures can be cataloged in groups (termed ''tours'') that can be organized either chronologically or spatially. Spatial organization enables the user to ''walk around'' the site and view desired areas or components instantly. Each photo is linked to a map (floor plan, topographical map, elevation drawing, etc.) with graphics displaying the location on the map and any available tour/component links. Chronological organization enables the user to view the physical results of the remediation efforts over time. Local and remote management teams can view these pictures at any time and from any location. The Visual Survey Data System (VSDS) allows users to record survey and sample data directly on photos and/or maps of areas and/or components. As survey information is collected for each area, survey data trends can be reviewed for any repetitively measured location or component. All data is stored in a Quality Assurance (Q/A) records database with reference to its physical sampling point on the site as well as other information to support the final closeout report for the site. The ease of use of these web-based products has allowed nuclear power plant clients to plan outage work from their desktop and realize significant savings with respect to dose and cost. These same tools are invaluable for remediation and decommissioning planning of any scale and for recording

  12. Operational Efficiency And Customer Satisfaction of Restaurants: Basis For Business Operation Enhancement

    Directory of Open Access Journals (Sweden)

    Annie Gay Barlan-Espino

    2017-02-01

    Full Text Available Restaurants’ primary objective is to provide comfort and satisfaction to guest without compromising the operational efficiency of the business. This research aimed to determine the operational efficiency and customer satisfaction of restaurants as a basis for business operation enhancement. Specifically to determine the operational efficiency of the restaurant in terms of kitchen operations and dining operations and the level of customer satisfaction of the restaurant business in terms of: Product, Policies, People, Processes and Proactivity as well as the problems encountered by the restaurant in their operation and customer service. Descriptive research design was used with managers and customers as respondents of the study. It was concluded that majority of the restaurants are operating for more than a year with sufficient number of employees having enough seating capacity that accommodate large volume of customers. Restaurants are efficient on the aspect of kitchen and dining operations and sometimes encountered problems. Customers are satisfied in terms of 5 P’s. It was found out that there is no significant difference in the operational efficiency of restaurant when grouped according to profile variables. An action plan for continuous business operation enhancement on operational efficiency and customer satisfaction was proposed.

  13. Topical Day on Site Remediation

    Energy Technology Data Exchange (ETDEWEB)

    Vandenhove, H [ed.

    1996-09-18

    Ongoing activities at the Belgian Nuclear Research Centre relating to site remediation and restoration are summarized. Special attention has been paid to the different phases of remediation including characterization, impact assessment, evaluation of remediation actions, and execution of remediation actions.

  14. [Cognitive remediation and work outcome in schizophrenia].

    Science.gov (United States)

    Franck, N

    2014-06-01

    Recovery is partly defined by the patients' capacity to work, since doing well in a job favors hope and responsibilities' taking. Diminished job placement or tenure is linked with cognitive disorders, which impact directly and indirectly (through negative symptoms) functional outcomes. Attention, executive functions and working memory disorders can result in an alteration of the ability to manage the tasks required in the workplace. Executive function, working memory and social cognition disorders may also have an impact on behavior in relationships. Cognitive disorders do not automatically directly contribute to vocational outcome, yet their effects may be mediated by other variables such as symptoms, metacognition, social skills and intrinsic motivation. Then, since all these dimensions have to be taken into account, reducing the impact of cognitive troubles becomes a major challenge for the care of schizophrenia. Cognitive remediation is the more effective therapeutic tool to reduce cognitive dysfunctions. It rests in particular on the development of new strategies that allow taking concrete situations into account more efficiently. Cognitive remediation reduces the detrimental consequences of cognitive disorders and permits their compensation. It has emerged as an effective treatment, that improves not only cognitive abilities but also functioning, as it has been shown by numerous randomized controlled studies and several meta-analyses. The present article considers the effects on cognitive remediation on work function in schizophrenia. Several randomized controlled trials that compared supported employment alone versus supported employment associated with cognitive remediation showed significant improvement of employment rates in the latter condition. These results favor the use of cognitive remediation before job placement. The specific needs of the occupation that will be provided and the cognitive profile of the user should be taken into account. Copyright

  15. Design of a plasmonic micromotor for enhanced photo-remediation of polluted anaerobic stagnant waters.

    Science.gov (United States)

    Zhang, Zhijun; Zhao, Andong; Wang, Faming; Ren, Jinsong; Qu, Xiaogang

    2016-04-25

    A motor plasmonic photocatalyst (MPP) is developed to promote photocatalysis in an anaerobic stagnant environment. The MPP is fabricated through the newly developed nano/micromotor fabrication method: template-assisted aqueous phase synthesis. With the help of H2O2 (fuel), the solar photocatalytic efficiency of the MPP can be enhanced more than 110 times.

  16. Application of Fe-Cu/Biochar System for Chlorobenzene Remediation of Groundwater in Inhomogeneous Aquifers

    OpenAIRE

    Xu Zhang; Yanqing Wu; Pingping Zhao; Xin Shu; Qiong Zhou; Zichen Dong

    2017-01-01

    Chlorobenzene (CB), as a typical Volatile Organic Contaminants (VOC), is toxic, highly persistent and easily migrates in water, posing a significant risk to human health and subsurface ecosystems. Therefore, exploring effective approaches to remediate groundwater contaminated by CB is essential. As an enhanced micro-electrolysis system for CB-contaminated groundwater remediation, this study attempted to couple the iron-copper bimetal with biochar. Two series of columns using sands with differ...

  17. Unintentional contaminant transfer from groundwater to the vadose zone during source zone remediation of volatile organic compounds.

    Science.gov (United States)

    Chong, Andrea D; Mayer, K Ulrich

    2017-09-01

    Historical heavy use of chlorinated solvents in conjunction with improper disposal practices and accidental releases has resulted in widespread contamination of soils and groundwater in North America and worldwide. As a result, remediation of chlorinated solvents is required at many sites. For source zone treatment, common remediation strategies include in-situ chemical oxidation (ISCO) using potassium or sodium permanganate, and the enhancement of biodegradation by primary substrate addition. It is well known that these remediation methods tend to generate gas (carbon dioxide (CO 2 ) in the case of ISCO using permanganate, CO 2 and methane (CH 4 ) in the case of bioremediation). Vigorous gas generation in the presence of chlorinated solvents, which are categorized as volatile organic contaminants (VOCs), may cause gas exsolution, ebullition and stripping of the contaminants from the treatment zone. This process may lead to unintentional 'compartment transfer', whereby VOCs are transported away from the contaminated zone into overlying clean sediments and into the vadose zone. To this extent, benchtop column experiments were conducted to quantify the effect of gas generation during remediation of the common chlorinated solvent trichloroethylene (TCE/C 2 Cl 3 H). Both ISCO and enhanced bioremediation were considered as treatment methods. Results show that gas exsolution and ebullition occurs for both remediation technologies. Facilitated by ebullition, TCE was transported from the source zone into overlying clean groundwater and was subsequently released into the column headspace. For the case of enhanced bioremediation, the intermediate degradation product vinyl chloride (VC) was also stripped from the treatment zone. The concentrations measured in the headspace of the columns (TCE ∼300ppm in the ISCO column, TCE ∼500ppm and VC ∼1380ppm in the bioremediation column) indicate that substantial transfer of VOCs to the vadose zone is possible. These findings

  18. Remediation of the low-level radioactive waste tailing pond at Kowary, Poland

    International Nuclear Information System (INIS)

    Goerner, R.; Hartsch, J.; Koszela, J.; Krzyskow, A.; Machniewicz, B.; Sennewald, R.; Sowa, J.

    2002-03-01

    The last remaining uranium mining tailing pond in Poland, situated at Kowary, was the subject of the Kowary Tailing Pond Remediation Programme financed by Polish public bodies (70%) and by the European Commission (30%) within the framework of its programme of co-operation on radioactive waste issues with candidate countries. The EC-part of the project comprised investigations of the site, project management duties and large-scale civil works following the initial remediation planning performed by the Wroclaw University of Technology (WUT) in 1998-2000. The EC-part was contracted to G.E.O.S. Freiberg Ingenieurgesellschaft mbH following an Open Call for Tender launched by the European Commission in 1999. The following general tasks were performed in close co-operation with WUT, with the construction works subcontracted to local companies, as proposed in the Terms of Reference (TOR) of the EC-part: review of General Remediation Plan (GRP), technical design of the pond cover, construction work: internal drainage system, pond cover and site reclamation. From the information in the TOR, the following aims of remediation were defined: minimise the detrimental impact of the tailing pond on the environment, provide long-term stability of the slopes surrounding the pond, ensure the remediated site is in harmony with the surrounding natural scenery. Based on the experience gathered in similar projects, which had been running under PHARE-MCE or which belonged to the WISMUT-remediation programme in Germany, cost efficient remediation solutions were designed in close co-operation with all involved parties. They were delineated in the detailed planning documents approved in the overall remediation programme managed by WUT. The planned remediation works were prepared and performed successfully according to Polish law and in agreement with the competent local authorities. The aims of remediation were met. However, some additional tasks have been recommended in zones adjacent to the

  19. Field-scale multi-phase LNAPL remediation: Validating a new computational framework against sequential field pilot trials.

    Science.gov (United States)

    Sookhak Lari, Kaveh; Johnston, Colin D; Rayner, John L; Davis, Greg B

    2018-03-05

    Remediation of subsurface systems, including groundwater, soil and soil gas, contaminated with light non-aqueous phase liquids (LNAPLs) is challenging. Field-scale pilot trials of multi-phase remediation were undertaken at a site to determine the effectiveness of recovery options. Sequential LNAPL skimming and vacuum-enhanced skimming, with and without water table drawdown were trialled over 78days; in total extracting over 5m 3 of LNAPL. For the first time, a multi-component simulation framework (including the multi-phase multi-component code TMVOC-MP and processing codes) was developed and applied to simulate the broad range of multi-phase remediation and recovery methods used in the field trials. This framework was validated against the sequential pilot trials by comparing predicted and measured LNAPL mass removal rates and compositional changes. The framework was tested on both a Cray supercomputer and a cluster. Simulations mimicked trends in LNAPL recovery rates (from 0.14 to 3mL/s) across all remediation techniques each operating over periods of 4-14days over the 78day trial. The code also approximated order of magnitude compositional changes of hazardous chemical concentrations in extracted gas during vacuum-enhanced recovery. The verified framework enables longer term prediction of the effectiveness of remediation approaches allowing better determination of remediation endpoints and long-term risks. Copyright © 2017 Commonwealth Scientific and Industrial Research Organisation. Published by Elsevier B.V. All rights reserved.

  20. Energy Efficient Clustering Protocol to Enhance Performance of Heterogeneous Wireless Sensor Network: EECPEP-HWSN

    Directory of Open Access Journals (Sweden)

    Santosh V. Purkar

    2018-01-01

    Full Text Available Heterogeneous wireless sensor network (HWSN fulfills the requirements of researchers in the design of real life application to resolve the issues of unattended problem. But, the main constraint faced by researchers is the energy source available with sensor nodes. To prolong the life of sensor nodes and thus HWSN, it is necessary to design energy efficient operational schemes. One of the most suitable approaches to enhance energy efficiency is the clustering scheme, which enhances the performance parameters of WSN. A novel solution proposed in this article is to design an energy efficient clustering protocol for HWSN, to enhance performance parameters by EECPEP-HWSN. The proposed protocol is designed with three level nodes namely normal, advanced, and super, respectively. In the clustering process, for selection of cluster head we consider different parameters available with sensor nodes at run time that is, initial energy, hop count, and residual energy. This protocol enhances the energy efficiency of HWSN and hence improves energy remaining in the network, stability, lifetime, and hence throughput. It has been found that the proposed protocol outperforms than existing well-known LEACH, DEEC, and SEP with about 188, 150, and 141 percent respectively.

  1. Chemical Oxygen Demand abatement in sewage using Micro-Aeration Enhanced Ecological Floating Bed

    Science.gov (United States)

    Shi, Hongle; Zhou, Gaofeng; Liu, Yiqing; Tan, Jiancong; Fu, Yongsheng

    2018-02-01

    The traditional ecological floating bed combined with micro-aeration system and artificial medium was developed for the removal of contaminants and remediation of surface water. This micro-aeration enhanced ecological floating bed (MAEEFB) consisted of aeration unit, microbial processing unit and aquatic plant unit. Batch experiments were conducted in different operating conditions on the removal of chemical oxygen demand (COD) in the sewage using MAEEFB. The removal rate of COD by MAEEFB, enhanced ecological floating bed (EEFB) and traditional ecological floating bed (TEFB) in the same reaction conditions was 59.2%, 56.9% and 30.6%, respectively, indicating that the combination of micro-aeration system and artificial medium could enhance the removal efficiency of COD in TEFB. In MAEEFB, the aeration intensity should be designed reasonablely considering both treatment efficiency and operation cost. Only increasing the specific surface area of the packing cannot effectively improve the purification efficiency of water. Factors like packing material, ability of intercepting organics and complicated extent of microorganisms attaching on the packing should also be considered.

  2. Enhanced phytoremediation in the vadose zone: Modeling and column studies

    Science.gov (United States)

    Sung, K.; Chang, Y.; Corapcioglu, M.; Cho, C.

    2002-05-01

    Phytoremediation is a plant-based technique with potential for enhancing the remediation of vadoese zone soils contaminated by pollutants. The use of deep-rooted plants is an alternative to conventional methodologies. However, when the phytoremediation is applied to the vadose zone, it might have some restrictions since it uses solely naturally driven energy and mechanisms in addition to the complesxity of the vadose zone. As a more innovative technique than conventional phytoremediation methods, air injected phytoremediation technique is introduced to enhance the remediation efficiency or to apply at the former soil vapor extraction or bio venting sites. Effects of air injection, vegetation treatment, and air injection with vegetation treatments on the removal of hydrocarbon were investigated by column studies to simulate the field situation. Both the removal efficiency and the microbial activity were highest in air-injected and vegetated column soils. It was suggested that increased microorganisms activity stimulated by plant root exudates enhanced biodegradation of hydrocarbon compounds. Air injection provided sufficient opportunity for promoting the microbial activity at depths where the conditions are anaerobic. Air injection can enhance the physicochemical properties of the medium and contaminant and increase the bioavailability i.e., the plant and microbial accessibility to the contaminant. A mathematical model that can be applied to phytoremediation, especially to air injected phytoremediation, for simulating the fate and the transport of a diesel contaminant in the vadose zone is developed. The approach includes a two-phase model of water flow in vegetated and unplanted vadose zone soil. A time-specific root distribution model and a microbial growth model in the rhizosphere of vegetated soil were combined with an unsaturated soil water flow equation as well as with a contaminant transport equation. The proposed model showed a satisfactory representation of

  3. Strategy paper. Remedial design/remedial action 100 Area. Revision 2

    International Nuclear Information System (INIS)

    Donahoe, R.L.

    1995-10-01

    This strategy paper identifies and defines the approach for remedial design and remedial action (RD/RA) for source waste sites in the 100 Area of the Hanford Site, located in southeastern Washington State. This paper provides the basis for the US Department of Energy (DOE) to assess and approve the Environmental Restoration Contractor's (ERC) approach to RD/RA. Additionally, DOE is requesting review/agreement from the US Environmental Protection Agency (EPA) and Washington State Department of Ecology (Ecology) on the strategy presented in this document in order to expedite remedial activities

  4. FY-95 technology catalog. Technology development for buried waste remediation

    International Nuclear Information System (INIS)

    1995-01-01

    The US Department of Energy's (DOE) Buried Waste Integrated Demonstration (BWID) program, which is now part of the Landfill Stabilization Focus Area (LSFA), supports applied research, development, demonstration, and evaluation of a multitude of advanced technologies dealing with underground radioactive and hazardous waste remediation. These innovative technologies are being developed as part of integrated comprehensive remediation systems for the effective and efficient remediation of buried waste sites throughout the DOE complex. These efforts are identified and coordinated in support of Environmental Restoration (EM-40) and Waste Management (EM-30) needs and objectives. Sponsored by the DOE Office of Technology Development (EM-50), BWID and LSFA work with universities and private industry to develop technologies that are being transferred to the private sector for use nationally and internationally. This report contains the details of the purpose, logic, and methodology used to develop and demonstrate DOE buried waste remediation technologies. It also provides a catalog of technologies and capabilities with development status for potential users. Past FY-92 through FY-94 technology testing, field trials, and demonstrations are summarized. Continuing and new FY-95 technology demonstrations also are described

  5. FY-95 technology catalog. Technology development for buried waste remediation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    The US Department of Energy`s (DOE) Buried Waste Integrated Demonstration (BWID) program, which is now part of the Landfill Stabilization Focus Area (LSFA), supports applied research, development, demonstration, and evaluation of a multitude of advanced technologies dealing with underground radioactive and hazardous waste remediation. These innovative technologies are being developed as part of integrated comprehensive remediation systems for the effective and efficient remediation of buried waste sites throughout the DOE complex. These efforts are identified and coordinated in support of Environmental Restoration (EM-40) and Waste Management (EM-30) needs and objectives. Sponsored by the DOE Office of Technology Development (EM-50), BWID and LSFA work with universities and private industry to develop technologies that are being transferred to the private sector for use nationally and internationally. This report contains the details of the purpose, logic, and methodology used to develop and demonstrate DOE buried waste remediation technologies. It also provides a catalog of technologies and capabilities with development status for potential users. Past FY-92 through FY-94 technology testing, field trials, and demonstrations are summarized. Continuing and new FY-95 technology demonstrations also are described.

  6. Flexible organic solar cells including efficiency enhancing grating structures

    International Nuclear Information System (INIS)

    De Oliveira Hansen, Roana Melina; Liu Yinghui; Madsen, Morten; Rubahn, Horst-Günter

    2013-01-01

    In this work, a new method for the fabrication of organic solar cells containing functional light-trapping nanostructures on flexible substrates is presented. Polyimide is spin-coated on silicon support substrates, enabling standard micro- and nanotechnology fabrication techniques, such as photolithography and electron-beam lithography, besides the steps required for the bulk-heterojunction organic solar cell fabrication. After the production steps, the solar cells on polyimide are peeled off the silicon support substrates, resulting in flexible devices containing nanostructures for light absorption enhancement. Since the solar cells avoid using brittle electrodes, the performance of the flexible devices is not affected by the peeling process. We have investigated three different nanostructured grating designs and conclude that gratings with a 500 nm pitch distance have the highest light-trapping efficiency for the selected active layer material (P3HT:PCBM), resulting in an enhancement of about 34% on the solar cell efficiency. The presented method can be applied to a large variety of flexible nanostructured devices in future applications. (paper)

  7. Efficiency of remediation of technogenic barrens around the Pechenganikel works in the Kola Subarctic

    Science.gov (United States)

    Koptsik, G. N.; Koptsik, S. V.; Smirnova, I. E.

    2014-05-01

    Remediation of the technogenic barrens around the Pechenganikel works on the Kola Peninsula resulted in the improvement of the soil properties, namely, in a decrease in acidity and enrichment with nutrients, which continued for several years. However, the reaction of most of the treated soils remained strongly acid, and the concentrations of available calcium, magnesium, potassium, and phosphorus were much lower than their background levels and the demands of the plants for nutrients (especially, for magnesium and potassium). The soils were depleted in available manganese and zinc. Most of the treated soils contained the same (or higher) amounts of available nickel and copper compounds in comparison with their untreated analogues. The willow plantations on the remediated plots were in a satisfactory state, but they experienced a deficit of magnesium, manganese, and zinc; they consumed elevated amounts of nickel and copper. Recommendations on the nutrient regime of the soils aimed at decreasing the mobility and biological availability of heavy metals were made.

  8. Surfactant-enhanced aquifer remediation at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Jackson, R.E.; Londergan, J.T.; Pickens, J.

    1995-01-01

    Many DOE facilities are situated in areas of sand and gravel which have become polluted with dense, non-aqueous phase liquids or DNAPLs, such as chlorinated solvents, from the various industrial operations at these facilities. The presence of such DNAPLs in sand and gravel aquifers is now recognized as the principal factor in the failure of standard ground-water remediation methods, i.e., open-quotes pump-and-treatclose quotes operations, to decontaminate such systems. The principal objective of this study is to demonstrate that multi-component DNAPLs can be readily solubilized in sand and gravel aquifers by dilute surfactant solutions

  9. Mycogenic Mn(II) oxidation promotes remediation of acid mine drainage and other anthropogenically impacted environments

    Science.gov (United States)

    Santelli, C. M.; Chaput, D.; Hansel, C. M.; Burgos, W. D.

    2014-12-01

    Manganese is a pollutant in worldwide environments contaminated with metals and organics, such as acid mine drainage (AMD), freshwater ponds, and agricultural waste storage sites. Microorganisms contribute to the removal of dissolved Mn compounds in the environment by promoting Mn(II) oxidation reactions. The oxidation of Mn(II) results in the precipitation of sparingly soluble Mn(IV) oxide minerals, effectively removing the metal from the aqueous milieu (e.g., groundwater or wastewater streams). In recent years, our research has identified a diversity of Mn(II)-oxidizing fungi inhabiting these polluted environments, however their overall contribution to the remediation process in situ remains poorly understood. Here we present results of culture-based and Next Generation Sequencing (NGS) studies in AMD treatment systems actively remediating Mn and other metals where we profile the bacterial, fungal, algal and archaeal communities to determine the overall community diversity and to establish the relative abundance of known Mn(II) oxidizers. A variety of treatment systems with varying Mn-removal efficiencies were sampled to understand the relationship between remediation efficiency and microbial community composition and activity. Targeted-amplicon sequencing of DNA and RNA of the 16S rRNA genes (bacteria and archaea), 23S rRNA genes (algae) and ITS region (fungi) was performed using both 454 pyrosequencing and Illumina platforms. Results showed that only the fungal taxonomic profiles significantly differed between sites that removed the majority of influent Mn and those that did not. Specifically, Ascomycota (which include known Mn(II) oxidizers isolated from these treatment systems) dominated greater efficiency systems whereas less efficient systems were dominated by Basidiomycota. Furthermore, known Mn(II) oxidizers accounted for only a minor proportion of bacterial sequences but a far greater proportion of fungal sequences. These culture-independent studies lend

  10. Enhanced efficiency of a fluorescing nanoparticle with a silver shell

    Energy Technology Data Exchange (ETDEWEB)

    Choy, Wallace C H; Chen Xuewen [Department of Electrical and Electronic Engineering, University of Hong Kong, Pokfulam Road (Hong Kong); He Sailing [Centre for Optical and Electromagnetic Research, Zhejiang University, Zhijingang campus, Hangzhou 310058 (China)], E-mail: chchoy@eee.hku.hk

    2009-09-01

    Spontaneous emission (SE) rate and the fluorescence efficiency of a bare fluorescing nanoparticle (NP) and the NP with a silver nanoshell are analyzed rigorously by using a classical electromagnetic approach with the consideration of the nonlocal effect of the silver nano-shell. The dependences of the SE rate and the fluorescence efficiency on the core-shell structure are carefully studied and the physical interpretations of the results are addressed. The results show that the SE rate of a bare NP is much slower than that in the infinite medium by almost an order of magnitude and consequently the fluorescence efficiency is usually low. However, by encapsulating the NP with a silver shell, highly efficient fluorescence can be achieved as a result of a large Purcell enhancement and high out-coupling efficiency (OQE) for a well-designed core-shell structure. We also show that a higher SE rate may not offer a larger fluorescence efficiency since the fluorescence efficiency not only depends on the internal quantum yield but also the OQE.

  11. Remedial Design/Remedial Action Work Plan for Operable Units 6-05 and 10-04, Phase III

    Energy Technology Data Exchange (ETDEWEB)

    R. P. Wells

    2006-09-19

    The remedial design/remedial action for Operable Unit 6-05 (Waste Area Group 6) and Operable Unit 10-04 (Waste Area Group 10) - collectively called Operable Unit 10-04 has been divided into four phases. Phase I consists of developing and implementing institutional controls at Operable Unit 10-04 sites and developing and implementing Idaho National Laboratory-wide plans for both institutional controls and ecological monitoring. Phase II will remediate sites contaminated with trinitrotoluene and Royal Demolition Explosive. Phase III will remediate lead contamination at a gun range, and Phase IV will remediate hazards from unexploded ordnance. This Phase III remedial Design/Remedial Action Work Plan addresses the remediation of lead-contaminated soils found at the Security Training Facility (STF)-02 Gun Range located at the Idaho National Laboratory. Remediation of the STF-02 Gun Range will include excavating contaminated soils; physically separating copper and lead for recycling; returning separated soils below the remediation goal to the site; stabilizing contaminated soils, as required, and disposing of the separated soils that exceed the remediation goal; encapsulating and disposing of creosote-contaminated railroad ties and power poles; removing and disposing of the wooden building and asphalt pads found at the STF-02 Gun Range; sampling and analyzing soil to determine the excavation requirements; and when the remediation goals have been met, backfilling and contouring excavated areas and revegetating the affected area.

  12. Documenting cost and performance for environmental remediation projects: Department of Energy Office of Environmental Management

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-08

    The purpose of this DOE guide is to facilitate the use of consistent procedures to document cost and performance information for projects involving the remediation of media contaminated with hazardous and radioactive wastes. It provides remedial action project managers with a standardized set of data to document completed remediation projects. Standardized reporting of data will broaden the utility of the information, increase confidence in the effectiveness of future remedial technologies, and enhance the organization, storage and retrieval of relevant information for future cleanup projects. The foundation for this guide was laid down by the Federal Remediation Technologies Roundtable (FRTR) in their publication, Guide to Documenting Cost and Performance for Remediation Projects, EPA-542-B- 95-002. Member agencies of the FRTR include the US EPA, the US DOD, the US DOE, and the US DOI. All the member agencies are involved in site remediation projects and anticipate following the guidance provided in the above reference. Therefore, there is much to be gained for DOE to be consistent with the other member agencies as it will be easier to compare projects across different agencies and also to learn from the experiences of a wider spectrum of prior completed projects.

  13. Harmful algal bloom removal and eutrophic water remediation by commercial nontoxic polyamine-co-polymeric ferric sulfate-modified soils.

    Science.gov (United States)

    Dai, Guofei; Zhong, Jiayou; Song, Lirong; Guo, Chunjing; Gan, Nanqin; Wu, Zhenbin

    2015-07-01

    Harmful algal bloom has posed great threat to drinking water safety worldwide. In this study, soils were combined with commercial nontoxic polyamine poly(epichlorohydrin-dimethylamine) (PN) and polymeric ferric sulfate (PFS) to obtain PN-PFS soils for Microcystis removal and eutrophic water remediation under static laboratory conditions. High pH and temperature in water could enhance the function of PN-PFS soil. Algal removal efficiency increased as soil particle size decreased or modified soil dose increased. Other pollutants or chemicals (such as C, P, and organic matter) in eutrophic water could participate and promote algal removal by PN-PFS soil; these pollutants were also flocculated. During PN-PFS soil application in blooming field samples, the removal efficiency of blooming Microcystis cells exceeded 99 %, the cyanotoxin microcystins reduced by 57 %. Water parameters (as TP, TN, SS, and SPC) decreased by about 90 %. CODMn, PO4-P, and NH4-N also sharply decreased by >45 %. DO and ORP in water improved. Netting and bridging effects through electrostatic attraction and complexation reaction could be the two key mechanisms of Microcystis flocculation and pollutant purification. Considering the low cost of PN-PFS soil and its nontoxic effect on the environment, we proposed that this soil combination could be applied to remove cyanobacterial bloom and remediate eutrophic water in fields.

  14. Public information experience in the uranium mill tailings remedial action (UMTRA) project

    International Nuclear Information System (INIS)

    Meyer, H.R.; Skinner, D.J.

    1986-01-01

    To enhance public perception of the UMTRA Project remedial actions at some 23 sites in the US, an information program has been designed to demonstrate the small risk associated with the work in each community. An unusual aspect of this information program has involved a specific effort to educate listeners concerning the Health Physics terminology being used. The information program has been successful in reducing the level of public anxiety associated with UMTRA remedial action at the first Project site, and is currently being applied at several new sites

  15. A novel MPPT method for enhancing energy conversion efficiency taking power smoothing into account

    International Nuclear Information System (INIS)

    Liu, Jizhen; Meng, Hongmin; Hu, Yang; Lin, Zhongwei; Wang, Wei

    2015-01-01

    Highlights: • We discuss the disadvantages of conventional OTC MPPT method. • We study the relationship between enhancing efficiency and power smoothing. • The conversion efficiency is enhanced and the volatility of power is suppressed. • Small signal analysis is used to verify the effectiveness of proposed method. - Abstract: With the increasing capacity of wind energy conversion system (WECS), the rotational inertia of wind turbine is becoming larger. And the efficiency of energy conversion is significantly reduced by the large inertia. This paper proposes a novel maximum power point tracking (MPPT) method to enhance the efficiency of energy conversion for large-scale wind turbine. Since improving the efficiency may increase the fluctuations of output power, power smoothing is considered as the second control objective. A T-S fuzzy inference system (FIS) is adapted to reduce the fluctuations according to the volatility of wind speed and accelerated rotor speed by regulating the compensation gain. To verify the effectiveness, stability and good dynamic performance of the new method, mechanism analyses, small signal analyses, and simulation studies are carried out based on doubly-fed induction generator (DFIG) wind turbine, respectively. Study results show that both the response speed and the efficiency of proposed method are increased. In addition, the extra fluctuations of output power caused by the high efficiency are reduced effectively by the proposed method with FIS

  16. Remediation challenges posed by the fate and transport properties of MTBE

    International Nuclear Information System (INIS)

    Day, M.J.

    2002-01-01

    Releases of fuel from underground tank systems have been a major source of groundwater contamination for several decades. The fate and transport characteristics of fuel components significantly influence the potential risk to groundwater supplies and the methodologies to manage and remediate contamination at fuel release sites. The recognition that MTBE can be more mobile in groundwater systems than other components of oxygenated fuels has put an increased emphasis on early detection and response to fuel leaks and spills. Remediation of oxygenated fuel releases usually follows a sequence of tasks: receptor protection, source control, residual and dissolved phase remediation, and monitored natural attenuation. Good characterization of hydrogeological and geochemical conditions is required because understanding the fate and transport of fuel components is critical to developing an appropriate management plan and an efficient remediation program. Understanding the specific site conditions allows appropriate selection and sequencing of remedial technologies. The physical and chemical characteristics of MTBE can result in a higher mobility in the subsurface, compared with the BTEX components of a gasoline release. These same characteristics make MTBE more readily extractable from the subsurface compared with BTEX. There is an impression that remediating gasoline releases containing MTBE requires costly, specialized technologies compared with those employed to deal with non-oxygenated fuel releases. However, the characteristics of MTBE are well suited to traditional, physical remedial approaches that have proven to be effective with the other components of gasoline. Technologies such as groundwater extraction, soil vapor extraction (SVE), and thermal desorption work exceptionally well with MTBE due to its low adsorptive and high vapor pressure characteristics. Similarly, recent studies have demonstrated that MTBE is biodegradable under a wide variety of conditions

  17. Arsenic Remediation by Synthetic and Natural Adsorbents

    Directory of Open Access Journals (Sweden)

    Muhammad Saqaf Jagirani

    2017-06-01

    Full Text Available The contagion of toxic metals in water is a serious environmental and health concern and threatening problem worldwide. Particularly arsenic contamination in ground water has became great dilemma in the earlier decades. With advent in research for arsenic remediation, standard of drinking water is improving and now reduced to few parts per million (ppm level of arsenic in drinking water sources. However, due to continuous enhancement in environmental pollution, remediation techniques are still needed to achieve the drinking water quality standard. Development of novel and economically feasible removal techniques or materials for selective separation of this toxic specie has been the main focus of research. Several arsenic removal techniques, including membrane separation, coagulation, precipitation, anion exchange have been developed. The aim of this article is to review briefly arsenic chemistry and previous and current available technologies that have been reported various low-cost adsorbents for arsenic removal.

  18. ELECTROKINETIC REMEDIATION STUDY FOR CADMIUM CONTAMINATED SOIL

    OpenAIRE

    P. Bala Ramudu; R. P. Tiwari; R. K. Srivastava

    2007-01-01

    This paper presents the results of an experimental research undertaken to evaluate different purging solutions to enhance the removal of cadmium from spiked contaminated field soil by electrokinetic remediation. Three experiments were conducted when soil was saturated with deionised water and subsequently deionised water, ammonium citrate and sodium citrate were used as purging solutions at anode end. One experiment was conducted when the soil was saturated with ammonium citrate and itself wa...

  19. Monitoring and remediation technologies of organochlorine pesticides in drainage water

    Directory of Open Access Journals (Sweden)

    Ismail Ahmed

    2015-03-01

    Full Text Available This study was carried out to monitor the presence of organochlorine in drainage water in Kafr-El-Sheikh Governorate, Egypt. Furthermore, to evaluate the efficiencies of different remediation techniques (advanced oxidation processes [AOPs] and bioremediation for removing the most frequently detected compound (lindane in drainage water. The results showed the presence of several organochlorine pesticides in all sampling sites. Lindane was detected with high frequency relative to other detected organochlorine in drainage water. Nano photo-Fenton like reagent was the most effective treatment for lindane removal in drainage water. Bioremediation of lindane by effective microorganisms (EMs removed 100% of the lindane initial concentration. There is no remaining toxicity in lindane contaminated-water after remediation on treated rats relative to control with respect to histopathological changes in liver and kidney. Advanced oxidation processes especially with nanomaterials and bioremediation using effective microorganisms can be regarded as safe and effective remediation technologies of lindane in water.

  20. DNA supercoiling enhances cooperativity and efficiency of an epigenetic switch

    DEFF Research Database (Denmark)

    Norregaard, Kamilla; Andersson, Magnus; Sneppen, Kim

    2013-01-01

    Bacteriophage λ stably maintains its dormant prophage state but efficiently enters lytic development in response to DNA damage. The mediator of these processes is the λ repressor protein, CI, and its interactions with λ operator DNA. This λ switch is a model on the basis of which epigenetic switch...... with relaxed DNA, the presence of supercoils greatly enhances juxtaposition probability. Also, the efficiency and cooperativity of the λ switch is significantly increased in the supercoiled system compared with a linear assay, increasing the Hill coefficient....

  1. Remediation of flare pit soils using supercritical fluid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, V.; Guigard, S.E. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil Engineering

    2005-09-01

    A laboratory study was conducted to examine the ability of supercritical fluid extraction (SFE) to remove petroleum hydrocarbons (PHCs) from two flare pit soils in Alberta. SFE is a technology for remediation of contaminated soils. In order to determine the optimal extraction conditions and to understand the effects of pressure, temperature, supercritical carbon dioxide flow rate, soil type, and extraction time on the extraction efficiency of SFE, extractions were performed on two flare pit soils at various pressures and temperatures. Chemicals in the study included diesel oil, SAE 10-30W motor oil, n-decane, hexadecane, tetratriacontane and pentacontane. The best extraction conditions were defined as conditions that result in a treated soil with a PHC concentration that meets the regulatory guidelines of the Canadian Council of Ministers of the Environment in the Canada-wide standard for PHC is soil. The study results indicate that the efficiency of the SFE process is solvent-density dependent for the conditions studied. The highest extraction efficiency for both soils was obtained at conditions of 24.1 MPa and 40 degrees C. An increase in pressure at a fixed temperature led to an increase in the extraction efficiency while an increase in temperature at a fixed pressure led to a decrease in the extraction efficiency. The treated soils were observed to be lighter in colour, drier, and grainier than the soil prior to extraction. It was concluded that SFE is an effective method for remediating flare pit soils. 63 refs., 4 tabs., 5 figs.

  2. Electrokinetic-Fenton remediation of organochlorine pesticides from historically polluted soil.

    Science.gov (United States)

    Ni, Maofei; Tian, Shulei; Huang, Qifei; Yang, Yanmei

    2018-04-01

    Soil contamination by persistent organic pollutants (POPs) poses a great threat to historically polluted soil worldwide. In this study, soils were characterized, and organochlorine pesticides contained in the soils were identified and quantified. Individual electrokinetic (IE), EK-Fenton-coupled technologies (EF), and enhanced EK-Fenton treatment (E-1, E-2, and E-3) were applied to remediate soils contaminated with hexachloro-cyclohexane soprocide (HCH) and dichloro-diphenyl-trichloroethane (DDT). Variation of pH, electrical conductivity, and electroosmotic flow was evaluated during the EK-Fenton process. The IE treatment showed low removal efficiency for HCHs (30.5%) and DDTs (25.9%). In the EF treatment, the highest removal level (60.9%) was obtained for α-HCH, whereas P,P-DDT was the lowest (40.0%). Low solubility of pollutants impeded the HCH and DDT removal. After enhanced EK-Fenton treatment, final removal of pollutants decreased as follows: β-HCH (82.6%) > γ-HCH (81.6%) > α-HCH (81.2%) > δ-HCH (80.0%) > P,P-DDD (73.8%) > P,P-DDE (73.1%) > P,P-DDT (72.6%) > O,P-DDT (71.5%). The results demonstrate that EK-Fenton is a promising technology for POP removal in historically polluted soil.

  3. Characterization of radioactively contaminated sites for remediation purposes

    International Nuclear Information System (INIS)

    1998-05-01

    Characterization of the contaminated site is essential before embarking on a programme for its remediation and ultimate restoration. Reliable and suitable data must be obtained regarding the distribution and physical, chemical and nuclear properties of all radioactive contaminants. Characterization data is necessary for assessing the associated radiation risks and is used in support of the required engineering design and project planning for the environmental restoration. In addition, continuing characterization can provide information regarding efficiency of the cleanup methods and influence possible redirection of work efforts. Similarly, at the end of the remediation phase, characterization and ongoing monitoring can be used to demonstrate completion and success of the cleanup process. The suggested methodology represents a contribution attempting to solve the issue of preremediation characterization in a general manner. However, a number of difficulties might make this methodology unsuitable for general application across the diverse social, environmental and political systems in the IAEA Member States. This TECDOC covers the methodologies used to characterize radioactively contaminated sites for the purpose of remediating the potential sources of radiation exposure and assessing the hazards to human health and the environment

  4. Efficient adsorption and antibacterial properties of electrospun CuO-ZnO composite nanofibers for water remediation

    Energy Technology Data Exchange (ETDEWEB)

    Malwal, Deepika [Nanobiotechnology Laboratory, Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667 (India); Gopinath, P., E-mail: pgopifnt@iitr.ernet.in [Nanobiotechnology Laboratory, Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667 (India); Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667 (India)

    2017-01-05

    Highlights: • Synthesis of CuO-ZnO composite nanofibers using simple electrospinning technique. • Characterization data confirmed the proper structure. • Exploited as effective adsorbent for congo red dye. • Several adsorption kinetic and isotherm models were discussed. • Evaluation of antibacterial activity against GFP-E.coli and S. aureus. - Abstract: On the face of impending global water resources, developing low-cost and efficient water treatment technologies and materials thereof is highly important. Herein, we explore the adsorption capacity and antibacterial properties of CuO-ZnO (CZ) composite nanofibers. The ultrafine nanofibers were fabricated using simple and inexpensive electrospinning technique and were further characterized using Field Emission-Scanning Electron Microscope (FE-SEM), Transmission electron microscope (TEM) and X-Ray Diffraction (XRD), Thermogravimetric analysis (TGA), Fourier transform Infrared Spectroscopy (FTIR). When employed as nanoadsorbents, CZ nanofibers exhibited excellent adsorption capacity for congo red dye. Adsorption Isotherms and kinetics were performed to determine the maximum adsorption capacity and the rate of adsorption, respectively, depicting the better efficiency of composite nanofibers as compared to their single counterparts. The mechanism of adsorption is also proposed with the evaluation of diffusion studies. The second part of this study deals with the examination of antibacterial activity of CZ composite nanofibers against antibiotic resistant GFP-E.coli and S. aureus. The antibacterial efficacy was monitored by visual turbidity assay, SEM analysis and reactive oxygen species (ROS) determination. Hence, such nanofibers have been explored as a single platform for the removal of biological as well organic contaminants so as to make them potential in the field of water remediation.

  5. Efficient adsorption and antibacterial properties of electrospun CuO-ZnO composite nanofibers for water remediation

    International Nuclear Information System (INIS)

    Malwal, Deepika; Gopinath, P.

    2017-01-01

    Highlights: • Synthesis of CuO-ZnO composite nanofibers using simple electrospinning technique. • Characterization data confirmed the proper structure. • Exploited as effective adsorbent for congo red dye. • Several adsorption kinetic and isotherm models were discussed. • Evaluation of antibacterial activity against GFP-E.coli and S. aureus. - Abstract: On the face of impending global water resources, developing low-cost and efficient water treatment technologies and materials thereof is highly important. Herein, we explore the adsorption capacity and antibacterial properties of CuO-ZnO (CZ) composite nanofibers. The ultrafine nanofibers were fabricated using simple and inexpensive electrospinning technique and were further characterized using Field Emission-Scanning Electron Microscope (FE-SEM), Transmission electron microscope (TEM) and X-Ray Diffraction (XRD), Thermogravimetric analysis (TGA), Fourier transform Infrared Spectroscopy (FTIR). When employed as nanoadsorbents, CZ nanofibers exhibited excellent adsorption capacity for congo red dye. Adsorption Isotherms and kinetics were performed to determine the maximum adsorption capacity and the rate of adsorption, respectively, depicting the better efficiency of composite nanofibers as compared to their single counterparts. The mechanism of adsorption is also proposed with the evaluation of diffusion studies. The second part of this study deals with the examination of antibacterial activity of CZ composite nanofibers against antibiotic resistant GFP-E.coli and S. aureus. The antibacterial efficacy was monitored by visual turbidity assay, SEM analysis and reactive oxygen species (ROS) determination. Hence, such nanofibers have been explored as a single platform for the removal of biological as well organic contaminants so as to make them potential in the field of water remediation.

  6. Untranslated regions of diverse plant viral RNAs vary greatly in translation enhancement efficiency

    Directory of Open Access Journals (Sweden)

    Fan Qiuling

    2012-05-01

    Full Text Available Abstract Background Whole plants or plant cell cultures can serve as low cost bioreactors to produce massive amounts of a specific protein for pharmacological or industrial use. To maximize protein expression, translation of mRNA must be optimized. Many plant viral RNAs harbor extremely efficient translation enhancers. However, few of these different translation elements have been compared side-by-side. Thus, it is unclear which are the most efficient translation enhancers. Here, we compare the effects of untranslated regions (UTRs containing translation elements from six plant viruses on translation in wheat germ extract and in monocotyledenous and dicotyledenous plant cells. Results The highest expressing uncapped mRNAs contained viral UTRs harboring Barley yellow dwarf virus (BYDV-like cap-independent translation elements (BTEs. The BYDV BTE conferred the most efficient translation of a luciferase reporter in wheat germ extract and oat protoplasts, while uncapped mRNA containing the BTE from Tobacco necrosis virus-D translated most efficiently in tobacco cells. Capped mRNA containing the Tobacco mosaic virus omega sequence was the most efficient mRNA in tobacco cells. UTRs from Satellite tobacco necrosis virus, Tomato bushy stunt virus, and Crucifer-infecting tobamovirus (crTMV did not stimulate translation efficiently. mRNA with the crTMV 5′ UTR was unstable in tobacco protoplasts. Conclusions BTEs confer the highest levels of translation of uncapped mRNAs in vitro and in vivo, while the capped omega sequence is most efficient in tobacco cells. These results provide a basis for understanding mechanisms of translation enhancement, and for maximizing protein synthesis in cell-free systems, transgenic plants, or in viral expression vectors.

  7. Functional remediation components: A conceptual method of evaluating the effects of remediation on risks to ecological receptors.

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Bunn, Amoret; Downs, Janelle; Jeitner, Christian; Pittfield, Taryn; Salisbury, Jennifer

    2016-01-01

    Governmental agencies, regulators, health professionals, tribal leaders, and the public are faced with understanding and evaluating the effects of cleanup activities on species, populations, and ecosystems. While engineers and managers understand the processes involved in different remediation types such as capping, pump and treat, and natural attenuation, there is often a disconnect between (1) how ecologists view the influence of different types of remediation, (2) how the public perceives them, and (3) how engineers understand them. The overall goal of the present investigation was to define the components of remediation types (= functional remediation). Objectives were to (1) define and describe functional components of remediation, regardless of the remediation type, (2) provide examples of each functional remediation component, and (3) explore potential effects of functional remediation components in the post-cleanup phase that may involve continued monitoring and assessment. Functional remediation components include types, numbers, and intensity of people, trucks, heavy equipment, pipes, and drill holes, among others. Several components may be involved in each remediation type, and each results in ecological effects, ranging from trampling of plants, to spreading invasive species, to disturbing rare species, and to creating fragmented habitats. In some cases remediation may exert a greater effect on ecological receptors than leaving the limited contamination in place. A goal of this conceptualization is to break down functional components of remediation such that managers, regulators, and the public might assess the effects of timing, extent, and duration of different remediation options on ecological systems.

  8. Efficiency enhancement of GT-MHRs applied on ship propulsion plants

    Energy Technology Data Exchange (ETDEWEB)

    Ferreiro Garcia, Ramon, E-mail: ferreiro@udc.es [Dept. Industrial Engineering, University of A Coruna, ETSNM, C/Paseo de Ronda, 51, 15011 A Coruna (Spain); Carril, Jose Carbia; Catoira, Alberto DeMiguel; Romero Gomez, Javier [Dept. Energy and Propulsion, University of A Coruna ETSNM, C/Paseo de Ronda, 51, 15011 A Coruna (Spain)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Efficient ship propulsion system powered by HTRs. Black-Right-Pointing-Pointer A conventional Rankine cycle renders high efficiency. Black-Right-Pointing-Pointer The intermediate heat exchanger isolates the nuclear reactor from the process heat application. Black-Right-Pointing-Pointer An intermediate heat exchanger allows the system to be built to non-nuclear standards. - Abstract: High temperature reactors including gas cooled fast reactors and gas turbine modular helium reactors (GT-MHR) may operate as electric power suppliers to be applied on ship propulsion plants. In such propulsion systems performance enhancement can be achieved at effective cost under safety conditions using alternative cycles to the conventional Brayton cycle. Mentioned improvements concern the implementation of an ultra supercritical Rankine cycle, in which water is used as working fluid. The proposed study is carried out in order to achieve performance enhancement on the basis of turbine temperature increasing. The helium cooled high temperature reactor supplies thermal energy to the Rankine cycle via an intermediate heat exchanger (IHE) under safety conditions. The results of the study show that the efficiency of the propulsion plant using a multi-reheat Rankine cycle is significantly improved (from actual 48% to more than 55%) while keeping safety standards.

  9. A Diagnostic-Remediation Teaching System for Enhancing Elementary Students' Science Listening Comprehension

    Science.gov (United States)

    Lin, Sheau-Wen; Liu, Yu

    2017-01-01

    The purpose of this study was to explore elementary students' listening comprehension changes using a Web-based teaching system that can diagnose and remediate students' science listening comprehension problems during scientific inquiry. The 3-component system consisted of a 9-item science listening comprehension test, a 37-item diagnostic test,…

  10. Electrokinetic remediation of copper mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, Adrián; Ottosen, Lisbeth M.

    2007-01-01

    Important process parameters to optimize in electrokinetic soil remediation are those influencing remediation time and power consumption since these directly affect the cost of a remediation action. This work shows how the electrokinetic remediation (EKR) process could be improved by implementing...... bipolar electrodes in the porous material. The bipolar electrodes in EKR meant two improvements: (1) a shorter migration pathway for the contaminant, and (2) an increased electrical conductivity in the remediation system. All together the remediation proceeded faster with lower electrical resistance than...... in similar experiments but without the bipolar electrodes. The new electrokinetic remediation design was tested on copper mine tailings with different applied electric fields, remediation times and pre-treatment. The results showed that the copper removal was increased from 8% (applying 20V for 8 days...

  11. Remediating Remediation: From Basic Writing to Writing across the Curriculum

    Science.gov (United States)

    Faulkner, Melissa

    2013-01-01

    This article challenges faculty members and administrators to rethink current definitions of remediation. First year college students are increasingly placed into basic writing courses due to a perceived inability to use English grammar correctly, but it must be acknowledged that all students will encounter the need for remediation as they attempt…

  12. Remediation of 137Cs contaminated concrete using electrokinetic phenomena and ionic salt washes in nuclear energy contexts.

    Science.gov (United States)

    Parker, Andrew J; Joyce, Malcolm J; Boxall, Colin

    2017-10-15

    This work describes the first known the use of electrokinetic treatments and ionic salt washes to remediate concrete contaminated with 137 Cs. A series of experiments were performed on concrete samples, contaminated with K + and 137 Cs, using a bespoke migration cell and an applied electric field (60V potential gradient and current limit of 35mA). Additionally, two samples were treated with an ionic salt wash (≤400molm -3 of KCl) alongside the electrokinetic treatment. The results show that the combined treatment produces removal efficiencies three times higher (>60%) than the electrokinetic treatment alone and that the decontamination efficiency appears to be proportional to the initial degree of contamination. Furthermore, the decontamination efficiencies are equivalent to previous electrokinetic studies that utilised hazardous chemical enhancement agents demonstrating the potential of the technique for use on nuclear licensed site. The results highlight the relationship between the initial contamination concentration within the concrete and achievable removal efficiency of electrokinetic treatment and other treatments. This information would be useful when selecting the most appropriate decontamination techniques for particular contamination scenarios. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Electrochemical remediation technologies for soil and groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Doering, F. [Electrochemical Processes I.I. c. Valley Forge, PA (United States)]|[P2 Soil Remediation, Inc. Stuttgart (Germany); Doering, N. [P2 Soil Remediation, Inc. Stuttgart (Germany)

    2001-07-01

    In Direct Current Technologies (DCTs) a direct current electricity is passed between at least two subsurface electrodes in order to effect the remediation of the groundwater and/or the soil. DCTs in line with the U.S.-terminology comprise of the ElectroChemical Remediation Technologies (ECRTs), and GeoKinetics. The primary distinction between ECRTs and ElectroKinetics are the power input, and the mode of operation, which are electrochemical reactions vs. mass transport. ECRTs combine phenomena of colloid (surface) electrochemistry with the phenomena of Induced Polarization (IP). This report focuses on ECRTs, comprising of the ElectroChemical GeoOxidation (ECGO) for the mineralization of organic pollutants to finally carbon dioxide and water, and Induced Complexation (IC), related to the electrochemical conversion of metals enhancing the mobilization and precipitation of heavy metals on both electrodes. Both technologies are based on reduction-oxidation (redox) reactions at the scale of the individual soil particles. (orig.)

  14. Engineered wetlands for on-site groundwater remediation

    International Nuclear Information System (INIS)

    Wallace, S.; Davis, B.M.

    2008-01-01

    Engineered wetlands have been touted as an emerging technology for the in situ remediation of hydrocarbon-contaminated soil and water. They incorporate a horizontal subsurface flow gravel bed reactor lined with impermeable liners, and are equipped with forced bed aeration systems that enhance oxygen delivery to the wetland's aerobic micro-organisms. Engineered wetlands generally emphasize specific characteristics of wetland ecosystems to improve treatment capacities. Design parameters include biodegradation rate coefficients, flowrate, hydraulic residence time plus influent and required effluent concentrations. This paper described the installation of an engineered wetland system at a former British Petroleum (BP) refinery in Wyoming where a pipeline terminal generated contact wastewater containing benzene, toluene, ethylbenzene and xylene (BTEX) and ammonia. The wetland treatment system was designed to treat 6000 m 3 of contaminated ground water per day and has been in operation since May 2003. It was concluded that engineered wetlands can offer long-term solutions to site remediation challenges. 16 refs., 3 tabs., 6 figs

  15. Use of solar cell in electrokinetic remediation of cadmium-contaminated soil.

    Science.gov (United States)

    Yuan, Songhu; Zheng, Zhonghua; Chen, Jing; Lu, Xiaohua

    2009-03-15

    This preliminary study used a solar cell, instead of direct current (DC) power supply, to generate electric field for electrokinetic (EK) remediation of cadmium-contaminated soil. Three EK tests were conducted and compared; one was conducted on a cloudy and rainy day with solar cell, one was conducted on a sunny day with solar cell and another was conducted periodically with DC power supply. It was found that the output potential of solar cell depended on daytime and was influenced by weather conditions; the applied potential in soil was affected by the output potential and weather conditions, and the current achieved by solar cell was comparable with that achieved by DC power supply. Solar cell could be used to drive the electromigration of cadmium in contaminated soil, and removal efficiency achieved by solar cell was comparable with that achieved by DC power supply. Compared with traditional DC power supply, using solar cell as power supply for EK remediation can greatly reduce energy expenditure. This study provided an alternative to improve the EK soil remediation and expanded the use of solar cell in environmental remediation.

  16. Use of solar cell in electrokinetic remediation of cadmium-contaminated soil

    International Nuclear Information System (INIS)

    Yuan Songhu; Zheng Zhonghua; Chen Jing; Lu Xiaohua

    2009-01-01

    This preliminary study used a solar cell, instead of direct current (DC) power supply, to generate electric field for electrokinetic (EK) remediation of cadmium-contaminated soil. Three EK tests were conducted and compared; one was conducted on a cloudy and rainy day with solar cell, one was conducted on a sunny day with solar cell and another was conducted periodically with DC power supply. It was found that the output potential of solar cell depended on daytime and was influenced by weather conditions; the applied potential in soil was affected by the output potential and weather conditions, and the current achieved by solar cell was comparable with that achieved by DC power supply. Solar cell could be used to drive the electromigration of cadmium in contaminated soil, and removal efficiency achieved by solar cell was comparable with that achieved by DC power supply. Compared with traditional DC power supply, using solar cell as power supply for EK remediation can greatly reduce energy expenditure. This study provided an alternative to improve the EK soil remediation and expanded the use of solar cell in environmental remediation

  17. Comprehensive Assessment of Struggling Learners Referred to a Graduate Medical Education Remediation Program.

    Science.gov (United States)

    Warburton, Karen M; Goren, Eric; Dine, C Jessica

    2017-12-01

    Implementation of the Next Accreditation System has provided a standardized framework for identifying learners not meeting milestones, but there is as yet no corresponding framework for remediation. We developed a comprehensive assessment process that allows correct diagnosis of a struggling learner's deficit(s) to promote successful remediation. At the University of Pennsylvania, resident learners within the Department of Medicine who are not meeting milestones are referred to the Early Intervention Remediation Committee (EIRC). The EIRC, composed of 14 faculty members with expertise in remediation, uses a standardized process to assess learners' deficits. These faculty members categorize primary deficits as follows: medical knowledge, clinical reasoning, organization and efficiency, professionalism, and communication skills. The standardized process of assessment includes an analysis of the learner's file, direct communication with evaluators, an interview focused on learner perception of the problem, screening for underlying medical or psychosocial issues, and a review of systems for deficits in the 6 core competencies. Participants were surveyed after participating in this process. Over a 2-year period, the EIRC assessed and developed remediation plans for 4% of learners (14 of a total 342). Following remediation and reassessment, the identified problems were satisfactorily resolved in all cases with no disciplinary action. While the process was time intensive, an average of 45 hours per learner, the majority of faculty and residents rated it as positive and beneficial. This structured assessment process identifies targeted areas for remediation and adds to the tools available to Clinical Competency Committees.

  18. Laboratory study on sequenced permeable reactive barrier remediation for landfill leachate-contaminated groundwater

    International Nuclear Information System (INIS)

    Dong Jun; Zhao Yongsheng; Zhang Weihong; Hong Mei

    2009-01-01

    Permeable reactive barrier (PRB) was a promising technology for groundwater remediation. Landfill leachate-polluted groundwater riches in various hazardous contaminants. Two lab-scale reactors (reactors A and B) were designed for studying the feasibility of PRB to remedy the landfill leachate-polluted groundwater. Zero valent iron (ZVI) and the mixture of ZVI and zeolites constitute the first section of the reactors A and B, respectively; the second section of two reactors consists of oxygen releasing compounds (ORCs). Experimental results indicated that BOD 5 /COD increased from initial 0.32 up to average 0.61 and 0.6 through reactors A and B, respectively. Removal efficiency of mixed media for pollutants was higher than that of single media (ZVI only). Zeolites exhibited selective removal of Zn, Mn, Mg, Cd, Sr, and NH 4 + , and removal efficiency was 97.2%, 99.6%, 95.9%, 90.5% and 97.4%, respectively. The maximum DO concentration of reactors A and B were 7.64 and 6.78 mg/L, respectively, while the water flowed through the ORC. Therefore, sequenced PRB system was effective and was proposed as an alternative method to remedy polluted groundwater by landfill leachate

  19. Arctigenin Efficiently Enhanced Sedentary Mice Treadmill Endurance

    Science.gov (United States)

    Chen, Jing; Yu, Liang; Hu, Lihong; Jiang, Hualiang; Shen, Xu

    2011-01-01

    Physical inactivity is considered as one of the potential risk factors for the development of type 2 diabetes and other metabolic diseases, while endurance exercise training could enhance fat oxidation that is associated with insulin sensitivity improvement in obesity. AMP-activated protein kinase (AMPK) as an energy sensor plays pivotal roles in the regulation of energy homeostasis, and its activation could improve glucose uptake, promote mitochondrial biogenesis and increase glycolysis. Recent research has even suggested that AMPK activation contributed to endurance enhancement without exercise. Here we report that the natural product arctigenin from the traditional herb Arctium lappa L. (Compositae) strongly increased AMPK phosphorylation and subsequently up-regulated its downstream pathway in both H9C2 and C2C12 cells. It was discovered that arctigenin phosphorylated AMPK via calmodulin-dependent protein kinase kinase (CaMKK) and serine/threonine kinase 11(LKB1)-dependent pathways. Mice treadmill based in vivo assay further indicated that administration of arctigenin improved efficiently mice endurance as reflected by the increased fatigue time and distance, and potently enhanced mitochondrial biogenesis and fatty acid oxidation (FAO) related genes expression in muscle tissues. Our results thus suggested that arctigenin might be used as a potential lead compound for the discovery of the agents with mimic exercise training effects to treat metabolic diseases. PMID:21887385

  20. Arctigenin efficiently enhanced sedentary mice treadmill endurance.

    Directory of Open Access Journals (Sweden)

    Xuan Tang

    Full Text Available Physical inactivity is considered as one of the potential risk factors for the development of type 2 diabetes and other metabolic diseases, while endurance exercise training could enhance fat oxidation that is associated with insulin sensitivity improvement in obesity. AMP-activated protein kinase (AMPK as an energy sensor plays pivotal roles in the regulation of energy homeostasis, and its activation could improve glucose uptake, promote mitochondrial biogenesis and increase glycolysis. Recent research has even suggested that AMPK activation contributed to endurance enhancement without exercise. Here we report that the natural product arctigenin from the traditional herb Arctium lappa L. (Compositae strongly increased AMPK phosphorylation and subsequently up-regulated its downstream pathway in both H9C2 and C2C12 cells. It was discovered that arctigenin phosphorylated AMPK via calmodulin-dependent protein kinase kinase (CaMKK and serine/threonine kinase 11(LKB1-dependent pathways. Mice treadmill based in vivo assay further indicated that administration of arctigenin improved efficiently mice endurance as reflected by the increased fatigue time and distance, and potently enhanced mitochondrial biogenesis and fatty acid oxidation (FAO related genes expression in muscle tissues. Our results thus suggested that arctigenin might be used as a potential lead compound for the discovery of the agents with mimic exercise training effects to treat metabolic diseases.

  1. Application of Fe-Cu/Biochar System for Chlorobenzene Remediation of Groundwater in Inhomogeneous Aquifers

    Directory of Open Access Journals (Sweden)

    Xu Zhang

    2017-12-01

    Full Text Available Chlorobenzene (CB, as a typical Volatile Organic Contaminants (VOC, is toxic, highly persistent and easily migrates in water, posing a significant risk to human health and subsurface ecosystems. Therefore, exploring effective approaches to remediate groundwater contaminated by CB is essential. As an enhanced micro-electrolysis system for CB-contaminated groundwater remediation, this study attempted to couple the iron-copper bimetal with biochar. Two series of columns using sands with different grain diameters were used, consisting of iron, copper and biochar fillings as the permeable reactive barriers (PRBs, to simulate the remediation of CB-contaminated groundwater in homogeneous and heterogeneous aquifers. Regardless of the presence of homogeneous or heterogeneous porous media, the CB concentrations in the effluent from the PRB columns were significantly lower than the natural sandy columns, suggesting that the iron and copper powders coupled with biochar particles could have a significant removal effect compared to the natural sand porous media in the first columns. CB was transported relatively quickly in the heterogeneous porous media, likely due to the fact that the contaminant residence time is proportional to the infiltration velocities in the different types of porous media. The average effluent CB concentrations from the heterogeneous porous media were lower than those from homogeneous porous media. The heterogeneity retarded the vertical infiltration of CB, leading to its extended lateral distribution. During the treatment process, benzene and phenol were observed as the products of CB degradation. The ultimate CB removal efficiency was 61.4% and 68.1%, demonstrating that the simulated PRB system with the mixture of iron, copper and biochar was effective at removing CB from homogeneous and heterogeneous aquifers.

  2. In situ remediation of uranium contaminated groundwater

    International Nuclear Information System (INIS)

    Dwyer, B.P.; Marozas, D.C.

    1997-01-01

    In an effort to develop cost-efficient techniques for remediating uranium contaminated groundwater at DOE Uranium Mill Tailing Remedial Action (UMTRA) sites nationwide, Sandia National Laboratories (SNL) deployed a pilot scale research project at an UMTRA site in Durango, CO. Implementation included design, construction, and subsequent monitoring of an in situ passive reactive barrier to remove Uranium from the tailings pile effluent. A reactive subsurface barrier is produced by emplacing a reactant material (in this experiment various forms of metallic iron) in the flow path of the contaminated groundwater. Conceptually the iron media reduces and/or adsorbs uranium in situ to acceptable regulatory levels. In addition, other metals such as Se, Mo, and As have been removed by the reductive/adsorptive process. The primary objective of the experiment was to eliminate the need for surface treatment of tailing pile effluent. Experimental design, and laboratory and field results are discussed with regard to other potential contaminated groundwater treatment applications

  3. Remediation of soils contaminated with heavy metals with an emphasis on immobilization technology.

    Science.gov (United States)

    Derakhshan Nejad, Zahra; Jung, Myung Chae; Kim, Ki-Hyun

    2018-06-01

    The major frequent contaminants in soil are heavy metals which may be responsible for detrimental health effects. The remediation of heavy metals in contaminated soils is considered as one of the most complicated tasks. Among different technologies, in situ immobilization of metals has received a great deal of attention and turned out to be a promising solution for soil remediation. In this review, remediation methods for removal of heavy metals in soil are explored with an emphasis on the in situ immobilization technique of metal(loid)s. Besides, the immobilization technique in contaminated soils is evaluated through the manipulation of the bioavailability of heavy metals using a range of soil amendment conditions. This technique is expected to efficiently alleviate the risk of groundwater contamination, plant uptake, and exposure to other living organisms. The efficacy of several amendments (e.g., red mud, biochar, phosphate rock) has been examined to emphasize the need for the simultaneous measurement of leaching and the phytoavailability of heavy metals. In addition, some amendments that are used in this technique are inexpensive and readily available in large quantities because they have been derived from bio-products or industrial by-products (e.g., biochar, red mud, and steel slag). Among different amendments, iron-rich compounds and biochars show high efficiency to remediate multi-metal contaminated soils. Thereupon, immobilization technique can be considered a preferable option as it is inexpensive and easily applicable to large quantities of contaminants derived from various sources.

  4. After-installation service, a contribution to enhanced economic efficiency of reactors

    International Nuclear Information System (INIS)

    Bilger, H.

    1996-01-01

    After-installation service agreements are concluded in general for the following plant systems or tasks: power operation, inspection and repair during outages, plant enhancements (retrofitting), instrumentation and control (software). The paper gives various examples selected from power plant practice in Germany, showing that service contracts are a major factor contributing to maintaining economic efficiency, or enhancing it. Examples of nuclear power plant management abroad relying on service contracts are also given (USA, France, Japan). (orig./HP) [de

  5. Application of persulfate to remediate petroleum hydrocarbon-contaminated soil: feasibility and comparison with common oxidants.

    Science.gov (United States)

    Yen, Chia-Hsien; Chen, Ku-Fan; Kao, Chih-Ming; Liang, Shu-Hao; Chen, Ting-Yu

    2011-02-28

    In this study, batch experiments were conducted to evaluate the feasibility of petroleum-hydrocarbon contaminated soil remediation using persulfate oxidation. Various controlling factors including different persulfate and ferrous ion concentrations, different oxidants (persulfate, hydrogen peroxide, and permanganate), and different contaminants (diesel and fuel oil) were considered. Results show that persulfate oxidation is capable of treating diesel and fuel oil contaminated soil. Higher persulfate and ferrous ion concentrations resulted in higher diesel degrading rates within the applied persulfate/ferrous ion molar ratios. A two-stage diesel degradation was observed in the batch experiments. In addition, treatment of diesel-contaminated soil using in situ metal mineral activation under ambient temperature (e.g., 25°C) may be a feasible option for site remediation. Results also reveal that persulfate anions could persist in the system for more than five months. Thus, sequential injections of ferrous ion to generate sulfate free radicals might be a feasible way to enhance contaminant oxidation. Diesel oxidation efficiency and rates by the three oxidants followed the sequence of hydrogen peroxide>permanganate>persulfate in the limited timeframes. Results of this study indicate that the application of persulfate oxidation is a feasible method to treat soil contaminated by diesel and fuel oil. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Applying short-duration pulses as a mean to enhance volatile organic compounds removal by air sparging.

    Science.gov (United States)

    Ben Neriah, Asaf; Paster, Amir

    2017-10-01

    Application of short-duration pulses of high air pressure, to an air sparging system for groundwater remediation, was tested in a two-dimensional laboratory setup. It was hypothesized that this injection mode, termed boxcar, can enhance the remediation efficiency due to the larger ZOI and enhanced mixing which results from the pressure pulses. To test this hypothesis, flow and transport experiments were performed. Results confirm that cyclically applying short-duration pressure pulses may enhance contaminant cleanup. Comparing the boxcar to conventional continuous air-injection shows up to a three-fold increase in the single well radius of influence, dependent on the intensity of the short-duration pressure-pulses. The cleanup efficiency of Toluene from the water was 95% higher than that achieved under continuous injection with the same average conditions. This improvement was attributed to the larger zone of influence and higher average air permeability achieved in the boxcar mode, relative to continuous sparging. Mixing enhancement resultant from recurring pressure pulses was suggested as one of the mechanisms which enhance the contaminant cleanup. The application of a boxcar mode in an existing, multiwell, air sparging setup can be relatively straightforward: it requires the installation of an on-off valve in each of the injection-wells and a central control system. Then, turning off some of the wells, for a short-duration, result in a stepwise increase in injection pressure in the rest of the wells. It is hoped that this work will stimulate the additional required research and ultimately a field scale application of this new injection mode. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. RS-1 enhances CRISPR/Cas9- and TALEN-mediated knock-in efficiency.

    Science.gov (United States)

    Song, Jun; Yang, Dongshan; Xu, Jie; Zhu, Tianqing; Chen, Y Eugene; Zhang, Jifeng

    2016-01-28

    Zinc-finger nuclease, transcription activator-like effector nuclease and CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9) are becoming major tools for genome editing. Importantly, knock-in in several non-rodent species has been finally achieved thanks to these customizable nucleases; yet the rates remain to be further improved. We hypothesize that inhibiting non-homologous end joining (NHEJ) or enhancing homology-directed repair (HDR) will improve the nuclease-mediated knock-in efficiency. Here we show that the in vitro application of an HDR enhancer, RS-1, increases the knock-in efficiency by two- to five-fold at different loci, whereas NHEJ inhibitor SCR7 has minimal effects. We then apply RS-1 for animal production and have achieved multifold improvement on the knock-in rates as well. Our work presents tools to nuclease-mediated knock-in animal production, and sheds light on improving gene-targeting efficiencies on pluripotent stem cells.

  8. RS-1 enhances CRISPR/Cas9- and TALEN-mediated knock-in efficiency

    Science.gov (United States)

    Song, Jun; Yang, Dongshan; Xu, Jie; Zhu, Tianqing; Chen, Y. Eugene; Zhang, Jifeng

    2016-01-01

    Zinc-finger nuclease, transcription activator-like effector nuclease and CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9) are becoming major tools for genome editing. Importantly, knock-in in several non-rodent species has been finally achieved thanks to these customizable nucleases; yet the rates remain to be further improved. We hypothesize that inhibiting non-homologous end joining (NHEJ) or enhancing homology-directed repair (HDR) will improve the nuclease-mediated knock-in efficiency. Here we show that the in vitro application of an HDR enhancer, RS-1, increases the knock-in efficiency by two- to five-fold at different loci, whereas NHEJ inhibitor SCR7 has minimal effects. We then apply RS-1 for animal production and have achieved multifold improvement on the knock-in rates as well. Our work presents tools to nuclease-mediated knock-in animal production, and sheds light on improving gene-targeting efficiencies on pluripotent stem cells. PMID:26817820

  9. GENOMIC ANALYSIS OF PLANT-ASSOCIATED BACTERIA AND THEIR POTENTIAL IN ENHANCING PHYTOREMEDIATION EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Artur Piński

    2017-07-01

    Full Text Available Phytoremediation is an emerging technology that uses plants in order to cleanup pollutants including xenobiotics and heavy metals from soil, water and air. Inoculation of plants with plant growth promoting endophytic and rhizospheric bacteria can enhance efficiency of phytoremediation. Genomic analysis of four plant-associated strains belonging to the Stenotrophomonas maltophilia species revealed the presence of genes encoding proteins involved in plant growth promotion, biocontrol of phytopathogens, biodegradation of xenobiotics, heavy metals resistance and plant-bacteria-environment interaction. The results of this analysis suggest great potential of bacteria belonging to Stenotrophomonas maltophilia species in enhancing phytoremediation efficiency.

  10. Decision support for large-scale remediation strategies by fused urban metabolism and life cycle assessment

    DEFF Research Database (Denmark)

    Ohms, Pernille; Andersen, Camilla; Landgren, Mathilde

    2018-01-01

    Purpose: This paper seeks to identify the most environmental friendly way of conducting a refurbishment of Broendby Strand, with focus on PCB remediation. The actual identification is conducted by comparing four remediation techniques using urban metabolism fused with life cycle assessment (UM......-LCA) in combination with information relating to cost and efficiency of the compared techniques. The methodological goal of our paper is to test UM-LCA as a decision support tool and discuss application of the method in relation to large refurbishment projects. Methods: To assess the environmental performance of PCB......-remediation techniques, the UM-LCA method was applied. By combining UM and LCA methodologies, the total environmental impact potentials of the remediation techniques were calculated. To build an inventory for each technique, we contacted and interviewed experts and studied existing literature, cases, and projects...

  11. Remediation of groundwater contaminated with arsenic through enhanced natural attenuation: Batch and column studies.

    Science.gov (United States)

    Hafeznezami, Saeedreza; Zimmer-Faust, Amity G; Jun, Dukwoo; Rugh, Megyn B; Haro, Heather L; Park, Austin; Suh, Jae; Najm, Tina; Reynolds, Matthew D; Davis, James A; Parhizkar, Tarannom; Jay, Jennifer A

    2017-10-01

    Batch and column laboratory experiments were conducted on natural sediment and groundwater samples from a contaminated site in Maine, USA with the aim of lowering the dissolved arsenate [As(V)] concentrations through chemical enhancement of natural attenuation capacity. In batch factorial experiments, two levels of treatment for three parameters (pH, Ca, and Fe) were studied at different levels of phosphate to evaluate their impact on As(V) solubility. Results illustrated that lowering pH, adding Ca, and adding Fe significantly increased the sorption capacity of sediments. Overall, Fe amendment had the highest individual impact on As(V) levels. To provide further evidence for the positive impact of Ca on As(V) adsorption, isotherm experiments were conducted at three different levels of Ca concentrations. A consistent increase in adsorption capacity (26-37%) of sediments was observed with the addition of Ca. The observed favorable effect of Ca on As(V) adsorption is likely caused by an increase in the surface positive charges due to surface accumulation of Ca 2+ ions. Column experiments were conducted by flowing contaminated groundwater with elevated pH, As(V), and phosphate through both uncontaminated and contaminated sediments. Potential in-situ remediation scenarios were simulated by adding a chemical amendment feed to the columns injecting Fe(II) or Ca as well as simultaneous pH adjustment. Results showed a temporary and limited decrease in As(V) concentrations under the Ca treatment (39-41%) and higher levels of attenuation in Fe(II) treated columns (50-91%) but only after a certain number of pore volumes (18-20). This study illustrates the importance of considering geochemical parameters including pH, redox potential, presence of competing ions, and sediment chemical and physical characteristics when considering enhancing the natural attenuation capacity of sediments to mitigate As contamination in natural systems. Copyright © 2017 Elsevier Ltd. All rights

  12. Radiation induced oxidation for water remediation

    International Nuclear Information System (INIS)

    Gehringer, P.

    1997-01-01

    The action of ionizing radiation on halogenated hydrocarbons, in the presence and absence of ozone, was studied in water and wastewater. The combined ozone/electron-beam irradiation process was found especially suited for remediation of low-level contaminated groundwater. This combined treatment was often more effective than irradiation alone for wastewater decontamination. It reduced the COD without a simultaneous increase of BOD. Introduction of gaseous ozone directly into the irradiation chamber improved the water-flow turbulence, allowing treatment in layers thicker than the penetration range of the electrons, with increased decontamination efficiency. (author)

  13. Thermal power plant efficiency enhancement with Ocean Thermal Energy Conversion

    International Nuclear Information System (INIS)

    Soto, Rodrigo; Vergara, Julio

    2014-01-01

    In addition to greenhouse gas emissions, coastal thermal power plants would gain further opposition due to their heat rejection distressing the local ecosystem. Therefore, these plants need to enhance their thermal efficiency while reducing their environmental offense. In this study, a hybrid plant based on the principle of Ocean Thermal Energy Conversion was coupled to a 740 MW coal-fired power plant project located at latitude 28°S where the surface to deepwater temperature difference would not suffice for regular OTEC plants. This paper presents the thermodynamical model to assess the overall efficiency gained by adopting an ammonia Rankine cycle plus a desalinating unit, heated by the power plant condenser discharge and refrigerated by cold deep seawater. The simulation allowed us to optimize a system that would finally enhance the plant power output by 25–37 MW, depending on the season, without added emissions while reducing dramatically the water temperature at discharge and also desalinating up to 5.8 million tons per year. The supplemental equipment was sized and the specific emissions reduction was estimated. We believe that this approach would improve the acceptability of thermal and nuclear power plant projects regardless of the plant location. -- Highlights: • An Ocean Thermal Energy Conversion hybrid plant was designed. • The waste heat of a power plant was delivered as an OTEC heat source. • The effect of size and operating conditions on plant efficiency were studied. • The OTEC implementation in a Chilean thermal power plant was evaluated. • The net efficiency of the thermal power plant was increased by 1.3%

  14. (Bio-)remediation of VCHC contaminants in a Technosol under unsaturated conditions.

    Science.gov (United States)

    Baumgarten, W; Fleige, H; Peth, S; Horn, R

    2013-07-01

    The remediation of dense non-aqueous phase liquids has always been a concern of both public and scientific interest groups. In this research work a modified physical concept of (bio)remediation of a volatile chlorinated hydrocarbon (VCHC) contamination was elaborated under laboratory conditions and modeled with HYDRUS-2D. In field dechlorination is influenced by both physicochemical and hydraulic properties of the substrate, e.g. texture, pore size distribution, pore liquid characteristics, e.g. viscosity, pH, surface tension, and dependent on the degree of saturation of the vadose zone. Undisturbed soil cores (100 cm³) were sampled from a Spolic Technosol. Considering hydraulic properties and functions, unsaturated percolation was performed with vertically and horizontally structured samples. VCHC concentrations were calculated prior, during, and after each percolation cycle. According to laboratory findings, microemulsion showed the most efficient results with regard to flow behavior in the unsaturated porous media and its accessibility for bacteria as nutrient. The efficiency of VCHC remediation could be increased by the application of a modified pump-and-treat system: the injection of bacteria Dehalococcoides ethanogenes with microemulsion, and extraction at a constant matric potential level of -6 kPa. Achieved data was used for HYDRUS-2D simulations, modeling in situ conditions, demonstrating the practical relevance (field scale) of performed unsaturated percolation (core scale), and in order to exclude capillary barrier effects.

  15. Interactive Computer-Enhanced Remote Viewing System (ICERVS)

    International Nuclear Information System (INIS)

    1993-08-01

    The Integrated Computer-Enhanced Remote Viewing System (ICERVS) supports the robotic remediation of hazardous environments such as underground storage tanks, buried waste sites, and contaminated production facilities. The success of these remediation missions will depend on reliable geometric descriptions of the work environment in order to achieve effective task planning, path planning, and collision avoidance. ICERVS provides a means for deriving a reliable geometric description more effectively and efficiently than current systems by combining a number of technologies: Sensing of the environment to acquire dimensional and material property data; integration of acquired data into a common data structure (based on octree technology); presentation of data to robotic task planners for analysis and visualization; interactive synthesis of geometric/surface models to denote features of interest in the environment and transfer of this information to robot control and collision avoidance systems. A key feature of ICERVS is that it will enable an operator to match xyz data from a sensor with surface models of the same region in space. This capability will help operators to better manage the complexities of task and path planning in three-dimensional (3D) space, thereby leading to safer and more effective remediation. The Phase 1 work performed by MTI has brought the ICERVS design to Maturity Level 3, Subscale Major Subsystem, and met the established success criteria

  16. Remediation plans in family medicine residency

    Science.gov (United States)

    Audétat, Marie-Claude; Voirol, Christian; Béland, Normand; Fernandez, Nicolas; Sanche, Gilbert

    2015-01-01

    Abstract Objective To assess use of the remediation instrument that has been implemented in training sites at the University of Montreal in Quebec to support faculty in diagnosing and remediating resident academic difficulties, to examine whether and how this particular remediation instrument improves the remediation process, and to determine its effects on the residents’ subsequent rotation assessments. Design A multimethods approach in which data were collected from different sources: remediation plans developed by faculty, program statistics for the corresponding academic years, and students’ academic records and rotation assessment results. Setting Family medicine residency program at the University of Montreal. Participants Family medicine residents in academic difficulty. Main outcome measures Assessment of the content, process, and quality of remediation plans, and students’ academic and rotation assessment results (successful, below expectations, or failure) both before and after the remediation period. Results The framework that was developed for assessing remediation plans was used to analyze 23 plans produced by 10 teaching sites for 21 residents. All plans documented cognitive problems and implemented numerous remediation measures. Although only 48% of the plans were of good quality, implementation of a remediation plan was positively associated with the resident’s success in rotations following the remediation period. Conclusion The use of remediation plans is well embedded in training sites at the University of Montreal. The residents’ difficulties were mainly cognitive in nature, but this generally related to deficits in clinical reasoning rather than knowledge gaps. The reflection and analysis required to produce a remediation plan helps to correct many academic difficulties and normalize the academic career of most residents in difficulty. Further effort is still needed to improve the quality of plans and to support teachers.

  17. New IAEA guidelines on environmental remediation

    Energy Technology Data Exchange (ETDEWEB)

    Fesenko, Sergey [International Atomic Energy Agency, A2444, Seibersdorf (Austria); Howard, Brenda [Centre for Ecology and Hydrology, Lancaster Environment Centre, LA1 4AP, Lancaster (United Kingdom); Kashparov, Valery [Ukrainian Institute of Agricultural Radiology, 08162, 7, Mashinobudivnykiv str., Chabany, Kyivo-Svyatoshin region, Kyiv (Ukraine); Sanzharova, Natalie [Russian Institute of Agricultural Radiology and Agroecology, Russian Federation, 249032, Obninsk (Russian Federation); Vidal, Miquel [Analytical Chemistry Department-Universitat de Barcelona, Barcelona, 08028 Barcelona (Spain)

    2014-07-01

    In response to the needs of its Member States, the International Atomic Energy Agency (IAEA) has published many documents covering different aspects of remediation of contaminated environments. These documents range from safety fundamentals and safety requirements to technical documents describing remedial technologies. Almost all the documents on environmental remediation are related to uranium mining areas and decommissioning of nuclear facilities. IAEA radiation safety standards on remediation of contaminated environments are largely based on these two types of remediation. The exception is a document related to accidents, namely the IAEA TRS No. 363 'Guidelines for Agricultural Countermeasures Following an Accidental Release of Radionuclides'. Since the publication of TRS 363, there has been a considerable increase in relevant information. In response, the IAEA initiated the development of a new document, which incorporated new knowledge obtained during last 20 years, lessons learned and subsequent changes in the regulatory framework. The new document covers all aspects related to the environmental remediation from site characterisation to a description of individual remedial actions and decision making frameworks, covering urban, agricultural, forest and freshwater environments. Decisions taken to commence remediation need to be based on an accurate assessment of the amount and extent of contamination in relevant environmental compartments and how they vary with time. Major aspects of site characterisation intended for remediation are described together with recommendations on effective sampling programmes and data compilation for decision making. Approaches for evaluation of remedial actions are given in the document alongside the factors and processes which affect their implementation for different environments. Lessons learned following severe radiation accidents indicate that remediation should be considered with respect to many different

  18. Enhanced optical-to-THz conversion efficiency of photoconductive antenna using dielectric nano-layer encapsulation

    Science.gov (United States)

    Gupta, Abhishek; Rana, Goutam; Bhattacharya, Arkabrata; Singh, Abhishek; Jain, Ravikumar; Bapat, Rudheer D.; Duttagupta, S. P.; Prabhu, S. S.

    2018-05-01

    Photoconductive antennas (PCAs) are among the most conventional devices used for emission as well as detection of terahertz (THz) radiation. However, due to their low optical-to-THz conversion efficiencies, applications of these devices in out-of-laboratory conditions are limited. In this paper, we report several factors of enhancement in THz emission efficiency from conventional PCAs by coating a nano-layer of dielectric (TiO2) on the active area between the electrodes of a semi-insulating GaAs-based device. Extensive experiments were done to show the effect of thicknesses of the TiO2 layer on the THz power enhancement with different applied optical power and bias voltages. Multiphysics simulations were performed to elucidate the underlying physics behind the enhancement of efficiency of the PCA. Additionally, this layer increases the robustness of the electrode gaps of the PCAs with high electrical insulation as well as protect it from external dust particles.

  19. Applications of microwave radiation environmental remediation technologies

    International Nuclear Information System (INIS)

    Krause, T.R.; Helt, J.E.

    1993-01-01

    A growing number of environmental remediation technologies (e.g., drying, melting, or sintering) utilize microwave radiation as an integral part of the process. An increasing number of novel applications, such as sustaining low-temperature plasmas or enhancing chemical reactivity, are also being developed. An overview of such technologies being developed by the Department of Energy is presented. A specific example being developed at Argonne National Laboratory, microwave-induced plasma reactors for the destruction of volatile organic compounds, is discussed in more detail

  20. Innovative vitrification for soil remediation

    International Nuclear Information System (INIS)

    Jetta, N.W.; Patten, J.S.; Hart, J.G.

    1995-01-01

    The objective of this DOE demonstration program is to validate the performance and operation of the Vortec Cyclone Melting System (CMS trademark) for the processing of LLW contaminated soils found at DOE sites. This DOE vitrification demonstration project has successfully progressed through the first two phases. Phase 1 consisted of pilot scale testing with surrogate wastes and the conceptual design of a process plant operating at a generic DOE site. The objective of Phase 2, which is scheduled to be completed the end of FY 95, is to develop a definitive process plant design for the treatment of wastes at a specific DOE facility. During Phase 2, a site specific design was developed for the processing of LLW soils and muds containing TSCA organics and RCRA metal contaminants. Phase 3 will consist of a full scale demonstration at the DOE gaseous diffusion plant located in Paducah, KY. Several DOE sites were evaluated for potential application of the technology. Paducah was selected for the demonstration program because of their urgent waste remediation needs as well as their strong management and cost sharing financial support for the project. During Phase 2, the basic nitrification process design was modified to meet the specific needs of the new waste streams available at Paducah. The system design developed for Paducah has significantly enhanced the processing capabilities of the Vortec vitrification process. The overall system design now includes the capability to shred entire drums and drum packs containing mud, concrete, plastics and PCB's as well as bulk waste materials. This enhanced processing capability will substantially expand the total DOE waste remediation applications of the technology

  1. Enhancing the Out-Coupling Efficiency of Organic Light-Emitting Diodes Using Two-Dimensional Periodic Nanostructures

    Directory of Open Access Journals (Sweden)

    Qingyang Yue

    2012-01-01

    Full Text Available The out-coupling efficiency of planar organic light emitting diodes (OLEDs is only about 20% due to factors, such as, the total internal reflection, surface plasmon coupling, and metal absorption. Two-dimensional periodic nanostructures, such as, photonic crystals (PhCs and microlenses arrays offer a potential method to improve the out-coupling efficiency of OLEDs. In this work, we employed the finite-difference time-domain (FDTD method to explore different mechanisms that embedded PhCs and surface PhCs to improve the out-coupling efficiency. The effects of several parameters, including the filling factor, the depth, and the lattice constant were investigated. The result showed that embedded PhCs play a key role in improving the out-coupling efficiency, and an enhancement factor of 240% was obtained in OLEDs with embedded PhCs, while the enhancement factor of OLEDs with surface PhCs was only 120%. Furthermore, the phenomena was analyzed using the mode theory and it demonstrated that the overlap between the mode and PhCs was related to the distribution of vertical mode profiles. The enhancement of the extraction efficiency in excess of 290% was observed for the optimized OLEDs structure with double PhCs. This proposed structure could be a very promising candidate for high extraction efficiency OLEDs.

  2. Electrodialytic Remediation of Soil Slurry-Removal of Cu, Cr, and As

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Jensen, Pernille Erland; Hansen, Henrik K.

    2009-01-01

    Severe soil contamination is often found at old wood preservation sites and a common combination of pollutants is Cu, Cr, and As. In the present work it is tested if simultaneous removal of Cu, Cr, and As can be obtained in an electrodialytic cell where the polluted soil is remediated as a stirred...... experiments; an experiment where the soil was suspended in distilled water and the remediation lasted 3 weeks with 2.5 mA and an experiment with acidification of the soil suspension with HNO3 to pH about 1.0 (2 weeks and 5 mA). The best separation of pollutants and soil was obtained in the experiment...... with suspension in distilled water. Based on soil concentrations, good Cu removal (95%) was obtained in both experiments. Removal of Cr was most efficient from the acidified soil suspension (74%). Both Cu and Cr concentrations were below the limiting values after the remediation. The As concentration, however...

  3. APPLIED PHYTO-REMEDIATION TECHNIQUES USING HALOPHYTES FOR OIL AND BRINE SPILL SCARS

    Energy Technology Data Exchange (ETDEWEB)

    M.L. Korphage; Bruce G. Langhus; Scott Campbell

    2003-03-01

    Produced salt water from historical oil and gas production was often managed with inadequate care and unfortunate consequences. In Kansas, the production practices in the 1930's and 1940's--before statewide anti-pollution laws--were such that fluids were often produced to surface impoundments where the oil would segregate from the salt water. The oil was pumped off the pits and the salt water was able to infiltrate into the subsurface soil zones and underlying bedrock. Over the years, oil producing practices were changed so that segregation of fluids was accomplished in steel tanks and salt water was isolated from the natural environment. But before that could happen, significant areas of the state were scarred by salt water. These areas are now in need of economical remediation. Remediation of salt scarred land can be facilitated with soil amendments, land management, and selection of appropriate salt tolerant plants. Current research on the salt scars around the old Leon Waterflood, in Butler County, Kansas show the relative efficiency of remediation options. Based upon these research findings, it is possible to recommend cost efficient remediation techniques for slight, medium, and heavy salt water damaged soil. Slight salt damage includes soils with Electrical Conductivity (EC) values of 4.0 mS/cm or less. Operators can treat these soils with sufficient amounts of gypsum, install irrigation systems, and till the soil. Appropriate plants can be introduced via transplants or seeded. Medium salt damage includes soils with EC values between 4.0 and 16 mS/cm. Operators will add amendments of gypsum, till the soil, and arrange for irrigation. Some particularly salt tolerant plants can be added but most planting ought to be reserved until the second season of remediation. Severe salt damage includes soil with EC values in excess of 16 mS/cm. Operators will add at least part of the gypsum required, till the soil, and arrange for irrigation. The following

  4. Simultaneous application of chemical oxidation and extraction processes is effective at remediating soil Co-contaminated with petroleum and heavy metals.

    Science.gov (United States)

    Yoo, Jong-Chan; Lee, Chadol; Lee, Jeung-Sun; Baek, Kitae

    2017-01-15

    Chemical extraction and oxidation processes to clean up heavy metals and hydrocarbon from soil have a higher remediation efficiency and take less time than other remediation processes. In batch extraction/oxidation process, 3% hydrogen peroxide (H 2 O 2 ) and 0.1 M ethylenediaminetetraacetic acid (EDTA) could remove approximately 70% of the petroleum and 60% of the Cu and Pb in the soil, respectively. In particular, petroleum was effectively oxidized by H 2 O 2 without addition of any catalysts through dissolution of Fe oxides in natural soils. Furthermore, heavy metals bound to Fe-Mn oxyhydroxides could be extracted by metal-EDTA as well as Fe-EDTA complexation due to the high affinity of EDTA for metals. However, the strong binding of Fe-EDTA inhibited the oxidation of petroleum in the extraction-oxidation sequential process because Fe was removed during the extraction process with EDTA. The oxidation-extraction sequential process did not significantly enhance the extraction of heavy metals from soil, because a small portion of heavy metals remained bound to organic matter. Overall, simultaneous application of oxidation and extraction processes resulted in highly efficient removal of both contaminants; this approach can be used to remove co-contaminants from soil in a short amount of time at a reasonable cost. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Some Similarities and Differences Between Compositions Written by Remedial and Non-Remedial College Freshmen.

    Science.gov (United States)

    House, Elizabeth B.; House, William J.

    The essays composed by 84 remedial and 77 nonremedial college freshmen were analyzed for some features proposed by Mina Shaughnessy as being characteristic of basic writers. The students were enrolled in either a beginning remedial class (098), a class at the next level of remediation (099), or a regular English class (101). The essays were…

  6. Enhancing the efficiency of polymerase chain reaction using graphene nanoflakes.

    Science.gov (United States)

    Abdul Khaliq, R; Kafafy, Raed; Salleh, Hamzah Mohd; Faris, Waleed Fekry

    2012-11-16

    The effect of the recently developed graphene nanoflakes (GNFs) on the polymerase chain reaction (PCR) has been investigated in this paper. The rationale behind the use of GNFs is their unique physical and thermal properties. Experiments show that GNFs can enhance the thermal conductivity of base fluids and results also revealed that GNFs are a potential enhancer of PCR efficiency; moreover, the PCR enhancements are strongly dependent on GNF concentration. It was found that GNFs yield DNA product equivalent to positive control with up to 65% reduction in the PCR cycles. It was also observed that the PCR yield is dependent on the GNF size, wherein the surface area increases and augments thermal conductivity. Computational fluid dynamics (CFD) simulations were performed to analyze the heat transfer through the PCR tube model in the presence and absence of GNFs. The results suggest that the superior thermal conductivity effect of GNFs may be the main cause of the PCR enhancement.

  7. DNAPL Surface Chemistry: Its Impact on DNAPL Distribution in the Vadose Zone and its Manipulation to Enhance Remediation

    Energy Technology Data Exchange (ETDEWEB)

    Suan Power; Stefan Grimberg; Miles Denham

    2003-06-16

    The remediation of DNAPLs in subsurface environments is often limited by the heterogeneous distribution of the organic fluid. The fraction of DNAPL that is in the high conductivity regions of the subsurface can often be recovered relatively easily, although DNAPL in lower conductivity regions is much more difficult to extract, either through direct pumping or remediation measures based on interface mass transfer. The distribution of DNAPL within the vadose zone is affected by a complex interplay of heterogeneities in the porous matrix and the interfacial properties defining the interactions among all fluid and solid phases. Decreasing the interfacial tension between a DNAPL and water in the vadose zone could change the spreading of the DNAPL, thereby increase the surface area for mass transfer and the effectiveness of soil vapor extraction remediation.

  8. Enhancement of CNT-based filters efficiency by ion beam irradiation

    Science.gov (United States)

    Elsehly, Emad M.; Chechenin, N. G.; Makunin, A. V.; Shemukhin, A. A.; Motaweh, H. A.

    2018-05-01

    It is shown in the report that disorder produced by ion beam irradiation can enhance the functionality of the carbon nanotubes. The filters of pressed multiwalled carbon nanotubes (MWNTs) were irradiated by He+ ions of the energy E = 80 keV with the fluence 2 × 1016 ion/cm2. The removal of manganese from aqueous solutions by using pristine and ion beam irradiated MWNTs filters was studied as a function of pH, initial concentration of manganese in aqueous solution, MWNT mass and contact time. The filters before and after filtration were characterized by Raman (RS) and energy dispersive X-ray spectroscopy (EDS) techniques to investigate the deposition content in the filter and defect formation in the MWNTs. The irradiated samples showed an enhancement of removal efficiency of manganese up to 97.5% for 10 ppm Mn concentration, suggesting that irradiated MWNT filter is a better Mn adsorbent from aqueous solutions than the pristine one. Radiation-induced chemical functionalization of MWNTs due to ion beam irradiation, suggesting that complexation between the irradiated MWNTs and manganese ions is another mechanism. This conclusion is supported by EDS and RS and is correlated with a larger disorder in the irradiated samples as follows from RS. The study demonstrates that ion beam irradiation is a promising tool to enhance the filtration efficiency of MWNT filters.

  9. Object reasoning for waste remediation

    International Nuclear Information System (INIS)

    Pennock, K.A.; Bohn, S.J.; Franklin, A.L.

    1991-08-01

    A large number of contaminated waste sites across the United States await size remediation efforts. These sites can be physically complex, composed of multiple, possibly interacting, contaminants distributed throughout one or more media. The Remedial Action Assessment System (RAAS) is being designed and developed to support decisions concerning the selection of remediation alternatives. The goal of this system is to broaden the consideration of remediation alternatives, while reducing the time and cost of making these considerations. The Remedial Action Assessment System is a hybrid system, designed and constructed using object-oriented, knowledge- based systems, and structured programming techniques. RAAS uses a combination of quantitative and qualitative reasoning to consider and suggest remediation alternatives. The reasoning process that drives this application is centered around an object-oriented organization of remediation technology information. This paper describes the information structure and organization used to support this reasoning process. In addition, the paper describes the level of detail of the technology related information used in RAAS, discusses required assumptions and procedural implications of these assumptions, and provides rationale for structuring RAAS in this manner. 3 refs., 3 figs

  10. Simple down conversion nano-crystal coatings for enhancing Silicon-solar cells efficiency

    Directory of Open Access Journals (Sweden)

    Gur Mittelman

    2016-09-01

    Full Text Available Utilizing self-assembled nano-structured coatings on top of existing solar cells has thepotential to increase the total quantum efficiency of the cell using a simple and cheap process. In ourwork we have exploited the controlled absorption of nano-crystal with different band gaps to realizedown conversion artificial antennas that self-assembled on the device surface. The UV sun light isconverted to the visible light enhancing the solar cell performance in two complementary routes; a.protecting the solar cell and coatings from the UV illumination and therefore reducing the UVradiation damage. b. enhancing the total external quantum efficiency of the cell by one percent. Thisis achieved using a simple cheap process that can be adjusted to many different solar cells.

  11. The UMTRA PEIS: A strategy for groundwater remediation

    International Nuclear Information System (INIS)

    Burt, C.; Ulland, L.; Weston, R.F.; Metzler, D.

    1993-01-01

    A programmatic environmental impact statement (PEIS) was initiated in 1992 for the uranium mill tailings remedial action (UMTRA) program. The PEIS kicked off the groundwater restoration phase of UMTRA, a project involving remediation of 24 sites in ten states and tribal lands contaminated with tailings from uranium mining and milling operations. The U.S. Department of Energy (DOE) agreed, in early 1992, that a PEIS was an appropriate strategy to comply with the National Environmental Policy Act (NEPA) for this second, groundwater phase of the project. This decision recognized that although a parallel effort was being undertaken in preparing a PEIS for DOE's Environmental Restoration/Waste Management (ER/WM) program, characteristics and the maturity of the UMTRA project made it more appropriate to prepare a separate PEIS. The ER/WM PEIS is intended to examine environmental restoration and waste management issues from a very broad perspective. For UMTRA, with surface remediation completed or well under way at 18 of the 24 sites, a more focused programmatic approach for groundwater restoration is more effective than including the UMTRA project within the ER/WM environmental impact statements. A separate document allows a more focused and detailed analysis necessary to efficiently tier site-specific environmental assessments for groundwater restoration at each of the 24 UMTRA former processing sites

  12. Valuing uncertain cash flows from investments that enhance energy efficiency.

    Science.gov (United States)

    Abadie, Luis M; Chamorro, José M; González-Eguino, Mikel

    2013-02-15

    There is a broad consensus that investments to enhance energy efficiency quickly pay for themselves in lower energy bills and spared emission allowances. However, investments that at first glance seem worthwhile usually are not undertaken. One of the plausible, non-excluding explanations is the numerous uncertainties that these investments face. This paper deals with the optimal time to invest in an energy efficiency enhancement at a facility already in place that consumes huge amounts of a fossil fuel (coal) and operates under carbon constraints. We follow the Real Options approach. Our model comprises three sources of uncertainty following different stochastic processes which allows for application in a broad range of settings. We assess the investment option by means of a three-dimensional binomial lattice. We compute the trigger investment cost, i.e., the threshold level below which immediate investment would be optimal. We analyze the major drivers of this decision thus aiming at the most promising policies in this regard. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Impact of heavy metal toxicity and constructed wetland system as a tool in remediation.

    Science.gov (United States)

    Usharani, B; Vasudevan, N

    2016-01-01

    The objective of this review is to throw light upon the global concern of heavy metal-contaminated sites and their remediation through an ecofriendly approach. Accumulated heavy metals in soil and water bodies gain entry through the food chain and pose serious threat to all forms of life. This has engendered interest in phytoremediation techniques where hyperaccumulators are used. Constructed wetland has a pivotal role and is a cost-effective technique in the remediation of heavy metals. Metal availability and mobility are influenced by the addition of chelating agents, which enhance the availability of metal uptake. This review helps in identifying the critical knowledge gaps and areas to enhance research in the future to develop strategies such as genetically engineered hyperaccumulators to attain an environment devoid of heavy metal contamination.

  14. Assessment of the immune-modulatory and antimicrobial effects of dietary chitosan on Nile tilapia (Oreochrmis niloticus) with special emphasis to its bio-remediating impacts.

    Science.gov (United States)

    Abu-Elala, Nermeen M; Mohamed, Samah H; Zaki, Manal M; Eissa, Alaa Eldin

    2015-10-01

    Fish, pathogen and environment are three counterparts who are sharing the same circle of life. To keep fish up to their optimal health, environment should be competently improved and pathogen count/virulence should be seized. Using of bioactive immunostimulants to achieve these objectives is the hypothesis under assessment. Thus, the present study was performed to evaluate the use of shrimp shells derived chitosan as an immunostimulant as well as preventive regime against Aeromonas hydrophila infection of Nile tilapia and to assess its antibacterial/aquatic bio-remediating effects. Results achieved by feeding 1% chitosan as preventive/therapeutic regimes have revealed a remarkably enhanced several innate immunological parameters (e.g., Phagocytic activity/index, NBT, Lysozyme activity and ACH50), increased resistance against A. hydrophila and strikingly improved water quality compared to the 0.5 and 2% chitosan containing diets. Conclusively, experimental results suggest the commercial usage of chitosan as an efficient immunostimulant and bio-remediating agent in aquaculture. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Environmental impact of ongoing sources of metal contamination on remediated sediments

    Energy Technology Data Exchange (ETDEWEB)

    Knox, Anna Sophia, E-mail: anna.knox@srn.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Paller, Michael H., E-mail: michael.paller@srnl.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Milliken, Charles E., E-mail: charles.milliken@srnl.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Redder, Todd M., E-mail: tredder@limno.com [LimnoTech, Ann Arbor, Minnesota 48108 (United States); Wolfe, John R., E-mail: jwolfe@limno.com [LimnoTech, Ann Arbor, Minnesota 48108 (United States); Seaman, John, E-mail: seaman@srel.uga.edu [Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802 (United States)

    2016-09-01

    aquatic organisms, and enhance remedial effectiveness. - Highlights: • Ongoing sources of contamination are a challenge to sediment remedial methods • Active caps removed metals from ongoing sources and reduced their bioavailability • Metals from ongoing sources contaminated uncapped sediment and passive caps • Whole-body metal concentrations were lower in Lumbriculus from active caps • Active caps can protect remediated sediments from continuing contaminant influxes.

  16. Environmental impact of ongoing sources of metal contamination on remediated sediments

    International Nuclear Information System (INIS)

    Knox, Anna Sophia; Paller, Michael H.; Milliken, Charles E.; Redder, Todd M.; Wolfe, John R.; Seaman, John

    2016-01-01

    aquatic organisms, and enhance remedial effectiveness. - Highlights: • Ongoing sources of contamination are a challenge to sediment remedial methods • Active caps removed metals from ongoing sources and reduced their bioavailability • Metals from ongoing sources contaminated uncapped sediment and passive caps • Whole-body metal concentrations were lower in Lumbriculus from active caps • Active caps can protect remediated sediments from continuing contaminant influxes

  17. Efficient Hardware Implementation For Fingerprint Image Enhancement Using Anisotropic Gaussian Filter.

    Science.gov (United States)

    Khan, Tariq Mahmood; Bailey, Donald G; Khan, Mohammad A U; Kong, Yinan

    2017-05-01

    A real-time image filtering technique is proposed which could result in faster implementation for fingerprint image enhancement. One major hurdle associated with fingerprint filtering techniques is the expensive nature of their hardware implementations. To circumvent this, a modified anisotropic Gaussian filter is efficiently adopted in hardware by decomposing the filter into two orthogonal Gaussians and an oriented line Gaussian. An architecture is developed for dynamically controlling the orientation of the line Gaussian filter. To further improve the performance of the filter, the input image is homogenized by a local image normalization. In the proposed structure, for a middle-range reconfigurable FPGA, both parallel compute-intensive and real-time demands were achieved. We manage to efficiently speed up the image-processing time and improve the resource utilization of the FPGA. Test results show an improved speed for its hardware architecture while maintaining reasonable enhancement benchmarks.

  18. Remediation of polluted sites. The risks, liabilities and costs; Rehabilitation de sites pollues. Quels risques? Quelles responsabilites? Quels couts?

    Energy Technology Data Exchange (ETDEWEB)

    Paquot, A. [Ministere de l' Ecologie et du Developpement Durable 75 - Paris (France); Darmendrail, D. [BRGM, 75 - Paris (France); Mensah, J. [Etablissement public foncier Nord Pas de Calais, 59 - Lille (France); Costil, J. [BURGEAP, 69 - Lyon (France); Carbon, S. [Gaz de France (GDF), 75 - Paris (France); Gervaise, Y. [SGS Multilab, 51 - Rouen (France); Bonin, H. [GRS Valtech, 69 - Rilleux-la-Pape (France); Delfaud, L. [Projenor, 59 - Lille (France); Croze, V. [ICF Environnement, 92 - Gennevilliers (France); Ricour, J. [ANTEA, des solutions globales, durables et rentables, 45 - Orleans (France); Langlois, P.

    2003-10-01

    This conference deals with the following topics: the mastery of the economic, regulation, juridical and contractual framework; liabilities and financing distribution between the intervenors; the diagnostic cost; the financial security in the sites acquisition and social right transfer; the efficient technologies of sites remediation; the communication near the site in remediation. (A.L.B.)

  19. Green and sustainable remediation (GSR) evaluation: framework, standards, and tool. A case study in Taiwan.

    Science.gov (United States)

    Huang, Wen-Yen; Hung, Weiteng; Vu, Chi Thanh; Chen, Wei-Ting; Lai, Jhih-Wei; Lin, Chitsan

    2016-11-01

    Taiwan has a large number of poorly managed contaminated sites in need of remediation. This study proposes a framework, a set of standards, and a spreadsheet-based evaluation tool for implementing green and sustainable principles into remediation projects and evaluating the projects from this perspective. We performed a case study to understand how the framework would be applied. For the case study, we used a spreadsheet-based evaluation tool (SEFA) and performed field scale cultivation tests on a site contaminated with total petroleum hydrocarbons (TPHs). The site was divided into two lots: one treated by chemical oxidation and the other by bioremediation. We evaluated five core elements of green and sustainable remediation (GSR): energy, air, water resources, materials and wastes, and land and ecosystem. The proposed evaluation tool and field scale cultivation test were found to efficiently assess the effectiveness of the two remediation alternatives. The framework and related tools proposed herein can potentially be used to support decisions about the remediation of contaminated sites taking into account engineering management, cost effectiveness, and social reconciliation.

  20. Co-remediation of the lead-polluted garden soil by exogenous natural zeolite and humic acids.

    Science.gov (United States)

    Shi, Wei-yu; Shao, Hong-bo; Li, Hua; Shao, Ming-an; Du, Sheng

    2009-08-15

    The current study reported the co-remediation effect on the lead-polluted garden soil by zeolite and humic acids (HA), which was from comparing with the remediation of single zeolite in term of the lead fraction of sequential extraction in the soil and the distribution of lead in different parts of rape. Mixed treatment (zeolite and HA) and single treatment (zeolite) were, respectively, applied to the artificially polluted garden soil to examine the difference of their remediation effects in pot experiment. Results indicated that the co-remediation led to significantly greater (plead concentration in plants than by singly adding to zeolite. The co-application of zeolite and HA reduced the available fraction of lead compounds, but slightly increased (plead compounds in the garden soil, compared with the application of single zeolite, especially in the severe lead-polluted soil (> or =1000 mg kg(-1)). This method might be an efficient way to remediate the lead-polluted soils on a large scale, although zeolite is a kind of hazardous material.

  1. Bioaccumulation in Porcellio scaber (Crustacea, Isopoda) as a measure of the EDTA remediation efficiency of metal-polluted soil

    International Nuclear Information System (INIS)

    Udovic, Metka; Drobne, Damjana; Lestan, Domen

    2009-01-01

    Leaching using EDTA applied to a Pb, Zn and Cd polluted soil significantly reduced soil metal concentrations and the pool of metals in labile soil fractions. Metal mobility (Toxicity Characteristic Leaching Procedure), phytoavailability (diethylenetriaminepentaacetic acid extraction) and human oral-bioavailability (Physiologically Based Extraction Test) were reduced by 85-92%, 68-91% and 88-95%, respectively. The metal accumulation capacity of the terrestrial isopod Porcellio scaber (Crustacea) was used as in vivo assay of metal bioavailability, before and after soil remediation. After feeding on metal contaminated soil for two weeks, P. scaber accumulated Pb, Zn and Cd in a concentration dependent manner. The amounts of accumulated metals were, however, higher than expected on the basis of extraction (in vitro) tests. The combined results of chemical extractions and the in vivo test with P. scaber provide a more relevant picture of the availability stripping of metals after soil remediation. - Bioaccumulation tests with Porcellio scaber isopods are proposed as a supplement to chemical extraction in assessing metal bioavailability before and after soil remediation.

  2. Expedited Remedial Action Program (SB 923): A California Brownfields initiative

    Energy Technology Data Exchange (ETDEWEB)

    Cambridge, M.; Wolfenden, A.K.

    1996-12-31

    California`s Expedited Remedial Action Program (ERAP) created a comprehensive program that promotes an equitable and expedited approach for redevelopment of properties contaminated with hazardous substances. This bill embodies an emerging trend in environmental policy that permits flexibility, cooperation and creativity without compromising protection to public health or the environment. Within the California Environmental Protection Agency, the Department of Toxic Substances Control (DTSC) is promoting a number of programs to facilitate the restoration of contaminated properties as part of its Brownfields initiative. ERAP represents a potentially more efficient process to remediate sites by minimizing economic risks through a clearly identified liability scheme, indemnifying future owners through a covenant not to sue, and providing risk based cleanups that are based on the permanent use of the site.

  3. Air-Based Remediation Workshop - Section 8 Air-Based Remediation Technology Selection Logic

    Science.gov (United States)

    Pursuant to the EPA-AIT Implementing Arrangement 7 for Technical Environmental Collaboration, Activity 11 "Remediation of Contaminated Sites," the USEPA Office of International Affairs Organized a Forced Air Remediation Workshop in Taipei to deliver expert training to the Environ...

  4. Site characterization techniques used in environmental remediation activities

    International Nuclear Information System (INIS)

    Kostelnik, K.M.

    2000-01-01

    As a result of decades of nuclear energy research, weapons production, as well as ongoing operations, a significant amount of radioactive contamination has occurred throughout the United States Department of Energy (DOE) complex. DOE facility are in the process of assessing and potentially remediating various sites according to the regulations imposed by a Federal Facility Agreement and Consent order (FFA/CO) between DOE, the state in which the facility is located, and the U.S. Environmental Protection Agency (EPA). In support of these active site remediation efforts, the DOE has devoted considerable resources towards the development of innovative site characterization techniques that support environmental restoration activities. These resources and efforts have focused on various aspects of this complex problem. Research and technology development conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) has resulted in the ability and state-of-the-art equipment required to obtain real-time, densely spaced, in situ characterization data (i.e. detection, speciation, and location) of various radionuclides and contaminants. The Remedial Action Monitoring System (RAMS), developed by the INEEL, consists of enhanced sensor technology, measurement modeling and interpretation techniques, and a suite of deployment platforms which can be interchanged to directly support remedial cleanup and site verification operations. In situ characterization techniques have advanced to the point where they are being actively deployed in support of remedial operations. The INEEL has deployed its system at various DOE and international sites. The deployment of in situ characterization systems during environmental restoration operations has shown that this approach results in several significant benefits versus conventional sampling techniques. A flexible characterization system permits rapid modification to satisfy physical site conditions, available site resources

  5. Immediate remediation of heavy metal (Cr(VI)) contaminated soil by high energy electron beam irradiation

    International Nuclear Information System (INIS)

    Zhang, Jing; Zhang, Guilong; Cai, Dongqing; Wu, Zhengyan

    2015-01-01

    Highlights: • An immediate remediation method for Cr(VI) contaminated soil (CCS) was developed. • High energy electron beam (HEEB) irradiation could reduce Cr(VI) in CCS to Cr(III). • This effect was attributed to electrons, hydrated electrons, and reductive radicals. • This remediation method was effective, environmentally friendly, and low-cost. - Abstract: This work developed an immediate and high-performance remediation method for Cr(VI) contaminated soil (CCS) using high energy electron beam (HEEB) irradiation. The result indicated that, compared with γ-ray irradiation, HEEB irradiation displayed a significant reduction efficiency on Cr(VI) in CCS to Cr(III) with substantially lower toxicity, which was mainly attributed to the reduction effects of electrons, hydrated electrons, and reductive radicals generated in the irradiation process of HEEB. This work could provide a one-step and effective method for the remediation of heavy metal contaminated soil (HMCS)

  6. Immediate remediation of heavy metal (Cr(VI)) contaminated soil by high energy electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jing; Zhang, Guilong [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei 230031 (China); Bioenergy Forest Research Center of State Forestry Administration, Hefei 230031 (China); Cai, Dongqing, E-mail: dqcai@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei 230031 (China); Bioenergy Forest Research Center of State Forestry Administration, Hefei 230031 (China); Wu, Zhengyan, E-mail: zywu@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei 230031 (China); Bioenergy Forest Research Center of State Forestry Administration, Hefei 230031 (China)

    2015-03-21

    Highlights: • An immediate remediation method for Cr(VI) contaminated soil (CCS) was developed. • High energy electron beam (HEEB) irradiation could reduce Cr(VI) in CCS to Cr(III). • This effect was attributed to electrons, hydrated electrons, and reductive radicals. • This remediation method was effective, environmentally friendly, and low-cost. - Abstract: This work developed an immediate and high-performance remediation method for Cr(VI) contaminated soil (CCS) using high energy electron beam (HEEB) irradiation. The result indicated that, compared with γ-ray irradiation, HEEB irradiation displayed a significant reduction efficiency on Cr(VI) in CCS to Cr(III) with substantially lower toxicity, which was mainly attributed to the reduction effects of electrons, hydrated electrons, and reductive radicals generated in the irradiation process of HEEB. This work could provide a one-step and effective method for the remediation of heavy metal contaminated soil (HMCS)

  7. 200-UP-1 groundwater remedial design/remedial action work plan. Revision 1

    International Nuclear Information System (INIS)

    1997-07-01

    This 200-UP-1 remedial design report presents the objective and rationale developed for the design and implementation of the selected interim remedial measure for the 200-UP-1 Operable Unit, located in the 200 West Area of the Hanford Site

  8. Nuclear Site Remediation and Restoration during Decommissioning of Nuclear Installations. A Report by the NEA Co-operative Programme on Decommissioning

    International Nuclear Information System (INIS)

    Orr, Peter; Mitchell, Nick; Mobbs, Shelly; Bennest, Terry; Abu-Eid, Rateb-Boby; Berton, Marie-Anne; Dehaye, Catherine Ollivier; Pellenz, Gilles; Cruikshank, Julian; Diaz Arocas, Paloma; Garcia Tapias, Ester; Hess, Norbert; Hong, Sam-Bung; Miller, Susan; Monken-Fernandes, Horst; ); Morse, John; Nitzsche, Olaf; Ooms, Bart; Osimani, Celso; Stuart Walker

    2014-01-01

    Decommissioning of nuclear facilities and related remedial actions are currently being undertaken around the world to enable sites or parts of sites to be reused for other purposes. Remediation has generally been considered as the last step in a sequence of decommissioning steps, but the values of prevention, long-term planning and parallel remediation are increasingly being recognised as important steps in the process. This report, prepared by the Task Group on Nuclear Site Restoration of the NEA Co-operative Programme on Decommissioning, highlights lessons learnt from remediation experiences of NEA member countries that may be particularly helpful to practitioners of nuclear site remediation, regulators and site operators. It provides observations and recommendations to consider in the development of strategies and plans for efficient nuclear site remediation that ensures protection of workers and the environment. (authors)

  9. Enhancing the Efficiency of Silicon-Based Solar Cells by the Piezo-Phototronic Effect.

    Science.gov (United States)

    Zhu, Laipan; Wang, Longfei; Pan, Caofeng; Chen, Libo; Xue, Fei; Chen, Baodong; Yang, Leijing; Su, Li; Wang, Zhong Lin

    2017-02-28

    Although there are numerous approaches for fabricating solar cells, the silicon-based photovoltaics are still the most widely used in industry and around the world. A small increase in the efficiency of silicon-based solar cells has a huge economic impact and practical importance. We fabricate a silicon-based nanoheterostructure (p + -Si/p-Si/n + -Si (and n-Si)/n-ZnO nanowire (NW) array) photovoltaic device and demonstrate the enhanced device performance through significantly enhanced light absorption by NW array and effective charge carrier separation by the piezo-phototronic effect. The strain-induced piezoelectric polarization charges created at n-doped Si-ZnO interfaces can effectively modulate the corresponding band structure and electron gas trapped in the n + -Si/n-ZnO NW nanoheterostructure and thus enhance the transport process of local charge carriers. The efficiency of the solar cell was improved from 8.97% to 9.51% by simply applying a static compress strain. This study indicates that the piezo-phototronic effect can enhance the performance of a large-scale silicon-based solar cell, with great potential for industrial applications.

  10. Remedial activities effectiveness verification in tailing areas

    International Nuclear Information System (INIS)

    Kluson, J.; Thinova, L.; Svoboda, T.; Neznal, M.

    2015-01-01

    The complex radiological study of the basin of sludge from the uranium ore mining and preprocessing was done. Air kerma rates (including its spectral analysis) at the reference height of 1 m above ground over the whole area were measured and radiation fields mapped during two measuring campaigns (years 2009 and 2014). K, U and Th concentrations in sludge and concentrations in depth profiles (including radon concentration and radon exhalation rates) in selected points were determined using gamma spectrometry for in situ as well as laboratory samples measurement. Results were used for the analysis, design evaluation and verification of the efficiency of the remediation measures. Efficiency of the sludge basin covering by the inert material was modelled using MicroShield code. (authors)

  11. Decommissioning end of life oilfield facilities and pipelines : the first step to the safe and efficient remediation of oil and gas sites

    International Nuclear Information System (INIS)

    Kitchen, J.; Thygesen, S.

    2005-01-01

    Environmentally sound decommissioning practices in the remediation and reclamation process were reviewed, with reference to abandoned oil and gas facilities and pipelines. There are inherent dangers associated with aged infrastructure, and decommissioning companies should be the first service on site to ensure that all facilities have been located, removed and cleaned. All licensed, unlicensed and on-lease pipelines are required to be properly abandoned. Site research is needed to identify any industry or government regulated requirements that may impact the decommissioning process. Decommissioning companies are also responsible for recording all relevant site information so that it can be conveyed to remediation and reclamation companies. A knowledge of landowner sensitivities, weather affected access, unlicensed facilities and locations of historic contamination are crucial to all parties involved. Additional documentation, such as photographs and survey drawings, can assist remediation and reclamation companies in locating areas of concern. Once a well has been abandoned in Alberta, surface equipment, cement pads, debris and produced liquids associated with the well license must be removed within 12 months of the cutting and capping operation. Records of the removal and cleanup activities must be retained by the licensee. Many sites have been sitting dormant for several years and can be harboring dangerous production fluids, asbestos, Hantavirus and other hazardous materials. All equipment must be steam-cleaned by qualified personnel and all production fluids and contaminated water from the cleaning process must be captured and transported to a waste facility. All equipment that is deemed re-usable can be returned to inventory or re-used. Equipment that can not be salvaged is sold for recycling at a steel mill. All pipelines are required to be cleaned of hydrocarbons, purged and left with a medium of inert gas or atmospheric air. Residual fluids left in a

  12. Electrokinetic remediation of fluorine-contaminated soil and its impact on soil fertility.

    Science.gov (United States)

    Zhou, Ming; Wang, Hui; Zhu, Shufa; Liu, Yana; Xu, Jingming

    2015-11-01

    Compared to soil pollution by heavy metals and organic pollutants, soil pollution by fluorides is usually ignored in China. Actually, fluorine-contaminated soil has an unfavorable influence on human, animals, plants, and surrounding environment. This study reports on electrokinetic remediation of fluorine-contaminated soil and the effects of this remediation technology on soil fertility. Experimental results showed that electrokinetic remediation using NaOH as the anolyte was a considerable choice to eliminate fluorine in contaminated soils. Under the experimental conditions, the removal efficiency of fluorine by the electrokinetic remediation method was 70.35%. However, the electrokinetic remediation had a significant impact on the distribution and concentrations of soil native compounds. After the electrokinetic experiment, in the treated soil, the average value of available nitrogen was raised from 69.53 to 74.23 mg/kg, the average value of available phosphorus and potassium were reduced from 20.05 to 10.39 mg/kg and from 61.31 to 51.58 mg/kg, respectively. Meanwhile, the contents of soil available nitrogen and phosphorus in the anode regions were higher than those in the cathode regions, but the distribution of soil available potassium was just the opposite. In soil organic matter, there was no significant change. These experiment results suggested that some steps should be taken to offset the impacts, after electrokinetic treatment.

  13. Modern approaches to remediation of heavy metal polluted soils: A review

    Science.gov (United States)

    Koptsik, G. N.

    2014-07-01

    The main principles and approaches to remediation of in situ polluted soils aimed at the removal or control of heavy metals (washing, stabilization, phytoremediation, and natural restoration) are analyzed. The prospects of gentle methods of stabilization oriented at the reduction of the mobility and biological availability of heavy metals due to the processes of adsorption, ionic exchange, and precipitation are emphasized. The use of sorbents and the traditional application of liming and phosphates to fix metal pollutants in soils is considered. The necessary conditions for successful soil remediation are the assessment of its economic efficiency, the analysis of the ecological risks, and confirming the achievement of the planned purposes related to the content of available metals in the soils.

  14. Recent advances in conventional and contemporary methods for remediation of heavy metal-contaminated soils.

    Science.gov (United States)

    Sharma, Swati; Tiwari, Sakshi; Hasan, Abshar; Saxena, Varun; Pandey, Lalit M

    2018-04-01

    Remediation of heavy metal-contaminated soils has been drawing our attention toward it for quite some time now and a need for developing new methods toward reclamation has come up as the need of the hour. Conventional methods of heavy metal-contaminated soil remediation have been in use for decades and have shown great results, but they have their own setbacks. The chemical and physical techniques when used singularly generally generate by-products (toxic sludge or pollutants) and are not cost-effective, while the biological process is very slow and time-consuming. Hence to overcome them, an amalgamation of two or more techniques is being used. In view of the facts, new methods of biosorption, nanoremediation as well as microbial fuel cell techniques have been developed, which utilize the metabolic activities of microorganisms for bioremediation purpose. These are cost-effective and efficient methods of remediation, which are now becoming an integral part of all environmental and bioresource technology. In this contribution, we have highlighted various augmentations in physical, chemical, and biological methods for the remediation of heavy metal-contaminated soils, weighing up their pros and cons. Further, we have discussed the amalgamation of the above techniques such as physiochemical and physiobiological methods with recent literature for the removal of heavy metals from the contaminated soils. These combinations have showed synergetic effects with a many fold increase in removal efficiency of heavy metals along with economic feasibility.

  15. Phytoavailability and geospeciation of cadmium in contaminated soil remediated by Rhodobacter sphaeroides.

    Science.gov (United States)

    Fan, Wenhong; Jia, Yingying; Li, Xiaomin; Jiang, Wei; Lu, Lin

    2012-07-01

    A microorganism was isolated from oil field injection water and identified as Rhodobacter sphaeroides. It was used for the remediation of simulated cadmium-contaminated soil. The phytoavailability of Cd was investigated through wheat seedling method to determine the efficiency of remediation. It was found that after remediation, the accumulation of Cd in wheat roots and leaves decreased by 67% and 53%, respectively. The Cd speciation in soil was determined with Tessier extraction procedure. It was found that the total Cd content in soil did not change during the experiments, but the geo-speciation of Cd changed remarkably. Among the five fractions, the concentration of exchangeable phases decreased by 27-46% and that of the phases bound to Fe-Mn oxides increased by 22-44%. The decrease of Cd accumulation in wheat showed significant positive correlation with the decrease of exchangeable phases. It could be concluded that the remediation of R. sphaeroides was carried out through the conversion of Cd to more stable forms. The decrease of sulfate concentration in supernatant indicated that the R. sphaeroides consumed sulfate. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Mold: Cleanup and Remediation

    Science.gov (United States)

    ... National Center for Environmental Health (NCEH) Cleanup and Remediation Recommend on Facebook Tweet Share Compartir On This ... CDC and EPA on mold cleanup, removal and remediation. Cleanup information for you and your family Homeowner’s ...

  17. [Effects of enhanced CO2 fertilization on phytoremediation of DEHP-polluted soil].

    Science.gov (United States)

    Diao, Xiao-Jun; Wang, Shu-Guang; Mu, Nan

    2013-03-01

    Low efficiency of remediation is one of the key issues to be solved in phytoremediation technology. Based on the necessity of reducing CO2 emission in China and the significance of CO2 in plant photosynthesis, this paper studied the effects of enhanced CO2 fertilization on the phytoremediation of polluted soil, selecting the C3 plant mung bean (Vigna radiate) and the C4 plant maize (Zea mays) as test plants for phytoremediation and the DEHP as the target pollutant. DEHP pollution had negative effects on the growth and rhizosphere micro-environment of the two plants. After enhanced CO2 fertilization, the aboveground dry mass of the two plants and the alkaline phosphatase activity in the rhizosphere soils of the two plants increased, the COD activity in the leaves of the two plants decreased, the microbial community in the rhizosphere soils shifted, and the numbers of the microbes with DEHP-tolerance in the rhizosphere soils increased. These changes indicated that enhanced CO2 fertilization could promote the plant growth and the plant tolerance to DEHP stress, and improve the rhizosphere micro-environment. Enhanced CO2 fertilization also increased the DEHP uptake by the two plants, especially their underground parts. All these effects induced the residual DEHP concentration in the rhizospheres of the two plants, especially that of mung bean, decreased obviously, and the phytoremediation efficiency increased. Overall, enhanced CO2 fertilization produced greater effects on C3 plant than on C4 plant. It was suggested that enhanced CO2 fertilization could be a useful measure to enhance the efficiency of phytoremediation.

  18. USING PHASE DIAGRAMS TO PREDICT THE PERFORMANCE OF COSOLVENT FLOODS FOR NAPL REMEDIATION

    Science.gov (United States)

    Cosolvent flooding using water miscible solvents such as alcohols has been proposed as an in-situ NAPL remediation technique. This process is conceptually similar to enhanced oil recovery (EOR) using alcohols and some surfactant formulations. As a result of interest in the EOR ...

  19. Foam - novel delivery technology for remediation of vadose zone environments - 59019

    International Nuclear Information System (INIS)

    Jansik, Danielle; Wellman, Dawn M.; Mattigod, Shas V.; Zhong, Lirong; Zhang, Fred; Foote, Martin; Wu, Yuxin; Hubbard, Susan

    2012-01-01

    Deep vadose zone environments can be a primary source and pathway for contaminant migration to groundwater. These environments present unique characterization and remediation challenges that necessitate scrutiny and research. The thickness, depth, and intricacies of the deep vadose zone, combined with a lack of understanding of the key subsurface processes (e.g., biogeochemical and hydrologic) affecting contaminant migration, make it difficult to create validated conceptual and predictive models of subsurface flow dynamics and contaminant behavior across multiple scales. These factors also make it difficult to design and deploy sustainable remedial approaches and monitor long-term contaminant behavior after remedial actions. Functionally, methods for addressing contamination must remove and/or reduce transport of contaminants. This problem is particularly challenging in the arid western United States where the vadose zone is hundreds of feet thick, rendering transitional excavation methods exceedingly costly and ineffective. Delivery of remedial amendments is one of the most challenging and critical aspects for all remedy-based approaches. The conventional approach for delivery is through injection of aqueous remedial solutions. However, heterogeneous deep vadose zone environments present hydrologic and geochemical challenges that limit the effectiveness. Because the flow of solution infiltration is dominantly controlled by gravity and suction, injected liquid preferentially percolates through highly permeable pathways, by-passing low-permeability zones that frequently contain the majority of contamination. Moreover, the wetting front can readily mobilize and enhance contaminant transport to the underlying aquifer prior to stabilization. Development of innovative in-situ technologies may be the only means to meet remedial action objectives and long-term stewardship goals. Surfactants can be used to lower the liquid surface tension and create stabile foams, which

  20. Escherichia coli NemA is an efficient chromate reductase that can be biologically immobilized to provide a cell free system for remediation of hexavalent chromium.

    Directory of Open Access Journals (Sweden)

    Katherine J Robins

    Full Text Available Hexavalent chromium is a serious and widespread environmental pollutant. Although many bacteria have been identified that can transform highly water-soluble and toxic Cr(VI to insoluble and relatively non-toxic Cr(III, bacterial bioremediation of Cr(VI pollution is limited by a number of issues, in particular chromium toxicity to the remediating cells. To address this we sought to develop an immobilized enzymatic system for Cr(VI remediation. To identify novel Cr(VI reductase enzymes we first screened cell extracts from an Escherichia coli library of soluble oxidoreductases derived from a range of bacteria, but found that a number of these enzymes can reduce Cr(VI indirectly, via redox intermediates present in the crude extracts. Instead, activity assays for 15 candidate enzymes purified as His6-tagged proteins identified E. coli NemA as a highly efficient Cr(VI reductase (k(cat/K(M= 1.1×10(5 M(-1 s(-1 with NADH as cofactor. Fusion of nemA to the polyhydroxyalkanoate synthase gene phaC from Ralstonia eutropha enabled high-level biosynthesis of functionalized polyhydroxyalkanoate granules displaying stable and active NemA on their surface. When these granules were combined with either Bacillus subtilis glucose dehydrogenase or Candida boidinii formate dehydrogenase as a cofactor regenerating partner, high levels of chromate transformation were observed with only low initial concentrations of expensive NADH cofactor being required, the overall reaction being powered by consumption of the cheap sacrificial substrates glucose or formic acid, respectively. This system therefore offers promise as an economic solution for ex situ Cr(VI remediation.

  1. Strategy paper. Remedial design/remedial action 100 Area. Revision 1

    International Nuclear Information System (INIS)

    Donahoe, R.L.

    1995-07-01

    The purpose of this planning document is to identify and define the approach for remedial design and remedial action (RD/RA) in the 100 Area of the Hanford Site, located in southeastern Washington State. Additionally, this document will support the Hanford Site Environmental Restoration Contract (ERC) team, the US Department of Energy (DOE), and regulatory agencies in identifying and agreeing upon the complete process for expedited cleanup of the 100 Area

  2. A dialogue-centric approach to environmental-remediation decision-making - 59115

    International Nuclear Information System (INIS)

    Boucher, Laurel; Clark, James F.

    2012-01-01

    This paper outlines a multi-step approach to streamline and enhance the decision-making process that guides environmental remediation. The inability of the responsible party and the various stakeholders to reach agreement on the remediation plan can delay the remediation, result in financial penalties, and lead to the development of an adversarial stance that inhibits the ability of the parties to work together in a creative and constructive manner. The approach presented by the authors is designed to expand dialogue in a way that moves it beyond technical or fiscal matters by addressing what the authors describe as the 'hidden barriers' to productive dialogue. These 'hidden barriers' include: self-interests, the perception as to how people are being treated, a lack of clarity or poor management of responsibilities and accountabilities, unclear or convoluted communication protocols, and an underlying tone of conflict and cynicism. A key element of the multi-step approach outlined in this paper is the process of uncovering these 'hidden barriers' and addressing them in a way that turns discourse into collaboration. The paper describes a model the authors have used to streamline and enhance the process of creating sustainable agreements both for the U.S. Department of Energy's Office of Environmental Management as well as the U.S. Department of Defense for a variety of environmental remediation projects. The results of this approach include the acceleration of an environmental clean-up from a projected 19 years to 11 years, the development of innovative technical strategies, the reduction of a major backlog of environmental proposals requiring review and comment, and the distinction accorded one group of being recognized as a model of effective partnering. The approach described has widespread implications not only because its use can be expanded to include a multitude of decision-making applications but also because of the impact it creates by expanding both the

  3. Electrodialytic Remediation of Copper Mine Tailings

    DEFF Research Database (Denmark)

    Hansen, H.K.; Rojo, A.; Ottosen, L.M.

    2012-01-01

    This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analysed, such as remediation time, addition of desorbing agents, and the use of pulsed electrical fields.......This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analysed, such as remediation time, addition of desorbing agents, and the use of pulsed electrical fields....

  4. Integrating remediation and resource recovery: On the economic conditions of landfill mining

    International Nuclear Information System (INIS)

    Frändegård, Per; Krook, Joakim; Svensson, Niclas

    2015-01-01

    Highlights: • We compare two remediation scenarios; one with resource recovery and one without. • Economic analysis includes relevant direct costs and revenues for the landfill owner. • High degrees of metal and/or combustible contents are important economic factors. • Landfill tax and the access to a CHP can have a large impact on the result. • Combining landfill mining and remediation may decrease the project cost. - Abstract: This article analyzes the economic potential of integrating material separation and resource recovery into a landfill remediation project, and discusses the result and the largest impact factors. The analysis is done using a direct costs/revenues approach and the stochastic uncertainties are handled using Monte Carlo simulation. Two remediation scenarios are applied to a hypothetical landfill. One scenario includes only remediation, while the second scenario adds resource recovery to the remediation project. Moreover, the second scenario is divided into two cases, case A and B. In case A, the landfill tax needs to be paid for re-deposited material and the landfill holder does not own a combined heat and power plant (CHP), which leads to disposal costs in the form of gate fees. In case B, the landfill tax is waived on the re-deposited material and the landfill holder owns its own CHP. Results show that the remediation project in the first scenario costs about €23/ton. Adding resource recovery as in case A worsens the result to −€36/ton, while for case B the result improves to −€14/ton. This shows the importance of landfill tax and the access to a CHP. Other important factors for the result are the material composition in the landfill, the efficiency of the separation technology used, and the price of the saleable material

  5. Integrating remediation and resource recovery: On the economic conditions of landfill mining

    Energy Technology Data Exchange (ETDEWEB)

    Frändegård, Per, E-mail: per.frandegard@liu.se; Krook, Joakim; Svensson, Niclas

    2015-08-15

    Highlights: • We compare two remediation scenarios; one with resource recovery and one without. • Economic analysis includes relevant direct costs and revenues for the landfill owner. • High degrees of metal and/or combustible contents are important economic factors. • Landfill tax and the access to a CHP can have a large impact on the result. • Combining landfill mining and remediation may decrease the project cost. - Abstract: This article analyzes the economic potential of integrating material separation and resource recovery into a landfill remediation project, and discusses the result and the largest impact factors. The analysis is done using a direct costs/revenues approach and the stochastic uncertainties are handled using Monte Carlo simulation. Two remediation scenarios are applied to a hypothetical landfill. One scenario includes only remediation, while the second scenario adds resource recovery to the remediation project. Moreover, the second scenario is divided into two cases, case A and B. In case A, the landfill tax needs to be paid for re-deposited material and the landfill holder does not own a combined heat and power plant (CHP), which leads to disposal costs in the form of gate fees. In case B, the landfill tax is waived on the re-deposited material and the landfill holder owns its own CHP. Results show that the remediation project in the first scenario costs about €23/ton. Adding resource recovery as in case A worsens the result to −€36/ton, while for case B the result improves to −€14/ton. This shows the importance of landfill tax and the access to a CHP. Other important factors for the result are the material composition in the landfill, the efficiency of the separation technology used, and the price of the saleable material.

  6. MGP site remediation: Working toward presumptive remedies

    International Nuclear Information System (INIS)

    Larsen, B.R.

    1996-01-01

    Manufactured Gas Plants (MGPs) were prevalent in the United States during the 19th and first half of the 20th centuries. MGPs produced large quantities of waste by-products, which varied depending on the process used to manufacture the gas, but most commonly were tars and polynuclear aromatic hydrocarbons. There are an estimated 3,000 to 5,000 abandoned MGP sites across the United States. Because these sites are not concentrated in one geographic location and at least three different manufacturing processes were used, the waste characteristics are very heterogeneous. The question of site remediation becomes how to implement a cost-effective remediation with the variety of cleanup technologies available for these sites. Because of the significant expenditure required for characterization and cleanup of MGP sites, owners and regulatory agencies are beginning to look at standardizing cleanup technologies for these sites. This paper discusses applicable cleanup technologies and the attitude of state regulatory agencies towards the use of presumptive remedies, which can reduce the amount of characterization and detailed analysis necessary for any particular site. Additionally, this paper outlines the process of screening and evaluating candidate technologies, and the progress being made to match the technology to the site

  7. Site remediation: The naked truth

    International Nuclear Information System (INIS)

    Calloway, J.M.

    1991-01-01

    The objective of any company faced with an environmental site remediation project is to perform the cleanup effectively at the lowest possible cost. Today, there are a variety of techniques being applied in the remediation of sites involving soils and sludges. The most popular include: stabilization, incineration, bioremediation and off-site treatment. Dewatering may also play an integral role in a number of these approaches. Selecting the most cost-effective technique for remediation of soils and sludges can be a formidable undertaking, namely because it is often difficult to quantify certain expenses in advance of the project. In addition to providing general cost guidelines for various aspects of soil and sludge remediation, this paper will show how some significant cost factors can be affected by conditions related to specific remediation projects and the cleanup technology being applied

  8. Remediation using trace element humate surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

    2016-08-30

    A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

  9. Remedial action and waste disposal project: 100-B/C remedial action readiness evaluation plan

    International Nuclear Information System (INIS)

    April, J.G.; Bryant, D.L.; Cislo, G.B.

    1996-06-01

    The Readiness Evaluation Plan presents the methodology used to assess the readiness of the 100-B/C Remedial Action Project. The 100 Areas Remedial Action Project will remediate the 100 Areas liquid waste site identified in the Interim Action Record of Decision for the 100- BC-1, 100-DR-1, and 100-HR-1 Operable Units. These sites are located in the 100 Area of the Hanford Site in Richland, Washington

  10. Electrodialytic remediation of suspended soil – Comparison of two different soil fractions

    DEFF Research Database (Denmark)

    Sun, Tian Ran; Ottosen, Lisbeth M.; Jensen, Pernille Erland

    2012-01-01

    Electrodialytic remediation (EDR) can be used for removal of heavy metals from suspended soil, which allows for the soil remediation to be a continuous process. The present paper focused on the processing parameters for remediation of a soil polluted with Cu and As from wood preservation. Six...... electrodialytic treatments lasting from 5 to 22 days with different liquid to solid ratio (L/S) and current intensity were conducted. Among treatments, the highest removal was obtained from the soil fines with 5mA current at L/S 3.5 after 22 days where 96% of Cu and 64% of As were removed. Comparing the removal...... from the original soil and the soil fines in experiments with identical charge transportation, higher removal efficiency was observed from the soil fines. Constant current with 5mA could be maintained at L/S 3.5 for the soil fines while not for the original soil. Doubling current to 10mA could...

  11. Assessment of a biological in situ remediation

    International Nuclear Information System (INIS)

    Wuerdemann, H.; Lund, N.C.; Gudehus, G.

    1995-01-01

    A field experiment using a bioventing technique has been conducted at the center of contamination at a former gasworks site for 3 years. The emphasis of this investigation is to determine the efficiency of in situ remediation. Due to an extremely heterogeneous distribution of contamination it was impossible to satisfactorily quantify the reduction of hydrocarbons. However, a comparison of highly contaminated soil samples shows a qualitative alteration. The analyses of pollutant composition reveal a significant decrease of low condensed PAHs up to anthracene. The relative increase of high condensed PAHs in the contaminant composition indicates a PAH degradation of 54%. Soil respiration is used to assess the course of remediation. Continuous monitoring of O 2 and CO 2 in the used air leads to an amount of about 2,400 kg of decomposed organics. Large-scale elution tests show a reduction of the sum parameters for the organic pollution of the flushing water of 80%. The PAHs have dropped about 97%. The Microtox test indicates a detoxification of 98%

  12. Remediation of organochlorine pesticides contaminated lake sediment using activated carbon and carbon nanotubes.

    Science.gov (United States)

    Hua, Shan; Gong, Ji-Lai; Zeng, Guang-Ming; Yao, Fu-Bing; Guo, Min; Ou, Xiao-Ming

    2017-06-01

    Organochlorine pesticides (OCPs) in sediment were a potential damage for humans and ecosystems. The aim of this work was to determine the effectiveness of carbon materials remedy hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethanes (DDTs) in sediment. Two different carbon materials including activated carbon (AC) and multi-walled carbon nanotubes (MWCNTs) were used in the present research. Sediment treated with 2 wt% AC and MWCNTs after 150 d contact showed 97%, and 75% reduction for HCH, and 93% and 59% decrease for DDTs in aqueous equilibrium concentration, respectively. Similarly, the reduction efficiencies of DDT and HCH uptake by semipermeable membrane devices (SPMDs) treated with AC (MWCNTs) were 97% (75%) and 92% (63%), respectively under the identical conditions. Furthermore, for 2 wt% AC (MWCNTs) system, a reduction of XAD beads uptake up to 87% (52%) and 73% (67%) was obtained in HCH and DDT flux to overlying water in quiescent system. Adding MWCNTs to contaminated sediment did not significantly decrease aqueous equilibrium concentration and DDTs and HCH availability in SPMDs compared to AC treatment. A series of results indicated that AC had significantly higher remediation efficiency towards HCH and DDTs in sediment than MWCNTs. Additionally, the removal efficiencies of two organic pollutants improved with increasing material doses and contact times. The greater effectiveness of AC was attributed to its greater specific surface area, which was favorable for binding contaminants. These results highlighted the potential for using AC as in-situ sorbent amendments for sediment remediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. [Mixture Leaching Remediation Technology of Arsenic Contaminated Soil].

    Science.gov (United States)

    Chen, Xun-feng; Li, Xiao-ming; Chen, Can; Yang, Qi; Deng, Lin-jing; Xie, Wei-qiang; Zhong, Yui; Huang, Bin; Yang, Wei-qiang; Zhang, Zhi-bei

    2016-03-15

    Soil contamination of arsenic pollution has become a severely environmental issue, while soil leaching is an efficient method for remediation of arsenic-contaminated soil. In this study, batch tests were primarily conducted to select optimal mixture leaching combination. Firstly, five conventional reagents were selected and combined with each other. Secondly, the fractions were analyzed before and after the tests. Finally, to explore the feasibility of mixed leaching, three soils with different arsenic pollution levels were used to compare the leaching effect. Comparing with one-step washing, the two-step sequential washing with different reagents increased the arsenic removal efficiency. These results showed that the mixture of 4 h 0.5 mol · L⁻¹ NaOH + 4 h 0.1 mol · L⁻¹ EDTA was found to be practicable, which could enhance the removal rate of arsenic from 66.67% to 91.83%, and the concentration of arsenic in soil was decreased from 186 mg · kg⁻¹ to 15.2 mg · kg⁻¹. Furthermore, the results indicated that the distribution of fractions of arsenic in soil changed apparently after mixture leaching. Leaching process could significantly reduce the available contents of arsenic in soil. Moreover, the mixture of 0.5 mol · L⁻¹ NaOH + 0.1 mol L⁻¹ EDTA could well decrease the arsenic concentration in aluminum-type soils, while the mixture of 0.5 mol · L⁻¹ OX + 0.5 mol · L⁻¹ NaOH could well decrease the arsenic concentration in iron-type soils.

  14. Remedial action and waste disposal project -- 300-FF-1 remedial action readiness assessment plan

    International Nuclear Information System (INIS)

    April, J.G.; Carlson, R.A.; Greif, A.A.; Johnson, C.R.; Orewiler, R.I.; Perry, D.M.; Plastino, J.C.; Roeck, F.V.; Tuttle, B.G.

    1997-04-01

    This Readiness Assessment Plan presents the methodology used to assess the readiness of the 300-FF-1 Remedial Action Project. Remediation involves the excavation, treatment if applicable, and final disposal of contaminated soil and debris associated with the waste sites in the 300-FF-1 Operable Unit. The scope of the 300-FF-1 remediation is to excavate, transport, and dispose of contaminated solid from sites identified in the 300-FF-1 Operable Unit

  15. Phyto-remediation of contaminated soils; La phytoremediation des sols contamines

    Energy Technology Data Exchange (ETDEWEB)

    Morel, J.L. [Ecole Nationale Superieure Agronomie et des Industries Alimentaires, 54 - Vandoeuvre les Nancy (France)

    2002-09-01

    Plants provide new ways for soil remediation. The activity of living roots (absorption, exudation of organic compounds, action on physical soil properties) contribute to decrease the negative effects of pollutants, as they are stabilised or eliminated (extraction or degradation). In the presence of plants, hydrocarbons, a rather ubiquitous group of soil pollutants, are degraded faster than in bare soil. Hydrocarbon degrading bacteria are stimulated by root exudates, which also create favourable conditions for co-metabolism. Also, the fragmentation of aggregates as well as the release of surfactants increase the exposure of organic pollutants to microorganism degradation. The phyto-remediation technology is efficient to reduce the dissemination of pollutants. On historically contaminated soils, effects are generally discrete within a short period of time and may be more effective in the long run. (author)

  16. Assessing sustainable remediation frameworks using sustainability principles.

    Science.gov (United States)

    Ridsdale, D Reanne; Noble, Bram F

    2016-12-15

    The remediation industry has grown exponentially in recent decades. International organizations of practitioners and remediation experts have developed several frameworks for integrating sustainability into remediation projects; however, there has been limited attention to how sustainability is approached and operationalized in sustainable remediation frameworks and practices - or whether sustainability plays any meaningful role at all in sustainable remediation. This paper examines how sustainability is represented in remediation frameworks and the guidance provided for practical application. Seven broad sustainability principles and review criteria are proposed and applied to a sample of six international remediation frameworks. Not all review criteria were equally satisfied and none of the frameworks fully met all criteria; however, the best performing frameworks were those identified as sustainability remediation frameworks. Intra-generational equity was addressed by all frameworks. Integrating social, economic and biophysical components beyond triple-bottom-line indicators was explicitly addressed only by the sustainable remediation frameworks. No frameworks provided principle- or rule-based guidance for dealing with trade-offs in sustainability decisions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Risk-based remediation: Approach and application

    International Nuclear Information System (INIS)

    Frishmuth, R.A.; Benson, L.A.

    1995-01-01

    The principle objective of remedial actions is to protect human health and the environment. Risk assessments are the only defensible tools available to demonstrate to the regulatory community and public that this objective can be achieved. Understanding the actual risks posed by site-related contamination is crucial to designing cost-effective remedial strategies. All to often remedial actions are overdesigned, resulting in little to no increase in risk reduction while increasing project cost. Risk-based remedial actions have recently been embraced by federal and state regulators, industry, government, the scientific community, and the public as a mechanism to implement rapid and cost-effective remedial actions. Emphasizing risk reduction, rather than adherence to ambiguous and generic standards, ensures that only remedial actions required to protect human health and the environment at a particular site are implemented. Two sites are presented as case studies on how risk-based approaches are being used to remediate two petroleum hydrocarbon contaminated sites. The sites are located at two US Air Force Bases, Wurtsmith Air Force Base (AFB) in Oscoda, Michigan and Malmstrom AFB in Great Falls, Montana

  18. Enhanced metabolism of halogenated hydrocarbons in transgenic plants containing mammalian cytochrome P450 2E1

    Science.gov (United States)

    Lafferty Doty, Sharon; Shang, Tanya Q.; Wilson, Angela M.; Tangen, Jeff; Westergreen, Aram D.; Newman, Lee A.; Strand, Stuart E.; Gordon, Milton P.

    2000-06-01

    Chlorinated solvents, especially trichloroethylene (TCE), are the most widespread groundwater contaminants in the United States. Existing methods of pumping and treating are expensive and laborious. Phytoremediation, the use of plants for remediation of soil and groundwater pollution, is less expensive and has low maintenance; however, it requires large land areas and there are a limited number of suitable plants that are known to combine adaptation to a particular environment with efficient metabolism of the contaminant. In this work, we have engineered plants with a profound increase in metabolism of the most common contaminant, TCE, by introducing the mammalian cytochrome P450 2E1. This enzyme oxidizes a wide range of important pollutants, including TCE, ethylene dibromide, carbon tetrachloride, chloroform, and vinyl chloride. The transgenic plants had a dramatic enhancement in metabolism of TCE of up to 640-fold as compared with null vector control plants. The transgenic plants also showed an increased uptake and debromination of ethylene dibromide. Therefore, transgenic plants with this enzyme could be used for more efficient remediation of many sites contaminated with halogenated hydrocarbons.

  19. Cost considerations in remediation and disposal

    International Nuclear Information System (INIS)

    Dance, J.T.; Huddleston, R.D.

    1999-01-01

    Opportunities for assessing the costs associated with the reclamation and remediation of sites contaminated by oilfield wastes are discussed. The savings can be maximized by paying close attention to five different aspects of the overall site remediation and disposal process. These are: (1) highly focused site assessment, (2) cost control of treatment and disposal options, (3) value added cost benefits, (4) opportunities to control outside influences during the remedial process, and (5) opportunities for managing long-term liabilities and residual risk remaining after the remedial program is completed. It is claimed that addressing these aspects of the process will ultimately lower the overall cost of site remediation and waste disposal

  20. Privatization considerations of environmental remediation of DOE wastes

    International Nuclear Information System (INIS)

    Zocher, M.A.; Paananen, O.H.; Kost, K.

    1997-01-01

    The US Department of Energy (DOE) is in the process of privatizing the application of environmental cleanup technologies to remediate nuclear waste within the DOE complex. These wastes are the legacy of the production of nuclear materials during the cold war era. It is anticipated that the privatization strategy will result in more efficient and less expensive approaches to the cleanup of DOE wastes. Similar privatization initiatives have the potential to achieve increased efficiency and cost savings at sites under the Department of Defense (DOD) and other Federal agencies. The DOE is privatizing a major, complex portion of the Tank Waste Remediation System (TWRS) Program at the Hanford nuclear reservation located in eastern Washington State. This effort will involve private companies that will design, permit, construct, operate, and finally deactivate waste treatment facilities that will be owned entirely by the private sector. The DOE will purchase treated waste products on a unit cost basis from the facilities after supplying the vendors with waste from the tank farm at Hanford. The privatization of selected United States and international Government functions involve decisions that are based on accurate and valid cost information. Private firms are beginning to privatize certain corporate activities so that they may concentrate business activities along main product or mission lines. In either the public or private sector, many aspects of cost engineering are utilized to make prioritization a success

  1. CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY

    Energy Technology Data Exchange (ETDEWEB)

    BERGMAN, T. B.; STEFANSKI, L. D.; SEELEY, P. N.; ZINSLI, L. C.; CUSACK, L. J.

    2012-09-19

    THE CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY WAS CONDUCTED TO DEVELOP AN OPTIMAL SEQUENCE OF REMEDIATION ACTIVITIES IMPLEMENTING THE CERCLA DECISION ON THE CENTRAL PLATEAU. THE STUDY DEFINES A SEQUENCE OF ACTIVITIES THAT RESULT IN AN EFFECTIVE USE OF RESOURCES FROM A STRATEGIC PERSPECTIVE WHEN CONSIDERING EQUIPMENT PROCUREMENT AND STAGING, WORKFORCE MOBILIZATION/DEMOBILIZATION, WORKFORCE LEVELING, WORKFORCE SKILL-MIX, AND OTHER REMEDIATION/DISPOSITION PROJECT EXECUTION PARAMETERS.

  2. [Cognitive remediation and nursing care].

    Science.gov (United States)

    Schenin-King, Palmyre; Thomas, Fanny; Braha-Zeitoun, Sonia; Bouaziz, Noomane; Januel, Dominique

    2016-01-01

    Therapies based on cognitive remediation integrate psychiatric care. Cognitive remediation helps to ease cognitive disorders and enable patients to improve their day-to-day lives. It is essential to complete nurses' training in this field. This article presents the example of a patient with schizophrenia who followed the Cognitive Remediation Therapy programme, enabling him to access mainstream employment. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. Remediation of Ni(2+)-contaminated water using iron powder and steel manufacturing byproducts.

    Science.gov (United States)

    Jin, Jian; Zhao, Wei-Rong; Xu, Xin-Hua; Hao, Zhi-Wei; Liu, Yong; He, Ping; Zhou, Mi

    2006-01-01

    Steel manufacturing byproducts and commercial iron powders were tested in the treatment of Ni(2+)-contaminated water. Ni2+ is a priority pollutant of some soils and groundwater. The use of zero-valent iron, which can reduce Ni2+ to its neural form appears to be an alternative approach for the remediation of Ni(2+)-contaminated sites. Our experimental data show that the removal efficiencies of Ni2+ were 95.15% and 94.68% at a metal to solution ratio of 20 g/L for commercial iron powders and the steel manufacturing byproducts in 60 min at room temperature, respectively. The removal efficiency reached 98.20% when the metal to solution ratio was 40 g/L for commercial iron powders. Furthermore, we found that the removal efficiency was also largely affected by other factors such as the pHs of the treated water, the length of time for the metal to be in contact with the Ni(2+)-contaminated water, initial concentrations of metal solutions, particle sizes and the amount of iron powders. Surprisingly, the reaction temperature appeared to have little effect on the removal efficiency. Our study opens the way to further optimize the reaction conditions of in situ remediation of Ni2+ or other heavy metals on contaminated sites.

  4. Natural bioventing remediation from tidal wave action at a field site

    International Nuclear Information System (INIS)

    Kampbell, D.H.; Kittel, J.A.

    1996-01-01

    A remediation research study has been implemented at a jet fuel spill site on an island airport. A buried pipeline fracture several years ago resulted in a fuel spill exceeding 160,000 gallons. The site hydrogeology is a fragmented coral matrix with fresh water overlying more dense salt water. Water table fluctuations of about two feet occur once every twelve hours from tidal action. The research approach being pursued is to recover free-phase floating petroleum liquid using vacuum-mediated subsurface skimming wells. The vacuum will create an active vadose zone aeration to enhance aerobic biodegradation processes and vaporization of fuel. Once the floating fuel is removed, a natural bioventing action caused by tidal oscillations will complete remediation of the spill site

  5. Methods for the analysis and remediation of contaminated sites

    International Nuclear Information System (INIS)

    Mariani, M.; Bemporad, E.; Berardi, S.; Marino, A.; Paglietti, F.

    2008-01-01

    In Italy, in recent years, the number of contaminated sites has multiplied disproportionately. In essence, contamination is caused by accidental spills or intentional discharge of pollutants into the soils or waters from industrial activities, or non-controlled deposits of urban and/or industrial waste, mostly part toxic and harmful. Contaminated sites clearly pose risks to human health and the environment; hence the need to remediate these sites. The remediation of soil and water and the restoration of degraded areas are complex operations requiring specific technical and scientific know-how, including knowledge of the methodologies and tools required to tackle problems arising during the different phases of the remediation process. These include, in particular: - health and environmental risk assessment procedures for the quantification of risks to human health (general population and workers) and the environment from a contaminated site; - remote sensing and the Geographical Information Systems (GIS), which are a fundamentally important IT support for each phase of planning and management of remediation interventions; - criteria for the management of sites contaminated by asbestos, a highly carcinogenic and therefore hazardous substance that was widely used in the past due to its particular mechanical and thermal characteristics; - analysis of the issues relating to waste management in contaminated sites; - relationship between safety procedures for workers and the general population. Identification of the best available techniques for an efficient, integrated management of contaminated sites, which will also take into account the health protection of workers and of the general population living near such sites

  6. Risk-based remediation of polluted sites: A critical perspective.

    Science.gov (United States)

    Kuppusamy, Saranya; Venkateswarlu, Kadiyala; Megharaj, Mallavarapu; Mayilswami, Srinithi; Lee, Yong Bok

    2017-11-01

    Sites contaminated with chemical pollutants represent a growing challenge, and remediation of such lands is of international concern. Risk-based land management (RBLM) is an emerging approach that integrates risk assessment practices with more traditional site-specific investigations and remediation activities. Developing countries are yet to adopt RBLM strategies for remediation. RBLM is considered to be practical, scientifically defensible and cost-efficient. However, it is inherently limited by: firstly, the accuracy of risk assessment models used; secondly, ramifications of the fact that they are more likely to leave contamination in place; and thirdly, uncertainties involved and having to consider the total concentrations of all contaminants in soils that overestimate the potential risks from exposure to the contaminants. Consideration of contaminant bioavailability as the underlying basis for risk assessment and setting remediation goals of those contaminated lands that pose a risk to environmental and human health may lead to the development of a more sophisticated risk-based approach. However, employing the bioavailability concept in RBLM has not been extensively studied and/or legalized. This review highlights the extent of global land contamination, and the concept of risk-based assessment and management of contaminated sites including its advantages and disadvantages. Furthermore, the concept of bioavailability-based RBLM strategy has been proposed, and the challenges of RBLM and the priority areas for future research are summarized. Thus, the present review may help achieve a better understanding and successful implementation of a sustainable bioavailability-based RBLM strategy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Plant-based remediation processes

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Dharmendra Kumar (ed.) [Belgian Nuclear Research Centre (SCK.CEN), Mol (Belgium). Radiological Impact and Performance Assessment Division

    2013-11-01

    A valuable source of information for scientists in the field of environmental pollution and remediation. Describes the latest biotechnological methods for the treatment of contaminated soils. Includes case studies and protocols. Phytoremediation is an emerging technology that employs higher plants for the clean-up of contaminated environments. Basic and applied research have unequivocally demonstrated that selected plant species possess the genetic potential to accumulate, degrade, metabolize and immobilize a wide range of contaminants. The main focus of this volume is on the recent advances of technologies using green plants for remediation of various metals and metalloids. Topics include biomonitoring of heavy metal pollution, amendments of higher uptake of toxic metals, transport of heavy metals in plants, and toxicity mechanisms. Further chapters discuss agro-technological methods for minimizing pollution while improving soil quality, transgenic approaches to heavy metal remediation and present protocols for metal remediation via in vitro root cultures.

  8. Testing the Nanoparticle-Allostatic Cross Adaptation-Sensitization Model for Homeopathic Remedy Effects

    Science.gov (United States)

    Bell, Iris R.; Koithan, Mary; Brooks, Audrey J.

    2012-01-01

    Key concepts of the Nanoparticle-Allostatic Cross-Adaptation-Sensitization (NPCAS) Model for the action of homeopathic remedies in living systems include source nanoparticles as low level environmental stressors, heterotypic hormesis, cross-adaptation, allostasis (stress response network), time-dependent sensitization with endogenous amplification and bidirectional change, and self-organizing complex adaptive systems. The model accommodates the requirement for measurable physical agents in the remedy (source nanoparticles and/or source adsorbed to silica nanoparticles). Hormetic adaptive responses in the organism, triggered by nanoparticles; bipolar, metaplastic change, dependent on the history of the organism. Clinical matching of the patient’s symptom picture, including modalities, to the symptom pattern that the source material can cause (cross-adaptation and cross-sensitization). Evidence for nanoparticle-related quantum macro-entanglement in homeopathic pathogenetic trials. This paper examines research implications of the model, discussing the following hypotheses: Variability in nanoparticle size, morphology, and aggregation affects remedy properties and reproducibility of findings. Homeopathic remedies modulate adaptive allostatic responses, with multiple dynamic short- and long-term effects. Simillimum remedy nanoparticles, as novel mild stressors corresponding to the organism’s dysfunction initiate time-dependent cross-sensitization, reversing the direction of dysfunctional reactivity to environmental stressors. The NPCAS model suggests a way forward for systematic research on homeopathy. The central proposition is that homeopathic treatment is a form of nanomedicine acting by modulation of endogenous adaptation and metaplastic amplification processes in the organism to enhance long-term systemic resilience and health. PMID:23290882

  9. Experimental design for assessment of electrokinetically enhanced delivery of lactate and bacteria in 1,2-cis-dichloroethylene contaminated limestone

    DEFF Research Database (Denmark)

    Hyldegaard, Bente Højlund; Nedergaard, L. W.; Ottosen, Lisbeth

    2015-01-01

    Bacterial dechlorination of chlorinated solvents often causes accumulation of the intermediate cis-DCE. Back diffusion of e.g. cis-DCE, due to the dual porosity of limestone, often limits the remediation efficiency. A remediation scheme capable of establishing contact between contaminant, degrading...... bacteria and electron donor within the low permeable limestone matrix is required. The technology EK-BIO, which combines enhanced reductive dechlorination and electrokinetics (EK), was assessed. This novel technology has not previously been tested in limestone. An experimental set-up was designed to meet...... that fermentative bacteria were distributed by electrophoresis. This study suggests that EK application can establish the essential contact and overcome back diffusion. Thereby, EK-BIO may be superior to advection-based technologies for bioremediation of chlorinated solvent contaminated limestone matrices....

  10. Enhancing dye-sensitized solar cell efficiency by anode surface treatments

    International Nuclear Information System (INIS)

    Chang, Chao-Hsuan; Lin, Hsin-Han; Chen, Chin-Cheng; Hong, Franklin C.-N.

    2014-01-01

    In this study, titanium substrates treated with HF solution and KOH solution sequentially forming micro- and nano-structures were used for the fabrication of flexible dye-sensitized solar cells (DSSCs). After wet etching treatments, the titanium substrates were then exposed to the O 2 plasma treatment and further immersed in titanium tetrachloride (TiCl 4 ) solution. The process conditions for producing a very thin TiO 2 blocking layer were studied, in order to avoid solar cell current leakage for increasing the solar cell efficiency. Subsequently, TiO 2 nanoparticles were spin-coated on Ti substrates with varied thickness. The dye-sensitized solar cells on the titanium substrates were subjected to simulate AM 1.5 G irradiation of 100 mW/cm 2 using backside illumination mode. Surface treatments of Ti substrate and TiO 2 anode were found to play a significant role in improving the efficiency of DSSC. The efficiencies of the backside illumination solar cells were raised from 4.6% to 7.8% by integrating these surface treatments. - Highlights: • The flexible dye-sensitized solar cell (DSSC) device can be fabricated. • Many effective surface treatment methods to improve DSSC efficiency are elucidated. • The efficiency is dramatically enhanced by integrating surface treatment methods. • The back-illuminated DSSC efficiency was raised from 4.6% to 7.8%

  11. IAEA Remediation Mission to Japan Concludes

    International Nuclear Information System (INIS)

    2011-01-01

    Full text: A team of international experts today completed a preliminary assessment of the strategy and plans being considered by the Japanese authorities to remediate the areas off-site the Fukushima Dai-ichi Nuclear Power Plant reported to have elevated levels of radiation. The IAEA dispatched the mission to Japan on 7 October following a request from the country's Government. The mission, comprising 12 international and IAEA experts from several countries, visited numerous locations in the Fukushima Prefecture and conducted meetings in Tokyo and Fukushima with Japanese officials from several Ministries and institutions. ''The meetings held and visits made by the team over the last eight days gave us a first-hand appreciation of the extraordinary efforts and dedication on the part of Japanese people in their effort to remediate the areas affected by elevated levels of radiation in the Fukushima Prefecture,'' says Mr. Juan Carlos Lentijo, Team Leader and General Director for Radiation Protection at Spain's nuclear regulatory authority. ''As Japan continues its current remediation efforts, it is our belief that this work will bring relief to the populations who are affected by the consequences of the nuclear accident at the Fukushima Dai-ichi nuclear power plant.'' In a Preliminary Summary Report delivered to Japanese authorities today, the team prepared a set of conclusions including, though not limited to, the following: - Japan developed an efficient program for remediation - allocating the necessary legal, financial and technological resources to bring relief to the people affected by the accident, with priority being given to children. The Team was impressed with the strong commitment to the remediation effort from all institutions and parties involved, including the public; - Japan has also taken practical measures to inform the public and involve residents and local institutions in the process of defining its remediation strategy; - Japan is advised to avoid

  12. Simultaneous removal of organic contaminants and heavy metals from kaolin using an upward electrokinetic soil remediation process

    International Nuclear Information System (INIS)

    Wang, J.-Y.; Huang, X.-J.; Kao, Jimmy C.M.; Stabnikova, Olena

    2007-01-01

    Kaolins contaminated with heavy metals, Cu and Pb, and organic compounds, p-xylene and phenanthrene, were treated with an upward electrokinetic soil remediation (UESR) process. The effects of current density, cathode chamber flushing fluid, treatment duration, reactor size, and the type of contaminants under the vertical non-uniform electric field of UESR on the simultaneous removal of the heavy metals and organic contaminants were studied. The removal efficiencies of p-xylene and phenanthrene were higher in the experiments with cells of smaller diameter or larger height, and with distilled water flow in the cathode chamber. The removal efficiency of Cu and Pb were higher in the experiments with smaller diameter or shorter height cells and 0.01 M HNO 3 solution as cathode chamber flow. In spite of different conditions for removal of heavy metals and organics, it is possible to use the upward electrokinetic soil remediation process for their simultaneous removal. Thus, in the experiments with duration of 6 days removal efficiencies of phenanthrene, p-xylene, Cu and Pb were 67%, 93%, 62% and 35%, respectively. The experiment demonstrated the feasibility of simultaneous removal of organic contaminants and heavy metals from kaolin using the upward electrokinetic soil remediation process

  13. Accounting for land-use efficiency and temporal variations between brownfield remediation alternatives in life-cycle assessment

    NARCIS (Netherlands)

    Beames, A.; Broekx, S.; Heijungs, R.; Lookman, R.; Boonen, K.; van Geert, Y.; Dendoncker, K.; Seuntjes, P.

    2015-01-01

    Abstract The latest life-cycle assessment methods account for land use, due to the production, use and disposal of products and services, in terms of ecosystem damage. The process of brownfield remediation converts otherwise idle urban space into productive space. The value to ecosystems in this

  14. Efficiency enhancement of InP nanowire solar cells by surface cleaning

    NARCIS (Netherlands)

    Cui, Y.; Wang, J.; Plissard, S.R.; Cavalli, A.; Vu, T.T.T.; Veldhoven, van P.J.; Gao, L.; Trainor, M.J.; Verheijen, M.A.; Haverkort, J.E.M.; Bakkers, E.P.A.M.

    2013-01-01

    We demonstrate an efficiency enhancement of an InP nanowire (NW) axial p–n junction solar cell by cleaning the NW surface. NW arrays were grown with in situ HCl etching on an InP substrate patterned by nanoimprint lithography, and the NWs surfaces were cleaned after growth by piranha etching. We

  15. A highly efficient electric additive for enhancing photovoltaic performance of dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    N-cetylpyridinium iodide (N-CPI) as a new electric additive for enhancing photovoltaic performance of the dye-sensitized solar cell (DSSC) was studied.It showed high efficiency for enhancing both the open-circuit voltage and the short-circuit current density of DSSC when the suitable amount of N-CPI as 0.02 M was added in liquid electrolyte.The energy conversion effi- ciency of DSSC increased from 4.429% to 6.535%,with 47.55% enhancement.Therefore,it is a highly efficient electric addi- tive for DSSC.The intrinsic reason is owing to the special molecular structure of N-CPI,which contains two different polarity groups.As a surfactant,N-CPI could form ordered arrangement in liquid electrolyte,which affects the diffusing ability and the redox reaction of I-/I3-,and further affects the photovoltaic performance of DSSC.

  16. DOE'S remedial action assurance program

    International Nuclear Information System (INIS)

    Welty, C.G. Jr.; Needels, T.S.; Denham, D.H.

    1984-10-01

    The formulation and initial implementation of DOE's Assurance Program for Remedial Action are described. It was initiated in FY 84 and is expected to be further implemented in FY 85 as the activities of DOE's Remedial Action programs continue to expand. Further APRA implementation will include additional document reviews, site inspections, and program office appraisals with emphasis on Uranium Mill Tailings Remedial Action Program and Surplus Facilities Management Program

  17. Remediation of spatial processing disorder (SPD).

    Science.gov (United States)

    Graydon, Kelley; Van Dun, Bram; Tomlin, Dani; Dowell, Richard; Rance, Gary

    2018-05-01

    To determine the efficacy of deficit-specific remediation for spatial processing disorder, quantify effects of remediation on functional listening, and determine if remediation is maintained. Participants had SPD, diagnosed using the Listening in Spatialised Noise-Sentences test. The LiSN and Learn software was provided as auditory training. Post-training, repeat LiSN-S testing was conducted. Questionnaires pre- and post-training acted as subjective measures of remediation. A late-outcome assessment established long-term effects of remediation. Sixteen children aged between 6;3 [years; months] and 10;0 completed between 20 and 146 training games. Post-training LiSN-S improved in measures containing spatial cues (p ≤ 0.001) by 2.0 SDs (3.6 dB) for DV90, 1.8 SDs for SV90 (3.2 dB), 1.4 SDs for spatial advantage (2.9 dB) and 1.6 SDs for total advantage (3.3 dB). Improvement was also found in the DV0 condition (1.4 dB or 0.5 SDs). Post-training changes were not significant in the talker advantage measure (1.0 dB or 0.4 SDs) or the SV0 condition (0.3 dB or 0.1 SDs). The late-outcome assessment demonstrated improvement was maintained. Subjective improvement post-remediation was observed using the parent questionnaire. Children with SPD had improved ability to utilise spatial cues following deficit-specific remediation, with the parent questionnaire sensitive to remediation. Effects of the remediation also appear to be sustained.

  18. Enhancement of efficiency and stability of phosphorescent OLEDs based on heterostructured light-emitting layers

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Byung Doo, E-mail: bdchin@dankook.ac.kr [Department of Polymer Science and Engineering and Center for Photofunctional Energy Materials, Dankook University, Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do 448-701 (Korea, Republic of)

    2011-03-23

    The light-emitting efficiency and stability of a phosphorescent organic light-emitting device (OLED), whose emission characteristics are strongly dominated not only by the energy transfer but also by the charge carrier trapping influenced by heterostructured emissive layers, are studied. The variation of the material combination of the heterostructured emitter, both for mixed and double layer configuration, affects the charge injection behaviour, luminous efficiency and stability. Both double and mixed emitter configurations yield low-voltage and high-efficiency behaviour (51 lm W{sup -1} at 1000 cd m{sup -2}; 30 lm W{sup -1} at 10 000 cd m{sup -2}). Such an improvement in power efficiency at elevated brightness is sufficiently universal, while the enhancement of device half-lifetime is rather sensitive to the circumstantial layout of heterostructural emitters. With an optimal mixture of hole-transport type and electron-transport type, a half-lifetime of more than 2500 h at 4000 cd m{sup -2} is obtained, which is 8 times the half-lifetime of control devices with a single emitter structure. The origin and criterion for enhancement of efficiency and lifetime are discussed in terms of the carrier transport behaviour with a specific device architecture.

  19. Putting ecology in environmental remediation: The strategic planning process

    International Nuclear Information System (INIS)

    Kapustka, L.A.; Williams, B.A.

    1991-01-01

    Traditional ecological studies have been conducted on many sites impacted by hazardous wastes. Yet in many cases, the information obtained has had limited value in the selection of remediation options. This paper discusses the importance of developing an ecological risk-based strategic plan to fulfill the scientific and social needs demanded in the remediation and restoration of hazardous waste sites. Ecological issues need to be considered seriously at the earliest phases of the scoping process. The decisions regarding selection of assessment endpoints and data quality objectives must be incorporated from the start to insure that cost-efficient and useful measurements are used. It is too late to develop effective ecological studies after the engineering decisions have been made. Strategic planning that integrates ecological concerns will minimize the frustration and the cost associated with clean up of hazardous waste sites and maximize the likelihood of successful site restoration

  20. Enhanced bioremediation of lead-contaminated soil by Solanum nigrum L. with Mucor circinelloides.

    Science.gov (United States)

    Sun, Liqun; Cao, Xiufeng; Li, Min; Zhang, Xu; Li, Xinxin; Cui, Zhaojie

    2017-04-01

    Strain selected from mine tailings in Anshan for Pb bioremediation was characterized at the genetic level by internal transcribed spacer (ITS) sequencing. Results revealed that the strain belongs to Mucor circinelloides. Bioremediation of lead-contaminated soil was conducted using Solanum nigrum L. combined with M. circinelloides. The removal efficacy was in the order microbial/phytoremediation > phytoremediation > microbial remediation > control. The bioremediation rates were 58.6, 47.2, and 40.2% in microbial/phytoremediation, microbial remediation, and phytoremediation groups, respectively. Inoculating soil with M. circinelloides enhanced Pb removal and S. nigrum L. growth. The bioaccumulation factor (BF, 1.43), enrichment factor (EF, 1.56), and translocation factor (TF, 1.35) were higher than unit, suggesting an efficient ability of S. nigrum L. in Pb bioremediation. Soil fertility was increased after bioremediation according to change in enzyme activities. The results indicated that inoculating S. nigrum L. with M. circinelloides enhanced its efficiency for phytoremediation of soil contaminated with Pb.

  1. 46 CFR 298.41 - Remedies after default.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Remedies after default. 298.41 Section 298.41 Shipping... Defaults and Remedies, Reporting Requirements, Applicability of Regulations § 298.41 Remedies after default... governing remedies after a default, which relate to our rights and duties, the rights and duties of the...

  2. Effect of pulse current on energy consumption and removal of heavy metals during electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Sun, Tian Ran

    pathways to unacceptable dosages, leading to intolerable adverse effects on both public health and the environment. In the last decades, soil and water remediation have gained growing awareness, as the necessity becomes clearer for development of such techniques for elimination of the negative impact from......: transport of water (electroosmosis) and ions (electromigration), with electromigration being the most important transport process when treating heavy metal contaminated soils. Electrodialytic remediation (EDR), one of the enhanced electrochemical remediation techniques, is developed at the Technical...... compartments. Therefore no current is wasted for carrying ions from one electrode compartment to the other. The EDR technique has been tested for decontamination of a variety of different heavy metal polluted particulate materials: mine tailings, soil, different types of fly ashes, sewage sludge, freshwater...

  3. Efficient perovskite/organic integrated solar cells with extended photoresponse to 930 nm and enhanced near-infrared external quantum efficiency of over 50.

    Science.gov (United States)

    Guo, Qiang; Liu, Hao; Shi, Zhenzhen; Wang, Fuzhi; Zhou, Erjun; Bian, Xingming; Zhang, Bing; Alsaedi, Ahmed; Hayat, Tasawar; Tan, Zhan'ao

    2018-02-15

    Enhancing the light-harvesting activity is an effective way to improve the power conversion efficiency of solar cells. Although rapid enhancement in the PCE up to a value of 22.1% has been achieved for perovskite solar cells, only part of the sunlight, i.e., with wavelengths below 800-850 nm is utilized due to the limited bandgap of the perovskite materials, resulting in most of the near infrared light being wasted. To broaden the photoresponse of perovskite solar cells, we demonstrate an efficient perovskite/organic integrated solar cell containing both CH 3 NH 3 PbI 3 perovskite and PBDTTT-E-T:IEICO organic photoactive layers. By integrating a low band gap PBDTTT-E-T:IEICO active layer on a perovskite layer, the maximum wavelength for light harvesting of the ISC increased to 930 nm, sharply increasing the utilization of near infrared radiation. In addition, the external quantum efficiency of the integrated device exceeded 50% in the near infrared range. The MAPbI 3 /PBDTTT-E-T:IEICO ISCs show an enhanced short-circuit current density of over 24 mA cm -2 , which is the highest existing value among perovskite/organic integrated solar cells and much higher than the traditional MAPbI 3 based perovskite solar cells. The results reveal that a perovskite/organic integrated structure is a promising strategy to extend and enhance sunlight utilization for perovskite solar cells.

  4. 32 CFR 310.47 - Civil remedies.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Civil remedies. 310.47 Section 310.47 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) PRIVACY PROGRAM DOD PRIVACY PROGRAM Privacy Act Violations § 310.47 Civil remedies. In addition to specific remedial...

  5. Efficiency Enhancement of Silicon Heterojunction Solar Cells via Photon Management Using Graphene Quantum Dot as Downconverters

    KAUST Repository

    Tsai, Meng-Lin

    2015-12-16

    By employing graphene quantum dots (GQDs), we have achieved a high efficiency of 16.55% in n-type Si heterojunction solar cells. The efficiency enhancement is based on the photon downconversion phenomenon of GQDs to make more photons absorbed in the depletion region for effective carrier separation, leading to the enhanced photovoltaic effect. The short circuit current and the fill factor are increased from 35.31 to 37.47 mA/cm2 and 70.29% to 72.51%, respectively. The work demonstrated here holds the promise for incorporating graphene-based materials in commercially available solar devices for developing ultra-high efficiency photovoltaic cells in the future.

  6. Efficiency Enhancement of Silicon Heterojunction Solar Cells via Photon Management Using Graphene Quantum Dot as Downconverters

    KAUST Repository

    Tsai, Meng-Lin; Tu, Wei-Chen; Tang, Libin; Wei, Tzu-Chiao; Wei, Wan-Rou; Lau, Shu Ping; Chen, Lih-Juann; He, Jr-Hau

    2015-01-01

    By employing graphene quantum dots (GQDs), we have achieved a high efficiency of 16.55% in n-type Si heterojunction solar cells. The efficiency enhancement is based on the photon downconversion phenomenon of GQDs to make more photons absorbed in the depletion region for effective carrier separation, leading to the enhanced photovoltaic effect. The short circuit current and the fill factor are increased from 35.31 to 37.47 mA/cm2 and 70.29% to 72.51%, respectively. The work demonstrated here holds the promise for incorporating graphene-based materials in commercially available solar devices for developing ultra-high efficiency photovoltaic cells in the future.

  7. Nuclear facility decommissioning and site remedial actions

    International Nuclear Information System (INIS)

    Knox, N.P.; Webb, J.R.; Ferguson, S.D.; Goins, L.F.; Owen, P.T.

    1990-09-01

    The 394 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the eleventh in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Citations to foreign and domestic literature of all types -- technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions -- have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy's Remedial Action Programs. Major sections are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Programs, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Grand Junction Remedial Action Program, (7) Uranium Mill Tailings Management, (8) Technical Measurements Center, (9) Remedial Action Program, and (10) Environmental Restoration Program. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and keywords. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects and analyzes information on remedial actions and relevant radioactive waste management technologies

  8. Nuclear facility decommissioning and site remedial actions

    Energy Technology Data Exchange (ETDEWEB)

    Knox, N.P.; Webb, J.R.; Ferguson, S.D.; Goins, L.F.; Owen, P.T.

    1990-09-01

    The 394 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the eleventh in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Citations to foreign and domestic literature of all types -- technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions -- have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy's Remedial Action Programs. Major sections are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Programs, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Grand Junction Remedial Action Program, (7) Uranium Mill Tailings Management, (8) Technical Measurements Center, (9) Remedial Action Program, and (10) Environmental Restoration Program. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and keywords. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects and analyzes information on remedial actions and relevant radioactive waste management technologies.

  9. Lessons Learned from Environmental Remediation Programmes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-03-15

    Several remediation projects have been developed to date, and experience with these projects has been accumulated. Lessons learned span from non-technical to technical aspects, and need to be shared with those who are beginning or are facing the challenge to implement environmental remediation works. This publication reviews some of these lessons. The key role of policy and strategies at the national level in framing the conditions in which remediation projects are to be developed and decisions made is emphasized. Following policy matters, this publication pays attention to the importance of social aspects and the requirement for fairness in decisions to be made, something that can only be achieved with the involvement of a broad range of interested parties in the decision making process. The publication also reviews the funding of remediation projects, planning, contracting, cost estimates and procurement, and issues related to long term stewardship. Lessons learned regarding technical aspects of remediation projects are reviewed. Techniques such as the application of cover systems and soil remediation (electrokinetics, phytoremediation, soil flushing, and solidification and stabilization techniques) are analysed with respect to performance and cost. After discussing soil remediation, the publication covers issues associated with water treatment, where techniques such as ‘pump and treat’ and the application of permeable barriers are reviewed. Subsequently, there is a section dedicated to reviewing briefly the lessons learned in the remediation of uranium mining and processing sites. Many of these sites throughout the world have become orphaned, and are waiting for remediation. The publication notes that little progress has been made in the management of some of these sites, particularly in the understanding of associated environmental and health risks, and the ability to apply prediction to future environmental and health standards. The publication concludes

  10. Lessons Learned from Environmental Remediation Programmes

    International Nuclear Information System (INIS)

    2014-01-01

    Several remediation projects have been developed to date, and experience with these projects has been accumulated. Lessons learned span from non-technical to technical aspects, and need to be shared with those who are beginning or are facing the challenge to implement environmental remediation works. This publication reviews some of these lessons. The key role of policy and strategies at the national level in framing the conditions in which remediation projects are to be developed and decisions made is emphasized. Following policy matters, this publication pays attention to the importance of social aspects and the requirement for fairness in decisions to be made, something that can only be achieved with the involvement of a broad range of interested parties in the decision making process. The publication also reviews the funding of remediation projects, planning, contracting, cost estimates and procurement, and issues related to long term stewardship. Lessons learned regarding technical aspects of remediation projects are reviewed. Techniques such as the application of cover systems and soil remediation (electrokinetics, phytoremediation, soil flushing, and solidification and stabilization techniques) are analysed with respect to performance and cost. After discussing soil remediation, the publication covers issues associated with water treatment, where techniques such as ‘pump and treat’ and the application of permeable barriers are reviewed. Subsequently, there is a section dedicated to reviewing briefly the lessons learned in the remediation of uranium mining and processing sites. Many of these sites throughout the world have become orphaned, and are waiting for remediation. The publication notes that little progress has been made in the management of some of these sites, particularly in the understanding of associated environmental and health risks, and the ability to apply prediction to future environmental and health standards. The publication concludes

  11. Considering bioavailability in the remediation of heavy metal contaminated sites

    Directory of Open Access Journals (Sweden)

    Leita L.

    2013-04-01

    Full Text Available Many years of research have demonstrated that instead of the total concentration of metals in soil, bioavailability is the key to understand the environmental risk derived by metals, since adverse effects are related only to the biologically available forms of these elements. The knowledge of bioavailability can decrease the uncertainties in evaluating exposure in human and ecological risk assessment. At the same time, the efficiency of remediation treatments could be greatly influenced by availability of the contaminants. Consideration of the bioavailability processes at contaminated sites could be useful in site-specific risk assessment: the fraction of mobile metals, instead of total content should be provided as estimates of metal exposure. Moreover, knowledge of the chemical forms of heavy metals in soils is a critical component in the evaluation of applicability of different remediation technologies such as phytoremdiation or soil washing.

  12. Remediation of persistent organic pollutant-contaminated soil using biosurfactant-enhanced electrokinetics coupled with a zero-valent iron/activated carbon permeable reactive barrier.

    Science.gov (United States)

    Sun, Yuchao; Gao, Ke; Zhang, Yun; Zou, Hua

    2017-12-01

    Zero-valent iron/activated carbon (Fe/C) particles can degrade persistent organic pollutants via micro-electrolysis and therefore, they may be used to develop materials for permeable reactive barriers (PRBs). In this study, surfactant-enhanced electrokinetics (EK) was coupled with a Fe/C-PRB to treat phenanthrene (PHE) and 2,4,6-trichlorophenol (TCP) co-contaminated clay soil. An environment-friendly biosurfactant, rhamnolipid, was selected as the solubility-enhancing agent. Five bench-scale tests were conducted to investigate the performance of EK-PRB on PHE and TCP removal from soil as well as the impact of pH and rhamnolipid concentration. The results show that both PHE and TCP, driven by electro-osmotic flow (EOF), moved toward the cathode and reacted with the Fe/C-PRB. Catholyte acidification and rhamnolipid concentration increase improved the removal efficiencies of PHE and TCP. The highest removal efficiency of PHE in soil column was five times the efficiency of the control group on which only EK was applied (49.89 versus 9.40%). The highest removal efficiency of TCP in soil column was 4.5 times the efficiency of the control group (64.60 versus 14.30%). Desorption and mobility of PHE and TCP improved with the increase of rhamnolipid concentration when this exceeded the critical micelle concentration. This study indicates that the combination of EK and a Fe/C-PRB is efficient and promising for removing persistent organic pollutants (POPs) from contaminated soil with the enhancement of rhamnolipid.

  13. Approaches for assessing sustainable remediation

    DEFF Research Database (Denmark)

    Søndergaard, Gitte Lemming; Binning, Philip John; Bjerg, Poul Løgstrup

    Sustainable remediation seeks to reduce direct contaminant point source impacts on the environment, while minimizing the indirect cost of remediation to the environment, society and economy. This paper presents an overview of available approaches for assessing the sustainability of alternative...... remediation strategies for a contaminated site. Most approaches use multi-criteria assessment methods (MCA) to structure a decision support process. Different combinations of environmental, social and economic criteria are employed, and are assessed either in qualitative or quantitative forms with various...... tools such as life cycle assessment and cost benefit analysis. Stakeholder involvement, which is a key component of sustainable remediation, is conducted in various ways. Some approaches involve stakeholders directly in the evaluation or weighting of criteria, whereas other approaches only indirectly...

  14. Self-potential and Complex Conductivity Monitoring of In Situ Hydrocarbon Remediation in Microbial Fuel Cell

    Science.gov (United States)

    Zhang, C.; Revil, A.; Ren, Z.; Karaoulis, M.; Mendonca, C. A.

    2013-12-01

    Petroleum hydrocarbon contamination of soil and groundwater in both non-aqueous phase liquid and dissolved forms generated from spills and leaks is a wide spread environmental issue. Traditional cleanup of hydrocarbon contamination in soils and ground water using physical, chemical, and biological remedial techniques is often expensive and ineffective. Recent studies show that the microbial fuel cell (MFC) can simultaneously enhance biodegradation of hydrocarbons in soil and groundwater and yield electricity. Non-invasive geophysical techniques such as self-potential (SP) and complex conductivity (induced polarization) have shown the potential to detect and characterize the nature of electron transport mechanism of in situ bioremediation of organic contamination plumes. In this study, we deployed both SP and complex conductivity in lab scale MFCs to monitor time-laps geophysical response of degradation of hydrocarbons by MFC. Two different sizes of MFC reactors were used in this study (DI=15 cm cylinder reactor and 94.5cm x 43.5 cm rectangle reactor), and the initial hydrocarbon concentration is 15 g diesel/kg soil. SP and complex conductivity measurements were measured using non-polarizing Ag/AgCl electrodes. Sensitivity study was also performed using COMSOL Multiphysics to test different electrode configurations. The SP measurements showed stronger anomalies adjacent to the MFC than locations afar, and both real and imaginary parts of complex conductivity are greater in areas close to MFC than areas further away and control samples without MFC. The joint use of SP and complex conductivity could in situ evaluate the dynamic changes of electrochemical parameters during this bioremediation process at spatiotemporal scales unachievable with traditional sampling methods. The joint inversion of these two methods to evaluate the efficiency of MFC enhanced hydrocarbon remediation in the subsurface.

  15. Effect of Remediation Parameters on in-Air Ambient Dose Equivalent Rates When Remediating Open Sites with Radiocesium-contaminated Soil.

    Science.gov (United States)

    Malins, Alex; Kurikami, Hiroshi; Kitamura, Akihiro; Machida, Masahiko

    2016-10-01

    Calculations are reported for ambient dose equivalent rates [H˙*(10)] at 1 m height above the ground surface before and after remediating radiocesium-contaminated soil at wide and open sites. The results establish how the change in H˙*(10) upon remediation depends on the initial depth distribution of radiocesium within the ground, on the size of the remediated area, and on the mass per unit area of remediated soil. The remediation strategies considered were topsoil removal (with and without recovering with a clean soil layer), interchanging a topsoil layer with a subsoil layer, and in situ mixing of the topsoil. The results show the ratio of the radiocesium components of H˙*(10) post-remediation relative to their initial values (residual dose factors). It is possible to use the residual dose factors to gauge absolute changes in H˙*(10) upon remediation. The dependency of the residual dose factors on the number of years elapsed after fallout deposition is analyzed when remediation parameters remain fixed and radiocesium undergoes typical downward migration within the soil column.

  16. 200-ZP-1 phase 2 interim remedial measure quarterly report, August--October 1996

    International Nuclear Information System (INIS)

    Freeman-Pollard, J.R.; Jacques, I.D.; McMahon, W.J.; Singleton, K.M.; Strope, S.A.; Swanson, L.C.; Windmueller, C.R.

    1996-11-01

    A groundwater pump-and-treat system is being operated in the 200-ZP-1 Operable Unit under authority of the Hanford Federal Facility Agreement and Consent Order . The purpose of the pump-and-treat system is to accomplish the following: Minimize further migration of the high-concentration portion of the carbon tetrachloride plume and co-contaminants chloroform and trichlorethylene in the 200-ZP-1 Operable Unit Provide data for evaluation of final remedy selection. The 200-ZP-1 pump-and-treat operations were conducted as a pilot-scale treatability test and interim remedial measure treatment system between August 1994 and July 1996 to assess the effectiveness of liquid-phase granular activated carbon carbon tetrachloride removal. The pilot-scale treatability test's removal efficiently was determined to be 99.96% for carbon tetrachloride, chloroform, and trichloroethylene. This report summarizes and evaluates treatment, hydraulic, and hydrochemistry data collected for the 200-ZP-1 interim remedial measure from August through September 1996

  17. Herbal remedies and supplements for weight loss

    Science.gov (United States)

    Weight loss - herbal remedies and supplements; Obesity - herbal remedies; Overweight - herbal remedies ... health care provider. Nearly all over-the-counter supplements with claims of weight-loss properties contain some ...

  18. Phytoextraction and estimating optimal time for remediation of Cd-contaminated soils by Spinach

    OpenAIRE

    Somayyeh Eisazadeh Lazarjan; safoora asadi kapourchal; Mehdi Homaee

    2016-01-01

    The so-called phytoextraction in which hyperaccumulator plants are used to remediate the contaminated soils is proven to be an efficient method. The objective of this study was to investigate the capability of Spinach for phytoremediation of cadmium from Cd-contaminated soils and determine the efficiency extent of spinach for phytoremediation. For this purpose, a randomized block experimental design whit five treatments including 0, 15, 30, 60 and 120 mg Cd/ kg soil and three replications was...

  19. New Mexico English Remediation Taskforce Report

    Science.gov (United States)

    New Mexico Higher Education Department, 2016

    2016-01-01

    In March, 2016, the state of New Mexico established a Remediation Task Force to examine remediation reform efforts across the state's higher education institutions. On March 11, the Task Force met for the "New Mexico Corequisite Remediation at Scale Policy Institute" in order to learn about the results of the latest national reform…

  20. Remediation: Higher Education's Bridge to Nowhere

    Science.gov (United States)

    Complete College America, 2012

    2012-01-01

    The intentions were noble. It was hoped that remediation programs would be an academic bridge from poor high school preparation to college readiness. Sadly, remediation has become instead higher education's "Bridge to Nowhere." This broken remedial bridge is travelled by some 1.7 million beginning students each year, most of whom will…

  1. Enhanced efficiency in single-host white organic light-emitting diode by triplet exciton conversion

    International Nuclear Information System (INIS)

    Wu, Qingyang; Zhang, Shiming; Yue, Shouzhen; Zhang, Zhensong; Xie, Guohua; Zhao, Yi; Liu, Shiyong

    2013-01-01

    The authors observe that the external quantum efficiency (EQE) of the Iridium (III) bis(4-phenylthieno [3,2-c]pyridinato-N,C 2′ )acetylacetonate (PO-01) based yellow organic light-emitting diode (OLED) is significantly increased by uniformly co-doping Iridium (III)bis[(4,6-difluorophenyl)-pyridinato-N,C 2− ] (FIrpic) and PO-01 into the same wide band-gap host of N,N ′ -dicarbazolyl-3, 5-benzene (mCP). Detailed investigation indicates that the efficiency enhancement is ascribed to effective triplet exciton gathering by FIrpic, followed by energy transfer to PO-01. Compared to the control device, which has maximum EQE of 10.5%, an improved maximum EQE of 13.2% is obtained in the optimization white device based on FIrpic and PO-01 emission according to this principle. This work makes it easier for a single host white OLED to simultaneously harvest high efficiency in both blue and yellow units. Comprehensive experimental results show that this phenomenon can also be found and utilized in other popular hosts to realize more efficient white devices. -- Highlights: • This work makes easier for a single host white OLED to harvest high efficiency in both blue and yellow units. • Efficiency enhancement is ascribed to effective triplet exciton gathering by FIrpic, followed by energy transfer to PO-01. • This phenomenon can also be found and utilized in other popular hosts to realize more efficient white devices

  2. Enhanced efficiency in single-host white organic light-emitting diode by triplet exciton conversion

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qingyang, E-mail: wqy1527@163.com [State Key laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Zhang, Shiming [State Key laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Département of Chemical Engineering, École Polytechnique de Montréal, Montréal, Québec, Canada H3C3J7 (Canada); Yue, Shouzhen; Zhang, Zhensong [State Key laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Xie, Guohua [Institut für Angewandte Photophysik, Technische Universtität Dresden, Dresden 01062 (Germany); Zhao, Yi; Liu, Shiyong [State Key laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

    2013-11-15

    The authors observe that the external quantum efficiency (EQE) of the Iridium (III) bis(4-phenylthieno [3,2-c]pyridinato-N,C{sup 2′})acetylacetonate (PO-01) based yellow organic light-emitting diode (OLED) is significantly increased by uniformly co-doping Iridium (III)bis[(4,6-difluorophenyl)-pyridinato-N,C{sup 2−}] (FIrpic) and PO-01 into the same wide band-gap host of N,N{sup ′}-dicarbazolyl-3, 5-benzene (mCP). Detailed investigation indicates that the efficiency enhancement is ascribed to effective triplet exciton gathering by FIrpic, followed by energy transfer to PO-01. Compared to the control device, which has maximum EQE of 10.5%, an improved maximum EQE of 13.2% is obtained in the optimization white device based on FIrpic and PO-01 emission according to this principle. This work makes it easier for a single host white OLED to simultaneously harvest high efficiency in both blue and yellow units. Comprehensive experimental results show that this phenomenon can also be found and utilized in other popular hosts to realize more efficient white devices. -- Highlights: • This work makes easier for a single host white OLED to harvest high efficiency in both blue and yellow units. • Efficiency enhancement is ascribed to effective triplet exciton gathering by FIrpic, followed by energy transfer to PO-01. • This phenomenon can also be found and utilized in other popular hosts to realize more efficient white devices.

  3. Monitoring and remediation technologies of organochlorine pesticides in drainage water

    OpenAIRE

    Ismail Ahmed; Derbalah Aly; Shaheen Sabry

    2015-01-01

    This study was carried out to monitor the presence of organochlorine in drainage water in Kafr-El-Sheikh Governorate, Egypt. Furthermore, to evaluate the efficiencies of different remediation techniques (advanced oxidation processes [AOPs] and bioremediation) for removing the most frequently detected compound (lindane) in drainage water. The results showed the presence of several organochlorine pesticides in all sampling sites. Lindane was detected with high frequency relative to other detect...

  4. Analysis of SPR salt cavern remedial leach program 2013.

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Paula D.; Gutierrez, Karen A.; Lord, David L.; Rudeen, David Keith

    2013-09-01

    The storage caverns of the US Strategic Petroleum Reserve (SPR) exhibit creep behavior resulting in reduction of storage capacity over time. Maintenance of oil storage capacity requires periodic controlled leaching named remedial leach. The 30 MMB sale in summer 2011 provided space available to facilitate leaching operations. The objective of this report is to present the results and analyses of remedial leach activity at the SPR following the 2011 sale until mid-January 2013. This report focuses on caverns BH101, BH104, WH105 and WH106. Three of the four hanging strings were damaged resulting in deviations from normal leach patterns; however, the deviations did not affect the immediate geomechanical stability of the caverns. Significant leaching occurred in the toes of the caverns likely decreasing the number of available drawdowns until P/D ratio criteria are met. SANSMIC shows good agreement with sonar data and reasonably predicted the location and size of the enhanced leaching region resulting from string breakage.

  5. Proceedings of the remediation technologies symposium 2007

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This conference provided a forum to discuss the remediation of contaminated sites. It was attended by all industry sectors that have an interest in learning about technical issues in environmental remediation research and the latest innovations in soil and groundwater remediation and industrial pollutant treatments. Cost effective in-situ and ex-situ soil reclamation strategies were presented along with groundwater and surface water remediation strategies. The diversified sessions at this conference were entitled: regulatory update; Montreal Centre of Excellence in Brownfields Rehabilitation; soil and groundwater remediation through the Program of Energy Research and Development at Environment Canada; technology from the Netherlands; bioremediation; hydrocarbons; in-situ remediation; phytoremediation; salt management; unique locations; and, miscellaneous issues. Some areas and case studies covered in the presentations included: biological and non-biological treatments; thermal desorption; encapsulation; natural attenuation; multi-phase extraction; electrochemical remediation; and membrane technology. The conference featured 63 presentations, of which 23 have been catalogued separately for inclusion in this database. tabs., figs.

  6. Proceedings of the remediation technologies symposium 2007

    International Nuclear Information System (INIS)

    2007-01-01

    This conference provided a forum to discuss the remediation of contaminated sites. It was attended by all industry sectors that have an interest in learning about technical issues in environmental remediation research and the latest innovations in soil and groundwater remediation and industrial pollutant treatments. Cost effective in-situ and ex-situ soil reclamation strategies were presented along with groundwater and surface water remediation strategies. The diversified sessions at this conference were entitled: regulatory update; Montreal Centre of Excellence in Brownfields Rehabilitation; soil and groundwater remediation through the Program of Energy Research and Development at Environment Canada; technology from the Netherlands; bioremediation; hydrocarbons; in-situ remediation; phytoremediation; salt management; unique locations; and, miscellaneous issues. Some areas and case studies covered in the presentations included: biological and non-biological treatments; thermal desorption; encapsulation; natural attenuation; multi-phase extraction; electrochemical remediation; and membrane technology. The conference featured 63 presentations, of which 23 have been catalogued separately for inclusion in this database. tabs., figs

  7. Remedial activities effectiveness verification in tailing areas.

    Science.gov (United States)

    Kluson, J; Thinova, L; Neznal, M; Svoboda, T

    2015-06-01

    The complex radiological study of the basin of sludge from the uranium ore mining and preprocessing was done. Air kerma rates (including its spectral analysis) at the reference height of 1 m above ground over the whole area were measured and radiation fields mapped during two measuring campaigns (years 2009 and 2014). K, U and Th concentrations in sludge and concentrations in depth profiles (including radon concentration and radon exhalation rates) in selected points were determined using gamma spectrometry for in situ as well as laboratory samples measurement. Results were used for the analysis, design evaluation and verification of the efficiency of the remediation measures. Efficiency of the sludge basin covering by the inert material was modelled using MicroShield code. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Cationic polyacrylamide enhancing cellulase treatment efficiency of hardwood kraft-based dissolving pulp.

    Science.gov (United States)

    Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ni, Yonghao

    2015-05-01

    Cellulase treatment for decreasing viscosity and increasing Fock reactivity of dissolving pulp is a promising approach to reduce the use of toxic chemicals, such as hypochlorite in the dissolving pulp manufacturing process in the industry. Improving the cellulase treatment efficiency during the process is of practical interest. In the present study, the concept of using cationic polyacrylamide (CPAM) to enhance the cellulase treatment efficiency was demonstrated. This was mainly attributed to the increased cellulase adsorption onto cellulose fibers based on the patching/bridging mechanism. Results showed that the cellulase adsorption was increased by about 20% with the addition of 250 ppm of CPAM under the same conditions as those of the control. It was found that the viscosity decrease and Fock reactivity increase for the cellulase treatment was enhanced from using CPAM. The CPAM-assisted cellulase treatment concept may provide a practical alternative to the present hypochlorite-based technology for viscosity control in the industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. E-FUSRAP: AUTOMATING THE CASE FILE FOR THE FORMERLY UTILIZED SITES REMEDIAL ACTION PROGRAM

    International Nuclear Information System (INIS)

    Mackenzie, D.; Marshall, K.

    2003-01-01

    The Department of Energy's (DOE) Office of Site Closure, EM-30, houses the document library pertaining to sites that are related to the Formerly Utilized Sites Remedial Action Program (FUSRAP) and regularly addresses ongoing information demands, primarily from Freedom of Information Act (FOIA) requests, interested members of the public, the DOE, and other Federal Agencies. To address these demands more efficiently, DOE has begun to implement a new multi-phase, information management process known as e-FUSRAP. The first phase of e-FUSRAP, the development of the Considered Sites Database, summarizes and allows public access to complex information on over 600 sites considered as candidates for FUSRAP. The second phase of e-FUSRAP, the development of the Document Indexing Database, will create an internal index of more than 10,000 documents in the FUSRAP library's case file, allowing more effective management and retrieval of case file documents. Together, the phases of e-FUSRAP will allow EM-30 to become an innovative leader in enhancing public information sources

  10. The atmospheric implications of radiation belt remediation

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2006-08-01

    Full Text Available High altitude nuclear explosions (HANEs and geomagnetic storms can produce large scale injections of relativistic particles into the inner radiation belts. It is recognised that these large increases in >1 MeV trapped electron fluxes can shorten the operational lifetime of low Earth orbiting satellites, threatening a large, valuable population. Therefore, studies are being undertaken to bring about practical human control of the radiation belts, termed "Radiation Belt Remediation" (RBR. Here we consider the upper atmospheric consequences of an RBR system operating over either 1 or 10 days. The RBR-forced neutral chemistry changes, leading to NOx enhancements and Ox depletions, are significant during the timescale of the precipitation but are generally not long-lasting. The magnitudes, time-scales, and altitudes of these changes are no more significant than those observed during large solar proton events. In contrast, RBR-operation will lead to unusually intense HF blackouts for about the first half of the operation time, producing large scale disruptions to radio communication and navigation systems. While the neutral atmosphere changes are not particularly important, HF disruptions could be an important area for policy makers to consider, particularly for the remediation of natural injections.

  11. Mechanism of plasmon-mediated enhancement of photovoltaic efficiency

    International Nuclear Information System (INIS)

    Jacak, W; Jacak, J; Donderowicz, W; Jacak, L; Krasnyj, J

    2011-01-01

    Metallic nanospheres (Au, Ag, Cu) deposited on a photovoltaic (PV)-active semiconductor surface can act as light converters, collecting energy of incident photons in plasmon oscillations. This energy can be next transferred to a semiconductor substrate via a near-field channel, in a more efficient manner in comparison with the direct photo-effect. We explain this enhancement by inclusion of indirect interband transitions in a semiconductor layer due to the near-field coupling with plasmon radiation in nanoscale of the metallic components, where the momentum is not conserved as the system is not translationally invariant. The model of the nanosphere plasmons is developed (random phase approximation, analytical version, adjusted to description of large metallic clusters, with a radius of 10-60 nm) including surface and volume modes. Damping of plasmons is analysed via Lorentz friction, and irradiation losses in the far- and near-field regimes. Resulting resonance shifts are verified experimentally for Au and Ag colloidal water solutions with respect to particle size. Probability of the electron interband transition (within the Fermi golden rule) in the substrate semiconductor induced by coupling to plasmons in the near-field regime turns out to be significantly larger than for coupling of electrons to planar-wave photons. This is of practical importance for enhancement of thin-film solar cell efficiency, both for semiconductor type (such as III-V semiconductor based cells) and for conjugate-polymer-based or dye organic plastic cells, intensively developed at present. We have described also a non-dissipative collective mode of surface plasmons in a chain of near-field-coupled metallic nanospheres, for particular size, separation parameters and wavelengths. This would find an application in sub-diffraction electro-photonic circuit arrangement and for possible energy transport in solar cells, in particular in organic materials with low mobility of carriers.

  12. Integrated remediation of soil and groundwater

    International Nuclear Information System (INIS)

    Dykes, R.S.; Howles, A.C.

    1992-01-01

    Remediation of sites contaminated with petroleum hydrocarbons and other organic chemicals frequently focuses on a single phase of the chemical in question. This paper describes an integrated approach to remediation involving selection of complimentary technologies designed to create a remedial system which achieves cleanup goals in affected media in the shortest possible time consistent with overall environmental protection

  13. Assessing the capacity of zero valent iron nanofluids to remediate NAPL-polluted porous media

    Energy Technology Data Exchange (ETDEWEB)

    Tsakiroglou, Christos, E-mail: ctsakir@iceht.forth.gr [Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras (Greece); Terzi, Katerina; Sikinioti-Lock, Alexandra [Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras (Greece); Department of Chemical Engineering, University of Patras, 26504 Patras (Greece); Hajdu, Kata; Aggelopoulos, Christos [Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras (Greece)

    2016-09-01

    A variety of aqueous suspensions (nanofluids) of zero-valent nano-particles (nZVI) are prepared by wet chemistry techniques, their stability and longevity is evaluated by physic-chemical methods of characterization, and their reactivity toward the dechlorination of per-chloro-ethylene (PCE) is examined with tests in batch reactors. For assessing the mobility, longevity and reactivity of nZVI suspensions (nanofluids), under flow-through conditions, visualization multiphase flow and transport tests are performed on a glass-etched pore network. The nZVI breakthrough curves are constructed by measuring the transient variation of the iron concentration in the effluent with atomic absorption spectroscopy. The capacity of nZVI to remediate the bulk phase of PCE is quantified by detecting the mass loss rate of PCE ganglia trapped in glass-etched pore networks during the continuous injection of nZVI suspension or pure water. The nZVI injection in porous media is simulated as an advection- dispersion process by accounting for the attachment/detachment of nanoparticles on the pore-walls, and describing the kinetics of PCE dissolution and reaction by 1st order equations. Visualization experiments reveal that the gradual elimination of PCE ganglia by the injected nZVI is associated with the preferential “erosion” of the upstream interfacial regions. The step controlling the overall process kinetics might be either (i) the enhanced PCE dissolution or (ii) the direct reaction of bulk PCE with the nZVI deposited upon the ganglia interfaces. Inverse modeling of the experiments under the simplifying assumption of one active mechanism indicates that the estimated kinetic coefficients are increasing functions of the flow rate. - Highlights: • The PCE remediation by nZVI is studied with visualization tests on pore networks. • The remediation of PCE ganglia by nZVI follows a non-uniform “erosion” pattern. • The preferential erosion of the upstream interfacial regions of

  14. Remediation of soil contaminated with pesticides by treatment with gamma radiation

    International Nuclear Information System (INIS)

    Santos, Janilson Silva

    2009-01-01

    The discharge of empty plastic packaging of pesticides can be an environmental concern mainly by soil contamination. Nowadays, Brazil figures in third place among the leading world pesticide markets. An understanding of the processes that affect the transport and fate of pesticides is crucial to assess their potential for contamination of soil and groundwater, and to develop efficient and cost-effective site management and soil remediation strategies. Due to its impact on soil remediation has made sorption a major topic of research on soil-pesticide interactions. The main objective of this study is the evaluation of the pesticides transferring from contaminated mixture of commercial polymeric packing of high-density polyethylene, HDPE, used in agriculture to soil and their removal by gamma irradiation. Two soil samples of argyles compositions and media composition were exposed to a mixture of commercial polymeric packing contaminated with the pesticides methomyl, dimethoate, carbofuran, methidathion, triazine, thiophos, atrazine, ametryne, endosulfan, chloropyrifos, thriazophos and trifluralin. The pesticides leaching from packaging to soil was homogeneous considering a experimental research. The radiation treatment presented high efficiency on removal pesticides from both soil, but it depends on the physical-chemical characteristics of the contaminated soil. The higher efficiency was obtained in soils with higher organic material and humidity. The higher efficiency was obtained for the medium texture soil, with 20 kGy all present pesticides were removed in all layers. In the case of argyles texture soil, it was necessary a 30 kGy to remove the totality of present pesticides. (author)

  15. Feasibility study of a self-remediation system for mine drainage using its thermal energy

    Science.gov (United States)

    Oh, Chamteut; Cheong, Youngwook; Yim, Giljae; Ji, Sangwoo

    2016-04-01

    Mine drainage is defined as the water which is discharged to the ground surface through shafts and/or cracks formed by mining activities. Typically, mine drainage features high concentration of acidity and metals since it passes through the underground. Therefore, for the purpose of protecting the surrounding natural environment, mine drainage should be remediated before being discharged to nature. Mine drainage, due to its nature of being retained underground, shows constant temperature which is independent from the temperature of the atmosphere above ground. This condition allows mine drainage to become a promising renewable energy source since energy can be recovered from water with constant temperature. In this research, a self-remediation system is proposed which remediates the mine drainage through electrochemical reactions powered by the thermal energy of mine drainage. High energy efficiency is able to be achieved by shortening the distance between the energy source and consumption, and therefore, this system has a strong advantage to be actualized. A feasibility study for the system was conducted in this research where the thermal energy of mine drainage over time and depth was calculated as energy supply and the required electrical energy for remediating the mine drainage was measured as energy consumption. While the technology of converting thermal energy directly into electrical energy is yet to be developed, energy balance analysis results showed that the proposed self-remediation system is theoretically possible.

  16. Enhanced Solar Photoelectrochemical Conversion Efficiency of ZnO:Cu Electrodes for Water-Splitting Application

    Directory of Open Access Journals (Sweden)

    Rekha Dom

    2013-01-01

    Full Text Available n-type ZnO:Cu photoanodes were fabricated by simple spray pyrolysis deposition technique. Influence of low concentration (range ~10−4–10−1% of Cu doping in hexagonal ZnO lattice on its photoelectrochemical performance has been investigated. The doped photoanodes displayed 7-time enhanced conversion efficiencies with respect to their undoped counterpart, as estimated from the photocurrents generated under simulated solar radiation. This is the highest enhancement in the solar conversion efficiency reported so far for the Cu-doped ZnO. This performance is attributed to the red shift in the band gap of the Cu-doped films and is in accordance with the incident-photon-current-conversion efficiency (IPCE measurements. Electrochemical studies reveal an n-type nature of these photoanodes. Thus, the study indicates a high potential of doped ZnO films for solar energy applications, in purview of the development of simple nanostructuring methodologies.

  17. French uranium mining sites remediation

    International Nuclear Information System (INIS)

    Roche, M.

    2002-01-01

    Following a presentation of the COGEMA's general policy for the remediation of uranium mining sites and the regulatory requirements, the current phases of site remediation operations are described. Specific operations for underground mines, open pits, milling facilities and confining the milled residues to meet long term public health concerns are detailed and discussed in relation to the communication strategies to show and explain the actions of COGEMA. A brief review of the current remediation situation at the various French facilities is finally presented. (author)

  18. Remediation Strategies for Learners at Risk of Failure: A Course Based Retention Model

    Science.gov (United States)

    Gajewski, Agnes; Mather, Meera

    2015-01-01

    This paper presents an overview and discussion of a course based remediation model developed to enhance student learning and increased retention based on literature. This model focuses on course structure and course delivery in a compressed semester format. A comparative analysis was applied to a pilot study of students enrolled in a course…

  19. Efficient and robust gradient enhanced Kriging emulators.

    Energy Technology Data Exchange (ETDEWEB)

    Dalbey, Keith R.

    2013-08-01

    %E2%80%9CNaive%E2%80%9D or straight-forward Kriging implementations can often perform poorly in practice. The relevant features of the robustly accurate and efficient Kriging and Gradient Enhanced Kriging (GEK) implementations in the DAKOTA software package are detailed herein. The principal contribution is a novel, effective, and efficient approach to handle ill-conditioning of GEK's %E2%80%9Ccorrelation%E2%80%9D matrix, RN%CC%83, based on a pivoted Cholesky factorization of Kriging's (not GEK's) correlation matrix, R, which is a small sub-matrix within GEK's RN%CC%83 matrix. The approach discards sample points/equations that contribute the least %E2%80%9Cnew%E2%80%9D information to RN%CC%83. Since these points contain the least new information, they are the ones which when discarded are both the easiest to predict and provide maximum improvement of RN%CC%83's conditioning. Prior to this work, handling ill-conditioned correlation matrices was a major, perhaps the principal, unsolved challenge necessary for robust and efficient GEK emulators. Numerical results demonstrate that GEK predictions can be significantly more accurate when GEK is allowed to discard points by the presented method. Numerical results also indicate that GEK can be used to break the curse of dimensionality by exploiting inexpensive derivatives (such as those provided by automatic differentiation or adjoint techniques), smoothness in the response being modeled, and adaptive sampling. Development of a suitable adaptive sampling algorithm was beyond the scope of this work; instead adaptive sampling was approximated by omitting the cost of samples discarded by the presented pivoted Cholesky approach.

  20. Radon remediation in irish schools

    International Nuclear Information System (INIS)

    Synnott, H.

    2006-01-01

    Full text: Commencing in 1998, the Radiological Protection Institute of Ireland carried out radon measurements in 3826 schools in the Republic of I reland on behalf of the Irish Department of Education and Science (D.E.S.). This represents approximately 97% of all schools in the country. Approximately 25% (984) schools had radon concentrations above the Irish national schools Reference Level for radon of 200 Bq/m 3 and required remedial work. The number of individual rooms with radon concentrations above 200 Bq/m 3 was 3020. Remedial work in schools commenced in early 2000. In general schools with maximum radon concentrations in the range 200 -400 Bq/m 3 in one or more rooms were remediated through the installation of passive systems such as an increase in permanent background ventilation mainly wall vents and trickle vents in windows. Schools with maximum radon concentrations greater than 400 Bq/m 3 were usually remediated through the provision of active systems mainly fan assisted sub -slab de pressurization or where this was not possible fan assisted under floor ventilation. The cost of the remedial programme was funded by central Government. Active systems were installed by specialized remedial contractors working to the specifications of a radon remedial expert appointed by the D.E.S. to design remedial systems for affected schools. Schools requiring increased ventilation were granted aided 190 pounds per affected room and had to organize the work themselves. In most schools radon remediation was successful in reducing existing radon concentrations to below the Reference Level. Average radon concentration reduction factors for sub-slab de pressurization systems and fan assisted fan assisted under floor ventilation ranged from 5 to 40 with greater reduction rates found at higher original radon concentrations. Increasing ventilation in locations with moderately elevated radon concentrations (200 - 400 Bq/m 3 ) while not as effective as active systems produced on

  1. GROUDWATER REMEDIATION AT THE 100-HR-3 OPERABLE UNIT HANFORD, SITE WASHINGTON, USA - 11507

    International Nuclear Information System (INIS)

    Smoot, J.L.; Biebesheimer, F.H.; Eluskie, J.A.; Spiliotopoulos, A.; Tonkin, M.J.; Simpkin, T.

    2011-01-01

    The 100-HR-3 Groundwater Operable Unit (OU) at the Hanford Site underlies three former plutonium production reactors and the associated infrastructure at the 100-D and 100-H Areas. The primary contaminant of concern at the site is hexavalent chromium; the secondary contaminants are strontium-90, technetium-99, tritium, uranium, and nitrate. The hexavalent chromium plume is the largest plume of its type in the state of Washington, covering an area of approximately 7 km 2 (2.7 mi 2 ) with concentrations greater than 20 (micro)g/L. Concentrations range from 60,000 (micro)g/L near the former dichromate transfer station in the 100-D Area to large areas of 20 to 100 (micro)g/L across much of the plume area. Pump-and-treat operations began in 1997 and continued into 2010 at a limited scale of approximately 200 gal/min. Remediation of groundwater has been fairly successful in reaching remedial action objectives (RAOs) of 20 (micro)g/L over a limited region at the 100-H, but less effective at 100-D. In 2000, an in situ, permeable reactive barrier was installed downgradient of the hotspot in 100-D as a second remedy. The RAOs are still being exceeded over a large portion of the area. The CH2M HILL Plateau Remediation Company was awarded the remediation contract for groundwater in 2008 and initiated a remedial process optimization study consisting of modeling and technical studies intended to enhance the remediation. As a result of the study, 1,400 gal/min of expanded treatment capacity are being implemented. These new systems are designed to meet 2012 and 2020 target milestones for protection of the Columbia River and cleanup of the groundwater plumes.

  2. Biochar based remediation of water and soil contaminated by phenanthrene and pentachlorophenol.

    Science.gov (United States)

    Rao, Maria A; Di Rauso Simeone, Giuseppe; Scelza, Rosalia; Conte, Pellegrino

    2017-11-01

    Phenanthrene (Phe) and pentachlorophenol (PCP) are classified as persistent organic pollutants and represent serious concern for the environment as they are toxic and ubiquitous. Biochar based remediation is an emerging technology used in water and soil contamination. In this study we used poplar (BP) and conifer (BC) biochars to remediate water and soil contaminated by Phe and PCP. BP and BC were able to remove completely either Phe or PCP from contaminated water within one to three days. When biochar was confined in a porous membrane, BC and BP maintained their sorption efficiency for several remediation cycles. However, in these conditions BC allowed faster Phe removal. In soil remediation experiments, addition of two biochar rates, i.e. 2.5 and 5 mg g -1 , strongly reduced Phe extractability (up to 2.7% of the initially added Phe with the larger BC dose). This was similar to the behavior observed when compost was applied in order to verify the role of soil organic matter in the fate of both contaminants. PCP extractability was reduced only up to 75% (in average) in all samples including those with compost amendment. Only larger amount of biochar (20 and 50 mg g -1 ) allowed reduction of the extractable PCP and nullified phytotoxicity of the contaminant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Electrokinetic remediation of anionic contamination from unsaturated soil: Field application

    International Nuclear Information System (INIS)

    Lindgren, E.R.; Mattson, E.D.

    1995-01-01

    Electrokinetic remediation is an in situ technique under development at Sandia National Laboratories for removal of ionic contaminants from soil. While to date most other studies of this technique have focused on saturated soils, usually clays, the work at Sandia has been to extend the process to unsaturated sandy soils typical of arid regions. The impetus for this study is a chromate plume located beneath an old Sandia chemical waste landfill. Working in unsaturated soils is complicated by moisture control requirements, both to prevent undesired hydraulic transport of contamination outside the treatment zone and to optimize soil properties for efficient electrokinetic remediation. Two field tests will be discussed. First, a field test in clean soil is in progress to demonstrate moisture control with the Sandia electrode system. The second field demonstration, planned to begin the Fall of 1995, involves chromate removal from a in a chemical waste landfill

  4. Traveling-Wave Tube Efficiency Enhancement

    Science.gov (United States)

    Dayton, James A., Jr.

    2011-01-01

    Traveling-wave tubes (TWT's) are used to amplify microwave communication signals on virtually all NASA and commercial spacecraft. Because TWT's are a primary power user, increasing their power efficiency is important for reducing spacecraft weight and cost. NASA Glenn Research Center has played a major role in increasing TWT efficiency over the last thirty years. In particular, two types of efficiency optimization algorithms have been developed for coupled-cavity TWT's. The first is the phase-adjusted taper which was used to increase the RF power from 420 to 1000 watts and the RF efficiency from 9.6% to 22.6% for a Ka-band (29.5 GHz) TWT. This was a record efficiency at this frequency level. The second is an optimization algorithm based on simulated annealing. This improved algorithm is more general and can be used to optimize efficiency over a frequency bandwidth and to provide a robust design for very high frequency TWT's in which dimensional tolerance variations are significant.

  5. Effects of peer social interaction on performance during computerized cognitive remediation therapy in patients with early course schizophrenia: A pilot study.

    Science.gov (United States)

    Sandoval, Luis R; González, Betzamel López; Stone, William S; Guimond, Synthia; Rivas, Cristina Torres; Sheynberg, David; Kuo, Susan S; Eack, Shaun; Keshavan, Matcheri S

    2017-09-04

    Recent studies show that computer-based training enhances cognition in schizophrenia; furthermore, socialization has also been found to improve cognitive functions. It is generally believed that non-social cognitive remediation using computer exercises would be a pre-requisite for therapeutic benefits from social cognitive training. However, it is also possible that social interaction by itself enhances non-social cognitive functions; this possibility has scarcely been explored in schizophrenia patients. This pilot study examined the effects of computer-based neurocognitive training, along with social interaction either with a peer (PSI) or without one (N-PSI). We hypothesized that PSI will enhance cognitive performance during computerized exercises in schizophrenia, as compared with N-PSI. Sixteen adult participants diagnosed with schizophrenia or schizoaffective disorder participating in an ongoing trial of Cognitive Enhancement Therapy completed several computerized neurocognitive remediation training sessions (the Orientation Remedial Module©, or ORM), either with a peer or without a peer. We observed a significant interaction between the effect of PSI and performance on the different cognitive exercises (p<0.05). More precisely, when patients performed the session with PSI, they demonstrated better cognitive performances than with N-PSI in the ORM exercise that provides training in processing speed, alertness, and reaction time (the standard Attention Reaction Conditioner, or ARC) (p<0.01, corrected). PSI did not significantly affect other cognitive domains such as target detection and spatial attention. Our findings suggest that PSI could improve cognitive performance, such as processing speed, during computerized cognitive training in schizophrenia. Additional studies investigating the effect of PSI during cognitive remediation are needed to further evaluate this hypothesis. Copyright © 2017. Published by Elsevier B.V.

  6. Program management strategies for following EPA guidance for remedial design/remedial action at DOE sites

    International Nuclear Information System (INIS)

    Hopper, J.P.; Chew, J.R.; Kowalski, T.E.

    1991-01-01

    At the US Department of Energy (DOE) facilities, environmental restoration is being conducted in accordance with Federal Facilities Compliance Agreements (or Interagency Agreements). These agreements establish a cooperative working relationship and often define roles, responsibilities and authorities for conduct and oversight of the Remedial Action Programs. The US Environmental Protection Agency (EPA) has guidelines on how to initiate and perform remedial actions for sites they are remediating under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) as amended by the Superfund Amendments and Re-Authorization Act (SARA). This paper addresses some of the difference and commonalities between the DOE project management procedures and EPA guidance documents. This report covers only the RD/RA phase of environmental restoration. On the surface, there are many apparent differences between the DOE and EPA project management processes. Upon closer review, however, many of the differences are the result of applying different terminology to the same phase of a project. By looking for the similarities in the two processes rather than hunting for differences, many communication problems are avoided. Understanding both processes also aids in figuring out when, how and to what extent EPA should participate in the RD/RA phase for DOE lead cleanup activities. The DOE Remedial Design and Remedial Action process is discussed in a stepwise manner and compared to the EPA process. Each element of the process is defined. Activities common to both the EPA and DOE are correlated. The annual DOE budget cycle for remediation projects and the four-year cycle for appropriation of remediation funds are discussed, and the constraints of this process examined. DOE orders as well as other requirements for RD/RA activities are summarized and correlated to EPA regulations where this is possible

  7. Thermodynamic comparison and efficiency enhancement mechanism of coal to alternative fuel systems

    International Nuclear Information System (INIS)

    Ji, Xiaozhou; Li, Sheng; Gao, Lin; Jin, Hongguang

    2016-01-01

    Highlights: • Energy and exergy analysis are presented to three coal-to-alternative-fuels systems. • Internal reasons for performance differences for different systems are disclosed. • The temperature and heat release of synthesis reactions are key to plant efficiency. • The distillation unit and purge gas recovery are important to efficiency enhancement. - Abstract: Coal to alternative fuels is an important path to enforce energy security and to provide clean energy. In this paper, we use exergy analysis and energy utilization diagram (EUD) methods to disclose the internal reasons for performance differences in typical coal to alternative fuel processes. ASPEN plus software is used to simulate the coal-based energy systems, and the simulation results are verified with engineering data. Results show that coal to substitute natural gas (SNG) process has a higher exergy efficiency of 56.56%, while the exergy efficiency of traditional coal to methanol process is 48.65%. It is indicated that three key factors impact the performance enhancement of coal to alternative fuel process: (1) whether the fuel is distillated, (2) the synthesis temperature and the amount of heat release from reactions, and (3) whether the chemical purge gases from synthesis and distillation units are recovered. Distillation unit is not recommended and synthesis at high temperature and with large heat release is preferable for coal to alternative fuel systems. Gasification is identified as the main source of exergy destruction, and thereby how to decrease its destruction is the key direction of plant efficiency improvement in the future. Also, decreasing the power consumption in air separation unit by seeking for advanced technologies, i.e. membrane, or using another kind of oxidant is another direction to improve plant performance.

  8. Remediation of hexavalent chromium spiked soil by using synthesized iron sulfide particles.

    Science.gov (United States)

    Li, Yujie; Wang, Wanyu; Zhou, Liqiang; Liu, Yuanyuan; Mirza, Zakaria A; Lin, Xiang

    2017-02-01

    Carboxymethyl cellulose (CMC) stabilized microscale iron sulfide (FeS) particles were synthesized and applied to remediate hexavalent chromium (Cr(VI)) spiked soil. The effects of parameters including dosage of FeS particles, soil moisture, and natural organic matter (NOM) in soil were investigated with comparison to iron sulfate (FeSO 4 ). The results show that the stabilized FeS particles can reduce Cr(VI) and immobilize Cr in soil quickly and efficiently. The soil moisture ranging from 40% to 70% and NOM in soil had no significant effects on Cr(VI) remediation by FeS particles. When molar ratio of FeS to Cr(VI) was 1.5:1, about 98% of Cr(VI) in soil was reduced by FeS particles in 3 d and Cr(VI) concentration decreased from 1407 mg kg -1 to 16 mg kg -1 . The total Cr and Cr(VI) in Toxicity Characteristic Leaching Procedure (TCLP) leachate were reduced by 98.4% and 99.4%, respectively. In FeS particles-treated soil, the exchangeable Cr fraction was mainly converted to Fe-Mn oxides bound fraction because of the precipitation of Cr(III)-Fe(III) hydroxides. The physiologically based extraction test (PBET) bioaccessibility of Cr was decreased from 58.67% to 6.98%. Compared to FeSO 4 , the high Cr(VI) removal and Cr immobilization efficiency makes prepared FeS particles a great potential in field application of Cr(VI) contaminated soil remediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Use of technical and economic analysis for optimizing technology selection and remedial design for contaminated sites

    International Nuclear Information System (INIS)

    Hardisty, P.E.; Brown, A.

    1996-01-01

    The decision to remediate a contaminated site can be seen from the macroeconomic and microeconomic viewpoints. Macroeconomics can be used to plan and account for the overall cost of pollution as part of a firm's production, and thus make overall decisions on the real cost of pollution and the level of clean-up which may be called for. Valuation of damaged resources, option values and intrinsic worth is an important part of this process. Once the decision to remediate has been taken, the question becomes how best to remediate. Microeconomic analysis deals with providing efficient allocative decisions for reaching specified goals. it is safe to say that cost is one of the single most important factors in site clean-up decision making. A basic rule of remediation is often taken to be the maximization of contaminant mass removed per dollar spent. However, remediation may also be governed by other objectives and constraints. In some situations, minimization of time, rather than cost, could be the constraint. Or perhaps the objective could be to achieve a set level of clean-up for the lowest possible cost, even if a large program would result in unit-cost reductions. Evaluation of the economics of a clean-up project is directly linked to the objectives of the site owner, and the constraints within which the remediation is to be performed. Economic analysis of remedial options for containment of a 350,000 L hydrocarbon spill migrating through fractured rock into a river in Alberta, Canada, clear direction to the site owner

  10. An aptamer cocktail-functionalized photocatalyst with enhanced antibacterial efficiency towards target bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Song, Min Young [Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792 (Korea, Republic of); Jurng, Jongsoo [Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792 (Korea, Republic of); Department of Energy and Environmental Engineering, University of Science and Technology (UST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792 (Korea, Republic of); Park, Young-Kwon [School of Environmental Engineering, University of Seoul, Seoulsiripdae-ro 163, Dongdaemun-gu, Seoul 02504 (Korea, Republic of); Kim, Byoung Chan, E-mail: bchankim@kist.re.kr [Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792 (Korea, Republic of); Department of Energy and Environmental Engineering, University of Science and Technology (UST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792 (Korea, Republic of)

    2016-11-15

    Highlights: • Aptamer-conjugated TiO{sub 2} was developed for target-specific bacterial inactivation. • TiO{sub 2}-aptamer cocktail can enhance inactivation of target bacteria faster than TiO{sub 2}. • TiO{sub 2}-aptamer cocktail can enhance inactivation of target bacteria in mixed culture. • Efficient ROS transfer to the bacteria is caused by close contact of TiO{sub 2}-aptamer. - Abstract: We developed TiO{sub 2} particles conjugated with an Escherichia coli surface-specific ssDNA aptamer cocktail (composed of three different aptamers isolated from E. coli) for targeted and enhanced disinfection of E. coli. We examined the target-specific and enhanced inactivation of this composite (TiO{sub 2}-Apc), which were compared to those of TiO{sub 2} conjugated with a single aptamer (one of the three different aptamers, TiO{sub 2}-Aps) and non-modified TiO{sub 2}. We found that TiO{sub 2}-Apc enhanced the inactivation of targeted E. coli under UV irradiation compared to both the non-modified TiO{sub 2} and TiO{sub 2}-Aps. A higher number of TiO{sub 2}-Apc than TiO{sub 2}-Aps particles was observed on the surface of E. coli. The amount of TiO{sub 2}-Apc required to inactivate ∼99.9% of E. coli (10{sup 6} CFU/ml) was 10 times lower than that of non-modified TiO{sub 2}. The close proximity of functionalized particles with E. coli resulting from the interaction between the target surface and the aptamer induced the efficient and fast transfer of reactive oxygen species to the cells. In a mixed culture of different bacteria (E. coli and Staphylococcus epidermidis), TiO{sub 2}-Apc enhanced the inactivation of only E. coli. Taken together, these results support the use of aptamer cocktail-conjugated TiO{sub 2} for improvement of the target-specific inactivation of bacteria.

  11. Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium.

    Science.gov (United States)

    Teixeira, Catarina; Almeida, C Marisa R; Nunes da Silva, Marta; Bordalo, Adriano A; Mucha, Ana P

    2014-09-15

    Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Site remediation techniques in India: a review

    International Nuclear Information System (INIS)

    Anomitra Banerjee; Miller Jothi

    2013-01-01

    India is one of the developing countries operating site remediation techniques for the entire nuclear fuel cycle waste for the last three decades. In this paper we intend to provide an overview of remediation methods currently utilized at various hazardous waste sites in India, their advantages and disadvantages. Over the years the site remediation techniques have been well characterized and different processes for treatment, conditioning and disposal are being practiced. Remediation Methods categorized as biological, chemical or physical are summarized for contaminated soils and environmental waters. This paper covers the site remediation techniques implemented for treatment and conditioning of wastelands arising from the operation of nuclear power plant, research reactors and fuel reprocessing units. (authors)

  13. Proceedings of the remediation technologies symposium 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This conference provided an opportunity for industry, practitioners, researchers and regulators to discuss technical issues in environmental remediation research and the latest innovations in soil and groundwater remediation. Cost effective in-situ and ex-situ soil reclamation strategies were presented along with groundwater and surface water remediation strategies in 13 sessions entitled: hydrocarbon contamination; salt management; liability management; chemical oxidation; light non-aqueous phase liquids (LNAPL); Montreal Center of Excellence in Brownfields Rehabilitation; Alberta government updates; phytoremediation; natural attenuation; Lake Wabamun; ex-situ remediation; in-situ remediation; and, miscellaneous issues. Technological solutions for erosion control and water clarification were highlighted. The conference featured 52 presentations, of which 17 have been catalogued separately for inclusion in this database. tabs., figs.

  14. Groundwater remediation in the Straz leaching operation

    International Nuclear Information System (INIS)

    Novak, J.

    2001-01-01

    The locality affected by consequences of the chemical mining of the uranium during underground leaching 'in situ' is found in the area of the Czech Republic in the northeastern part of the Ceska Lipa district. In the contribution the complex groundwater remediation project is discussed. First, the risks of the current state are expressed. Then the alternatives of remediation of the both Cenomanian and Turonian aquifers are presented. Evaluation of the remediation alternatives with the view to the time-consumption, economy, ecology and the elimination of unacceptable risks for the population and environment is done. Finally, the present progress of remediation and the conception of remediation of chemical mining on deposit of Straz pod Ralskem are presented. (orig.)

  15. ICDF Complex Remedial Action Report

    Energy Technology Data Exchange (ETDEWEB)

    W. M. Heileson

    2007-09-26

    This Idaho CERCLA Disposal Facility (ICDF) Remedial Action Report has been prepared in accordance with the requirements of Section 6.2 of the INEEL CERCLA Disposal Facility Remedial Action Work Plan. The agency prefinal inspection of the ICDF Staging, Storage, Sizing, and Treatment Facility (SSSTF) was completed in June of 2005. Accordingly, this report has been developed to describe the construction activities completed at the ICDF along with a description of any modifications to the design originally approved for the facility. In addition, this report provides a summary of the major documents prepared for the design and construction of the ICDF, a discussion of relevant requirements and remedial action objectives, the total costs associated with the development and operation of the facility to date, and identification of necessary changes to the Agency-approved INEEL CERCLA Disposal Facility Remedial Action Work Plan and the ICDF Complex Operations and Maintenance Plan.

  16. Electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Ottosen, Lisbeth M.; Hansen, Lene

    1997-01-01

    It is not possible for all heavy metal polluted soils to remediate it by an applied electric field alone. A desorbing agent must in different cases be added to the soil in order to make the process possible or to make it cost effective......It is not possible for all heavy metal polluted soils to remediate it by an applied electric field alone. A desorbing agent must in different cases be added to the soil in order to make the process possible or to make it cost effective...

  17. High-efficiency intracavity second-harmonic enhancement for a few-cycle laser pulse train

    International Nuclear Information System (INIS)

    Cai, Yi; Xu, Shixiang; Zeng, Xuanke; Zou, Da; Li, Jingzhen

    2012-01-01

    This paper presents an intracavity second-harmonic (SH) enhancement technology without the need of input impedance-matching for optimal coupling between the cavity and its input frequency comb. More than 10% SH energy conversion efficiency is available, thus the power of the SH frequency comb can be enhanced beyond 100 relative to single-pass SH generation. Compared with a conventional passive enhancing cavity, for the purpose of high power enhancement, our scheme can operate at much lower finesse and thus broader bandwidth so that it can support several-optical-cycle pulses more easily. If they have the same finesse, both methods perform with similar operating stability. The results show that our novel design is suitable for some applications which need a short wavelength, high intensity, and ultra-broad bandwidth pulse train. (paper)

  18. DOE's Assurance Program for Remedial Action (APRA)

    International Nuclear Information System (INIS)

    Denham, D.H.; Stenner, R.D.; Welty, C.G. Jr.; Needels, T.S.

    1985-01-01

    The US Department of Energy's (DOE) Office of Operational Safety (OOS) is presently developing and implementing the Assurance Program for Remedial Action (APRA) to overview DOE's Remedial Action programs. APRA's objective is to ensure the adequacy of environmental, safety and health (ES and H) protection practices within the four DOE Remedial Action programs: Grand Junction Remedial Action Program (GJRAP), Uranium Mill Tailings Remedial Action Program (UMTRAP), Formerly Utilized Sites Remedial Action Program (FUSRAP), and Surplus Facilities Management Program (SFMP). APRA encompasses all ES and H practices of DOE and its contractors/subcontractors within the four Remedial Action programs. Specific activities of APRA include document reviews, selected site visits, and program office appraisals. Technical support and assistance to OOS is being provided by APRA contractors in the evaluation of radiological standards and criteria, quality assurance measures, radiation measurements, and risk assessment practices. This paper provides an overview of these activities and discusses program to date, including the roles of OOS and the respective contractors. The contractors involved in providing technical support and assistance to OOS are Aerospace Corporation, Oak Ridge Associated Universities, and Pacific Northwest Laboratory

  19. Remedial action of radium contaminated residential properties

    International Nuclear Information System (INIS)

    White, D.; Eng, J.

    1986-01-01

    Since November 1983, the New Jersey Department of Environmental Protection (NJDEP) and the US Environmental Protection Agency (USEPA) have been in the process of identifying properties in Montclair, Glen Ridge and West Orange, New Jersey, which were built over radium contaminated soil landfilled areas. Elevated indoor radon concentrations prompted the Centers for Disease Control (CDC) to issue a health advisory which included permanent remediation of radon progeny levels in excess of 0.02 Working Levels within two years of discovery. In order to expedite remedial action, NJDEP undertook a ten million dollar cleanup program. Remedial Action at the 12 residential properties encountered some unanticipated problems despite the efforts of numerous government agencies and their contractors to characterize the contamination as much as possible prior to remediation. Some of the unanticipated issues include contamination from other radionuclides, underestimation of removal volumes, and controversy over the transportation and disposal of the radium contaminated soil at a commercial facility in Nevada. This paper will review the approach taken by NJDEP to the remedial action for radium contaminated soil, discuss some of the issues encountered during the remedial action, and provide post remedial action data

  20. DOE's Assurance Program for Remedial Action (APRA)

    International Nuclear Information System (INIS)

    Denham, D.H.; Stenner, R.D.; Welty, C.G. Jr.; Needels, T.S.

    1984-10-01

    The US Department of Energy's (DOE) Office of Operational Safety (OOS) is presently developing and implementing the Assurance Program for Remedial Action (APRA) to overview DOE's Remedial Action programs. APRA's objective is to ensure the adequacy of environmental, safety and health (ES and H) protection practices within the four DOE Remedial Action programs: Grand Junction Remedial Action Program (GJRAP), Uranium Mill Tailings Remedial Action Program (UMTRAP), Formerly Utilized Sites Remedial Action Program (FUSRAP), and Surplus Facilities Management Program (SFMP). APRA encompasses all ES and H practices of DOE and its contractors/subcontractors within the four Remedial Action programs. Specific activities of APRA include document reviews, selected site visits, and program office appraisals. Technical support and assistance to OOS is being provided by APRA contractors in the evaluation of radiological standards and criteria, quality assurance measures, radiation measurements, and risk assessment practices. This paper provides an overview of these activities and discusses progress to date, including the roles of OOS and the respective contractors. The contractors involved in providing technical support and assistance to OOS are Aerospace Corporation, Oak Ridge Associated Universities, and Pacific Northwest Laboratory

  1. Electrodialytic Remediation of Different Cu-Polluted Soils

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Hansen, Henrik K.; Hansen, Lene

    1999-01-01

    Based on characterization of a polluted soil a proper desorbing agent to be added to the soil before the remediation can be found. The desorbing agent can improve the remediation according to both energy consumption and duration of the action......Based on characterization of a polluted soil a proper desorbing agent to be added to the soil before the remediation can be found. The desorbing agent can improve the remediation according to both energy consumption and duration of the action...

  2. The adoption of energy efficiency enhancing technologies. Market Performance and Policy Strategies in Case of Heterogeneous Firms

    Energy Technology Data Exchange (ETDEWEB)

    Verhoef, E.; Nijkamp, P. [Department of Spatial Economics, Free University Amsterdam, Amsterdam (Netherlands)

    1997-07-01

    The adoption of energy-efficiency enhancing technologies by heterogeneous firms is analyzed. The fact that energy use does not only cause external environmental costs through pollution, but also directly affects the profitability of the firm and hence its behaviour on input and output markets is taken for granted. It is demonstrated that the consideration of such market processes may have important implications for the efficiency of environmental policies concerned with energy use. The analysis focuses in particular on the efficiency of the market-led adoption and diffusion process under various policy regimes. It is shown that the promotion of energy-efficiency enhancing technologies might have unexpected effects in that it could lead to an increase in energy use, while the use of energy taxes might actually reduce the attractiveness of energy-saving technologies. 22 refs.

  3. Electrodialytic remediation of solid waste

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Ottosen, Lisbeth M.; Karlsmose, Bodil

    1996-01-01

    Electrodialytic remediation of heavy metal polluted solid waste is a method that combines the technique of electrodialysis with the electromigration of ions in the solid waste. Results of laboratory scale remediation experiments of soil are presented and considerations are given on how to secure...

  4. Sustainability: A new imperative in contaminated land remediation

    International Nuclear Information System (INIS)

    Hou, Deyi; Al-Tabbaa, Abir

    2014-01-01

    Highlights: • Reviewed the emerging green and sustainable remediation movement in the US and Europe. • Identified three sources of pressures for emphasizing sustainability in the remediation field. • Presented a holistic view of sustainability considerations in remediation. • Developed an integrated framework for sustainability assessment and decision making. - Abstract: Land is not only a critical component of the earth's life support system, but also a precious resource and an important factor of production in economic systems. However, historical industrial operations have resulted in large areas of contaminated land that are only slowly being remediated. In recent years, sustainability has drawn increasing attention in the environmental remediation field. In Europe, there has been a movement towards sustainable land management; and in the US, there is an urge for green remediation. Based on a questionnaire survey and a review of existing theories and empirical evidence, this paper suggests the expanding emphasis on sustainable remediation is driven by three general factors: (1) increased recognition of secondary environmental impacts (e.g., life-cycle greenhouse gas emissions, air pollution, energy consumption, and waste production) from remediation operations, (2) stakeholders’ demand for economically sustainable brownfield remediation and “green” practices, and (3) institutional pressures (e.g., social norm and public policy) that promote sustainable practices (e.g., renewable energy, green building, and waste recycling). This paper further argues that the rise of the “sustainable remediation” concept represents a critical intervention point from where the remediation field will be reshaped and new norms and standards will be established for practitioners to follow in future years. This paper presents a holistic view of sustainability considerations in remediation, and an integrated framework for sustainability assessment and decision making

  5. Aerobic and anaerobic biosynthesis of nano-selenium for remediation of mercury contaminated soil.

    Science.gov (United States)

    Wang, Xiaonan; Zhang, Daoyong; Pan, Xiangliang; Lee, Duu-Jong; Al-Misned, Fahad A; Mortuza, M Golam; Gadd, Geoffrey Michael

    2017-03-01

    Selenium (Se) nanoparticles are often synthesized by anaerobes. However, anaerobic bacteria cannot be directly applied for bioremediation of contaminated top soil which is generally aerobic. In this study, a selenite-reducing bacterium, Citrobacter freundii Y9, demonstrated high selenite reducing power and produced elemental nano-selenium nanoparticles (nano-Se 0 ) under both aerobic and anaerobic conditions. The biogenic nano-Se 0 converted 45.8-57.1% and 39.1-48.6% of elemental mercury (Hg 0 ) in the contaminated soil to insoluble mercuric selenide (HgSe) under anaerobic and aerobic conditions, respectively. Addition of sodium dodecyl sulfonate enhanced Hg 0 remediation, probably owing to the release of intracellular nano-Se 0 from the bacterial cells for Hg fixation. The reaction product after remediation was identified as non-reactive HgSe that was formed by amalgamation of nano-Se 0 and Hg 0 . Biosynthesis of nano-Se 0 both aerobically and anaerobically therefore provides a versatile and cost-effective remediation approach for Hg 0 -contaminated surface and subsurface soils, where the redox potential often changes dramatically. Copyright © 2016. Published by Elsevier Ltd.

  6. Biostimulation proved to be the most efficient method in the comparison of in situ soil remediation treatments after a simulated oil spill accident.

    Science.gov (United States)

    Simpanen, Suvi; Dahl, Mari; Gerlach, Magdalena; Mikkonen, Anu; Malk, Vuokko; Mikola, Juha; Romantschuk, Martin

    2016-12-01

    The use of in situ techniques in soil remediation is still rare in Finland and most other European countries due to the uncertainty of the effectiveness of the techniques especially in cold regions and also due to their potential side effects on the environment. In this study, we compared the biostimulation, chemical oxidation, and natural attenuation treatments in natural conditions and pilot scale during a 16-month experiment. A real fuel spill accident was used as a model for experiment setup and soil contamination. We found that biostimulation significantly decreased the contaminant leachate into the water, including also the non-aqueous phase liquid (NAPL). The total NAPL leachate was 19 % lower in the biostimulation treatment that in the untreated soil and 34 % lower in the biostimulation than oxidation treatment. Soil bacterial growth and community changes were first observed due to the increased carbon content via oil amendment and later due to the enhanced nutrient content via biostimulation. Overall, the most effective treatment for fresh contaminated soil was biostimulation, which enhanced the biodegradation of easily available oil in the mobile phase and consequently reduced contaminant leakage through the soil. The chemical oxidation did not enhance soil cleanup and resulted in the mobilization of contaminants. Our results suggest that biostimulation can decrease or even prevent oil migration in recently contaminated areas and can thus be considered as a potentially safe in situ treatment also in groundwater areas.

  7. Remediating a design tool

    DEFF Research Database (Denmark)

    Jensen, Mads Møller; Rädle, Roman; Klokmose, Clemens N.

    2018-01-01

    digital sticky notes setup. The paper contributes with a nuanced understanding of what happens when remediating a physical design tool into digital space, by emphasizing focus shifts and breakdowns caused by the technology, but also benefits and promises inherent in the digital media. Despite users......' preference for creating physical notes, handling digital notes on boards was easier and the potential of proper documentation make the digital setup a possible alternative. While the analogy in our remediation supported a transfer of learned handling, the users' experiences across technological setups impact......Sticky notes are ubiquitous in design processes because of their tangibility and ease of use. Yet, they have well-known limitations in professional design processes, as documentation and distribution are cumbersome at best. This paper compares the use of sticky notes in ideation with a remediated...

  8. High-efficiency, 154  W CW, diode-pumped Raman fiber laser with brightness enhancement.

    Science.gov (United States)

    Glick, Yaakov; Fromzel, Viktor; Zhang, Jun; Ter-Gabrielyan, Nikolay; Dubinskii, Mark

    2017-01-20

    We demonstrate a high-power, high-efficiency Raman fiber laser pumped directly by laser diode modules at 978 nm. 154 W of CW power were obtained at a wavelength of 1023 nm with an optical to optical efficiency of 65%. A commercial graded-index (GRIN) core fiber acts as the Raman fiber in a power oscillator configuration, which includes spectral selection to prevent generation of the second Stokes. In addition, brightness enhancement of the pump beam by a factor of 8.4 is attained due to the Raman gain distribution profile in the GRIN fiber. To the best of our knowledge this is the highest power and highest efficiency Raman fiber laser demonstrated in any configuration allowing brightness enhancement (i.e., in either cladding-pumped configuration or with GRIN fibers, excluding step-index core pumped), regardless of pumping scheme (i.e., either diode pumped or fiber laser pumped).

  9. Job Endings and Work Trajectories of Persons Receiving Supported Employment and Cognitive Remediation.

    Science.gov (United States)

    Teixeira, Carina; Mueser, Kim T; Rogers, E Sally; McGurk, Susan R

    2018-05-02

    This study examined job endings and work trajectories among participants in a study comparing the effects of adding cognitive remediation to supported employment among individuals who had not benefited from supported employment. Data were from a controlled trial of 107 persons with serious mental illness enrolled in supported employment but who had not obtained or sustained competitive work. Participants were randomly assigned to enhanced supported employment only (with employment specialists trained to recognize cognitive difficulties and teach coping strategies) or to the Thinking Skills for Work program (enhanced supported employment plus cognitive remediation). For the 52 participants who worked, the two groups were compared on types of job endings, reasons for job endings, successful versus unsuccessful jobs, and work trajectories over the two-year study period. The two groups did not differ in types of job ending, although participants in Thinking Skills for Work were less likely than those in enhanced supported employment only to cite dissatisfaction with the job as a reason for the job ending. Participants in Thinking Skills for Work were also less likely to have an overall unsuccessful work trajectory, more likely to have only successful jobs, and more likely to be employed at the end of the study. The Thinking Skills for Work program appeared to help participants who had not benefited from supported employment stick with and master their jobs more effectively than those in enhanced supported employment only, resulting in better work trajectories over the course of the study.

  10. Degradation of oil products in a soil from a Russian Barents hot-spot during electrodialytic remediation

    DEFF Research Database (Denmark)

    Pedersen, Kristine B.; Lejon, Tore; Jensen, Pernille Erland

    2016-01-01

    A highly oil-polluted soil from Krasnoe in North-West Russia was used to investigate the degradation of organic pollutants during electrodialytic remediation. Removal efficiencies were up to 70 % for total hydrocarbons (THC) and up to 65 % for polyaromatic hydrocarbons (PAH). Relatively more...... of the lighter PAH compounds and THC fractions were degraded. A principal component analysis (PCA) revealed a difference in the distribution of PAH compounds after the remediation. The observed clustering of experiments in the PCA scores plot was assessed to be related to the stirring rate. Multivariate analysis...... of the experimental settings and final concentrations in the 12 experiments revealed that the stirring rate of the soil suspension was by far the most important parameter for the remediation for both THC and PAH. Light was the second most important variable for PAH and seems to influence degradation. The experimental...

  11. Alternative Remedies

    Science.gov (United States)

    ... Home › Aging & Health A to Z › Alternative Remedies Font ... medical treatment prescribed by their healthcare provider. Using this type of alternative therapy along with traditional treatments is ...

  12. Case study of an approved corrective action integrating active remediation with intrinsic remediation

    International Nuclear Information System (INIS)

    Teets, D.B.; Guest, P.R.; Blicker, B.R.

    1996-01-01

    Parsons Engineering Science, Inc., performed UST removals and/or site assessments at UST system locations at a former US Air Force Base (AFB) in Denver, Colorado. Four UST systems, incorporating 17 USTs, were located within the petroleum, oils, and lubricants bulk storage yard (POL Yard) of the former AFB. During the tank removals and subsequent site investigations, petroleum hydrocarbon contamination was found in soils at each site. Significant releases from two of the UST systems resulted in a dissolved benzene, toluene, ethylbenzene, and xylenes (BTEX) plume in the groundwater, and smear-zone contamination of soils beneath the majority of the POL Yard. Because of the close proximity of the UST systems, and the presence of the groundwater plume beneath the POL Yard, a corrective action plan (CAP) was prepared that encompassed all four UST systems. An innovative, risk-based CAP integrated active remediation of petroleum-contaminated soils with intrinsic remediation of groundwater. A natural attenuation evaluation for the dissolved BTEX was performed to demonstrate that natural attenuation processes are providing adequate remediation of groundwater and to predict the fate of the groundwater plume. BTEX concentrations versus distance were regressed to obtain attenuation rates, which were then used to calculate BTEX degradation rates using a one-dimensional, steady-state analytical solution. Additionally, electron acceptor concentrations in groundwater were compared to BTEX concentrations to provide evidence that natural attenuation of BTEX compounds was occurring. The natural attenuation evaluation was used in the CAP to support the intrinsic remediation with long-term monitoring alternative for groundwater, thereby avoiding the installation of an expensive groundwater remediation system

  13. Geophysical Monitoring of Hydrocarbon-Contaminated Soils Remediated with a Bioelectrochemical System.

    Science.gov (United States)

    Mao, Deqiang; Lu, Lu; Revil, André; Zuo, Yi; Hinton, John; Ren, Zhiyong Jason

    2016-08-02

    Efficient noninvasive techniques are desired for monitoring the remediation process of contaminated soils. We applied the direct current resistivity technique to image conductivity changes in sandbox experiments where two sandy and clayey soils were initially contaminated with diesel hydrocarbon. The experiments were conducted over a 230 day period. The removal of hydrocarbon was enhanced by a bioelectrochemical system (BES) and the electrical potentials of the BES reactors were also monitored during the course of the experiment. We found that the variation in electrical conductivity shown in the tomograms correlate well with diesel removal from the sandy soil, but this is not the case with the clayey soil. The clayey soil is characterized by a larger specific surface area and therefore a larger surface conductivity. In sandy soil, the removal of the diesel and products from degradation leads to an increase in electrical conductivity during the first 69 days. This is expected since diesel is electrically insulating. For both soils, the activity of BES reactors is moderately imaged by the inverted conductivity tomogram of the reactor. An increase in current production by electrochemically active bacteria activity corresponds to an increase in conductivity of the reactor.

  14. Green remediation: enhanced reductive dechlorination using recycled rinse water as bioremediation substrate

    International Nuclear Information System (INIS)

    Dawson, Gaynor; McKeon, Tom

    2007-01-01

    Enhanced reductive dechlorination (ERD) has rapidly become a remedy of choice for use on chlorinated solvent contamination when site conditions allow. With this approach, solutions of an organic substrate are injected into the affected aquifer to stimulate biological growth and the resultant production of reducing conditions in the target zone. Under the reducing conditions, hydrogen is produced and ultimately replaces chlorine atoms on the contaminant molecule causing sequential dechlorination. Under suitable conditions the process continues until the parent hydrocarbon precursor is produced, such as the complete dechlorination of trichloroethylene (TCE) to ethene. The process is optimized by use of a substrate that maximizes hydrogen production per unit cost. When natural biota are not present to promote the desired degradation, inoculates can be added with the substrate. The in-situ method both reduces cost and accelerates cleanup. Successful applications have been extended from the most common chlorinated compounds perchloroethylene (PCE) and TCE and related products of degradation, to perchlorate, and even explosives such as RDX and trinitrotoluene on which nitrates are attacked in lieu of chloride. In recent work, the process has been further improved through use of beverage industry wastewaters that are available at little or no cost. With material cost removed from the equation, applications can maximize the substrate loading without significantly increasing total cost. The extra substrate loading both accelerates reaction rates and extends the period of time over which reducing conditions are maintained. In some cases, the presence of other organic matter in addition to simple sugars provides for longer performance times of individual injections, thereby working in a fashion similar to emulsified vegetable oil. The paper discusses results of applications at three different sites contaminated with chlorinated ethylenes. The applications have included

  15. Data base management for the Remedial Action Program at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Voorhees, L.D.; Cushman, R.M.; Faulkner, M.A.; Horwedel, B.M.

    1986-08-01

    The Oak Ridge National Laboratory's (ORNL's) Remedial Action Program was established to provide appropriate corrective measures at over 140 sites that were contaminated with radioactive and/or hazardous chemical wastes. To achieve this goal, numerous and varied studies are being conducted which will result in the collection of an unprecedented amount of data for the ORNL site. To manage such data effectively and efficiently, a computerized data base is being developed. The data base provides a unified repository for all data generated within the Remedial Action Program, to allow for necessary storage, manipulation, analyses, assessment, display, and report generation. Data base management for the Remedial Action Program is documented in this report by: (1) defining the organization of the data management staff and the services provided; (2) describing the design of the data base, including its management system, organization, and applications; (3) providing examples of the current and anticipated tasks; and (4) discussing quality assurance measures implemented to control the accuracy of the data entries and the security of the data

  16. The blessings of energy efficiency in an enhanced EU sustainability scenario. Volume 1

    International Nuclear Information System (INIS)

    Lechtenboehmer, Stefan

    2007-01-01

    Although the anticipated 'end of cheap oil' has boosted the interest in energy efficiency as a cornerstone of energy and climate strategies, it is usually taken into account on the basis of rather narrowly defined cost-benefit considerations. As a consequence, substantial ancillary benefits are usually barely considered.In a recent study for the European Parliament (EP), the authors assessed two enhanced climate strategies compared to a more conventional strategy. One enhanced climate policy scenario relies, in particular, on raising the annual pace of energy efficiency improvement. The other aims at a radical boost of the market share of renewable energy forms, which, however, presupposes an equally radical improvement of energy efficiency.The present article presents the scenario results and places them in the context of risk characterisation of the considered climate policy scenarios. Risks of international turmoil and energy price hikes could be reduced if dependency rates for fossil fuel imports went down. A more ambitious climate policy can also strengthen the EU position in post-Kyoto global climate agreements and a moderated need for emission trading can, for example, reduce conflicting pressures on clean technology transfer. On the other hand, the implementation of the efficiency strategy will entail increased domestic risks because it will involve a re-prioritisation of resource allocation and will thus affect the current distribution of wealth in both the energy sector and some other closely related sectors.The article outlines the main drivers behind the ambitious energy efficiency scenario and it attaches tentative price tags to the ancillary effects, with special emphasis on the above sketched swapping of risks. It will, therefore, strongly argue for a more holistic view, which underscores the need for political action and the benefits of such proactive policies in favour of energy efficiency

  17. The Orbital Debris Problem and the Challenges for Environment Remediation

    Science.gov (United States)

    Liou, J.-C.

    2014-01-01

    LEO debris population will continue to increase even with a good implementation of the commonly-adopted mitigation measures. The root-cause of the increase is catastrophic collisions involving large/massive intact objects (rocket bodies or spacecraft). The major mission-ending risks for most operational spacecraft, however, come from impacts with debris just above the threshold of the protection shields (5-mm to 1-cm). A solution-driven approach is to seek: Concepts for removal of massive intacts with high P(collision); Concepts capable of preventing collisions involving intacts; Concepts for removal of 5-mm to 1-cm debris; Enhanced impact protection shields for valuable space assets. Key questions for remediation consideration of orbital debris: What is the acceptable threat level? What are the mission objectives? What is the appropriate roadmap/timeframe for remediation? Support advanced technology development when an economically viable approach is identified. Address non-technical issues, such as policy, coordination, ownership, legal, and liability at the national and international levels.

  18. CENTRAL PLATEAU REMEDIATION

    International Nuclear Information System (INIS)

    ROMINE, L.D.

    2006-01-01

    A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress

  19. Enhancement of mosquito trapping efficiency by using pulse width modulated light emitting diodes

    OpenAIRE

    Liu, Yu-Nan; Liu, Yu-Jen; Chen, Yi-Chian; Ma, Hsin-Yi; Lee, Hsiao-Yi

    2017-01-01

    In this study, a light-driving bug zapper is presented for well controlling the diseases brought by insects, such as mosquitoes. In order to have the device efficient to trap the insect pests in off-grid areas, pulse width modulated light emitting diodes (PWM-LED) combined with a solar power module are proposed and implemented. With specific PWM electric signals to drive the LED, it is found that no matter what the ability of catching insects or the consumed power efficiency can be enhanced t...

  20. Microorganisms in heavy metal bioremediation: strategies for applying microbial-community engineering to remediate soils

    Directory of Open Access Journals (Sweden)

    Jennifer L. Wood

    2016-06-01

    Full Text Available The remediation of heavy-metal-contaminated soils is essential as heavy metals persist and do not degrade in the environment. Remediating heavy-metal-contaminated soils requires metals to be mobilized for extraction whilst, at the same time, employing strategies to avoid mobilized metals leaching into ground-water or aquatic systems. Phytoextraction is a bioremediation strategy that extracts heavy metals from soils by sequestration in plant tissues and is currently the predominant bioremediation strategy investigated for remediating heavy-metal-contaminated soils. Although the efficiency of phytoextraction remains a limiting feature of the technology, there are numerous reports that soil microorganisms can improve rates of heavy metal extraction.This review highlights the unique challenges faced when remediating heavy-metal-contaminated soils as compared to static aquatic systems and suggests new strategies for using microorganisms to improve phytoextraction. We compare how microorganisms are used in soil bioremediation (i.e. phytoextraction and water bioremediation processes, discussing how the engineering of microbial communities, used in water remediation, could be applied to phytoextraction. We briefly outline possible approaches for the engineering of soil communities to improve phytoextraction either by mobilizing metals in the rhizosphere of the plant or by promoting plant growth to increase the root-surface area available for uptake of heavy metals. We highlight the technological advances that make this research direction possible and how these technologies could be employed in future research.

  1. Remedial action and waste disposal project: 100-DR-1 remedial action readiness evaluation plan

    International Nuclear Information System (INIS)

    April, J.G.; Bryant, D.L.; Calverley, C.

    1996-08-01

    This plan presents the method used to assess the readiness of the 100- DR-1 Remedial Action Project. Remediation of the 100-D sites (located on the Hanford Site) involves the excavation (treatment if applicable) and final disposal of contaminated soil and debris associated with the high-priority waste sites in the 100 Areas

  2. RCRA corrective action ampersand CERCLA remedial action reference guide

    International Nuclear Information System (INIS)

    1994-07-01

    This reference guide provides a side-by-side comparison of RCRA corrective action and CERCLA Remedial Action, focusing on the statutory and regulatory requirements under each program, criterial and other factors that govern a site's progress, and the ways in which authorities or requirements under each program overlap and/or differ. Topics include the following: Intent of regulation; administration; types of sites and/or facilities; definition of site and/or facility; constituents of concern; exclusions; provisions for short-term remedies; triggers for initial site investigation; short term response actions; site investigations; remedial investigations; remedial alternatives; clean up criterial; final remedy; implementing remedy; on-site waste management; completion of remedial process

  3. Y-12 Plant remedial action Technology Logic Diagram: Volume 3, Technology evaluation data sheets: Part A, Remedial action

    International Nuclear Information System (INIS)

    1994-09-01

    The Y-12 Plant Remedial Action Technology Logic Diagram (TLD) was developed to provide a decision-support tool that relates environmental restoration (ER) problems at the Y-12 Plant to potential technologies that can remediate these problems. The TLD identifies the research, development, demonstration, testing, and evaluation needed for sufficient development of these technologies to allow for technology transfer and application to remedial action (RA) activities. The TLD consists of three volumes. Volume 1 contains an overview of the TLD, an explanation of the program-specific responsibilities, a review of identified technologies, and the rankings of remedial technologies. Volume 2 contains the logic linkages among environmental management goals, environmental problems and the various technologies that have the potential to solve these problems. Volume 3 contains the TLD data sheets. This report is Part A of Volume 3 and contains the Remedial Action section

  4. Y-12 Plant remedial action Technology Logic Diagram: Volume 3, Technology evaluation data sheets: Part A, Remedial action

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-09-01

    The Y-12 Plant Remedial Action Technology Logic Diagram (TLD) was developed to provide a decision-support tool that relates environmental restoration (ER) problems at the Y-12 Plant to potential technologies that can remediate these problems. The TLD identifies the research, development, demonstration, testing, and evaluation needed for sufficient development of these technologies to allow for technology transfer and application to remedial action (RA) activities. The TLD consists of three volumes. Volume 1 contains an overview of the TLD, an explanation of the program-specific responsibilities, a review of identified technologies, and the rankings of remedial technologies. Volume 2 contains the logic linkages among environmental management goals, environmental problems and the various technologies that have the potential to solve these problems. Volume 3 contains the TLD data sheets. This report is Part A of Volume 3 and contains the Remedial Action section.

  5. 40 CFR 761.61 - PCB remediation waste.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false PCB remediation waste. 761.61 Section... PROHIBITIONS Storage and Disposal § 761.61 PCB remediation waste. This section provides cleanup and disposal options for PCB remediation waste. Any person cleaning up and disposing of PCBs managed under this section...

  6. Effects of microarrangement of solid particles on PCE migration and its remediation in porous media

    Science.gov (United States)

    Wu, Ming; Wu, Jianfeng; Wu, Jichun; Hu, Bill X.

    2018-02-01

    Groundwater can be stored abundantly in granula-composed aquifers with high permeability. The microstructure of granular materials has important effect on the permeability of aquifers and the contaminant migration and remediation in aquifers is also influenced by the characteristics of porous media. In this study, two different microscale arrangements of sand particles are compared to reveal the effects of microstructure on the contaminant migration and remediation. With the help of fractal theory, the mathematical expressions of permeability and entry pressure are conducted to delineate granular materials with regular triangle arrangement (RTA) and square pitch arrangement (SPA) at microscale. Using a sequential Gaussian simulation (SGS) method, a synthetic heterogeneous site contaminated by perchloroethylene (PCE) is then used to investigate the migration and remediation affected by the two different microscale arrangements. PCE is released from an underground storage tank into the aquifer and the surfactant is used to clean up the subsurface contamination. Results suggest that RTA can not only cause more groundwater contamination, but also make remediation become more difficult. The PCE remediation efficiency of 60.01-99.78 % with a mean of 92.52 and 65.53-99.74 % with a mean of 95.83 % is achieved for 200 individual heterogeneous realizations based on the RTA and SPA, respectively, indicating that the cleanup of PCE in aquifer with SPA is significantly easier. This study leads to a new understanding of the microstructures of porous media and demonstrates how microscale arrangements control contaminant migration in aquifers, which is helpful to design successful remediation scheme for underground storage tank spill.

  7. A laboratory test of NOM-assisted remediation of arsenic and copper contaminated soils

    DEFF Research Database (Denmark)

    Rasmussen, Signe Bonde; Jensen, Julie Katrine; Borggaard, Ole K.

    2015-01-01

    Soils contaminated by arsenic (As) and copper (Cu) must be remediated because As and Cu are non-degradable and toxic. On moderately contaminated soils, As and Cu may be removed by in-situ plant uptake (phytoremediation), whereas strongly contaminated soils must be removed and cleaned by soil...... at neutral pH to enhance in-situ phytoremediation of moderately contaminated soils. Citrate (and NTA) cannot be suggested for enhancement of on-site phytoremediation because of high mobilization rates caused by these extractants, which through leaching and runoff may lead to contamination of recipient waters...

  8. An introduction to geographic information systems as applied to a groundwater remediation program

    International Nuclear Information System (INIS)

    Hammock, J.K.; Lorenz, R.

    1989-01-01

    While the attention to environmental issues has grown over the past several years, so has the focus on groundwater protection. Addressing the task of groundwater remediation often involves a large-scale program with numerous wells and enormous amounts of data. This data must be manipulated and analyzed in an efficient manner for the remediation program to be truly effective. Geographic Information System's (GIS) have proven to be an extremely effective tool in handling and interpreting this type of groundwater information. The purpose of this paper is to introduce the audience to GIS technology, describe how it is being used at the Savannah River Site (SRS) to handle groundwater data and demonstrate how it may be used in the corporate Westinghouse environment

  9. Cognitive Training Enhances Auditory Attention Efficiency in Older Adults

    Directory of Open Access Journals (Sweden)

    Jennifer L. O’Brien

    2017-10-01

    Full Text Available Auditory cognitive training (ACT improves attention in older adults; however, the underlying neurophysiological mechanisms are still unknown. The present study examined the effects of ACT on the P3b event-related potential reflecting attention allocation (amplitude and speed of processing (latency during stimulus categorization and the P1-N1-P2 complex reflecting perceptual processing (amplitude and latency. Participants completed an auditory oddball task before and after 10 weeks of ACT (n = 9 or a no contact control period (n = 15. Parietal P3b amplitudes to oddball stimuli decreased at post-test in the trained group as compared to those in the control group, and frontal P3b amplitudes show a similar trend, potentially reflecting more efficient attentional allocation after ACT. No advantages for the ACT group were evident for auditory perceptual processing or speed of processing in this small sample. Our results provide preliminary evidence that ACT may enhance the efficiency of attention allocation, which may account for the positive impact of ACT on the everyday functioning of older adults.

  10. Numerical modeling analysis of VOC removal processes in different aerobic vertical flow systems for groundwater remediation

    NARCIS (Netherlands)

    De Biase, C.; Carminati, A.; Oswald, S.E.; Thullner, M.

    2013-01-01

    Vertical flow systems filled with porous medium have been shown to efficiently remove volatile organic contaminants (VOCs) from contaminated groundwater. To apply this semi-natural remediation strategy it is however necessary to distinguish between removal due to biodegradation and due to volatile

  11. Efficient optical absorption enhancement in organic solar cells by using a 2-dimensional periodic light trapping structure

    Energy Technology Data Exchange (ETDEWEB)

    Zu, Feng-Shuo [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215123 (China); Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (China); Shi, Xiao-Bo; Liang, Jian; Xu, Mei-Feng; Wang, Zhao-Kui, E-mail: lsliao@suda.edu.cn, E-mail: zkwang@suda.edu.cn, E-mail: apcslee@cityu.edu.hk; Liao, Liang-Sheng, E-mail: lsliao@suda.edu.cn, E-mail: zkwang@suda.edu.cn, E-mail: apcslee@cityu.edu.hk [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215123 (China); Lee, Chun-Sing, E-mail: lsliao@suda.edu.cn, E-mail: zkwang@suda.edu.cn, E-mail: apcslee@cityu.edu.hk [Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (China)

    2014-06-16

    We have investigated the effects induced by periodic nanosphere arrays on the performance of organic solar cells (OSCs). Two-dimensional periodic arrays of polystyrene nanospheres were formed by using a colloidal lithography method together with plasma etching to trim down the size to various degrees on the substrates of OSCs. It is found that the devices prepared on such substrates can have improved light harvesting, resulting in as high as 35% enhancement in power conversion efficiency over that of the reference devices. The measured external quantum efficiency and finite-difference time-domain simulation reveal that the controlled periodic morphology of the substrate can efficiently increase light scattering in the device and thus enhance the absorption of incident light.

  12. The atmospheric implications of radiation belt remediation

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2006-08-01

    Full Text Available High altitude nuclear explosions (HANEs and geomagnetic storms can produce large scale injections of relativistic particles into the inner radiation belts. It is recognised that these large increases in >1 MeV trapped electron fluxes can shorten the operational lifetime of low Earth orbiting satellites, threatening a large, valuable population. Therefore, studies are being undertaken to bring about practical human control of the radiation belts, termed "Radiation Belt Remediation" (RBR. Here we consider the upper atmospheric consequences of an RBR system operating over either 1 or 10 days. The RBR-forced neutral chemistry changes, leading to NOx enhancements and Ox depletions, are significant during the timescale of the precipitation but are generally not long-lasting. The magnitudes, time-scales, and altitudes of these changes are no more significant than those observed during large solar proton events. In contrast, RBR-operation will lead to unusually intense HF blackouts for about the first half of the operation time, producing large scale disruptions to radio communication and navigation systems. While the neutral atmosphere changes are not particularly important, HF disruptions could be an important area for policy makers to consider, particularly for the remediation of natural injections.

  13. Sustainable remediation of mercury contaminated soils by thermal desorption.

    Science.gov (United States)

    Sierra, María J; Millán, Rocio; López, Félix A; Alguacil, Francisco J; Cañadas, Inmaculada

    2016-03-01

    Mercury soil contamination is an important environmental problem that needs the development of sustainable and efficient decontamination strategies. This work is focused on the application of a remediation technique that maintains soil ecological and environmental services to the extent possible as well as search for alternative sustainable land uses. Controlled thermal desorption using a solar furnace at pilot scale was applied to different types of soils, stablishing the temperature necessary to assure the functionality of these soils and avoid the Hg exchange to the other environmental compartments. Soil mercury content evolution (total, soluble, and exchangeable) as temperature increases and induced changes in selected soil quality indicators are studied and assessed. On total Hg, the temperature at which it is reduced until acceptable levels depends on the intended soil use and on how restrictive are the regulations. For commercial, residential, or industrial uses, soil samples should be heated to temperatures higher than 280 °C, at which more than 80 % of the total Hg is released, reaching the established legal total Hg level and avoiding eventual risks derived from high available Hg concentrations. For agricultural use or soil natural preservation, conversely, maintenance of acceptable levels of soil quality limit heating temperatures, and additional treatments must be considered to reduce available Hg. Besides total Hg concentration in soils, available Hg should be considered to make final decisions on remediation treatments and potential future uses. Graphical Abstract Solar energy use for remediation of soils affected by mercury.

  14. Physicochemical Approaches for the Remediation of Former Manufactured Gas Plant Tars

    Science.gov (United States)

    Hauswirth, S.; Miller, C. T.

    2014-12-01

    Former manufactured gas plant (FMGP) tars are one of the most challenging non-aqueous phase liquid (NAPL) contaminants to remediate due to their complex chemical composition, high viscosities, and ability to alter wettability. In this work, we investigate several in situ remediation techniques for the removal of tar from porous media. Batch and column experiments were conducted to test the effectiveness of mobilization, solubilization, and chemical oxidation remediation approaches. Alkaline (NaOH), surfactant (Triton X-100), and polymer (xanthan gum) agents were used in various combinations to reduce tar-water interfacial tension, increase flushing solution viscosity, and increase the solubilities of tar components. Base-activated sodium persulfate was used alone and in combination with surfactant to chemically oxidized tar components. The effectiveness of each method was assessed in terms of both removal of PAHs from the system and reduction of dissolved-phase effluent polycyclic aromatic hydrocarbon (PAH) concentrations. In column studies, alkaline-polymer (AP) and alkaline-surfactant-polymer (ASP) solutions efficiently mobilized 81-93% and 95-96% of residual PAHs, respectively, within two pore volumes. The impact of AP flushing on dissolved-phase PAH concentrations was relatively low; however, the concentrations of several low molar mass PAHs were significantly reduced after ASP flushing. Surfactant-polymer (SP) solutions removed over 99% of residual PAHs through a combination of mobilization and solubilization, and reduced the post-remediation, dissolved-phase total PAH concentration by 98.4-99.1%. Degradation of residual PAHs by base-activated sodium persulfate was relatively low (30-50%), and had little impact on dissolved-phase PAH concentrations.

  15. The Research of Nanoparticle and Microparticle Hydroxyapatite Amendment in Multiple Heavy Metals Contaminated Soil Remediation

    Directory of Open Access Journals (Sweden)

    Zhangwei Li

    2014-01-01

    Full Text Available It was believed that when hydroxyapatite (HAP was used to remediate heavy metal-contaminated soils, its effectiveness seemed likely to be affected by its particle size. In this study, a pot trial was conducted to evaluate the efficiency of two particle sizes of HAP: nanometer particle size of HAP (nHAP and micrometer particle size of HAP (mHAP induced metal immobilization in soils. Both mHAP and nHAP were assessed for their ability to reduce lead (Pb, zinc (Zn, copper (Cu, and chromium (Cr bioavailability in an artificially metal-contaminated soil. The pakchoi (Brassica chinensis L. uptake and soil sequential extraction method were used to determine the immobilization and bioavailability of Pb, Zn, Cu, and Cr. The results indicated that both mHAP and nHAP had significant effect on reducing the uptake of Pb, Zn, Cu, and Cr by pakchoi. Furthermore, both mHAP and nHAP were efficient in covering Pb, Zn, Cu, and Cr from nonresidual into residual forms. However, mHAP was superior to nHAP in immobilization of Pb, Zn, Cu, and Cr in metal-contaminated soil and reducing the Pb, Zn, Cu, and Cr utilized by pakchoi. The results suggested that mHAP had the better effect on remediation multiple metal-contaminated soils than nHAP and was more suitable for applying in in situ remediation technology.

  16. Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

    International Nuclear Information System (INIS)

    Perez, C.F.

    1984-08-01

    The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT + colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references

  17. Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Perez, C.F.

    1984-08-01

    The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT/sup +/ colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references.

  18. DEMONSTRATION OF ELECTROCHEMICAL REMEDIATION TECHNOLOGIES-INDUCED COMPLEXATION

    Energy Technology Data Exchange (ETDEWEB)

    Barry L. Burks

    2002-12-01

    The Project Team is submitting this Topical Report on the results of its bench-scale demonstration of ElectroChemical Remediation Technologies (ECRTs) and in particular the Induced Complexation (ECRTs-IC) process for remediation of mercury contaminated soils at DOE Complex sites. ECRTs is an innovative, in-situ, geophysically based soil remediation technology with over 50 successful commercial site applications involving remediation of over two million metric tons of contaminated soils. ECRTs-IC has been successfully used to remediate 220 cu m of mercury-contaminated sediments in the Union Canal, Scotland. In that operation, ECRTs-IC reduced sediment total mercury levels from an average of 243 mg/kg to 6 mg/kg in 26 days of operation. The clean up objective was to achieve an average total mercury level in the sediment of 20 mg/kg.

  19. Remediation of Site of Decommissioning Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Danilovich, A.S.; Ivanov, O.P.; Lemus, A.V.; Pavlenko, V.I.; Potapov, V.N.; Semenov, S.G.; Shisha, A.D.; Chesnokov, A.V. [National Research Center ' Kurchatov Institute' , 123182, Moscow (Russian Federation)

    2014-07-01

    In the world the most widespread method of soil decontamination consists of removing the contaminated upper layer and sending it for long-term controlled storage. However, implementation of this soil cleanup method for remediation of large contaminated areas would involve high material and financial expenditures, because it produces large amounts of radioactive waste demanding removal to special storage sites. Contaminated soil extraction and cleanup performed right on the spot of remediation activities represents a more advanced and economically acceptable method. Radiological separation of the radioactive soil allows reducing of amount of radwaste. Studies performed during the liquidation of the Chernobyl accident consequences revealed that a considerable fraction of radioactivity is accumulated in minute soil grains. So, the separation of contaminated soil by size fractions makes it possible to extract and concentrate the major share of radioactivity in the fine fraction. Based on these researches water gravity separation technology was proposed by Bochvar Institute. The method extracts the fine fraction from contaminated soil. Studies carried out by Bochvar Institute experts showed that, together with the fine fraction (amounting to 10-20% of the initial soil), this technology can remove up to 85-90% of contaminating radionuclides. The resulting 'dirty' soil fraction could be packaged into containers and removed as radwaste, and decontaminated fractions returned back to their extraction site. Use of radiological and water gravity separations consequently increases the productivity of decontamination facility. Efficiency of this technology applied for contaminated soil cleanup was confirmed in the course of remediation of the contaminated territories near decommissioning research reactor in the Kurchatov Institute. For soil cleaning purposes, a special facility implementing the technology of water gravity separation and radiometric monitoring of soil

  20. Remediation in Practicing Physicians: Current and Alternative Conceptualizations.

    Science.gov (United States)

    Bourgeois-Law, Gisèle; Teunissen, Pim W; Regehr, Glenn

    2018-04-24

    Suboptimal performance in practicing physicians is a decades-old problem. The lack of a universally accepted definition of remediation, the paucity of research on best remediation practices, and the ongoing controversy regarding the institutional responsibility for enacting and overseeing this activity suggests that the remediation of physicians is not merely a difficult problem to solve, but a problem that the community does not grapple with meaningfully. Undoubtedly, logistical and political considerations contribute to this state of affairs; however, other underlying conceptual issues may also play a role in the medical profession's difficulties in engaging with the challenges around remediation.Through a review of the medical education and other literatures, the authors examined current conceptualizations of both remediation itself and the individual being remediated, as well as how the culture of medicine influences these conceptions. The authors explored how conceptualizations of remediation and the surrounding culture might affect not only the medical community's ability to support, but also its willingness to engage with physicians in need of remediation.Viewing remediation as a means of supporting practice change-rather than as a means of redressing gaps in knowledge and skill-might be a useful alternative conceptualization, providing a good place to start exploring new avenues of research. However, moving forward will require more than simply a reconceptualizion of remediation; it will also necessitate a change in how the community views its struggling members and a change in the medical culture that currently positions professional autonomy as the foundational premise for individual practice improvement.