WorldWideScience

Sample records for biodegradation remedy selection

  1. Key Principles of Superfund Remedy Selection

    Science.gov (United States)

    Guidance on the primary considerations of remedy selection which are universally applicable at Superfund sites. Key guidance here include: Rules of Thumb for Superfund Remedy Selection and Role of the Baseline Risk Assessment.

  2. Application of Rice-Straw Biochar and Microorganisms in Nonylphenol Remediation: Adsorption-Biodegradation Coupling Relationship and Mechanism.

    Science.gov (United States)

    Lou, Liping; Yao, Lingdan; Cheng, Guanghuan; Wang, Lixiao; He, Yunfeng; Hu, Baolan

    2015-01-01

    Biochar adsorption presents a potential remediation method for the control of hydrophobic organic compounds (HOCs) pollution in the environment. It has been found that HOCs bound on biochar become less bioavailable, so speculations have been proposed that HOCs will persist for longer half-life periods in biochar-amended soil/sediment. To investigate how biochar application affects coupled adsorption-biodegradation, nonylphenol was selected as the target contaminant, and biochar derived from rice straw was applied as the adsorbent. The results showed that there was an optimal dosage of biochar in the presence of both adsorption and biodegradation for a given nonylphenol concentration, thus allowing the transformation of nonylphenol to be optimized. Approximately 47.6% of the nonylphenol was biodegraded in two days when 0.005 g biochar was added to 50 mg/L of nonylphenol, which was 125% higher than the relative quantity biodegraded without biochar, though the resistant desorption component of nonylphenol reached 87.1%. All adsorptive forms of nonylphenol (frap, fslow, fr) decreased gradually during the biodegradation experiment, and the resistant desorption fraction of nonylphenol (fr) on biochar could also be biodegraded. It was concluded that an appropriate amount of biochar could stimulate biodegradation, not only illustrating that the dosage of biochar had an enormous influence on the half-life periods of HOCs but also alleviating concerns that enhanced HOCs binding by biochar may cause secondary pollution in biochar-modified environment.

  3. Enzymatic remediated biodegradation of propylene glycol 1,2-dinitrate

    Energy Technology Data Exchange (ETDEWEB)

    Meng, M.; Geelhaar, L.; Speedie, M.K. [Univ. of Maryland, Baltimore, MD (United States)

    1995-12-31

    Two bacterial species, Enterobacter agglomerans and Bacillus thuringiensis/cereus, which were selected from nitroglycerin (GTN) contaminated soil, have previously been shown to have denitrating ability on nitroglycerin. This abstract presents the investigation of the cell free extracts from both microorganisms for the degradation of another nitrate ester contaminant; propylene glycol 1,2-dinitrate (PGDN). This compound has been previously considered resistant to the biodegradation. In order to probe the pathway, the whole process was monitored by using [1-{sup 14}C]-PGDN as substrate and the intermediates were identified by HPLC and TLC chromatography. Long term biodegradation experiments have shown that the enzymes in the cytoplasm fraction of Bacillus thuringiensis/cereus and the membrane fraction of Enterobacter agglomerans convert PGDN successively into propylene glycol 1-mononitrate (1-PGMN) and propylene glycol 2-mononitrate (2-PGMN), and finally, propylene glycol. The capacity to achieve sequential and complete degradation of PGDN implies that it follows a similar mechanism to that observed in the GTN degradation. Cofactor requirements for PGDN breakdown have been studied, it was found that no dissociable, dialyzable cofactors are required.

  4. Remediation of toxic metal contaminated soil by washing with biodegradable aminopolycarboxylate chelants.

    Science.gov (United States)

    Begum, Zinnat A; Rahman, Ismail M M; Tate, Yousuke; Sawai, Hikaru; Maki, Teruya; Hasegawa, Hiroshi

    2012-06-01

    Ex situ soil washing with synthetic extractants such as, aminopolycarboxylate chelants (APCs) is a viable treatment alternative for metal-contaminated site remediation. EDTA and its homologs are widely used among the APCs in the ex situ soil washing processes. These APCs are merely biodegradable and highly persistent in the aquatic environments leading to the post-use toxic effects. Therefore, an increasing interest is focused on the development and use of the eco-friendly APCs having better biodegradability and less environmental toxicity. The paper deals with the results from the lab-scale washing treatments of a real sample of metal-contaminated soil for the removal of the ecotoxic metal ions (Cd, Cu, Ni, Pb, and Zn) using five biodegradable APCs, namely [S,S]-ethylenediaminedisuccinic acid, imminodisuccinic acid, methylglycinediacetic acid, DL-2-(2-carboxymethyl) nitrilotriacetic acid (GLDA), and 3-hydroxy-2,2'-iminodisuccinic acid. The performance of those biodegradable APCs was evaluated for their interaction with the soil mineral constituents in terms of the solution pH and metal-chelant stability constants, and compared with that of EDTA. Speciation calculations were performed to identify the optimal conditions for the washing process in terms of the metal-chelant interactions as well as to understand the selectivity in the separation ability of the biodegradable chelants towards the metal ions. A linear relationship between the metal extraction capacity of the individual chelants towards each of the metal ions from the soil matrix and metal-chelant conditional stability constants for a solution pH greater than 6 was observed. Additional considerations were derived from the behavior of the major potentially interfering cations (Al, Ca, Fe, Mg, and Mn), and it was hypothesized that use of an excess of chelant may minimize the possible competition effects during the single-step washing treatments. Sequential extraction procedure was used to determine the

  5. REMEDIATION OF SOILS CONTAMINATED WITH MOTOR OIL BY HIGHLY BIODEGRADABLE SURFACTANTS

    Directory of Open Access Journals (Sweden)

    Ignacio Moya-Ramírez

    2014-06-01

    Full Text Available The remediation of a sandy soil contaminated with motor oil was studied by applying two different washing procedures: one discontinuous and the other continuous. In addition the capacity of three highly biodegradable surfactants, two synthetic (Glucopon 600 and Findet 1214N/23 and a biosurfactant from Bacillus subtilis, to enhance oil removal was tested. The results obtained with the continuous procedure were much better than those achieved with the discontinuous one, even in experiments conducted with distilled water. Both the addition of surfactants and the rise in temperature significantly increased the removal of the pollutant in experiments conducted with the discontinuous procedure, but the biosurfactant showed a higher capacity for soil remediation than the synthetic surfactants at concentrations close to its CMC. Conversely, when the continuous method was used, surfactant concentration seems to have a lower effect on motor oil removal, at least below the CMC.

  6. Optimal selection of biochars for remediating metals ...

    Science.gov (United States)

    Approximately 500,000 abandoned mines across the U.S. pose a considerable, pervasive risk to human health and the environment due to possible exposure to the residuals of heavy metal extraction. Historically, a variety of chemical and biological methods have been used to reduce the bioavailability of the metals at mine sites. Biochar with its potential to complex and immobilize heavy metals, is an emerging alternative for reducing bioavailability. Furthermore, biochar has been reported to improve soil conditions for plant growth and can be used for promoting the establishment of a soil-stabilizing native plant community to reduce offsite movement of metal-laden waste materials. Because biochar properties depend upon feedstock selection, pyrolysis production conditions, and activation procedures used, they can be designed to meet specific remediation needs. As a result biochar with specific properties can be produced to correspond to specific soil remediation situations. However, techniques are needed to optimally match biochar characteristics with metals contaminated soils to effectively reduce metal bioavailability. Here we present experimental results used to develop a generalized method for evaluating the ability of biochar to reduce metals in mine spoil soil from an abandoned Cu and Zn mine. Thirty-eight biochars were produced from approximately 20 different feedstocks and produced via slow pyrolysis or gasification, and were allowed to react with a f

  7. Characterization and aerobic biodegradation of selected monoterpenes

    Energy Technology Data Exchange (ETDEWEB)

    Misra, G.; Pavlostathis, S.G.; Li, J.; Purdue, E.M. [Georgia Institute of Technology, Atlanta, GA (United States)

    1996-12-31

    Monoterpenes are biogenic chemicals and occur in abundance in nature. Large-scale industrial use of these chemicals has recently been initiated in an attempt to replace halogenated solvents and chlorofluorocarbons which have been implicated in the stratospheric depletion of ozone. This study examined four hydrocarbon monoterpenes (d-limonene, {alpha}-pinene, {gamma}-terpinene, and terpinolene) and four alcohols (arbanol, linalool, plinol, and {alpha}-terpineol). Water solubility, vapor pressure, and octanol/water partition coefficients were estimated. Aerobic biodegradability tests were conducted in batch reactors by utilizing forest soil extract and enriched cultures as inoculum. The hydrophobic nature and high volatility of the hydrocarbons restricted the investigation to relatively low aqueous concentrations. Each monoterpene was analyzed with a gas chromatograph equipped with a flame ionization detector after extraction from the aqueous phase with isooctane. Terpene mineralization was tested by monitoring liquid-phase carbon, CO{sub 2} production and biomass growth. All four hydrocarbons and two alcohols readily degraded under aerobic conditions. Plinol resisted degradation in assays using inocula from diverse sources, while arbanol degraded very slowly. The intrinsic biokinetics coefficients for the degradation of d-limonene and {alpha}-terpineol were estimated by using cultures enriched with the respective monoterpenes. Monoterpene biodegradation followed Monod kinetics.

  8. Remediation of hydrocarbon contaminants in cold environments - Electrokinetically enhanced bioremediation and biodegradable oil sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Suni, S. [Helsinki Univ. (Finland). Dept. of Environmental and Ecological Sciences

    2006-07-01

    Owing to the vast amounts of oil in the world, oil spills are common on land as well as at sea. In addition to oil products, other industrially used hydrocarbons, such as creosote, also contaminate soils. Most hydrocarbons are biodegradable. Hence, bioremediation is an attractive alternative for cleaning up hydrocarbon spills. In cold climate areas, however, biodegradation is often a slow process. The aim of this thesis was to develop efficient, cost-effective, and ecologically sound techniques for cold climate areas for the treatment of both oil spills on water or solid surfaces and for subsurface contamination. For subsurface hydrocarbon spills, the approach was to use electrokinetics in order to deliver nutrients and possibly microorganisms to contaminated soils, and in order to heat the soil to increase contaminant bioavailability and microbial activity. Electroosmosis proved to be an effective method to disperse bacteria and nutrients in medium- or fine-grained soils, where uncharged particles migrated with water through the soil towards the cathode. Creosote degradation proceeded faster with electroosmotically added nutrients than in controls without additions. However, inoculation with enriched creosote-degraders was not necessary because the indigenous microbes of the soil were well adapted to the creosote contaminants. For small-scale oil spills, the usual remediation method involves absorption with oil sorbents. Most sorbents in use today are synthetic and incineration is the only method for their disposal. A biodegradable sorbent, however, could be processed, for instance, in compost-like systems. Cotton grass is a common plant in peat bogs and its water-repellent fibre is a by-product of peat excavation. Cotton grass proved to be an excellent oil sorbent especially for spills on the surface of water: It absorbed up to three times as much oil as a commercial, synthetic oil sorbent. Cotton grass performed extremely well also in conditions simulating

  9. Assessing Biodegradation Susceptibilities of Selected Petroleum Hydrocarbons at Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Markus Heryanto Langsa

    2010-01-01

    Full Text Available The susceptibility to biodegradation of selected saturated hydrocarbons (SHCs, polycyclic aromatichydrocarbons (PAHs and asphaltenes in a Barrow crude oil and extracts isolated from soils contaminated with theBarrow crude oil at day 0 and 39 was determined. Soil samples were contaminated with a Barrow crude oil across thesurface (5% w/w as part of a mesocosm experiment in order to mimic similar conditions in the environment. Theextent of biodegradation of the Barrow oil extracted from the contaminated soils at day 0 and day 39 was assessed byGC-MS analyses of SHCs and PAHs fractions. Changes in the relative abundances of n-alkanes (loss of low-molecularweighthydrocarbons and pristane relative to phytane (Pr/Ph and their diastereoisomers were determined. Changesin the diastereoisomer ratios of Pr and Ph relate to the decrease in abundance of the phytol-derived 6(R,10(Sisoprenoids with increasing biodegradation. The percentage change in abundances of each of selectedalkylnaphathalenes with time (day 0 to 39 was determined, enabling an order of susceptibility of their isomers tobiodegradation. It was established that the 2-methylnaphthalene isomers (2-MN is more susceptible to microbialattack than 1-MN isomer indicated by decreasing in percent abundance from day 0 to 39 for the 2-MN isomer. TheGC-MS analyses of the original Barrow oil indicated the oil had not undergone biodegradation. When this oil wasused in the soil mesocosm experiments the oil was shown to biodegrade to about a level 2 -3 based on the biodegradationsusceptibility of the various SHCs and PAHs described above

  10. Selection of monitoring times to assess remediation performance

    International Nuclear Information System (INIS)

    Kueper, B.H.; Mundle, K.

    2007-01-01

    Several factors determine the time needed for a plume to respond to non-aqueous phase liquid (NAPL) source zone remediation. Most spills of NAPLs (fuels, chlorinated solvents, PCB oils, creosote and coal tar) require mass removal in order to implement remediation technologies such as chemical oxidation, thermal treatments, alcohol flushing, surfactant flushing and hydraulic displacement. While much attention has been given to the development of these remediation technologies, little attention has been given to the response of the plume downstream of the treatment zone and selection of an appropriate monitoring time scale to adequately evaluate the impacts of remediation. For that reason, this study focused on the prevalence of diffusive sinks, the mobility of the contaminant and the hydraulic conductivity of subsurface materials. Typically, plumes in subsurface environments dominated by diffusive sinks or low permeability materials need long periods of time to detach after source removal. This paper presented generic plume response model simulations that illustrated concentration rebound following the use of in-situ chemical oxidation in fractured clay containing trichloroethylene. It was determined that approximately 2 years are needed to reach peak rebound concentration after cessation remedial action. It was concluded that downgradient monitoring well concentrations may be greatly reduced during remedial action due to the fact that oxidant occupies the fracture and because oxidant diffuses into the clay matrix, creating a short period of contaminant reduction in the area of flowing groundwater. 9 refs., 2 tabs., 7 figs

  11. Remediation of hydrocarbon contaminants in cold environments : electrokinetically enhanced bioremediation and biodegradable oil sorbents

    OpenAIRE

    Suni, Sonja

    2006-01-01

    Owing to the vast amounts of oil in the world, oil spills are common on land as well as at sea. In addition to oil products, other industrially used hydrocarbons, such as creosote, also contaminate soils. Most hydrocarbons are biodegradable. Hence, bioremediation is an attractive alternative for cleaning up hydrocarbon spills. In cold climate areas, however, biodegradation is often a slow process. The aim of this thesis was to develop efficient, cost-effective, and ecologically sound techniqu...

  12. Using risk-based remedy selection to minimize remedial response costs -- A case history

    International Nuclear Information System (INIS)

    Cox, S.A.; Hochreiter, J.J. Jr.; Stout, D.J.

    1995-01-01

    The authors used a risk-based remedy selection at a former coal tar emulsion production facility in a heavily industrialized area of northern New Jersey. Historical site activities resulted in extensive contamination of shallow site soils from high molecular weight Polycyclic Aromatic Hydrocarbons (PAHs), including potentially carcinogenic PAHs (cPAHs). Then-current risk-based proposed soil cleanup goals developed by the New Jersey Department of Environmental Protection (NJDEP) were not representative of potential exposures under current or future exposure scenarios. Alternate soil cleanup goals were calculated, incorporating relevant input variables that accurately reflected site conditions and potential receptors/exposure scenarios; these cleanup goals demonstrated the site did not pose the degree of risk assumed by the NJDEP. However, they were not accepted by NJDEP as performance standards for remedial activities for ''policy'' reasons

  13. Selectivity of solid-phase extraction phases in the determination of biodegradation products.

    Science.gov (United States)

    Bielicka, K; Voelkel, A

    2001-05-18

    The extraction techniques connected with gas chromatography were used to describe quantitatively and qualitatively the biodegradation process. We investigated the biodegradation of hydrocarbons and non-ionic surfactants. Solid-phase extraction (SPE) and liquid-liquid extraction were used for the isolation of the non-degraded compounds and their degradation products. The selectivity of SPE has a significant influence on the isolation and preconcentration of organic compounds from water.

  14. The potential impact on the biodegradation of organic pollutants from composting technology for soil remediation.

    Science.gov (United States)

    Ren, Xiaoya; Zeng, Guangming; Tang, Lin; Wang, Jingjing; Wan, Jia; Wang, Jiajia; Deng, Yaocheng; Liu, Yani; Peng, Bo

    2018-02-01

    Large numbers of organic pollutants (OPs), such as polycyclic aromatic hydrocarbons, pesticides and petroleum, are discharged into soil, posing a huge threat to natural environment. Traditional chemical and physical remediation technologies are either incompetent or expensive, and may cause secondary pollution. The technology of soil composting or use of compost as soil amendment can utilize quantities of active microbes to degrade OPs with the help of available nutrients in the compost matrix. It is highly cost-effective for soil remediation. On the one hand, compost incorporated into contaminated soil is capable of increasing the organic matter content, which improves the soil environment and stimulates the metabolically activity of microbial community. On the other hand, the organic matter in composts would increase the adsorption of OPs and affect their bioavailability, leading to decreased fraction available for microorganism-mediated degradation. Some advanced instrumental analytical approaches developed in recent years may be adopted to expound this process. Therefore, the study on bioavailability of OPs in soil is extremely important for the application of composting technology. This work will discuss the changes of physical and chemical properties of contaminated soils and the bioavailability of OPs by the adsorption of composting matrix. The characteristics of OPs, types and compositions of compost amendments, soil/compost ratio and compost distribution influence the bioavailability of OPs. In addition, the impact of composting factors (composting temperature, co-substrates and exogenous microorganisms) on the removal and bioavailability of OPs is also studied. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. A technicoeconomic approach for the selection of a site remediation strategy--part B: model application.

    Science.gov (United States)

    Bage, Gontran F; Samson, Réjean; Sinclair-Desgagné, Bernard

    2003-01-01

    Different tools, such as a screening matrix or decision framework, are available to select a remediation technology to treat a contaminated site. However, unless these methods can point out the appropriate technology in regards to the decision-maker's knowledge about the contaminated site, they are less useful to evaluate both the technical effectiveness and the cost of the remediation, and to assess different remediation strategies from either future data acquisition or the use of an irreversible remediation technology. A model developed to allow such evaluations has been used to simulate the remediation of a virtual contaminated site. From this, four remediation recommendations have been made. These recommendations are guidelines for the build up of a remediation strategy that would both maximize the effectiveness of the decontamination and minimize its total cost.

  16. 40 CFR 300.430 - Remedial investigation/feasibility study and selection of remedy.

    Science.gov (United States)

    2010-07-01

    ... and maintenance costs; and (3) Net present value of capital and O&M costs. (H) State acceptance... information make it possible to do so. Accordingly, EPA has established the following program goal... to support decisions regarding remedial response activities. (6) Prepare site-specific health and...

  17. Nuclear facility decommissioning and site remedial actions: a selected bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Owen, P.T.; Knox, N.P.; Fielden, J.M.; Johnson, C.A.

    1982-09-01

    This bibliography contains 693 references with abstracts on the subject of nuclear facility decommissioning, uranium mill tailings management, and site remedial actions. Foreign, as well as domestic, literature of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - has been included in this publication. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's Remedial Action Program. Major chapters are Surplus Facilities Management Program, Nuclear Facilities Decommissioning, Formerly Utilized Sites Remedial Action Program, Uranium Mill Tailings Remedial Action Program, Grand Junction Remedial Action Program, and Uranium Mill Tailings Management. Chapter sections for chapters 1 and 2 include: Design, Planning, and Regulations; Site Surveys; Decontamination Studies; Dismantlement and Demolition; Land Decontamination and Reclamation; Waste Disposal; and General Studies. The references within each chapter are arranged alphabetically by leading author. References having no individual author are arranged by corporate author or by title. Indexes are provided for (1) author; (2) corporate affiliation; (3) title; (4) publication description; (5) geographic location; and (6) keywords. An appendix of 202 bibliographic references without abstracts or indexes has been included in this bibliography. This appendix represents literature identified but not abstracted due to time constraints.

  18. Nuclear facility decommissioning and site remedial actions: a selected bibliography

    International Nuclear Information System (INIS)

    Owen, P.T.; Knox, N.P.; Fielden, J.M.; Johnson, C.A.

    1982-09-01

    This bibliography contains 693 references with abstracts on the subject of nuclear facility decommissioning, uranium mill tailings management, and site remedial actions. Foreign, as well as domestic, literature of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - has been included in this publication. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's Remedial Action Program. Major chapters are Surplus Facilities Management Program, Nuclear Facilities Decommissioning, Formerly Utilized Sites Remedial Action Program, Uranium Mill Tailings Remedial Action Program, Grand Junction Remedial Action Program, and Uranium Mill Tailings Management. Chapter sections for chapters 1 and 2 include: Design, Planning, and Regulations; Site Surveys; Decontamination Studies; Dismantlement and Demolition; Land Decontamination and Reclamation; Waste Disposal; and General Studies. The references within each chapter are arranged alphabetically by leading author. References having no individual author are arranged by corporate author or by title. Indexes are provided for (1) author; (2) corporate affiliation; (3) title; (4) publication description; (5) geographic location; and (6) keywords. An appendix of 202 bibliographic references without abstracts or indexes has been included in this bibliography. This appendix represents literature identified but not abstracted due to time constraints

  19. Inclusion of social indicators in decision support tools for the selection of sustainable site remediation options.

    Science.gov (United States)

    Cappuyns, Valérie

    2016-12-15

    Sustainable remediation requires a balanced decision-making process in which environmental, economic and social aspects of different remediation options are all considered together and the optimum remediation solution is selected. More attention has been paid to the evaluation of environmental and economic aspects, in particular to reduce the human and environmental risks and the remediation costs, to the exclusion of social aspects of remediation. This paper investigates how social aspects are currently considered in sustainability assessments of remediation projects. A selection of decision support tools (DSTs), used for the sustainability assessment of a remediation project, is analyzed to define how social aspects are considered in those tools. The social indicator categories of the Sustainable Remediation Forum - United Kingdom (SuRF-UK), are used as a basis for this evaluation. The consideration of social aspects in the investigated decision support tools is limited, but a clear increase is noticed in more recently developed tools. Among the five social indicator categories defined by SuRF-UK to facilitate a holistic consideration of social aspects of a remediation project only "Human health and safety" is systematically taken into account. "Neighbourhood and locality" is also often addressed, mostly emphasizing the potential disturbance caused by the remediation activities. However, the evaluation of 'Ethics and Equality', Communities and community involvement', and 'Uncertainty and evidence' is often neglected. Nevertheless, concrete examples can be found in some of the investigated tools. Specific legislation, standard procedures, and guidelines that have to be followed in a region or country are mainly been set up in the context of protecting human and ecosystem health, safety and prevention of nuisance. However, they sometimes already include some of the aspects addressed by the social indicators. In this perspective the use of DST to evaluate the

  20. 40 CFR 258.57 - Selection of remedy.

    Science.gov (United States)

    2010-07-01

    ... which may offer significant advantages over already available technologies in terms of effectiveness... environment from exposure to contamination prior to completion of the remedy; (6) Resource value of the... substances that have originated from a source other than a MSWLF unit and those substances are present in...

  1. Biodegradation studies of selected priority acidic pesticides and diclofenac in different bioreactors

    International Nuclear Information System (INIS)

    Gonzalez, Susana; Mueller, Jutta; Petrovic, Mira; Barcelo, Damia; Knepper, Thomas P.

    2006-01-01

    The biodegradation of selected priority acidic pesticides MCPP, MCPA, 2,4-D, 2,4-DP and bentazone and the acidic pharmaceutical diclofenac was investigated using a membrane bioreactor (MBR) and a fixed-bed bioreactor (FBBR). A pilot plant MBR was fed with raw water spiked with the selected compounds. The experiment was repeated every week during four weeks to enhance the adaptation of microorganisms. In order to further study the biodegradability of these compounds, degradation studies in a FBBR were carried out. All the samples were analysed by solid phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS). The results indicate that in the MBR compounds except for bentazone were eliminated within the first day of the experiment at rates ranging from 44% to 85%. Comparing these results with the degradation rates in the FBBR showed that in the latter only MCPP, MCPA 2,4-D and 2,4-DP were degraded after a much longer adaptation phase of microorganisms. - Biodegradation rate of selected acidic pesticides and pharmaceuticals depends on adaptation

  2. A technicoeconomic approach for the selection of a site remediation strategy--part A: theory.

    Science.gov (United States)

    Bage, Gontran F; Samson, Réjean; Sinclair-Desgagné, Bernard

    2002-12-01

    A technicoeconomic model is developed to select an optimal strategy for the remediation of a contaminated site and to determine the value of this remediation strategy. The model is an extension of actual cost-benefit analysis, with consideration of "irreversible" remediation technology choices, technology effectiveness, and uncertainty on the site's level of contamination. The model considers the possibility of reducing uncertainty by both acquiring more and better information on the level of contamination and by offering the decision-maker the opportunity to reevaluate his decision and switch to a more appropriate technology. It is believed that this model will help decision-makers in the selection of a remediation strategy by presenting all potentially feasible strategies, and how uncertainty on the site's level of contamination affects these strategies.

  3. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Vol. 18. Part 2. Indexes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This bibliography contains 3638 citations with abstracts of documents relevant to environmental restoration, nuclear facility decontamination and decommissioning (D&D), uranium mill tailings management, and site remedial actions. This report is the eighteenth in a series of bibliographies prepared annually for the U.S. Department of Energy (DOE) Office of Environmental Restoration. 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 in Part 1 of the report. The bibliography contains scientific, technical, financial, and regulatory information that pertains to DOE environmental restoration programs. The citations are separated by topic into 16 sections, including (1) DOE Environmental Restoration Program; (2) DOE D&D Program; (3) Nuclear Facilities Decommissioning; (4) DOE Formerly Utilized Sites Remedial Action Programs; (5) NORM-Contaminated Site Restoration; (6) DOE Uranium Mill Tailings Remedial Action Project; (7) Uranium Mill Tailings Management; (8) DOE Site-Wide Remedial Actions; (9) DOE Onsite Remedial Action Projects; (10) Contaminated Site Remedial Actions; (11) DOE Underground Storage Tank Remediation; (12) DOE Technology Development, Demonstration, and Evaluations; (13) Soil Remediation; (14) Groundwater Remediation; (15) Environmental Measurements, Analysis, and Decision-Making; and (16) Environmental Management Issues. Within the 16 sections, the citations are sorted by geographic location. If a geographic location is not specified, the citations are sorted according to the document title. In Part 2 of the report, indexes are provided for author, author affiliation, selected title phrase, selected title word, publication description, geographic location, and keyword.

  4. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Vol. 18. Part 2. Indexes

    International Nuclear Information System (INIS)

    1997-09-01

    This bibliography contains 3638 citations with abstracts of documents relevant to environmental restoration, nuclear facility decontamination and decommissioning (D ampersand D), uranium mill tailings management, and site remedial actions. This report is the eighteenth in a series of bibliographies prepared annually for the U.S. Department of Energy (DOE) Office of Environmental Restoration. 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 in Part 1 of the report. The bibliography contains scientific, technical, financial, and regulatory information that pertains to DOE environmental restoration programs. The citations are separated by topic into 16 sections, including (1) DOE Environmental Restoration Program; (2) DOE D ampersand D Program; (3) Nuclear Facilities Decommissioning; (4) DOE Formerly Utilized Sites Remedial Action Programs; (5) NORM-Contaminated Site Restoration; (6) DOE Uranium Mill Tailings Remedial Action Project; (7) Uranium Mill Tailings Management; (8) DOE Site-Wide Remedial Actions; (9) DOE Onsite Remedial Action Projects; (10) Contaminated Site Remedial Actions; (11) DOE Underground Storage Tank Remediation; (12) DOE Technology Development, Demonstration, and Evaluations; (13) Soil Remediation; (14) Groundwater Remediation; (15) Environmental Measurements, Analysis, and Decision-Making; and (16) Environmental Management Issues. Within the 16 sections, the citations are sorted by geographic location. If a geographic location is not specified, the citations are sorted according to the document title. In Part 2 of the report, indexes are provided for author, author affiliation, selected title phrase, selected title word, publication description, geographic location, and keyword

  5. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 12

    Energy Technology Data Exchange (ETDEWEB)

    Owen, P. T.; Webb, J. R.; Knox, N. P.; Goins, L. F.; Harrell, R. E.; Mallory, P. K.; Cravens, C. D.

    1991-09-01

    The 664 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the twelfth in a series of reports prepared annually for the US Department of Energy 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 Remedial Action Programs. Major sections are (1) Decontamination and Decommissioning Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Program, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Uranium Mill Tailings Management, (7) Technical Measurements Center, and (8) 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 key word. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects, analyzes, and disseminates information on environmental restoration and remedial actions. RAPIC staff and resources are available to meet a variety of information needs. Contact the center at FTS 624-7764 or (615) 574-7764.

  6. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 12. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    The 664 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the twelfth in a series of reports prepared annually for the US Department of Energy 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 Remedial Action Programs. Major sections are (1) Decontamination and Decommissioning Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Program, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Uranium Mill Tailings Management, (7) Technical Measurements Center, and (8) 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 key word. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects, analyzes, and disseminates information on environmental restoration and remedial actions. RAPIC staff and resources are available to meet a variety of information needs. Contact the center at FTS 624-7764 or (615) 574-7764.

  7. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 12

    International Nuclear Information System (INIS)

    1991-09-01

    The 664 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the twelfth in a series of reports prepared annually for the US Department of Energy 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 Remedial Action Programs. Major sections are (1) Decontamination and Decommissioning Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Program, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Uranium Mill Tailings Management, (7) Technical Measurements Center, and (8) 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 key word. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects, analyzes, and disseminates information on environmental restoration and remedial actions. RAPIC staff and resources are available to meet a variety of information needs. Contact the center at FTS 624-7764 or (615) 574-7764

  8. Nuclear facility decommissioning and site remedial actions: A selected bibliography, volume 9

    Energy Technology Data Exchange (ETDEWEB)

    Owen, P.T.; Knox, N.P.; Michelson, D.C.; Turmer, G.S.

    1988-09-01

    The 604 abstracted references on nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the ninth in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Foreign and domestic literature of all types--technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions--has 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 Program, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Uranium Mill Tailings Management, (7) Technical Measurements Center, and (8) General Remedial Action Program Studies. Subsections for sections 1, 2, 5, and 6 include: Design, Planning, and Regulations; Environmental Studies and Site Surveys; Health, Safety, and Biomedical Studies; Decontamination Studies; Dismantlement and Demolition; Site Stabilization and Reclamation; Waste Disposal; Remedial Action Experience; and General Studies. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication description. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, 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. RAPIC staff and resources are available to meet a variety of information needs. Contact the center at (615) 576-0568 or FTS 626-0568.

  9. Demonstration of risk-based decision analysis in remedial alternative selection and design

    International Nuclear Information System (INIS)

    Evans, E.K.; Duffield, G.M.; Massmann, J.W.; Freeze, R.A.; Stephenson, D.E.

    1993-01-01

    This study demonstrates the use of risk-based decision analysis (Massmann and Freeze 1987a, 1987b) in the selection and design of an engineering alternative for groundwater remediation at a waste site at the Savannah River Site, a US Department of Energy facility in South Carolina. The investigation focuses on the remediation and closure of the H-Area Seepage Basins, an inactive disposal site that formerly received effluent water from a nearby production facility. A previous study by Duffield et al. (1992), which used risk-based decision analysis to screen a number of ground-water remediation alternatives under consideration for this site, indicated that the most attractive remedial option is ground-water extraction by wells coupled with surface water discharge of treated effluent. The aim of the present study is to demonstrate the iterative use of risk-based decision analysis throughout the design of a particular remedial alternative. In this study, we consider the interaction between two episodes of aquifer testing over a 6-year period and the refinement of a remedial extraction well system design. Using a three-dimensional ground-water flow model, this study employs (1) geostatistics and Monte Carlo techniques to simulate hydraulic conductivity as a stochastic process and (2) Bayesian updating and conditional simulation to investigate multiple phases of aquifer testing. In our evaluation of a remedial alternative, we compute probabilistic costs associated with the failure of an alternative to completely capture a simulated contaminant plume. The results of this study demonstrate the utility of risk-based decision analysis as a tool for improving the design of a remedial alternative through the course of phased data collection at a remedial site

  10. Nuclear facility decommissioning and site remedial actions: A selected bibliography, volume 9

    International Nuclear Information System (INIS)

    Owen, P.T.; Knox, N.P.; Michelson, D.C.; Turmer, G.S.

    1988-09-01

    The 604 abstracted references on nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the ninth in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Foreign and domestic literature of all types--technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions--has 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 Program, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Uranium Mill Tailings Management, (7) Technical Measurements Center, and (8) General Remedial Action Program Studies. Subsections for sections 1, 2, 5, and 6 include: Design, Planning, and Regulations; Environmental Studies and Site Surveys; Health, Safety, and Biomedical Studies; Decontamination Studies; Dismantlement and Demolition; Site Stabilization and Reclamation; Waste Disposal; Remedial Action Experience; and General Studies. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication description. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, 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. RAPIC staff and resources are available to meet a variety of information needs. Contact the center at (615) 576-0568 or FTS 626-0568

  11. Formation of biodegradable microcapsules utilizing 3D, selectively surface-modified PDMS microfluidic devices.

    Science.gov (United States)

    Liao, Chung-Yu; Su, Yu-Chuan

    2010-02-01

    We have successfully demonstrated the formation of biodegradable microcapsules utilizing PDMS double-emulsification devices. Specially designed 3D PDMS microchannels with surfaces selectively modified by a self-aligned photografting process are employed to generate monodisperse water-in-organic-solvent-in-water (W/O/W) emulsions in a controlled manner. Mainly by varying the outer and inner fluid flow-rates, the dimensions of resulting double emulsions can be adjusted as desired. Meanwhile, biodegradable materials are dissolved in the middle organic solvent (in this work ethyl acetate is used), and solidified into microcapsules once the solvent is extracted. In the prototype demonstration, microcapsules made up of poly(L-lactic acid), trilaurin, and phosphocholine were successfully fabricated. In addition, it was also demonstrated that gamma-Fe(2)O(3) nanoparticles can be simultaneously embedded into the microcapsules, which consequently become responsive to electromagnetic stimulation. As such, the presented PDMS microfluidic devices could potentially serve as versatile encapsulation apparatus, and the fabricated biodegradable microcapsules could function as controlled delivery systems, which are desired for a variety of biological and pharmaceutical applications.

  12. Voracious larvae Hermetia illucens and treatment of selected types of biodegradable waste

    Directory of Open Access Journals (Sweden)

    Markéta Kalová

    2013-01-01

    Full Text Available This report is focused on the ability of larvae Hermetia illucens (Diptera: Stratiomyidae to consume different types of biodegradable waste. Waste was selected in groups 02, 19 a 20 according to the Waste Catalogue (in Decree No. 381/2001 Coll., Czech Republic. Experiments were carried out in 14 BioPods Plus that are especially designed for insect Hermetia illucens (HI in order to consume waste. The experiments were measured in laboratory conditions (relatively constant temperature and humidity.The highest weight reduction of waste material (by 66.53% of the original mass was reached in waste plant tissues. Weight reduction for food scraps – highly problematic kind of waste – was calculated by 46.04%. Worst results were achieved with compost tea from garden waste – larvae reduced the initial amount of waste by only 8.47%. Firstly grubs finished their life cycle after 35 days in catering waste, together with waste plant tissues, quality culled biodegradable municipal waste and poorly culled biodegradable municipal waste. The experiment was finished in 35 days.

  13. Remedial action selection report Maybell, Colorado, site. Final report

    International Nuclear Information System (INIS)

    1996-12-01

    The Maybell uranium mill tailings site is 25 miles (mi) (40 kilometers [km]) west of the town of Craig, Colorado, in Moffat County, in the northwestern part of the state. The unincorporated town of Maybell is 5 road mi (8 km) southwest of the site. The site is 2.5 mi (4 km) northeast of the Yampa River on relatively flat terrain broken by low, flat-topped mesas. U.S. Highway 40 runs east-west 2 mi (3.2 km) south of the site. The designated site covers approximately 110 acres (ac) (45 hectares [ha]) and consists of a concave-shaped tailings pile and rubble from the demolition of the mill buildings buried in the former mill area. The site is situated between Johnson Wash to the east and Rob Pit Mine to the west. Numerous reclaimed and unreclaimed mines are in the immediate vicinity. Aerial photographs (included at the end of this executive summary) show evidence of mining activity around the Maybell site. Contaminated materials at the Maybell processing site include the tailings pile, which has an average depth of 20 feet (ft) (6 meters [ml]) and contains 2.8 million cubic yards (yd 3 ) (2.1 million cubic meters [m 3 ]) of tailings. The former mill processing area is on the north side of the site and contains 20,000 yd 3 (15,000 m 3 ) of contaminated demolition debris. Off-pile contamination is present and includes areas adjacent to the tailings pile, as well as contamination dispersed by wind and surface water flow. The volume of off-pile contamination to be placed in the disposal cell is 550,000 yd 3 (420,000 m 3 ). The total volume of contaminated materials to be disposed of as part of the remedial action is estimated to be 3.37 million yd 3 (2.58 million m 3 )

  14. Manufacturing of individual biodegradable bone substitute implants using selective laser melting technique.

    Science.gov (United States)

    Lindner, Markus; Hoeges, Simon; Meiners, Wilhelm; Wissenbach, Konrad; Smeets, Ralf; Telle, Rainer; Poprawe, Reinhart; Fischer, Horst

    2011-06-15

    The additive manufacturing technique selective laser melting (SLM) has been successfully proved to be suitable for applications in implant manufacturing. SLM is well known for metal parts and offers direct manufacturing of three-dimensional (3D) parts with high bulk density on the base of individual 3D data, including computer tomography models of anatomical structures. Furthermore, an interconnecting porous structure with defined and reproducible pore size can be integrated during the design of the 3D virtual model of the implant. The objective of this study was to develop the SLM processes for a biodegradable composite material made of β-tricalcium phosphate (β-TCP) and poly(D, L)-lactide (PDLLA). The development of a powder composite material (β-TCP/PDLLA) suitable for the SLM process was successfully performed. The microstructure of the manufactured samples exhibit a homogeneous arrangement of ceramic and polymer. The four-point bending strength was up to 23 MPa. The X-ray diffraction (XRD) analysis of the samples confirmed β-TCP as the only present crystalline phase and the gel permeations chromatography (GPC) analysis documented a degradation of the polymer caused by the laser process less than conventional manufacturing processes. We conclude that SLM presents a new possibility to manufacture individual biodegradable implants made of β-TCP/PDLLA. Copyright © 2011 Wiley Periodicals, Inc.

  15. Biodegradation Resistance and Bioactivity of Hydroxyapatite Enhanced Mg-Zn Composites via Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Cijun Shuai

    2017-03-01

    Full Text Available Mg-Zn alloys have attracted great attention as implant biomaterials due to their biodegradability and biomechanical compatibility. However, their clinical application was limited due to the too rapid degradation. In the study, hydroxyapatite (HA was incorporated into Mg-Zn alloy via selective laser melting. Results showed that the degradation rate slowed down due to the decrease of grain size and the formation of protective layer of bone-like apatite. Moreover, the grain size continually decreased with increasing HA content, which was attributed to the heterogeneous nucleation and increased number of nucleation particles in the process of solidification. At the same time, the amount of bone-like apatite increased because HA could provide favorable areas for apatite nucleation. Besides, HA also enhanced the hardness due to the fine grain strengthening and second phase strengthening. However, some pores occurred owing to the agglomerate of HA when its content was excessive, which decreased the biodegradation resistance. These results demonstrated that the Mg-Zn/HA composites were potential implant biomaterials.

  16. Biodegradation Resistance and Bioactivity of Hydroxyapatite Enhanced Mg-Zn Composites via Selective Laser Melting.

    Science.gov (United States)

    Shuai, Cijun; Zhou, Yuanzhuo; Yang, Youwen; Feng, Pei; Liu, Long; He, Chongxian; Zhao, Mingchun; Yang, Sheng; Gao, Chengde; Wu, Ping

    2017-03-17

    Mg-Zn alloys have attracted great attention as implant biomaterials due to their biodegradability and biomechanical compatibility. However, their clinical application was limited due to the too rapid degradation. In the study, hydroxyapatite (HA) was incorporated into Mg-Zn alloy via selective laser melting. Results showed that the degradation rate slowed down due to the decrease of grain size and the formation of protective layer of bone-like apatite. Moreover, the grain size continually decreased with increasing HA content, which was attributed to the heterogeneous nucleation and increased number of nucleation particles in the process of solidification. At the same time, the amount of bone-like apatite increased because HA could provide favorable areas for apatite nucleation. Besides, HA also enhanced the hardness due to the fine grain strengthening and second phase strengthening. However, some pores occurred owing to the agglomerate of HA when its content was excessive, which decreased the biodegradation resistance. These results demonstrated that the Mg-Zn/HA composites were potential implant biomaterials.

  17. Using the natural biodegradation potential of shallow soils for in-situ remediation of deep vadose zone and groundwater

    International Nuclear Information System (INIS)

    Avishai, Lior; Siebner, Hagar; Dahan, Ofer; Ronen, Zeev

    2017-01-01

    Highlights: • Integrated in-situ remediation treatment for soil, vadose zone and groundwater. • Turning the topsoil into an efficient bioreactor for perchlorate degradation. • Treating perchlorate leachate from the deep vadose zone in the topsoil. • Zero effluents discharge from the remediation process. - Abstract: In this study, we examined the ability of top soil to degrade perchlorate from infiltrating polluted groundwater under unsaturated conditions. Column experiments designed to simulate typical remediation operation of daily wetting and draining cycles of contaminated water amended with an electron donor. Covering the infiltration area with bentonite ensured anaerobic conditions. The soil remained unsaturated, and redox potential dropped to less than −200 mV. Perchlorate was reduced continuously from ∼1150 mg/L at the inlet to ∼300 mg/L at the outlet in daily cycles. Removal efficiency was between 60 and 84%. No signs of bioclogging were observed during three operation months although occasional iron reduction observed due to excess electron donor. Changes in perchlorate reducing bacteria numbers were inferred from an increased in pcrA gene abundances from ∼10 5 to 10 7 copied per gram at the end of the experiment indicating the growth of perchlorate-reducing bacteria. We proposed that the topsoil may serve as a bioreactor to treat high concentrations of perchlorate from the contaminated groundwater. The treated water that infiltrates from the topsoil through the vadose zone could be used to flush perchlorate from the deep vadose zone into the groundwater where it is retrieved again for treatment in the topsoil.

  18. Using the natural biodegradation potential of shallow soils for in-situ remediation of deep vadose zone and groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Avishai, Lior; Siebner, Hagar; Dahan, Ofer, E-mail: odahan@bgu.ac.il; Ronen, Zeev, E-mail: zeevrone@bgu.ac.il

    2017-02-15

    Highlights: • Integrated in-situ remediation treatment for soil, vadose zone and groundwater. • Turning the topsoil into an efficient bioreactor for perchlorate degradation. • Treating perchlorate leachate from the deep vadose zone in the topsoil. • Zero effluents discharge from the remediation process. - Abstract: In this study, we examined the ability of top soil to degrade perchlorate from infiltrating polluted groundwater under unsaturated conditions. Column experiments designed to simulate typical remediation operation of daily wetting and draining cycles of contaminated water amended with an electron donor. Covering the infiltration area with bentonite ensured anaerobic conditions. The soil remained unsaturated, and redox potential dropped to less than −200 mV. Perchlorate was reduced continuously from ∼1150 mg/L at the inlet to ∼300 mg/L at the outlet in daily cycles. Removal efficiency was between 60 and 84%. No signs of bioclogging were observed during three operation months although occasional iron reduction observed due to excess electron donor. Changes in perchlorate reducing bacteria numbers were inferred from an increased in pcrA gene abundances from ∼10{sup 5} to 10{sup 7} copied per gram at the end of the experiment indicating the growth of perchlorate-reducing bacteria. We proposed that the topsoil may serve as a bioreactor to treat high concentrations of perchlorate from the contaminated groundwater. The treated water that infiltrates from the topsoil through the vadose zone could be used to flush perchlorate from the deep vadose zone into the groundwater where it is retrieved again for treatment in the topsoil.

  19. Knowledge engineering of an intelligent system for selection of remediation methods at petroleum contaminated sites

    International Nuclear Information System (INIS)

    Geng, L.; Chan, C.; Chen, Z.; Huang, G.

    1999-01-01

    A rule-based expert system for the management of petroleum contaminated sites is described which was developed using a variety of methodologies such as Inferential Modelling Technique (IMT) for knowledge analysis, decision trees and object-oriented methodology for knowledge representation. To enhance the system's flexibility, a user interface and an engineer interface were constructed for capturing different types of input. The system was implemented in real time with the real time expert system G2. An important feature of the system is its capability of dealing with imprecision in the inputs on the site conditions and contamination levels. The developed system contributes to the selection task by allowing for a more comprehensive and realistic consideration of the many factors related to the remediation selection decision. The results from case studies indicate that the expert system can aid the environmental engineer identify the most optimal alternatives for site remediation and thereby help industry reduce costs of site remediation practices. The system's inputs and outputs are directly useful for further modelling studies on remediation processes and contaminant transport in soil and groundwater. 10 refs., 6 figs

  20. Record of Decision Remedial Alternative Selection for the Gunsite 113 Access Road (631-24G) Operable Unit: Final Action

    International Nuclear Information System (INIS)

    Palmer, E.

    1997-01-01

    This decision document presents the selected remedial action for the Gunsite 113 Access Road Unit located at the Savannah River Site near Aiken, SC. The selected action was developed in accordance with CERCLA, as amended, and to the extent practicable, the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). The selected remedy satisfies both CERCLA and RCRA 3004(U) requirements. This decision is based ont he Administrative Record File for this specific RCRA/CERCLA Unit

  1. Nuclear facility decommissioning and site remedial actions. Volume 1. A selected bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Faust, R.A.; Fore, C.S.; Knox, N.P.

    1980-09-01

    This bibliography of 633 references represents the first in a series to be produced by the Remedial Actions Program Information Center (RAPIC) containing scientific, technical, economic, and regulatory information concerning the decommissioning of nuclear facilities. Major chapters selected for this bibliography are Facility Decommissioning, Uranium Mill Tailings Cleanup, Contaminated Site Restoration, and Criteria and Standards. The references within each chapter are arranged alphabetically by leading author, corporate affiliation, or title of the document. When the author is not given, the corporate affiliation appears first. If these two levels of authorship are not given, the title of the document is used as the identifying level. Indexes are provided for (1) author(s), (2) keywords, (3) title, (4) technology development, and (5) publication description. An appendix of 123 entries lists recently acquired references relevant to decommissioning of nuclear facilities. These references are also arranged according to one of the four subject categories and followed by author, title, and publication description indexes. The bibliography was compiled from a specialized data base established and maintained by RAPIC to provide information support for the Department of Energy's Remedial Actions Program, under the cosponsorship of its three major components: Surplus Facilities Management Program, Uranium Mill Tailings Remedial Actions Program, and Formerly Utilized Sites Remedial Actions Program. RAPIC is part of the Ecological Sciences Information Center within the Information Center Complex at Oak Ridge National Laboratory.

  2. Nuclear facility decommissioning and site remedial actions. Volume 1. A selected bibliography

    International Nuclear Information System (INIS)

    Faust, R.A.; Fore, C.S.; Knox, N.P.

    1980-09-01

    This bibliography of 633 references represents the first in a series to be produced by the Remedial Actions Program Information Center (RAPIC) containing scientific, technical, economic, and regulatory information concerning the decommissioning of nuclear facilities. Major chapters selected for this bibliography are Facility Decommissioning, Uranium Mill Tailings Cleanup, Contaminated Site Restoration, and Criteria and Standards. The references within each chapter are arranged alphabetically by leading author, corporate affiliation, or title of the document. When the author is not given, the corporate affiliation appears first. If these two levels of authorship are not given, the title of the document is used as the identifying level. Indexes are provided for (1) author(s), (2) keywords, (3) title, (4) technology development, and (5) publication description. An appendix of 123 entries lists recently acquired references relevant to decommissioning of nuclear facilities. These references are also arranged according to one of the four subject categories and followed by author, title, and publication description indexes. The bibliography was compiled from a specialized data base established and maintained by RAPIC to provide information support for the Department of Energy's Remedial Actions Program, under the cosponsorship of its three major components: Surplus Facilities Management Program, Uranium Mill Tailings Remedial Actions Program, and Formerly Utilized Sites Remedial Actions Program. RAPIC is part of the Ecological Sciences Information Center within the Information Center Complex at Oak Ridge National Laboratory

  3. Interim action record of decision remedial alternative selection: TNX area groundwater operable unit

    International Nuclear Information System (INIS)

    Palmer, E.R.

    1994-10-01

    This document presents the selected interim remedial action for the TNX Area Groundwater Operable Unit at the Savannah River Site (SRS), which was developed in accordance with CERCLA of 1980, as amended by the Superfund Amendments and Reauthorization Act (SARA) of 1986, and to the extent practicable, the National Oil and Hazardous Substances Pollution contingency Plan (NCP). This decision is based on the Administrative Record File for this specific CERCLA unit

  4. Role of nitrification in the biodegradation of selected artificial sweetening agents in biological wastewater treatment process.

    Science.gov (United States)

    Tran, N H; Nguyen, V T; Urase, T; Ngo, H H

    2014-06-01

    The biodegradation of the six artificial sweetening agents including acesulfame (ACE), aspartame (ASP), cyclamate (CYC), neohesperidindihydrochalcone (NHDC), saccharin (SAC), and sucralose (SUC) by nitrifying activated sludge was first examined. Experimental results showed that ASP and NHDC were the most easily degradable compounds even in the control tests. CYC and SAC were efficiently biodegraded by the nitrifying activated sludge, whereas ACE and SUC were poorly removed. However, the biodegradation efficiencies of the ASs were increased with the increase in initial ammonium concentrations in the bioreactors. The association between nitrification and co-metabolic degradation was investigated and a linear relationship between nitrification rate and co-metabolic biodegradation rate was observed for the target artificial sweeteners (ASs). The contribution of heterotrophic microorganisms and autotrophic ammonia oxidizers in biodegradation of the ASs was elucidated, of which autotrophic ammonia oxidizers played an important role in the biodegradation of the ASs, particularly with regards to ACE and SUC. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Use of LCA as decision support for the selection of remedial strategies for remediation of contaminated soil and groundwater

    DEFF Research Database (Denmark)

    Lemming, Gitte; Hauschild, Michael Zwicky; Bjerg, Poul Løgstrup

    , there is a trade-off between obtaining local beneficial effects from the remediation and generating environmental impacts on the regional and global scale due to the remedial actions. Therefore there is a need for including the impact of soil contaminants that will potentially leach to the groundwater, e......Groundwater is the dominant source of drinking water in Denmark and the general policy is to maintain the groundwater as a clean source of drinking water. The risk of groundwater contamination is therefore often the prime reason for remediating a contaminated site. Chlorinated solvents are among...... the contaminants most frequently found to be threatening the groundwater quality in Denmark and worldwide. Life cycle assessment has recently been applied as part of decision support for contaminated site management and subsurface remediation techniques. Impacts in the groundwater compartment have only gained...

  6. Characterization of Pseudomonas monteilii CCM 3423 and its physiological potential for biodegradation of selected organic pollutants.

    Science.gov (United States)

    Vojtková, Hana; Kosina, Marcel; Sedláček, Ivo; Mašlaňová, Ivana; Harwotová, Markéta; Molinková, Veronika

    2015-09-01

    Pseudomonas monteilii CCM 3423 bacterial strain, deposited at the Czech Collection of Microorganisms, was originally isolated by Haľama and Augustín (1980) as a bacterium degrading aromatic hydrocarbons and derivates. A detailed study supported by a molecular genetics method of sequence analyses of rrs and rpoD genes was used to reclassify the strain, originally stored as 'Pseudomonas putida'. The physiological characteristics of the strain are complemented with research in the capacity to utilize selected organic pollutants (anthracene, benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, fluorene, naphthalene, phenanthrene). The obtained results point at very good biodegradation properties of the strain. Already after 7 days of the bacterial strain's action, there was a decrease in all the organic contaminants to 79.8 ± 2.6 %. In 14 days, the amount of organic contaminants dropped to 59.3 ± 2.8 %. After 21 days of biodegradation experiments, the overall quantity of the observed organic substances fell below the half limit to 45.7 ± 2.5 % of residuals. Finally, after 28 days, the residue was 35.4 ± 2.2 %, and after 35 days of the action of P. monteilii, the tested samples contained mere 27.8 ± 2.8 % of organic pollutants. The results imply that Pseudomonas monteilii CCM 3423 is a prospective strain in terms of further biotechnological application in contaminated environment.

  7. Using the natural biodegradation potential of shallow soils for in-situ remediation of deep vadose zone and groundwater.

    Science.gov (United States)

    Avishai, Lior; Siebner, Hagar; Dahan, Ofer; Ronen, Zeev

    2017-02-15

    In this study, we examined the ability of top soil to degrade perchlorate from infiltrating polluted groundwater under unsaturated conditions. Column experiments designed to simulate typical remediation operation of daily wetting and draining cycles of contaminated water amended with an electron donor. Covering the infiltration area with bentonite ensured anaerobic conditions. The soil remained unsaturated, and redox potential dropped to less than -200mV. Perchlorate was reduced continuously from ∼1150mg/L at the inlet to ∼300mg/L at the outlet in daily cycles. Removal efficiency was between 60 and 84%. No signs of bioclogging were observed during three operation months although occasional iron reduction observed due to excess electron donor. Changes in perchlorate reducing bacteria numbers were inferred from an increased in pcrA gene abundances from ∼10 5 to 10 7 copied per gram at the end of the experiment indicating the growth of perchlorate-reducing bacteria. We proposed that the topsoil may serve as a bioreactor to treat high concentrations of perchlorate from the contaminated groundwater. The treated water that infiltrates from the topsoil through the vadose zone could be used to flush perchlorate from the deep vadose zone into the groundwater where it is retrieved again for treatment in the topsoil. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. A CERCLA-Based Decision Model to Support Remedy Selection for an Uncertain Volume of Contaminants at a DOE Facility

    National Research Council Canada - National Science Library

    Kerschus, Christine

    1997-01-01

    The Paducah Gaseous Diffusion Plant (PGDP) operated by the Department of Energy is challenged with selecting the appropriate remediation technology to cleanup contaminants at Waste Area Group (WAG) 6...

  9. Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Remedial action selection report

    International Nuclear Information System (INIS)

    1991-12-01

    The uranium mill tailings site near Durango, Colorado, was one of 24 inactive uranium mill sites designated to be remediated by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). Part of the UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE's Remedial Action Plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). Included in the RAP is this Remedial Action Selection Report (RAS), which has been developed to serve a two-fold purpose. First, it describes the activities that have been conducted by the DOE to accomplish remediation and long-term stabilization and control of the radioactive materials at the inactive uranium mill processing site near Durango, Colorado. Secondly, this document and the rest of the RAP, upon concurrence and execution by the DOE, the State of Colorado, and the NRC, become Appendix B of the Cooperative Agreement between the DOE and the State of Colorado

  10. A life cycle framework to support materials selection for Ecodesign: A case study on biodegradable polymers

    International Nuclear Information System (INIS)

    Ribeiro, I.; Peças, P.; Henriques, E.

    2013-01-01

    Highlights: • Life cycle framework to support material selection in Ecodesign. • Early design stage estimates and sensitivity analyses based on process-based models. • Sensitivity analysis to product geometry, industrial context and EoL scenarios. • Cost and environmental performance comparison – BDP vs. fossil based polymers. • Best alternatives mapping integrating cost and environmental performances. - Abstract: Nowadays society compels designers to develop more sustainable products. Ecodesign directs product design towards the goal of reducing environmental impacts. Within Ecodesign, materials selection plays a major role on product cost and environmental performance throughout its life cycle. This paper proposes a comprehensive life cycle framework to support Ecodesign in material selection. Dealing with new materials and technologies in early design stages, process-based models are used to represent the whole life cycle and supply integrated data to assess material alternatives, considering cost and environmental dimensions. An integrated analysis is then proposed to support decision making by mapping the best alternative materials according to the importance given to upstream and downstream life phases and to the environmental impacts. The proposed framework is applied to compare the life cycle performance of injection moulded samples made of four commercial biodegradable polymers with different contents of Thermo Plasticized Starch and PolyLactic Acid and a common fossil based polymer, Polypropylene. Instead of labelling materials just as “green”, the need to fully capture all impacts in the whole life cycle was shown. The fossil based polymer is the best economic alternative, but polymers with higher content of Thermo Plasticized Starch have a better environmental performance. However, parts geometry and EoL scenarios play a major role on the life cycle performance of candidate materials. The selection decision is then supported by mapping

  11. Selected remedy at the Queen City Farms superfund site: A risk management approach

    International Nuclear Information System (INIS)

    Weber, E.F.; Wilson, J.; Kirk, M.; Tochko, S.

    1994-01-01

    A risk management approach at a former industrial waste disposal site in western Washington resulted in a selected remedy that is cost-effective and that meets the CERCLA threshold criterion of protecting human health and the environment. The proposed remedy, which addresses contamination in soil and groundwater, does not require an ARARs waiver and received state and community acceptance. By analyzing the current and potential risk at the site, a proposed remedy was chosen that would control the source and naturally attenuate the groundwater plume. Source control will include removal and treatment of some light nonaqueous phase liquid (LNAPL) and some soil, followed by isolation of the remaining soil and LNAPL within a slurry wall and beneath a multilayer cap. A contingent groundwater extraction and treatment system was included to address uncertainty in the risk characterization. Implementing source control is predicted to result in a steady decline in volatile organic compound levels in the drinking water aquifer through adsorption, degradation, and dispersion. Exposure to groundwater during the period of natural attenuation will be controlled by monitoring, institutional controls, and a thorough characterization of the plume and receptors. 7 figs., 1 tab

  12. Accelerated biodegradation of selected nematicides in tropical crop soils from Costa Rica.

    Science.gov (United States)

    Chin-Pampillo, Juan Salvador; Carazo-Rojas, Elizabeth; Pérez-Rojas, Greivin; Castro-Gutiérrez, Víctor; Rodríguez-Rodríguez, Carlos E

    2015-01-01

    Degradation and mineralization behavior of selected nematicides was studied in soil samples from fields cultivated with banana, potato, and coffee. Degradation assays in most of the studied soils revealed shorter half-lives for carbofuran (CBF) and ethoprophos (ETP) in samples with a history of treatment with these compounds, which may have been caused by enhanced biodegradation. A short half-life value for CBF degradation was also observed in a banana field with no previous exposure to this pesticide, but with a recent application of the carbamate insecticide oxamyl, which supports the hypothesis that preexposure to oxamyl may cause microbial adaptation towards degradation of CBF, an observation of a phenomenon not yet tested according to the literature reviewed. Mineralization assays for CBF and terbufos (TBF) revealed that history of treatment with these nematicides did not cause higher mineralization rates in preexposed soils when compared to unexposed ones, except in the case of soils from coffee fields. Mineralization half-lives for soils unexposed to these pesticides were significantly shorter than most reports in the literature in the same conditions. Mineralization rates for soils with a previous exposure to these pesticides were also obtained, adding to the very few reports found. This paper contributes valuable data to the low number of reports dealing with pesticide fate in soils from tropical origin.

  13. Biodegradable Polymeric Nanoparticles for Tumor-Selective Tamoxifen Delivery: In Vitro and In Vivo Studies

    National Research Council Canada - National Science Library

    Shenoy, Dinesh B; Chawla, Jugminder S; Amiji, Mansoor M

    2005-01-01

    ... into biodegradable, surface-modified poly(e-caprolactone) (PCL) nanoparticles. PCL (MW ̂ 15,000) nanoparticles were prepared by the solvent displacement method and characterized for particle size/change and surface morphology...

  14. Decision support tools for evaluation and selection of technologies for soil remediation and disposal of halogenated waste

    Energy Technology Data Exchange (ETDEWEB)

    Khelifi, O.; Zinovyev, S.; Lodolo, A.; Vranes, S.; Miertus, S. [ICS-UNIDO, Trieste (Italy)

    2004-09-15

    One of the most justified demands in abating the pollution created by polychlorinated substances is the remediation of contaminated sites, mainly soil remediation, which is also the most complex technical task in removing pollution because of the necessity to process huge quantities of matrix and to account for numerous side factors. The commercial technologies are usually based on rather direct and simplified but also secure processes, which often approach remediation in a general way, where different types of pollutants can be decontaminated at the same time by each technology. A number of different soil remediation technologies are nowadays available and the continuous competition among environmental service companies and technology developers generates a further increase in the clean-up options. The demand for decision support tools that could help decision makers in selecting the most appropriate technology for the specific contaminated site has consequently increased. These decision support tools (DST) are designed to help decision makers (site owners, local community representatives, environmentalists, regulators, etc.) to assess available technologies and preliminarily select the preferred remedial options. The analysis for the identification of the most suitable options in the DST is based on technical, economic, environmental, and social criteria. These criteria are ranked by all parties involved in the decision process to determine their relative importance for a particular remediation project. The aim of the present paper is to present the new approach for building decision support tool to evaluate different technologies for remediation and disposal of halogenated waste.

  15. Design and development of self-passivating biodegradable magnesium alloys using selective element oxidation

    Science.gov (United States)

    Brar, Harpreet Singh

    Metallic biomaterials such as stainless steels, titanium alloys, and cobalt-chromium alloys have been used as structural implant materials for many years. However, due to their limitations in temporary implant applications, there has been increased interest in the development of a biodegradable structural implant device. Magnesium (Mg) alloys have shown great potential as a material for biodegradable structural implant applications. However, low strength and high degradation rate of Mg under physiological conditions are major limitations, causing the implant to lose its structural integrity before the healing process is complete. The main aim of this work was to investigate the possibility of designing Mg-based alloys with ability to form selective protective oxides, thereby aiding in the reduction of the initial degradation rate. A thermodynamics-driven design was utilized to select three elements, namely Gadolinium (Gd), Scandium (Sc) and Yttrium (Y), due to the low enthalpy of formation associated with their oxide species. First, binary alloys were cast under inert atmosphere, solution treated and investigated for degradation rate in Hanks' solution. The Mg-Gd binary alloy showed the fastest degradation rate whereas the Mg-Sc binary alloy showed the slowest degradation rate. The degradation of Mg-Gd and Mg-Y was 18 and 5 times faster than Mg-Sc alloy, respectively. The microstructural analysis of the alloys was performed using X-ray Diffraction (XRD), Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). It was observed that the grain size of Mg-Sc alloys is significantly smaller than Mg-Gd and Mg-Y alloys and can be a contributing factor to the reduction in degradation rate. The hardness behavior of the alloys was also investigated using Vickers microhardness Testing. To understand the oxidation behavior and kinetics, samples were oxidized in pure oxygen environment and investigated using microstructural and thermogravimetric analysis (TGA). Auger

  16. Remedial action plan and site design for stabilization of the inactive uranium processing site at Naturita, Colorado. Remedial action selection report, Attachment 2, Geology report: Preliminary final

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    The uranium processing site near Naturita, Colorado, is one of 24 inactive uranium mill sites designated to be cleaned up by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), Public Law 95-604. Part of the UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). Included in the RAP is this Remedial Action Selection Report (RAS), which serves two purposes. First, it describes the activities that are proposed by the DOE to accomplish remediation and long-term stabilization and control of the radioactive materials at the inactive uranium processing site near Naturita, Colorado. Second, this document and the rest of the RAP, upon concurrence and execution by the DOE, the state of Colorado, and the NRC, become Appendix B of the cooperative agreement between the DOE and the State of Colorado.

  17. THE INFLUENCE OF THE INSTALLATION METHOD ON THE SELECTED PROPERTIES OF BIODEGRADABLE GEOTEXTILES USED IN ENVIRONMENTAL ENGINEERING

    Directory of Open Access Journals (Sweden)

    Joanna Beata Grzybowska-Pietras

    2017-06-01

    Full Text Available In the engineering constructions there are used biodegradable geotextiles, that are performing primarily a function of surface anti-erosion protection. Their biodegradability supports the development of vegetation, and protects the surface of the slope from the moment of installation in the ground. In order to achieve this functionality there are used mainly biononwovens and woven fabrics made of natiral fibers. In the paper there are presented results of studies on the effect of the instalation of the biononwoven (Maliwatt type with grass seeds applied in real conditions at a specified time (from November to June, on the selected physical, mechanical and hydraulic properties , and the development of vegetation (grasses. The experiment adopted two versions of instalation of nonwovens. In the first case geotextile was mounted directly on the ground, in the second additionally have been covered with a layer of native soil.

  18. Selection of innovative technologies for the remediation of soils contaminated with radioactive and mixed wastes

    International Nuclear Information System (INIS)

    Steude, J.; Tucker, B.

    1991-01-01

    The remediation of sites containing radioactive and mixed wastes is in a period of rapid growth. The state of the art of remediation is progressing to handle the shortcomings of conventional pump and treat or disposal technologies. The objective of this paper is to review the status of selected innovative technologies which treat soils contaminated with radioactive and mixed waste. Technologies are generally classified as innovative if they are fully developed, but lack sufficient cost or performance data for comparison with conventional technologies. The Environmental Protection Agency recommends inclusion of innovative technologies in the RI/FS screening process if there is reason to believe that they would offer advantages in performance, implementability, cost, etc. This paper serves as a compilation of the pertinent information necessary to gain an overview of the selected innovative technologies to aid in the RI/F'S screening process. The innovative technologies selected for evaluation are listed below. Bioremediation, although innovative, was not included due to the combination of the vast amount of literature on this subject and the limited scope of this project. 1. Soil washing and flushing; 2. Low temperature thermal treatment; 3. Electrokinetics; 4. Infrared incineration; 5. Ultrasound; 6. In situ vitrification; 7. Soil vapor extraction; 8. Plasma torch slagging; 9. In situ hot air/steam extraction; 10. Cyclone reactor treatment; 11. In situ radio frequency; 12. Vegetative radionuclide uptake; and 13. In situ soil heating. The information provided on each technology includes a technical description, status, summary of results including types of contaminants and soils treated, technical effectiveness, feasibility and estimated cost

  19. The cost and benefit analysis of a contaminated area remediation: case study of dose level selection

    International Nuclear Information System (INIS)

    Lauria, D.C.

    2006-01-01

    In recent years there has been an increasing awareness of the radiological impact of non-nuclear industries that extract and/or process ores and minerals containing naturally occurring radioactive material (NORM). Without radiological rules, these industrial activities may result in significant radioactive contamination of installations and sites. Depending on the potential hazardous to the environment and public health, the radioactive contaminated sites may require remediation. The extent of the site cleanup is a function of the size, localization, complexity, potential risks and on possible future uses envisioned for the site. Since worker and public health, public anxiety and economics factors are involved; the selection of an appropriate dose level can be quite complicated. This paper discusses the selection of a dose level criterion to remedy a site, which was contaminated by wastes from monazite processing. The site is located in the Sao Paulo city; the most densely populated Brazilian City. In its 60,000 square meters of area, a preliminary survey showed contaminated zones covering an area of 6,500 square meters. In some places, contamination was found below the superficial layer of the soil, being the radionuclide vertical distribution not uniform. The 228 Ra soil activity concentration reached values up to 33,000 Bq/kg while those for 226 Ra reached values up to 6,700 Bq/kg. Based on pathway analysis model and considering both the current land use and a hypothetical residential scenario, the residual contamination levels of radionuclides in soil have been derived for dose values of 10 mSv/y (dose level for intervention), 5 mSv/y, 3 mSv/y, 1 mSv/y (dose limit for practices) and 0.3 mSv/y (dose constraint for practices). An optimized value o f annual dose of about 5 mSv/y would be a good option for intervention level, but taking into account the public concern and anxiety, the site location and size, and the remediation costs, it is suggested the

  20. Indoor radon in selected homes in Aburi Municipality: measurement uncertainty, decision analysis and remediation strategy

    International Nuclear Information System (INIS)

    Yeboah, M. S.

    2014-07-01

    The main source of natural internal irradiation of man is radon and its decay products. In this study, the radon concentration levels in selected homes in Aburi of the Akuapim North Municipal Assembly in Eastern Region, Ghana were estimated using time-intergrated passive radon detector; LR-115 Type II solid state nuclear track detector (SSNTD) technique. The primary objective of the study was to measure radon levels in 30 selected homes in the Aburi municipality and determine the uncertainties associated with the measured radon concentrations in order to take a decision on remedial actions to be adopted in case of any abnormality using simple qualitative decision analysis method. Measurements were carried out from December, 2013 to March, 2014. After each month of exposure for a period of three months, the detectors were subjected to chemical etching in a 2.5M analytical grade of sodium hydroxide solution at (60 ± I )OC, for 90mins in a constant temperature water bath to enlarge the latent tracks produced by alpha particles from the decay of radon. The etched tracks were magnified using the microfiche reader and counted with a tally counter. The results obtained from the study revealed that concentration of radon in most of the selected homes in the Aburi municipality is low and it is within the internationally accepted action level of 100Bqm-3 set by WHO (2009). The analysis of the results established that the average radon concentrations vary in the range 23.72- 92.24Bqm -3 , 19.07-124.36 Bqm -3 and 31.63-123.87 Bqm -3 for month I, month 2 and month 3 respectively. The corresponding mean values are 46.77, 45.92 and 56.66 Bqm -3 respectively with standard deviations of ±2.18. ±2.38 and ±2.76. These gave a mean of 49.78 ± 12.50 for the three months. Two (2) of the rooms investigated had values above 20 % of the remedial action level of 100Bqm -3 in two of the months but with their average values slightly lower than the remedial action level. From the

  1. Biodegradation of polycyclic aromatic hydrocarbons, selection and dynamics of bacterial populations in the rhizosphere in relation with the distance to roots; Biodegradation des Hydrocarbures Aromatiques Polycycliques, selection et dynamique des populations bacteriennes dans la rhizosphere en fonction de la distance aux racines

    Energy Technology Data Exchange (ETDEWEB)

    Corgie, St.

    2004-03-01

    The biodegradation of Polycyclic Aromatic Hydrocarbons (PAH) is mainly performed by microorganisms that can use these compounds as sole source of carbon and energy. Such capacity has been amply studied to use and optimise microbial activity for remediation of contaminated soils. The use of plants has been suggested to increase and accelerate biodegradation rate by improving microbial activity. However, biodegradation mechanisms still remain poorly described as the interactions between plant, pollutant and rhizosphere microflora are often complex. A simplified compartmented device was developed to study rhizospheric processes, especially biodegradation of PAH, as a function of distance to roots, where root exudates and/or PAH were the only carbon sources for microbial growth. The development and use of bio-molecular techniques (nucleic acid isolation, PCR, RT-PCR, TGGE, hybridization with a degradation gene specific probe) permitted to follow the structure of bacterial communities. Gradients of phenanthrene biodegradation were observed as a function of distance to roots, in parallel to spatial and temporal variations in bacterial community structure. These bacterial communities, as well as PAH biodegradation rate, also depended on the aromaticity of PAH and were modified by the symbiosis between plant and an arbuscular mycorrhizal fungus. (author)

  2. Nuclear facility decommissioning and site remedial actions: A selected bibliography: Volume 7

    International Nuclear Information System (INIS)

    Owen, P.T.; Michelson, D.C.; Knox, N.P.; Fowler, J.W.

    1986-09-01

    The 644 abstracted references on nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the seventh in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Foreign and domestic literature of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - has been included. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's remedial action program. Major chapters are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Program, (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, and (9) General Remedial Action Program Studies. Chapter sections for chapters 1, 2, 5, and 7 include Design, Planning, and Regulations; Environmental Studies and Site Surveys; Health, Safety, and Biomedical Studies; Decontamination Studies; Dismantlement and Demolition; Site Stabilization and Reclamation; Waste Disposal; Remedial Action Experience; and General Studies. References are arranged alphabetically by leading author. Those references having no individual author are listed by corporate affiliation or by publication description. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, and keywords. The appendix contains a list of frequently used acronyms and abbreviations

  3. Nuclear facility decommissioning and site remedial actions. Volume 6. A selected bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Owen, P.T.; Michelson, D.C.; Knox, N.P.

    1985-09-01

    This bibliography of 683 references with abstracts on the subject of nuclear facility decommissioning, uranium mill tailings management, and site remedial actions is the sixth in a series of annual reports prepared for the US Department of Energy's Remedial Action Programs. Foreign as well as domestic literature of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - has been included. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's remedial action program. Major chapters are: (1) Surplus Facilities Management Program; (2) Nuclear Facilities Decommissioning; (3) Formerly Utilized Sites Remedial Action Program; (4) Facilities Contaminated with Natural Radioactivity; (5) Uranium Mill Tailings Remedial Action Program; (6) Grand Junction Remedial Action Program; (7) Uranium Mill Tailings Management; (8) Technical Measurements Center; and (9) General Remedial Action Program Studies. Chapter sections for chapters 1, 2, 5, and 7 include Design, Planning, and Regulations; Environmental Studies and Site Surveys; Health, Safety, and Biomedical Studies; Decontamination Studies; Dismantlement and Demolition; Site Stabilization and Reclamation; Waste Disposal; Remedial Action Experience; and General Studies. The references within each chapter or section are arranged alphabetically by leading author. References having no individual author are arranged by corporate affiliation or by publication description.

  4. Nuclear facility decommissioning and site remedial actions. Volume 6. A selected bibliography

    International Nuclear Information System (INIS)

    Owen, P.T.; Michelson, D.C.; Knox, N.P.

    1985-09-01

    This bibliography of 683 references with abstracts on the subject of nuclear facility decommissioning, uranium mill tailings management, and site remedial actions is the sixth in a series of annual reports prepared for the US Department of Energy's Remedial Action Programs. Foreign as well as domestic literature of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - has been included. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's remedial action program. Major chapters are: (1) Surplus Facilities Management Program; (2) Nuclear Facilities Decommissioning; (3) Formerly Utilized Sites Remedial Action Program; (4) Facilities Contaminated with Natural Radioactivity; (5) Uranium Mill Tailings Remedial Action Program; (6) Grand Junction Remedial Action Program; (7) Uranium Mill Tailings Management; (8) Technical Measurements Center; and (9) General Remedial Action Program Studies. Chapter sections for chapters 1, 2, 5, and 7 include Design, Planning, and Regulations; Environmental Studies and Site Surveys; Health, Safety, and Biomedical Studies; Decontamination Studies; Dismantlement and Demolition; Site Stabilization and Reclamation; Waste Disposal; Remedial Action Experience; and General Studies. The references within each chapter or section are arranged alphabetically by leading author. References having no individual author are arranged by corporate affiliation or by publication description

  5. Biodegradative Activities of Selected Environmental Fungi on a Polyester Polyurethane Varnish and Polyether Polyurethane Foams.

    Science.gov (United States)

    Álvarez-Barragán, Joyce; Domínguez-Malfavón, Lilianha; Vargas-Suárez, Martín; González-Hernández, Ricardo; Aguilar-Osorio, Guillermo; Loza-Tavera, Herminia

    2016-09-01

    Polyurethane (PU) is widely used in many aspects of modern life because of its versatility and resistance. However, PU waste disposal generates large problems, since it is slowly degraded, there are limited recycling processes, and its destruction may generate toxic compounds. In this work, we isolated fungal strains able to grow in mineral medium with a polyester PU (PS-PU; Impranil DLN) or a polyether PU (PE-PU; Poly Lack) varnish as the only carbon source. Of the eight best Impranil-degrading strains, the six best degraders belonged to the Cladosporium cladosporioides complex, including the species C. pseudocladosporioides, C. tenuissimum, C. asperulatum, and C. montecillanum, and the two others were identified as Aspergillus fumigatus and Penicillium chrysogenum The best Impranil degrader, C. pseudocladosporioides strain T1.PL.1, degraded up to 87% after 14 days of incubation. Fourier transform infrared (FTIR) spectroscopy analysis of Impranil degradation by this strain showed a loss of carbonyl groups (1,729 cm(-1)) and N-H bonds (1,540 and 1,261 cm(-1)), and gas chromatography-mass spectrometry (GC-MS) analysis showed a decrease in ester compounds and increase in alcohols and hexane diisocyanate, indicating the hydrolysis of ester and urethane bonds. Extracellular esterase and low urease, but not protease activities were detected at 7 and 14 days of culture in Impranil. The best eight Impranil-degrading fungi were also able to degrade solid foams of the highly recalcitrant PE-PU type to different extents, with the highest levels generating up to 65% of dry-weight losses not previously reported. Scanning electron microscopy (SEM) analysis of fungus-treated foams showed melted and thinner cell wall structures than the non-fungus-treated ones, demonstrating fungal biodegradative action on PE-PU. Polyurethane waste disposal has become a serious problem. In this work, fungal strains able to efficiently degrade different types of polyurethanes are reported, and

  6. Nuclear Facilities Decommissioning and site remedial actions: a selected bibliography. Vol. 2

    International Nuclear Information System (INIS)

    Owen, P.T.; Fielden, J.M.; Knox, N.P.; Trotter, ES.

    1981-10-01

    This bibliography of 643 references represents the second in a series on nuclear facility decommissioning and site remedial actions to be produced by the Radiation Effects Information Center (REIC) within the Information Center Complex, Information Division, Oak Ridge National Laboratory. The bibliography contains scientific, technical, economic, and regulatory information pertaining to the US Department of Energy's Remedial Action Program. Major chapters are: Surplus Facilities Management Program; Nuclear Facilities Decommissioning; Formerly Utilized Sites Remedial Action Program; and Uranium Mill Tailings Management. The references within each chapter are arranged alphabetically by leading author. References having no individual author are arranged by corporate affiliation or by title. Indexes are provided for: (1) author; (2) corporate affiliation; (3) title; (4) publication description; (5) geographic location; and (6) keywords. The bibliography was compiled from a specialized data base established and maintained by REIC to provide information support for the US Department of Energy's Remedial Action Program, under the cosponsorship of its four major components: Surplus Facilities Management Program; Formerly Utilized Sites Remedial Action Program; Uranium Mill Tailings Remedial Action Program; and the Grand Junction Remedial Action Program

  7. Nuclear facility decommissioning and site remedial actions: a selected bibliography. Volume 5

    International Nuclear Information System (INIS)

    Owen, P.T.; Knox, N.P.; Chilton, B.D.; Baldauf, M.F.

    1984-09-01

    This bibliography of 756 references with abstracts on the subject of nuclear facility decommissioning, uranium mill tailings management, and site remedial actions is the fifth in a series of annual reports prepared for the US Department of Energy, Division of Remedial Action Projects. Foreign as well as domestic literature of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - has been included in this publication. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's Remedial Action Program. Major chapters are: (1) Surplus Facilities Management Program; (2) Nuclear Facilities Decommissioning; (3) Formerly Utilized Sites Remedial Action Program; (4) Uranium Mill Tailings Remedial Action Program; (5) Grand Junction Remedial Action Program; (6) Uranium Mill Tailings Management; and (7) Technical Measurements Center. Chapter sections for chapters 1, 2, 4, and 6 include Design, Planning, and Regulations; Environmental Studies and Site Surveys; Decontamination Studies; Dismantlement and Demolition; Site Stabilization and Reclamation; Waste Disposal; Remedial Action Experience; and General Studies. The references within each chapter or section are arranged alphabetically by leading author. References having no individual author are arranged by corporate author or by title. Indexes are provided for the categories of author, corporate affiliation, title, publication description, geographic location, and keywords. The Appendix contains a list of frequently used acronyms

  8. Nuclear facility decommissioning and site remedial actions: a selected bibliography. Volume 5

    Energy Technology Data Exchange (ETDEWEB)

    Owen, P.T.; Knox, N.P.; Chilton, B.D.; Baldauf, M.F.

    1984-09-01

    This bibliography of 756 references with abstracts on the subject of nuclear facility decommissioning, uranium mill tailings management, and site remedial actions is the fifth in a series of annual reports prepared for the US Department of Energy, Division of Remedial Action Projects. Foreign as well as domestic literature of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - has been included in this publication. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's Remedial Action Program. Major chapters are: (1) Surplus Facilities Management Program; (2) Nuclear Facilities Decommissioning; (3) Formerly Utilized Sites Remedial Action Program; (4) Uranium Mill Tailings Remedial Action Program; (5) Grand Junction Remedial Action Program; (6) Uranium Mill Tailings Management; and (7) Technical Measurements Center. Chapter sections for chapters 1, 2, 4, and 6 include Design, Planning, and Regulations; Environmental Studies and Site Surveys; Decontamination Studies; Dismantlement and Demolition; Site Stabilization and Reclamation; Waste Disposal; Remedial Action Experience; and General Studies. The references within each chapter or section are arranged alphabetically by leading author. References having no individual author are arranged by corporate author or by title. Indexes are provided for the categories of author, corporate affiliation, title, publication description, geographic location, and keywords. The Appendix contains a list of frequently used acronyms.

  9. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 13: Part 2, Indexes

    Energy Technology Data Exchange (ETDEWEB)

    Goins, L.F.; Webb, J.R.; Cravens, C.D.; Mallory, P.K.

    1992-09-01

    This is part 2 of a bibliography on nuclear facility decommissioning and site remedial action. This report contains indexes on the following: authors, corporate affiliation, title words, publication description, geographic location, subject category, and key word.

  10. Sampling design and analytical method selection strategies for expedited CERCLA remediations

    International Nuclear Information System (INIS)

    Price, W.H.

    1996-01-01

    Decision makers from the Washington State Department of Ecology, EPA, and the US DOE recently assembled to discuss data collection requirements for supporting expedited Comprehensive Environmental Response, Compensation, and Liability Act of 1980 remediations at the Hanford Site. The decision makers indicated that one of their primary goals is to reduce remediation cost of sampling and analysis at the Hanford Site from approximately 40% of total soil remediation project costs to 8% of total cost, while providing data sufficient to support defensible decisions. Because many areas of the Hanford Site are contaminated primarily with metals and radionuclides, the decision makers decided that cost reductions should be focused initially on metals and radionuclide contaminated sites. This strategy document addresses the cost reduction goal and is to be used by the projects when preparing sampling and analysis plans for remedial actions

  11. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 13: Part 1, Main text

    Energy Technology Data Exchange (ETDEWEB)

    Goins, L.F.; Webb, J.R.; Cravens, C.D.; Mallory, P.K.

    1992-09-01

    This publication contains 1035 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions. These citations constitute the thirteenth in a series of reports prepared annually for the US Department of Energy (DOE) Environmental Restoration programs. Citations to foreign and domestic literature of all types. There are 13 major sections of the publication, including: (1) DOE Decontamination and Decommissioning Program; (2) Nuclear Facilities Decommissioning; (3) DOE Formerly Utilized Sites Remedial Action Program; (4) DOE Uranium Mill Tailings Remedial Action Project; (5) Uranium Mill Tailings Management; (6) DOE Environmental Restoration Program; (7) DOE Site-Specific Remedial Actions; (8) Contaminated Site Restoration; (9) Remediation of Contaminated Soil and Groundwater; (10) Environmental Data Measurements, Management, and Evaluation; (11) Remedial Action Assessment and Decision-Making; (12) Technology Development and Evaluation; and (13) Environmental and Waste Management Issues. Bibliographic references are arranged in nine subject categories by geographic location and then alphabetically by first author, corporate affiliation, or publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and key word.

  12. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 13: Part 1, Main text

    International Nuclear Information System (INIS)

    Goins, L.F.; Webb, J.R.; Cravens, C.D.; Mallory, P.K.

    1992-09-01

    This publication contains 1035 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions. These citations constitute the thirteenth in a series of reports prepared annually for the US Department of Energy (DOE) Environmental Restoration programs. Citations to foreign and domestic literature of all types. There are 13 major sections of the publication, including: (1) DOE Decontamination and Decommissioning Program; (2) Nuclear Facilities Decommissioning; (3) DOE Formerly Utilized Sites Remedial Action Program; (4) DOE Uranium Mill Tailings Remedial Action Project; (5) Uranium Mill Tailings Management; (6) DOE Environmental Restoration Program; (7) DOE Site-Specific Remedial Actions; (8) Contaminated Site Restoration; (9) Remediation of Contaminated Soil and Groundwater; (10) Environmental Data Measurements, Management, and Evaluation; (11) Remedial Action Assessment and Decision-Making; (12) Technology Development and Evaluation; and (13) Environmental and Waste Management Issues. Bibliographic references are arranged in nine subject categories by geographic location and then alphabetically by first author, corporate affiliation, or publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and key word

  13. Nuclear facility decommissioning and site remedial actions: A selected bibliography: Volume 8

    Energy Technology Data Exchange (ETDEWEB)

    Owen, P.T.; Michelson, D.C.; Knox, N.P.

    1987-09-01

    The 553 abstracted references on nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the eighth in a series of reports. Foreign and domestic literature of all types - technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions - has been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of energy's remedial action program. Major chapters are Surplus Facilities Management Program, Nuclear Facilities Decommissioning, Formerly Utilized Sites Remedial Action Program, Facilities Contaminated with Naturally Occurring Radionuclides, Uranium Mill Tailings Remedial Action Program, Uranium Mill Tailings Management, Technical Measurements Center, and General Remedial Action Program Studies. Chapter sections for chapters 1, 2, 5, and 6 include Design, Planning, and Regulations; Environmental Studies and Site Surveys; Health, Safety, and Biomedical Studies; Decontamination Studies; Dismantlement and Demolition; Site Stabilization and Reclamation; Waste Disposal; Remedial Action Experience; and General Studies. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication description. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, and keywords. The appendix contains a list of frequently used acronyms and abbreviations.

  14. Nuclear facility decommissioning and site remedial actions: A selected bibliography: Volume 8

    International Nuclear Information System (INIS)

    Owen, P.T.; Michelson, D.C.; Knox, N.P.

    1987-09-01

    The 553 abstracted references on nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the eighth in a series of reports. Foreign and domestic literature of all types - technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions - has been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of energy's remedial action program. Major chapters are Surplus Facilities Management Program, Nuclear Facilities Decommissioning, Formerly Utilized Sites Remedial Action Program, Facilities Contaminated with Naturally Occurring Radionuclides, Uranium Mill Tailings Remedial Action Program, Uranium Mill Tailings Management, Technical Measurements Center, and General Remedial Action Program Studies. Chapter sections for chapters 1, 2, 5, and 6 include Design, Planning, and Regulations; Environmental Studies and Site Surveys; Health, Safety, and Biomedical Studies; Decontamination Studies; Dismantlement and Demolition; Site Stabilization and Reclamation; Waste Disposal; Remedial Action Experience; and General Studies. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication description. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, and keywords. The appendix contains a list of frequently used acronyms and abbreviations

  15. 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

  16. Molecular Weight and Charge Density Effects of Guanidinylated Biodegradable Polycarbonates on Antimicrobial Activity and Selectivity.

    Science.gov (United States)

    Hae Cho, Chloe A; Liang, Chao; Perera, Janesha; Liu, Jie; Varnava, Kyriakos G; Sarojini, Vijayalekshmi; Cooney, Ralph P; McGillivray, Duncan J; Brimble, Margaret A; Swift, Simon; Jin, Jianyong

    2017-11-21

    Six guanidine functionalized aliphatic biodegradable polycarbonates with varying molecular weights and charge densities were synthesized via postsynthesis modification of alkyne containing polycarbonates using Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry. The concept of passive diluting group was to modify the cationic charge density of the polycarbonate without changing its hydrophilicity. Within the molecular weight range from 8000 to 30000 g mol -1 , these guanidine polycarbonates exhibited broad-spectrum biocidal activity with low toxicity to red blood cells (RBCs). The lowest molecular weight homopolymer sample (PG-8k-100) showed the best antimicrobial activity (MIC = 40 μg/mL against Escherichia coli and MIC = 20 μg/mL against Staphylococcus epidermidis) and least RBC toxicity (0.6% hemolysis at MIC). Within the three guanidine charge densities from 20% to 70%, the low to medium dilution samples (PG-8k-7030 and PG-8k-5050) had no obvious loss in antimicrobial activities compared to the nondiluted control sample PG-8k-100. However, upon further dilution, PG-8k-2080 gave the lowest antimicrobial activity.

  17. Nuclear facility decommissioning and site remedial actions: a selected bibliography. Volume 4

    International Nuclear Information System (INIS)

    Owen, P.T.; Knox, N.P.; Fielden, J.M.; Faust, R.A.

    1983-09-01

    This bibliography of 657 references with abstracts on the subject of nuclear facility decommissioning, uranium mill tailings management, and site remedial actions is the fourth in a series of annual reports prepared for the US Department of Energy, Division of Remedial Action Projects. Foreign as well as domestic documents of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - have been references in this publication. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's Remedial Action Program. Major chapters are: (1) Surplus Facilities Management Program; (2) Nuclear Facilities Decommissioning; (3) Formerly Utilized Sites Remedial Action Program; (4) Uranium Mill Tailings Remedial Action Program; (5) Grand Junction Remedial Action Program; and (6) Uranium Mill Tailings Management. Chapter sections for chapters 1 and 2 include: Design, Planning, and Regulations; Site Surveys; Decontamination Studies; Dismantlement and Demolition; Land Decontamination and Reclamation; Waste Disposal; and General studies. The references within each chapter or section are arranged alphabetically by leading author. References having no individual author are arranged by corporate author, or by title. Indexes are provided for the categories of author, corporate affiliation, title, publication description, geographic location, and keywords. Appendix A lists 264 bibliographic references to literature identified during this reporting period but not abstracted due to time constraints. Title and publication description indexes are given for this appendix. Appendix B defines frequently used acronyms, and Appendix C lists the recipients of this report according to their corporate affiliation

  18. Nuclear facility decommissioning and site remedial actions: a selected bibliography. Volume 4

    Energy Technology Data Exchange (ETDEWEB)

    Owen, P.T.; Knox, N.P.; Fielden, J.M.; Faust, R.A.

    1983-09-01

    This bibliography of 657 references with abstracts on the subject of nuclear facility decommissioning, uranium mill tailings management, and site remedial actions is the fourth in a series of annual reports prepared for the US Department of Energy, Division of Remedial Action Projects. Foreign as well as domestic documents of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - have been references in this publication. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's Remedial Action Program. Major chapters are: (1) Surplus Facilities Management Program; (2) Nuclear Facilities Decommissioning; (3) Formerly Utilized Sites Remedial Action Program; (4) Uranium Mill Tailings Remedial Action Program; (5) Grand Junction Remedial Action Program; and (6) Uranium Mill Tailings Management. Chapter sections for chapters 1 and 2 include: Design, Planning, and Regulations; Site Surveys; Decontamination Studies; Dismantlement and Demolition; Land Decontamination and Reclamation; Waste Disposal; and General studies. The references within each chapter or section are arranged alphabetically by leading author. References having no individual author are arranged by corporate author, or by title. Indexes are provided for the categories of author, corporate affiliation, title, publication description, geographic location, and keywords. Appendix A lists 264 bibliographic references to literature identified during this reporting period but not abstracted due to time constraints. Title and publication description indexes are given for this appendix. Appendix B defines frequently used acronyms, and Appendix C lists the recipients of this report according to their corporate affiliation.

  19. A Guide for Selecting Remedies for Subsurface Releases of Chlorinated Solvents

    Science.gov (United States)

    2011-03-01

    52 Risk-Based Corrective Action ( RBCA ...complex (NRC, 2005). Risk-Based Corrective Action ( RBCA ) In the late 1990s, “Risk-Based Corrective Action” ( RBCA ) become an important decision- making...component of many remediation programs. The RBCA process was formalized in the American Society for Testing and Materials (ASTM) RBCA standard

  20. Improving the biodegradative capacity of subsurface bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Romine, M.F.; Brockman, F.J.

    1993-04-01

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates.

  1. Improving the biodegradative capacity of subsurface bacteria

    International Nuclear Information System (INIS)

    Romine, M.F.; Brockman, F.J.

    1993-04-01

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates

  2. Theoretical stability assessment of uranyl phosphates and apatites: Selection of amendments for in situ remediation of uranium

    Energy Technology Data Exchange (ETDEWEB)

    Raicevic, S. [Institute of Nuclear Sciences VINCA, Radiation and Environmental Protection Laboratory, P.O.Box 522, 11001 Belgrade (Serbia and Montenegro)]. E-mail: raich@beotel.yu; Wright, J.V. [PIMS NW, Inc., 201 North Edison, Suite 226, Richland, WA 99336 (United States); Veljkovic, V. [Institute of Nuclear Sciences VINCA, Center for Multidisciplinary Research and Engineering, P.O.Box 522, 11001 Belgrade (Serbia and Montenegro); Conca, J.L. [Los Alamos National Laboratory, 115 North Main Street, Carlsbad, NM 88220 (United States)

    2006-02-15

    Addition of an amendment or reagent to soil/sediment is a technique that can decrease mobility and reduce bioavailability of uranium (U) and other heavy metals in the contaminated site. According to data from literature and results obtained in field studies, the general mineral class of apatites was selected as a most promising amendment for in situ immobilization/remediation of U. In this work we presented theoretical assessment of stability of U(VI) in four apatite systems (hydroxyapatite (HAP), North Carolina Apatite (NCA), Lisina Apatite (LA), and Apatite II) in order to determine an optimal apatite soil amendment which could be used for in situ remediation of uranium. In this analysis we used a theoretical criterion which is based on calculation of the ion-ion interaction potential, representing the main term of the cohesive energy of the matrix/pollutant system. The presented results of this analysis indicate (i) that the mechanism of immobilization of U by natural apatites depends on their chemical composition and (ii) that all analyzed apatites represent, from the point of view of stability, promising materials which could be used in field remediation of U-contaminated sites.

  3. Theoretical stability assessment of uranyl phosphates and apatites: Selection of amendments for in situ remediation of uranium

    International Nuclear Information System (INIS)

    Raicevic, S.; Wright, J.V.; Veljkovic, V.; Conca, J.L.

    2006-01-01

    Addition of an amendment or reagent to soil/sediment is a technique that can decrease mobility and reduce bioavailability of uranium (U) and other heavy metals in the contaminated site. According to data from literature and results obtained in field studies, the general mineral class of apatites was selected as a most promising amendment for in situ immobilization/remediation of U. In this work we presented theoretical assessment of stability of U(VI) in four apatite systems (hydroxyapatite (HAP), North Carolina Apatite (NCA), Lisina Apatite (LA), and Apatite II) in order to determine an optimal apatite soil amendment which could be used for in situ remediation of uranium. In this analysis we used a theoretical criterion which is based on calculation of the ion-ion interaction potential, representing the main term of the cohesive energy of the matrix/pollutant system. The presented results of this analysis indicate (i) that the mechanism of immobilization of U by natural apatites depends on their chemical composition and (ii) that all analyzed apatites represent, from the point of view of stability, promising materials which could be used in field remediation of U-contaminated sites

  4. Biodegradation and detoxification of olive mill wastewater by selected strains of the mushroom genera Ganoderma and Pleurotus.

    Science.gov (United States)

    Ntougias, Spyridon; Baldrian, Petr; Ehaliotis, Constantinos; Nerud, Frantisek; Antoniou, Theodoros; Merhautová, Věra; Zervakis, Georgios I

    2012-07-01

    Thirty-nine white-rot fungi belonging to nine species of Agaricomycotina (Basidiomycota) were initially screened for their ability to decrease olive-mill wastewater (OMW) phenolics. Four strains of Ganoderma australe, Ganoderma carnosum, Pleurotus eryngii and Pleurotus ostreatus, were selected and further examined for key-aspects of the OMW biodegradation process. Fungal growth in OMW-containing batch cultures resulted in significant decolorization (by 40-46% and 60-65% for Ganoderma and Pleurotus spp. respectively) and reduction of phenolics (by 64-67% and 74-81% for Ganoderma and Pleurotus spp. respectively). COD decrease was less pronounced (12-29%). Cress-seeds germination increased by 30-40% when OMW was treated by Pleurotus strains. Toxicity expressed as inhibition of Aliivibrio fischeri luminescence was reduced in fungal-treated OMW samples by approximately 5-15 times compared to the control. As regards the pertinent enzyme activities, laccase and Mn-independent peroxidase were detected for Ganoderma spp. during the entire incubation period. In contrast, Pleurotus spp. did not exhibit any enzyme activities at early growth stages; instead, high laccase (five times greater than those of Ganoderma spp.) and Mn peroxidases activities were determined at the end of treatment. OMW decolorization by Ganoderma strains was strongly correlated to the reduction of phenolics, whereas P. eryngii laccase activity was correlated with the effluent's decolorization. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Biodegradable Polymers

    OpenAIRE

    Vroman, Isabelle; Tighzert, Lan

    2009-01-01

    Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. ...

  6. A Cercla-Based Decision Model to Support Remedy Selection for an Uncertain Volume of Contaminants at a DOE Facility

    Energy Technology Data Exchange (ETDEWEB)

    Christine E. Kerschus

    1999-03-31

    The Paducah Gaseous Diffusion Plant (PGDP) operated by the Department of Energy is challenged with selecting the appropriate remediation technology to cleanup contaminants at Waste Area Group (WAG) 6. This research utilizes value-focused thinking and multiattribute preference theory concepts to produce a decision analysis model designed to aid the decision makers in their selection process. The model is based on CERCLA's five primary balancing criteria, tailored specifically to WAG 6 and the contaminants of concern, utilizes expert opinion and the best available engineering, cost, and performance data, and accounts for uncertainty in contaminant volume. The model ranks 23 remediation technologies (trains) in their ability to achieve the CERCLA criteria at various contaminant volumes. A sensitivity analysis is performed to examine the effects of changes in expert opinion and uncertainty in volume. Further analysis reveals how volume uncertainty is expected to affect technology cost, time and ability to meet the CERCLA criteria. The model provides the decision makers with a CERCLA-based decision analysis methodology that is objective, traceable, and robust to support the WAG 6 Feasibility Study. In addition, the model can be adjusted to address other DOE contaminated sites.

  7. A Cercla-Based Decision Model to Support Remedy Selection for an Uncertain Volume of Contaminants at a DOE Facility

    International Nuclear Information System (INIS)

    Christine E. Kerschus

    1999-01-01

    The Paducah Gaseous Diffusion Plant (PGDP) operated by the Department of Energy is challenged with selecting the appropriate remediation technology to cleanup contaminants at Waste Area Group (WAG) 6. This research utilizes value-focused thinking and multiattribute preference theory concepts to produce a decision analysis model designed to aid the decision makers in their selection process. The model is based on CERCLA's five primary balancing criteria, tailored specifically to WAG 6 and the contaminants of concern, utilizes expert opinion and the best available engineering, cost, and performance data, and accounts for uncertainty in contaminant volume. The model ranks 23 remediation technologies (trains) in their ability to achieve the CERCLA criteria at various contaminant volumes. A sensitivity analysis is performed to examine the effects of changes in expert opinion and uncertainty in volume. Further analysis reveals how volume uncertainty is expected to affect technology cost, time and ability to meet the CERCLA criteria. The model provides the decision makers with a CERCLA-based decision analysis methodology that is objective, traceable, and robust to support the WAG 6 Feasibility Study. In addition, the model can be adjusted to address other DOE contaminated sites

  8. Remedial action plan and site design for stabilization of the inactive uranium processing site at Naturita, Colorado. Remedial Action Selection Report, Appendix B of Attachment 2: Geology report, Final

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    The uranium processing site near Naturita, Colorado, is one of 24 inactive uranium mill sites designated to be cleaned up by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), 42 USC {section} 7901 et seq. Part of the UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). Included in the RAP is this Remedial Action Selection Report (RAS), which describes the proposed remedial action for the Naturita site. An extensive amount of data and supporting information has been generated and evaluated for this remedial action. These data and supporting information are not incorporated into this single document but are included or referenced in the supporting documents. The RAP consists of this RAS and four supporting documents or attachments. This Attachment 2, Geology Report describes the details of geologic, geomorphic, and seismic conditions at the Dry Flats disposal site.

  9. Remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Lowman, Idaho: Remedial action selection report for the Lowman UMTRA project site, Idaho

    International Nuclear Information System (INIS)

    Matthews, M.L.; Nagel, J.

    1991-09-01

    The inactive uranium mill tailings site near Lowman, Idaho, was designated as one of 24 abandoned uranium tailings sites to be remediated by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). The UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE's remedial action plan and certify that the remedial action complies with the standards promulgated by the US Environmental Protection Agency (EPA). The remedial action plan (RAP), which includes this remedial action selection report (RAS), has been developed to serve a two-fold purpose. First, it describes the activities that are proposed by the DOE to accomplish long-term stabilization and control of residual radioactive materials at the inactive uranium processing site near Lowman, Idaho. Second, this document and the remainder of the RAP, upon concurrence and execution by the DOE, the State of Idaho, and the NRC, becomes Appendix B of the Cooperative Agreement (No. DE-FC04-85AL20535) between the DOE and the State of Idaho

  10. Designing of Biodegradable and Biocompatible Release and Delivery Systems of Selected Antioxidants Used in Cosmetology.

    Science.gov (United States)

    Maksymiak, Magdalena; Debowska, Renata; Bazela, Karolina; Dzwigalowska, Agata; Orchel, Arkadiusz; Jelonek, Katarzyna; Dolegowska, Barbara; Kowalczuk, Marek; Adamus, Grazyna

    2015-11-09

    Conjugates of antioxidants p-anisic (p-AA) and vanillic (VA) acids with nontoxic, biocompatible, and biodegradedable oligo-(R,S)-(3-hydoxybutyrate) carrier were synthesized, and their structural and biological characterization was performed. The molecular structure of the bioconjugates, in which antioxidants are covalently bonded with oligo(3-hydroxybutyrate) (OHB) chains, has been proven by mass spectrometry supported by NMR. The bioconjugate hydrolytic degradation studies allowed gaining thorough insight into the hydrolysis process and confirmed the release of p-AA and VA. In vitro studies demonstrated that all of the conjugates studied were well tolerated by KB and HaCaT cell lines, as they had no marked cytotoxicity, while conjugates with a relatively short OHB carrier are optimal to support keratinocyte function. The preliminary study of the biological activity confirmed the protective effect of VA-OHB conjugates against H2O2-induced lipid peroxidation in human keratinocytes (HaCaT). It was also demonstrated that the selected bioconjugates can penetrate all layers of the skin, which shows their functionality and opens up their potential application in cosmetology.

  11. Approach for selecting the best remediation option for a closed uranium mine in Slovenia

    International Nuclear Information System (INIS)

    Kontiae, B.

    1999-01-01

    For uranium mine and mill at Zirovski vrh, Slovenia, which stopped operating in July 1990, four remediation options were evaluated. Basically, these options were close-down alternatives focusing on final disposition of the residues, primarily mill tailings. A multi-attribute evaluation approach was applied for the comparison between alternatives and as a decision support. The main considerations were given to the economy of the alternatives and their environmental and health impacts. Altogether, fifty seven basic attributes, organized in an evaluation (decision) tree, were applied. In the paper, results of the first two iterations of the evaluation are presented. The third iteration, which is presently under execution and involves more thorough long-term performance and uncertainty assessment associated to mill tailings disposal, are also briefly discussed. (author)

  12. Evaluation of physicochemical and biodegradability properties of selected nigerian non-edible oilseeds as potential cutting fluids

    International Nuclear Information System (INIS)

    Jayeoye, T.J.

    2015-01-01

    This paper reports evaluation of physicochemical and biodegradability properties of selectednon edible Nigerian oilseeds as a potential cutting fluid. Oil extraction process was carried on the oilseeds, with physicochemical parameters and biodegradability of the extracts were equally assessed. The established physicochemical parameters were percentage oil yield (5.58-61.8%), specific gravity (0.86-0.94), acid value (2.89-18.2 mgKOH/g), iodine value (15.7-104 mg iodine/g), peroxide value (1.35-10.9 mg/g oil), saponification value (173-286 mg KOH/g) and viscosity (37.9-53.1centipoises), while biodegradability ranged between (50.0-63.8%) in comparison with the mineral oil with values less than 20%. Based on this study, the oil extracts of Caesalpinia bonduc and Calophyllum inophyllum appeared to be the most suitable as potential cutting fluids for further formulation studies and machining trials. (author)

  13. Selection of discriminant mid-infrared wavenumbers by combining a naïve Bayesian classifier and a genetic algorithm: Application to the evaluation of lignocellulosic biomass biodegradation.

    Science.gov (United States)

    Rammal, Abbas; Perrin, Eric; Vrabie, Valeriu; Assaf, Rabih; Fenniri, Hassan

    2017-07-01

    Infrared spectroscopy provides useful information on the molecular compositions of biological systems related to molecular vibrations, overtones, and combinations of fundamental vibrations. Mid-infrared (MIR) spectroscopy is sensitive to organic and mineral components and has attracted growing interest in the development of biomarkers related to intrinsic characteristics of lignocellulose biomass. However, not all spectral information is valuable for biomarker construction or for applying analysis methods such as classification. Better processing and interpretation can be achieved by identifying discriminating wavenumbers. The selection of wavenumbers has been addressed through several variable- or feature-selection methods. Some of them have not been adapted for use in large data sets or are difficult to tune, and others require additional information, such as concentrations. This paper proposes a new approach by combining a naïve Bayesian classifier with a genetic algorithm to identify discriminating spectral wavenumbers. The genetic algorithm uses a linear combination of an a posteriori probability and the Bayes error rate as the fitness function for optimization. Such a function allows the improvement of both the compactness and the separation of classes. This approach was tested to classify a small set of maize roots in soil according to their biodegradation process based on their MIR spectra. The results show that this optimization method allows better discrimination of the biodegradation process, compared with using the information of the entire MIR spectrum, the use of the spectral information at wavenumbers selected by a genetic algorithm based on a classical validity index or the use of the spectral information selected by combining a genetic algorithm with other methods, such as Linear Discriminant Analysis. The proposed method selects wavenumbers that correspond to principal vibrations of chemical functional groups of compounds that undergo degradation

  14. On using residual risk to assess the cost effectiveness and health protectiveness of remedy selection at superfund sites

    International Nuclear Information System (INIS)

    Katsumata, Peter T.; Kastenberg, William E.

    1998-01-01

    This article examines the importance of determining residual risk and its impact on remedy selection at Superfund Sites. Within this examination, risks are assessed using probabilistic models that incorporate the uncertainty and variability of the input parameters, and utilize parameter distributions based on current and applicable site-specific data. Monte Carlo methods are used to propagate these uncertainties and variabilities through the risk calculations resulting in a distribution for the estimate of both risk and residual risk. Such an approach permits an informed decision based on a broad information base which involves considering the entire uncertainty distribution of risk rather than a point estimate for each exposure scenario. Using the probabilistic risk estimates, with current and applicable site-specific data, alternative decisions regarding cleanup are obtained for two Superfund Sites

  15. Insights on the criteria of selection of vegetable and mineral dielectric fluids used in power transformers on the basis of their biodegradability and toxicity assessments.

    Science.gov (United States)

    Módenes, Aparecido Nivaldo; Sanderson, Karina; Trigueros, Daniela Estelita Goes; Schuelter, Adilson Ricken; Espinoza-Quiñones, Fernando Rodolfo; Neves, Camila Vargas; Zanão Junior, Luiz Antônio; Kroumov, Alexander Dimitrov

    2018-05-01

    Leakage of transformer dielectric fluids is a concern because it may pose a risk of environmental contamination. In this study, the deleterious effects of vegetable and mineral dielectric fluids in water bodies were investigated using biodegradability and acute toxicity tests with Danio rerio and Artemia salina. Regarding biodegradability, all four tested vegetable oils (soy, canola, sunflower and crambe) were considered as easily biodegradable, presenting degradation rates significantly higher than the Lubrax-type mineral fluid. Acute toxicity tests were performed in two separate experiments without solution renewal. In the first experiment, the organisms were exposed in direct contact to different concentrations of vegetable (soy) and mineral (Lubrax) oils. Total soy-type vegetable oil has a higher toxic effect than Lubrax-type mineral oil. In the second experiment, the organisms were exposed to increasing percentages of the water-soluble fraction (WSF) of both types of tested oils. The LC 50 values for the water-soluble fraction of the Lubrax-type mineral oil were about 5 and 8% for the Danio rerio and Artemia salina bioindicators, respectively, whereas the vegetable oil did not present toxic effect, regardless of its WSF. These results have shown that a strict selection of dielectric fluids and monitoring the leakage from power transformers is a serious duty of environmental protection agencies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Sorption and biodegradation of selected benzotriazoles and hydroxybenzothiazole in activated sludge and estimation of their fate during wastewater treatment

    DEFF Research Database (Denmark)

    Mazioti, Aikaterini A.; Stasinakis, Athanasios S.; Gatidou, Georgia

    2015-01-01

    Biodegradation of benzotriazole (BTR), 5-chlorobenzotriazole (CBTR), xylytriazole (XTR), 4-methyl-1H-benzotriazole (4TTR), 5-methy-1H-lbenzotriazole (5TTR) and 2-hydroxybenzothiazole (OHBTH) was studied in activated sludge batch experiments under aerobic and anoxic conditions, presence of organic...

  17. Dopamine selectively remediates 'model-based' reward learning: a computational approach.

    Science.gov (United States)

    Sharp, Madeleine E; Foerde, Karin; Daw, Nathaniel D; Shohamy, Daphna

    2016-02-01

    Patients with loss of dopamine due to Parkinson's disease are impaired at learning from reward. However, it remains unknown precisely which aspect of learning is impaired. In particular, learning from reward, or reinforcement learning, can be driven by two distinct computational processes. One involves habitual stamping-in of stimulus-response associations, hypothesized to arise computationally from 'model-free' learning. The other, 'model-based' learning, involves learning a model of the world that is believed to support goal-directed behaviour. Much work has pointed to a role for dopamine in model-free learning. But recent work suggests model-based learning may also involve dopamine modulation, raising the possibility that model-based learning may contribute to the learning impairment in Parkinson's disease. To directly test this, we used a two-step reward-learning task which dissociates model-free versus model-based learning. We evaluated learning in patients with Parkinson's disease tested ON versus OFF their dopamine replacement medication and in healthy controls. Surprisingly, we found no effect of disease or medication on model-free learning. Instead, we found that patients tested OFF medication showed a marked impairment in model-based learning, and that this impairment was remediated by dopaminergic medication. Moreover, model-based learning was positively correlated with a separate measure of working memory performance, raising the possibility of common neural substrates. Our results suggest that some learning deficits in Parkinson's disease may be related to an inability to pursue reward based on complete representations of the environment. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Highly-selective and Regenerable Ion Exchange for Perchlorate Remediation, Recovery, and Environmental Forensics

    Science.gov (United States)

    Gu, B.; Brown, G.

    2007-12-01

    Perchlorate (ClO4-) has recently emerged as a widespread contaminant found in drinking water and groundwater supplies in the United States and is known to disrupt thyroid function by inhibiting iodide uptake. Among various treatment technologies, the highly-selective and regenerable ion-exchange technology has recently been developed at ORNL for removing ClO4- from contaminated water. The selective ion exchange technology relies on a unique, highly specific resin to trap ClO4- from contaminated water. The treatment system is then regenerated and perchlorate is destroyed. The reaction that destroys ClO4- produces Cl- and Fe(III) that are used to regenerate the resin, resulting in practically zero secondary waste production. In comparison with conventional non-selective ion-exchange technology, this new treatment process is expected to result in not only a reduced O&M cost but also the elimination of the disposal of hazardous wastes containing perchlorate. Additionally, the selective and regenerable ion exchange technology has allowed the quantitative recovery of perchlorate from contaminated water for reuse, or from other environmental matrices such as sediment, groundwater, and salt deposits for perchlorate isotopic and source identification. Naturally-forming perchlorate has been found to contain distinct oxygen and chlorine isotope signatures or anomalies as compared with anthropogenic perchlorate and can thus provide unambiguous identification of the sources of perchlorate contamination as a powerful tool for the forensics of perchlorate in the environment.

  19. Alternate site selection process for UMTRA [Uranium Mill Tailings Remedial Action] project sites

    International Nuclear Information System (INIS)

    1988-06-01

    The purpose of this document is to describe the guidelines and processes to be used by the Department of Energy (DOE) with input from the affected states and tribes to select alternate disposal sites in compliance with each established cooperative agreement. This document supersedes two previous DOE documents, Criteria for Evaluating Disposal Sites (DOE, 1982) and Alternate Site Selection Process (ASSP) for UMTRA Project Sites (DOE, 1986). This revision of the ASSP was prepared in response to the proposed groundwater protection standards that amend 40 CF 192. The principal modifications are to the ASSP screening criteria for hydrological and geological conditions at candidate disposal sites. The revised screening and selection criteria will assist the project in selecting disposal sites where the probability of compliance with the proposed groundwater standards is high. The ASSP described in Section 2.0 consists of three phases: Phases I -- designation of a search region; Phase II -- preliminary screening of the designated search region; and Phase III -- identification and evaluation of candidate sites. Section 3.0 discusses how the results of the ASSP will be reported. This process provides a technically sound and publicly defensible approach for identifying potentially suitable disposal sites. 4 refs., 1 fig., 3 tabs

  20. Selected properties of biodegradable material produced from thermoplastic starch with by-products of food industry addition

    Directory of Open Access Journals (Sweden)

    Zdybel Ewa

    2017-06-01

    Full Text Available In this work extrusion process were used to create thermoplastic starch and to mix obtained starch with linen, quince and apple pomace at the same time. Obtained starch beads were formed in shapes. In experimental material was determined thermal conductivity, water absorption and the solubility in water. It is possible to get the biodegradable material produced from thermoplastic starch with an addition of fruit pomace. Adding pomace and glycerine to the biodegradable material made from starch change of susceptibility on water action. In the case of materials containing pomace, glycerine addition decreases the susceptibility on water action compared to the material manufactured with pomace addition but without glycerine. In the material containing pomace, glycerine addition caused the increase of the thermal insulation time compared to the material with pomace but no glycerine in it.

  1. Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill Tailings Site, Maybell, Colorado. Remedial action selection report: Attachment 2, Geology report, Final

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    The Maybell uranium mill tailings site is 25 miles (mi) (40 kilometers [km]) west of the town of Craig, Colorado, in Moffat County, in the northwestern part of the state. The unincorporated town of Maybell is 5 road mi (8 km) southwest of the site. The designated site covers approximately 110 acres (ac) (45 hectares [ha]) and consists of a concave-shaped tailings pile and rubble from the demolition of the mill buildings buried in the former mill area. Contaminated materials at the Maybell processing site include the tailings pile, which has an average depth of 20 feet (ft) (6 meters [m]) and contains 2.8 million cubic yards (yd{sup 3}) (2.1 million cubic meters [m{sup 3}]) of tailings. The former mill processing area is on the north side of the site and contains 20,000 yd{sup 3} (15,000 m{sup 3}) of contaminated demolition debris. Off-pile contamination is present and includes areas adjacent to the tailings pile, as well as contamination dispersed by wind and surface water flow. The volume of off-pile contamination to be placed in the disposal cell is 550,000 yd{sup 3} (420,000 m{sup 3}). The total volume of contaminated materials to be disposed of as part of the remedial action is estimated to be 3.37 million yd{sup 3} (2.58 million m{sup 3}). Information presented in this Final Remedial Action Plan (RAP) and referenced in supporting documents represents the current disposal cell design features and ground water compliance strategy proposed by the US Department of Energy (DOE) for the Maybell, Colorado, tailings site. Both the disposal cell design and the ground water compliance strategy have changed from those proposed prior to the preliminary final RAP document as a result of prudent site-specific technical evaluations.

  2. Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill Tailings Site, Maybell, Colorado. Remedial action selection report: Attachment 2, Geology report, Final

    International Nuclear Information System (INIS)

    1994-06-01

    The Maybell uranium mill tailings site is 25 miles (mi) (40 kilometers [km]) west of the town of Craig, Colorado, in Moffat County, in the northwestern part of the state. The unincorporated town of Maybell is 5 road mi (8 km) southwest of the site. The designated site covers approximately 110 acres (ac) (45 hectares [ha]) and consists of a concave-shaped tailings pile and rubble from the demolition of the mill buildings buried in the former mill area. Contaminated materials at the Maybell processing site include the tailings pile, which has an average depth of 20 feet (ft) (6 meters [m]) and contains 2.8 million cubic yards (yd 3 ) (2.1 million cubic meters [m 3 ]) of tailings. The former mill processing area is on the north side of the site and contains 20,000 yd 3 (15,000 m 3 ) of contaminated demolition debris. Off-pile contamination is present and includes areas adjacent to the tailings pile, as well as contamination dispersed by wind and surface water flow. The volume of off-pile contamination to be placed in the disposal cell is 550,000 yd 3 (420,000 m 3 ). The total volume of contaminated materials to be disposed of as part of the remedial action is estimated to be 3.37 million yd 3 (2.58 million m 3 ). Information presented in this Final Remedial Action Plan (RAP) and referenced in supporting documents represents the current disposal cell design features and ground water compliance strategy proposed by the US Department of Energy (DOE) for the Maybell, Colorado, tailings site. Both the disposal cell design and the ground water compliance strategy have changed from those proposed prior to the preliminary final RAP document as a result of prudent site-specific technical evaluations

  3. Remediation and selective recovery of metals from acidic mine waters using novel modular bioreactors.

    Science.gov (United States)

    Hedrich, Sabrina; Johnson, D Barrie

    2014-10-21

    Mine waters are widely regarded as environmental pollutants, but are also potential sources of valuable metals. Water draining the Maurliden mine (Sweden) is highly acidic (pH 2.3) and rich in zinc (∼ 460 mg L(-1)) and iron (∼ 400 mg L(-1)), and contains smaller concentrations (0.3-49 mg L(-1)) of other transition metals and arsenic. We have developed novel techniques that promote the concurrent amelioration of acidic waste waters and selective recovery of metals, and have used these systems to treat synthetic Maurliden mine water in the laboratory. The two major metals present were removed via controlled biomineralization: zinc as ZnS in a sulfidogenic bioreactor, and iron as schwertmannite by microbial iron oxidation and precipitation of ferric iron. A small proportion (∼ 11%) of the schwertmannite produced was used to remove arsenic as the initial step in the process, and other chalcophilic metals (copper, cadmium and cobalt) were removed (as sulfides) in the stage 1 metal sulfide precipitation reactor. Results from this work have demonstrated that modular biomineralization units can be effective at processing complex mine waters and generating metal products that may be recycled. The economic and environmental benefits of using an integrated biological approach for treating metal-rich mine waters is discussed.

  4. Oil biodegradation

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Langenhoff, Alette A.M.; Smit, Martijn P.J.; Eenennaam, van Justine S.; Murk, Tinka; Rijnaarts, Huub H.M.

    2017-01-01

    During the Deepwater Horizon (DwH) oil spill, interactions between oil, clay particles and marine snow lead to the formation of aggregates. Interactions between these components play an important, but yet not well understood, role in biodegradation of oil in the ocean water. The aim of this study

  5. The effects of PLA biodegradable and polypropylene nonwoven crop mulches on selected components of tomato grown in the field

    Directory of Open Access Journals (Sweden)

    Zawiska Izabela

    2014-12-01

    Full Text Available The results of two years (2010-2011 of field studies using two types of nonwoven mulches (one biodegradable, polylactic acid PLA 54 g m-2, and traditional polypropylene PP 50 g m-2 on the yield and quality of tomato are presented. Seeds of tomato (‘Mundi’ F1 were sown in a greenhouse, in containers filled with perlite and sand, and then the plants at the cotyledon stage were replanted in multipot trays filled with substrate for vegetable plants. In the last week of May, seedlings were planted on mulches in the field at a spacing of 50 × 100 cm. The mulch was maintained throughout the growing season. A plot that remained unmulched served as the control. Tomatoes were harvested once a week. The fruits were evaluated for L-ascorbic acid, dry matter, soluble sugars and nitrate content. In 2011, the analysis of the plant material showed that the concentration of L-ascorbic acid was about 23% higher in the tomato fruits harvested from plants grown on biodegradable PLA 61 g m-2 mulch in comparison to the control. A similar effect was demonstrated for the soluble sugar concentration in 2011 for both types of nonwovens.

  6. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 13: Part 2, Indexes. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Goins, L.F.; Webb, J.R.; Cravens, C.D.; Mallory, P.K.

    1992-09-01

    This is part 2 of a bibliography on nuclear facility decommissioning and site remedial action. This report contains indexes on the following: authors, corporate affiliation, title words, publication description, geographic location, subject category, and key word.

  7. Tuning the processability, morphology and biodegradability of clay incorporated PLA/LLDPE blends via selective localization of nanoclay induced by melt mixing sequence

    Directory of Open Access Journals (Sweden)

    S. H. Jafari

    2013-01-01

    Full Text Available Polylactic acid (PLA/linear low density polyethylene (LLDPE blend nanocomposites based on two different commercial-grade nanoclays, Cloisite® 30B and Cloisite® 15A, were produced via different melt mixing procedures in a counter-rotating twin screw extruder. The effects of mixing sequence and clay type on morphological and rheological behaviors as well as degradation properties of the blends were investigated. The X-ray diffraction (XRD results showed that generally the level of exfoliation in 30B based nanocomposites was better than 15A based nanocomposites. In addition, due to difference in hydrophilicity and kind of modifiers in these two clays, the effect of 30B on refinement of dispersed phase and enhancement of biodegradability of PLA/LLDPE blend was much more remarkable than that of 15A nanoclay. Unlike the one step mixing process, preparation of nanocomposites via a two steps mixing process improved the morphology. Based on the XRD and TEM (transmission electron microscopic results, it is found that the mixing sequence has a remarkable influence on dispersion and localization of the major part of 30B nanoclay in the PLA matrix. Owing to the induced selective localization of nanoclays in PLA phase, the nanocomposites prepared through a two steps mixing sequence exhibited extraordinary biodegradability, refiner morphology and better melt elasticity.

  8. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 13: Part 1, Main text. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Goins, L.F.; Webb, J.R.; Cravens, C.D.; Mallory, P.K.

    1992-09-01

    This publication contains 1035 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions. These citations constitute the thirteenth in a series of reports prepared annually for the US Department of Energy (DOE) Environmental Restoration programs. Citations to foreign and domestic literature of all types. There are 13 major sections of the publication, including: (1) DOE Decontamination and Decommissioning Program; (2) Nuclear Facilities Decommissioning; (3) DOE Formerly Utilized Sites Remedial Action Program; (4) DOE Uranium Mill Tailings Remedial Action Project; (5) Uranium Mill Tailings Management; (6) DOE Environmental Restoration Program; (7) DOE Site-Specific Remedial Actions; (8) Contaminated Site Restoration; (9) Remediation of Contaminated Soil and Groundwater; (10) Environmental Data Measurements, Management, and Evaluation; (11) Remedial Action Assessment and Decision-Making; (12) Technology Development and Evaluation; and (13) Environmental and Waste Management Issues. Bibliographic references are arranged in nine subject categories by geographic location and then alphabetically by first author, corporate affiliation, or publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and key word.

  9. Anaerobic biodegradability of macropollutants

    DEFF Research Database (Denmark)

    Angelidaki, Irini

    2002-01-01

    A variety of test procedures for determination of anaerobic biodegradability has been reported. This paper reviews the methods developed for determination of anaerobic biodegradability of macro-pollutants. Anaerobic biodegradability of micro-pollutants is not included. Furthermore, factors...

  10. Full-scale performance of selected starch-based biodegradable polymers in sludge dewatering and recommendation for applications.

    Science.gov (United States)

    Zhou, Kuangxin; Stüber, Johan; Schubert, Rabea-Luisa; Kabbe, Christian; Barjenbruch, Matthias

    2018-01-01

    Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the use of starch-based polymers for full-scale dewatering of municipal sewage sludge. The laboratory-scale and pilot-scale trials paved the way for full-scale trials at three WWTPs in Germany. The general feasibility of applying starch-based 'green' polymers in full-scale centrifugation was demonstrated. Depending on the sludge type and the process used, the substitution potential was up to 70%. Substitution of 20-30% of the polyacrylamide (PAM)-based polymer was shown to achieve similar total solids (TS) of the dewatered sludge. Optimization of operational parameters as well as machinery set up in WWTPs is recommended in order to improve the shear stability force of sludge flocs and to achieve higher substitution potential. This study suggests that starch-based biodegradable polymers have great potential as alternatives to synthetic polymers in sludge dewatering.

  11. Enhanced phytoextraction of uranium and selected heavy metals by Indian mustard and ryegrass using biodegradable soil amendments

    Energy Technology Data Exchange (ETDEWEB)

    Duquene, L. [SCK-CEN, Biosphere Impact Studies, Boeretang 200, B-2400 Mol (Belgium); Vandenhove, H. [SCK-CEN, Biosphere Impact Studies, Boeretang 200, B-2400 Mol (Belgium)], E-mail: hvandenh@sckcen.be; Tack, F.; Meers, E. [Ghent University, Laboratory for Analytical Chemistry and Applied Ecochemistry, Coupure Links 653, B-9000 Gent (Belgium); Baeten, J. [Katholieke Hogeschool Kempen, Department of Health-Care and Chemistry, Kleinhoefstraat 4, B-2440 Geel (Belgium); Wannijn, J. [SCK-CEN, Biosphere Impact Studies, Boeretang 200, B-2400 Mol (Belgium)

    2009-02-15

    The applicability of biodegradable amendments in phytoremediation to increase the uptake of uranium (U), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn) by Indian mustard (Brassica juncea) and ryegrass (Lolium perenne) was tested in a greenhouse experiment. Plants were cultivated during one month on two soils with naturally or industrially increased contaminant levels of U. Treatments with citric acid, NH{sub 4}-citrate/citric acid, oxalic acid, S,S-ethylenediamine disuccinic acid (EDDS) or nitrilotriacetic acid (NTA) at a rate of 5 mmol kg{sup -1} dry soil caused increases in soil solution concentrations that were up to 18 times higher for U and up to 1570 times higher for other heavy metals, compared to the controls. Shoot concentrations increased to a much smaller extent. With EDDS, 19-, 34-, and 37-fold increases were achieved in shoots of Indian mustard for U, Pb and Cu, respectively. The increases in plant uptake of Cd, Cr and Zn were limited to a factor of four at most. Ryegrass generally extracted less U and metals than Indian mustard. Despite a marked increase of U and metal concentrations in shoots after addition of amendments, the estimated time required to obtain an acceptable reduction in soil contaminant concentrations was impractically long. Only for Cu and Zn in one of the studied soils, could the Flemish standards for clean soil theoretically be attained in less than 100 years.

  12. Enhanced phytoextraction of uranium and selected heavy metals by Indian mustard and ryegrass using biodegradable soil amendments.

    Science.gov (United States)

    Duquène, L; Vandenhove, H; Tack, F; Meers, E; Baeten, J; Wannijn, J

    2009-02-15

    The applicability of biodegradable amendments in phytoremediation to increase the uptake of uranium (U), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn) by Indian mustard (Brassica juncea) and ryegrass (Lolium perenne) was tested in a greenhouse experiment. Plants were cultivated during one month on two soils with naturally or industrially increased contaminant levels of U. Treatments with citric acid, NH4-citrate/citric acid, oxalic acid, S,S-ethylenediamine disuccinic acid (EDDS) or nitrilotriacetic acid (NTA) at a rate of 5 mmol kg(-1) dry soil caused increases in soil solution concentrations that were up to 18 times higher for U and up to 1570 times higher for other heavy metals, compared to the controls. Shoot concentrations increased to a much smaller extent. With EDDS, 19-, 34-, and 37-fold increases were achieved in shoots of Indian mustard for U, Pb and Cu, respectively. The increases in plant uptake of Cd, Cr and Zn were limited to a factor of four at most. Ryegrass generally extracted less U and metals than Indian mustard. Despite a marked increase of U and metal concentrations in shoots after addition of amendments, the estimated time required to obtain an acceptable reduction in soil contaminant concentrations was impractically long. Only for Cu and Zn in one of the studied soils, could the Flemish standards for clean soil theoretically be attained in less than 100 years.

  13. Biodegradation and bioremediation

    DEFF Research Database (Denmark)

    Albrechtsen, H.-J.

    1996-01-01

    Anmeldelse af Alexander,M.: Biodegradation and bioremediation. Academic Press, Sandiego, USA, 1994......Anmeldelse af Alexander,M.: Biodegradation and bioremediation. Academic Press, Sandiego, USA, 1994...

  14. Hybrid Titanium/Biodegradable Polymer Implants with an Hierarchical Pore Structure as a Means to Control Selective Cell Movement

    Science.gov (United States)

    Vrana, Nihal Engin; Dupret, Agnès; Coraux, Christelle; Vautier, Dominique; Debry, Christian; Lavalle, Philippe

    2011-01-01

    In order to improve implant success rate, it is important to enhance their responsiveness to the prevailing conditions following implantation. Uncontrolled movement of inflammatory cells and fibroblasts is one of these in vivo problems and the porosity properties of the implant have a strong effect on these. Here, we describe a hybrid system composed of a macroporous titanium structure filled with a microporous biodegradable polymer. This polymer matrix has a distinct porosity gradient to accommodate different cell types (fibroblasts and epithelial cells). The main clinical application of this system will be the prevention of restenosis due to excessive fibroblast migration and proliferation in the case of tracheal implants. Methodology/Principal Findings A microbead-based titanium template was filled with a porous Poly (L-lactic acid) (PLLA) body by freeze-extraction method. A distinct porosity difference was obtained between the inner and outer surfaces of the implant as characterized by image analysis and Mercury porosimetry (9.8±2.2 µm vs. 36.7±11.4 µm, p≤0.05). On top, a thin PLLA film was added to optimize the growth of epithelial cells, which was confirmed by using human respiratory epithelial cells. To check the control of fibroblast movement, PKH26 labeled fibroblasts were seeded onto Titanium and Titanium/PLLA implants. The cell movement was quantified by confocal microscopy: in one week cells moved deeper in Ti samples compared to Ti/PLLA. Conclusions In vitro experiments showed that this new implant is effective for guiding different kind of cells it will contact upon implantation. Overall, this system would enable spatial and temporal control over cell migration by a gradient ranging from macroporosity to nanoporosity within a tracheal implant. Moreover, mechanical properties will be dependent mainly on the titanium frame. This will make it possible to create a polymeric environment which is suitable for cells without the need to meet mechanical

  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...

  16. Selective isolation of potentially phosphate-mobilizing, biosurfactant-producing and biodegradative bacteria associated with a sub-Arctic, terricolous lichen, Peltigera membranacea.

    Science.gov (United States)

    Sigurbjörnsdóttir, Margrét Auður; Vilhelmsson, Oddur

    2016-06-01

    Lichens are the symbiotic association of fungi and a photosynthetic partner. However, non-phototrophic bacteria are also present and thought to comprise an essential part of the lichen symbiosis, although their roles in the symbiosis are still poorly understood. In this study, we isolated and characterized 110 non-phototrophic bacterial lichen associates from thalli of the terricolous lichen Peltigera membranacea The biodegradative and other nutrient-scavenging properties studied among selected isolates were phosphate mobilization, biosurfactant production and degradation of napthalene and several biopolymers, suggesting organic and inorganic nutrient scavenging as roles for bacteria in the lichen symbiotic association. Identification by partial 16S rRNA gene sequencing revealed that the isolates comprised 18 genera within the Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes, many with high similarities with bacteria typically associated with the plant and rhizosphere environments, could suggest that plants may be important sources of terricolous lichen-associated bacteria, or vice versa. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Selective adsorption of Pb (II) ions by amylopectin-g-poly (acrylamide-co-acrylic acid): A bio-degradable graft copolymer.

    Science.gov (United States)

    Sasmal, Dinabandhu; Maity, Jayanta; Kolya, Haradhan; Tripathy, Tridib

    2017-04-01

    Amylopectin-g-poly (acrylamide-co-acrylic acid) [AP-g-poly (AM-co-AA)] was synthesised in water medium by using potassium perdisulphate as an initiator. The graft copolymer was characterized by molecular weight determination by size exclusion chromatography (SEC), fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscope (SEM) studies, thermal analysis, measurement of neutralisation equivalent and biodegradation studies. The graft copolymer was used for Pb (II) ion removal from aqueous solution. The Pb (II) ion removal capacity of the graft copolymer was also compared with another laboratory developed graft copolymer Amylopectin-g-poly (acrylamide) (AP-g-PAM). Both the graft copolymers were also used for the competitive metal ions removal with Pb (II)/Cd (II), Pb (II)/Zn (II), Pb (II)/Ni (II), Pb (II)/Cu (II) pairs separately under similar conditions. AP-g-poly (AM-co-AA) showed better Pb (II) ion adsorbing power over AP-g-PAM and also much selective towards Pb (II) ions. The adsorption follows a second order rate equation and Langmuir isotherm model. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 18. Part 1B: Citations with abstracts, sections 10 through 16

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This bibliography contains 3,638 citations with abstracts of documents relevant to environmental restoration, nuclear facility decontamination and decommissioning (D and D), uranium mill tailings management, and site remedial actions. The bibliography contains scientific, technical, financial, and regulatory information that pertains to DOE environmental restoration programs. The citations are separated by topic into 16 sections, including (1) DOE Environmental Restoration Program; (2) DOE D and D Program; (3) Nuclear Facilities Decommissioning; (4) DOE Formerly Utilized sites Remedial Action Program; (5) NORM-Contaminated Site Restoration; (6) DOE Uranium Mill Tailings Remedial Action Project; (7) Uranium Mill Tailings Management; (8) DOE Site-Wide Remedial Actions; (9) DOE Onsite Remedial Action Projects; (10) Contaminated Site Remedial Actions; (11) DOE Underground Storage Tank Remediation; (12) DOE Technology Development, Demonstration, and Evaluation; (13) Soil Remediation; (14) Groundwater Remediation; (15) Environmental Measurements, Analysis, and Decision-Making; and (16) Environmental Management Issues.

  19. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 18. Part 1A: Citations with abstracts, sections 1 through 9

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This bibliography contains 3,638 citations with abstracts of documents relevant to environmental restoration, nuclear facility decontamination and decommissioning (D and D), uranium mill tailings management, and site remedial actions. The bibliography contains scientific, technical, financial, and regulatory information that pertains to DOE environmental restoration programs. The citations are separated by topic into 16 sections, including (1) DOE Environmental Restoration program; (2) DOE D and D Program; (3) Nuclear Facilities Decommissioning; (4) DOE Formerly Utilized Sites Remedial Action Program; (5) NORM-Contaminated Site Restoration; (6) DOE Uranium Mill Tailings Remedial Action Project; (7) Uranium Mill Tailings Management; (8) DOE Site-Wide Remedial Actions; (9) DOE Onsite Remedial Action Projects; (10) Contaminated Site Remedial Actions; (11) DOE Underground Storage Tank Remediation; (12) DOE Technology Development, Demonstration, and Evaluation; (13) Soil Remediation; (14) Groundwater Remediation; (15) Environmental Measurements, Analysis, and Decision-Making; and (16) Environmental Management Issues.

  20. Chemical Composition of Selected Commercial Herbal Remedies in Relation to Geographical Origin and Inter-Species Diversity.

    Science.gov (United States)

    Konieczynski, Pawel; Viapiana, Agnieszka; Lysiuk, Roman; Wesolowski, Marek

    2018-03-01

    Infusions prepared from medicinal herbs that are rich in flavonoids are very popular herbal remedies in societies of Eastern Europe. Therefore, the content of essential elements together with total flavonoids was analyzed in 65 commercially available samples of herbal drugs originating from Ukraine, Romania, and Belarus. The results showed that metallic elements (in mg kg -1 d.w.) have occurred in the following order: Fe > Mn > Zn > Cu, both for total and water-extractable species. Total flavonoids were determined in the range from 10.0 to 191.8 mg g -1 d.w. Several significant correlations have been found between the analytes, especially among water-extractable Fe with other metals, and total flavonoids and Fe, Zn, and Mn. Analysis of variance has revealed significant differences among studied samples due to their origin from different countries, especially between Belarussian samples and others. Differences owing to belonging to various plant species were also found, as it was noticed in the case of Polygoni aviculare herba in comparison with other botanical plant species. Moreover, multivariate statistical techniques, such as cluster analysis (CA) and principal component analysis (PCA) were used to gather herbal drugs based on similarity of chemical composition. CA grouped the samples into clusters with similar level of elements and total flavonoid contents, and PCA has indicated Hyperici herba, Tiliae flores, and Crataegi fructus as herbal remedies with close concentration of studied elements and flavonoids.

  1. A Short Assessment of Select Remediation Issues at the Russian Research Center-Kurchatov Institute, Moscow, Russia

    International Nuclear Information System (INIS)

    Gephart, Roy E.

    2007-01-01

    At the invitation of the National Academies, Roy Gephart traveled to Russia with an eight-member U.S. team during June, 2008 to participate in a workshop hosted by the National Academies and the Russian Academy of Sciences on radiation contamination and remediation issues in the former Soviet Union. Cleanup problems were assessed by the American participants for six Russian sites: Kurchatov Institute, Lakes 10 and 11 at Mayak, Andreev Bay, Krasnokamensk Mining Enterprise (Siberia), Almaz Mining Enterprise (North Caucasus), and one site for testing peaceful nuclear explosions. Roy lead the Russian Research Center-Kurchatov Institute review session and wrote an assessment of key cleanup issues. Kurchatov is the leading institute in the Former Soviet Union devoted to military and civilian nuclear programs. Founded in 1943 in the outskirts of Moscow, this 100 hectare site of nearly undeveloped, prime real estate is now surrounded by densely populated urban and business districts. Today there are growing concerns over the public safety and environmental security of the site resulting from increasingly obsolete nuclear facilities and a legacy of inadequate waste management practices that resulted in contaminant releases and challenging remediation problems. In addition, there is growing concern over the presence of nuclear facilities within urban areas creating potential targets for terrorist attacks.

  2. A Short Assessment of Select Remediation Issues at the Russian Research Center-Kurchatov Institute, Moscow, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Gephart, Roy E.

    2007-06-01

    At the invitation of the National Academies, Roy Gephart traveled to Russia with an eight-member U.S. team during June, 2008 to participate in a workshop hosted by the National Academies and the Russian Academy of Sciences on radiation contamination and remediation issues in the former Soviet Union. Cleanup problems were assessed by the American participants for six Russian sites: Kurchatov Institute, Lakes 10 and 11 at Mayak, Andreev Bay, Krasnokamensk Mining Enterprise (Siberia), Almaz Mining Enterprise (North Caucasus), and one site for testing peaceful nuclear explosions. Roy lead the Russian Research Center-Kurchatov Institute review session and wrote an assessment of key cleanup issues. Kurchatov is the leading institute in the Former Soviet Union devoted to military and civilian nuclear programs. Founded in 1943 in the outskirts of Moscow, this 100 hectare site of nearly undeveloped, prime real estate is now surrounded by densely populated urban and business districts. Today there are growing concerns over the public safety and environmental security of the site resulting from increasingly obsolete nuclear facilities and a legacy of inadequate waste management practices that resulted in contaminant releases and challenging remediation problems. In addition, there is growing concern over the presence of nuclear facilities within urban areas creating potential targets for terrorist attacks.

  3. GIS-based multi-criteria site selection for zebra mussel cultivation: Addressing end-of-pipe remediation of a eutrophic coastal lagoon ecosystem.

    Science.gov (United States)

    Bagdanavičiūtė, Ingrida; Umgiesser, Georg; Vaičiūtė, Diana; Bresciani, Mariano; Kozlov, Igor; Zaiko, Anastasija

    2018-04-11

    Farming of shellfish and seaweeds is a tested tool for mitigating eutrophication consequences in coastal environments, however as many other marine economic activities it should be a subject of marine spatial planning for designating suitable sites. The present study proposes site selection framework for provisional zebra mussel farming in a eutrophic lagoon ecosystem, aimed primarily at remediation purposes. GIS-based multi-criteria approach was applied, combining data from empirical maps, numerical models and remote sensing to estimate suitability parameters. Site selection and prioritisation of suitable areas considered 15 environmental and socio-economic criteria, which contributed to 4 optimisation models (settlement, growth and survival of mussels, environmental and socio-economic) and 3 predefined scenarios representing provisional goals of mussel cultivation: spat production, biomass production and bioremediation. The relative importance of each criterion was assessed utilizing the Analytical Hierarchy Process. Site suitability index was calculated and the final result of the site selection analysis was summarized for 3 scenarios and overall suitability map. Four suitability classes (unsuitable, least, moderately and most suitable) were applied, and 3 most suitable zones for provisional zebra mussel cultivation with 12 candidate sites were selected accordingly. The integrated approach presented in this study can be adjusted for designating zebra mussel farming sites in other estuarine lagoon ecosystems, or cultivation of other mussel species for bioremediation purposes. The analytical framework and the workflow designed in this study are also adoptable for addressing other aquaculture-related spatial planning issues. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Remedial action plan for the inactive uranium processing site at Naturita, Colorado. Remedial action selection report: Attachment 2, geology report; Attachment 3, ground water hydrology report; Attachment 4, supplemental information

    International Nuclear Information System (INIS)

    1998-03-01

    The uranium processing site near Naturita, Colorado, is one of 24 inactive uranium mill sites designated to be cleaned up by the U.S. Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), 42 USC section 7901 et seq. Part of the UMTRCA requires that the U.S. Nuclear Regulatory Commission (NRC) concur with the DOE's remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the U.S. Environmental Protection Agency (EPA). This RAP serves two purposes. First, it describes the activities that are proposed by the DOE to accomplish remediation and long-term stabilization and control of the radioactive materials at the inactive uranium processing site near Naturita, Colorado. Second, this RAP, upon concurrence and execution by the DOE, the state of Colorado, and the NRC, becomes Appendix B of the cooperative agreement between the DOE and the state of Colorado

  5. Evaluation of ethyl tert-butyl ether biodegradation in a contaminated aquifer by compound-specific isotope analysis and in situ microcosms

    Energy Technology Data Exchange (ETDEWEB)

    Bombach, Petra, E-mail: petra.bombach@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, D-04318 Leipzig (Germany); Isodetect GmbH Leipzig, Deutscher Platz 5b, D-04103 Leipzig (Germany); Nägele, Norbert [Kuvier the Biotech Company S.L., Ctra. N-I, p.k. 234–P.E. INBISA 23" a, E-09001 Burgos (Spain); Rosell, Mònica [UFZ – Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, D-04318 Leipzig (Germany); Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristallografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona (Spain); Richnow, Hans H. [UFZ – Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, D-04318 Leipzig (Germany); Fischer, Anko [Isodetect GmbH Leipzig, Deutscher Platz 5b, D-04103 Leipzig (Germany)

    2015-04-09

    Highlights: • In situ biodegradation of ETBE was investigated in a fuel contaminated aquifer. • Degradation was studied by CSIA and in situ microcosms in combination with TLFA-SIP. • ETBE was degraded when ETBE was the main groundwater contaminant. • ETBE was also degraded in the presence of BTEX and MTBE. • Hydrochemical analysis indicated aerobic and anaerobic ETBE biodegradation. - Abstract: Ethyl tert-butyl ether (ETBE) is an upcoming groundwater pollutant in Europe whose environmental fate has been less investigated, thus far. In the present study, we investigated the in situ biodegradation of ETBE in a fuel-contaminated aquifer using compound-specific stable isotope analysis (CSIA), and in situ microcosms in combination with total lipid fatty acid (TLFA)-stable isotope probing (SIP). In a first field investigation, CSIA revealed insignificant carbon isotope fractionation, but low hydrogen isotope fractionation of up to +14‰ along the prevailing anoxic ETBE plume suggesting biodegradation of ETBE. Ten months later, oxygen injection was conducted to enhance the biodegradation of petroleum hydrocarbons (PH) at the field site. Within the framework of this remediation measure, in situ microcosms loaded with [{sup 13}C{sub 6}]-ETBE (BACTRAP{sup ®}s) were exposed for 119 days in selected groundwater wells to assess the biodegradation of ETBE by TLFA-SIP under the following conditions: (i) ETBE as main contaminant; (ii) ETBE as main contaminant subjected to oxygen injection; (iii) ETBE plus other PH; (iv) ETBE plus other PH subjected to oxygen injection. Under all conditions investigated, significant {sup 13}C-incorporation into microbial total lipid fatty acids extracted from the in situ microcosms was found, providing clear evidence of ETBE biodegradation.

  6. Current knowledge on biodegradable microspheres in drug delivery.

    Science.gov (United States)

    Prajapati, Vipul D; Jani, Girish K; Kapadia, Jinita R

    2015-08-01

    Biodegradable microspheres have gained popularity for delivering a wide variety of molecules via various routes. These types of products have been prepared using various natural and synthetic biodegradable polymers through suitable techniques for desired delivery of various challenging molecules. Selection of biodegradable polymers and technique play a key role in desired drug delivery. This review describes an overview of the fundamental knowledge and status of biodegradable microspheres in effective delivery of various molecules via desired routes with consideration of outlines of various compendial and non-compendial biodegradable polymers, formulation techniques and release mechanism of microspheres, patents and commercial biodegradable microspheres. There are various advantages of using biodegradable polymers including promise of development with different types of molecules. Biocompatibility, low dosage and reduced side effects are some reasons why usage biodegradable microspheres have gained in popularity. Selection of biodegradable polymers and formulation techniques to create microspheres is the biggest challenge in research. In the near future, biodegradable microspheres will become the eco-friendly product for drug delivery of various genes, hormones, proteins and peptides at specific site of body for desired periods of time.

  7. Best conditions for biodegradation of diesel oil by chemometric tools

    OpenAIRE

    Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Héberger, Károly; Kemény, Sándor; Olszanowski, Andrzej; Voelkel, Adam

    2014-01-01

    Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences). These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positiv...

  8. Big Data Challenges of High-Dimensional Continuous-Time Mean-Variance Portfolio Selection and a Remedy.

    Science.gov (United States)

    Chiu, Mei Choi; Pun, Chi Seng; Wong, Hoi Ying

    2017-08-01

    Investors interested in the global financial market must analyze financial securities internationally. Making an optimal global investment decision involves processing a huge amount of data for a high-dimensional portfolio. This article investigates the big data challenges of two mean-variance optimal portfolios: continuous-time precommitment and constant-rebalancing strategies. We show that both optimized portfolios implemented with the traditional sample estimates converge to the worst performing portfolio when the portfolio size becomes large. The crux of the problem is the estimation error accumulated from the huge dimension of stock data. We then propose a linear programming optimal (LPO) portfolio framework, which applies a constrained ℓ 1 minimization to the theoretical optimal control to mitigate the risk associated with the dimensionality issue. The resulting portfolio becomes a sparse portfolio that selects stocks with a data-driven procedure and hence offers a stable mean-variance portfolio in practice. When the number of observations becomes large, the LPO portfolio converges to the oracle optimal portfolio, which is free of estimation error, even though the number of stocks grows faster than the number of observations. Our numerical and empirical studies demonstrate the superiority of the proposed approach. © 2017 Society for Risk Analysis.

  9. Justification for Selecting Level A vs. Level B Personal Protective Equipment to Remediate a Room Containing Concentrated Acids, Bases and Radiological Constituents

    International Nuclear Information System (INIS)

    Hylko, J. M.; Thompson, A. L.; Walter, J. F.; Deecke, T. A.

    2002-01-01

    Selecting the appropriate personal protective equipment (PPE) is based on providing an adequate level of employee protection relative to the task-specific conditions and hazards. PPE is categorized into four ensembles, based on the degree of protection afforded; e.g., Levels A (most restrictive), B, C, and D (least restrictive). What is often overlooked in preparing an ensemble is that the PPE itself can create significant worker hazards; i.e., the greater the level of PPE, the greater the associated risks. Furthermore, there is confusion as to whether a more ''conservative approach'' should always be taken since Level B provides the same level of respiratory protection as Level A but less skin protection. This paper summarizes the Occupational Safety and Health Administration regulations addressing Level A versus Level B, and provides justification for selecting Level B over Level A without under-protecting the employee during a particular remediation scenario. The scenario consisted of an entry team performing (1) an initial entry into a room containing concentrated acids (e.g., hydrofluoric acid), bases, and radiological constituents; (2) sampling and characterizing container contents; and (3) retrieving characterized containers. The invasive nature of the hydrofluoric acid sampling and characterization scenario created a high potential for splash, immersion, and exposure to hazardous vapors, requiring additional skin protection. The hazards associated with this scenario and the chemical nature of hydrofluoric acid provided qualitative evidence to justify Level A. Once the hydrofluoric acid was removed from the room, PPE performance was evaluated against the remaining chemical inventory. If chemical breakthrough from direct contact was not expected to occur and instrument readings confirmed the absence of any hazardous vapors, additional skin protection afforded by wearing a vapor-tight, totally-encapsulated suit was not required. Therefore, PPE performance and

  10. 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.

  11. Remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Falls City, Texas. Remedial action selection report, attachment 2, geology report; attachment 3, groundwater hydrology report; and attachment 4, water resources protection strategy. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-09-01

    The uranium processing site near Falls City, Texas, was one of 24 inactive uranium mill sites designated to be remediated by the U.S. Department of Energy (DOE) under Title I of the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). The UMTRCA requires that the U.S. Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the U.S. Environmental Protection Agency (EPA). The RAP, which includes this summary remedial action selection report (RAS), serves a two-fold purpose. First, it describes the activities proposed by the DOE to accomplish long-term stabilization and control of the residual radioactive materials at the inactive uranium processing site near Falls City, Texas. Second, this document and the remainder of the RAP, upon concurrence and execution by the DOE, the State of Texas, and the NRC, becomes Appendix B of the Cooperative Agreement between the DOE and the State of Texas.

  12. Remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Falls City, Texas. Remedial action selection report, attachment 2, geology report; attachment 3, groundwater hydrology report; and attachment 4, water resources protection strategy. Final report

    International Nuclear Information System (INIS)

    1992-09-01

    The uranium processing site near Falls City, Texas, was one of 24 inactive uranium mill sites designated to be remediated by the U.S. Department of Energy (DOE) under Title I of the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). The UMTRCA requires that the U.S. Nuclear Regulatory Commission (NRC) concur with the DOE's remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the U.S. Environmental Protection Agency (EPA). The RAP, which includes this summary remedial action selection report (RAS), serves a two-fold purpose. First, it describes the activities proposed by the DOE to accomplish long-term stabilization and control of the residual radioactive materials at the inactive uranium processing site near Falls City, Texas. Second, this document and the remainder of the RAP, upon concurrence and execution by the DOE, the State of Texas, and the NRC, becomes Appendix B of the Cooperative Agreement between the DOE and the State of Texas

  13. Remedial action plan for the inactive uranium processing site at Naturita, Colorado. Remedial action selection report: Attachment 2, geology report; Attachment 3, ground water hydrology report; Attachment 4, supplemental information

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The uranium processing site near Naturita, Colorado, is one of 24 inactive uranium mill sites designated to be cleaned up by the U.S. Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), 42 USC {section} 7901 et seq. Part of the UMTRCA requires that the U.S. Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the U.S. Environmental Protection Agency (EPA). This RAP serves two purposes. First, it describes the activities that are proposed by the DOE to accomplish remediation and long-term stabilization and control of the radioactive materials at the inactive uranium processing site near Naturita, Colorado. Second, this RAP, upon concurrence and execution by the DOE, the state of Colorado, and the NRC, becomes Appendix B of the cooperative agreement between the DOE and the state of Colorado.

  14. Operable Unit 3-13, Group 3, Other Surface Soils Remediation Sets 4-6 (Phase II) Remedial Design/Remedial Action Work Plan

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Shanklin

    2006-06-01

    This Remedial Design/Remedial Action Work Plan provides the framework for defining the remedial design requirements, preparing the design documentation, and defining the remedial actions for Waste Area Group 3, Operable Unit 3-13, Group 3, Other Surface Soils, Remediation Sets 4-6 (Phase II) located at the Idaho Nuclear Technology and Engineering Center at the Idaho National Laboratory. This plan details the design developed to support the remediation and disposal activities selected in the Final Operable Unit 3-13, Record of Decision.

  15. Grey water biodegradability.

    Science.gov (United States)

    Ghunmi, Lina Abu; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

    2011-02-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different conditions in the biodegradation test. The maximum aerobic and anaerobic biodegradability and conversion rate for the different COD fractions is determined. The results show that, on average, dormitory grey water COD fractions are 28% suspended, 32% colloidal and 40% dissolved. The studied factors incubation time, inoculum addition and temperature are influencing the determined biodegradability. The maximum biodegradability and biodegradation rate differ between different COD fractions, viz. COD(ss), COD(col) and COD(diss). The dissolved COD fraction is characterised by the lowest degradation rate, both for anaerobic and aerobic conditions. The maximum biodegradability for aerobic and anaerobic conditions is 86 and 70% respectively, whereas the first order conversion rate constant, k₂₀, is 0.119 and 0.005 day⁻¹, respectively. The anaerobic and aerobic conversion rates in relation to temperature can be described by the Arrhenius relation, with temperature coefficients of 1.069 and 1.099, respectively.

  16. Environmental biodegradability of diesel oil: composition and performances of degradative micro-floras; Biodegradabilite du gazole dans l'environnement: composition et performances des microflores degradatrices

    Energy Technology Data Exchange (ETDEWEB)

    Penet, S.

    2004-09-01

    The large use of petroleum products makes them a significant source of pollutants in ground water and soils. Biodegradation studies are therefore relevant either to evaluate possibilities of natural attenuation or define bio-remediation strategies. In this study, the possible relationship between the environmental microflora structures and their capabilities for diesel oil biodegradation was investigated. The degradation capacities, i.e. kinetics and extent of biodegradation, were evaluated in closed batch systems by hydrocarbon consumption and CO{sub 2} production, both determined by gas chromatography. The intrinsic biodegradability of different types of diesel oils and the degradation capacities of microflora from ten polluted and ten unpolluted soils samples were determined. The data showed that: i) diesel oil was biodegradable, ii) n-alkanes were totally degraded by each microflora, the final amount of residual hydrocarbons being variable, iii) polluted-soil samples exhibited a slightly higher degradation rate (80%) that polluted-soil samples (67%) or activated sludge (64%). In order to define the contribution of various bacterial groups to diesel oil degradation, enrichment cultures were performed on hydrocarbons representative from the structural classes of diesel oil: hexadecane for n-alkanes, pristane for iso-alkanes, decalin for cyclo-alkanes, phenanthrene for aromatics. By using a 16S rDNA-sequencing method, the bacterial structures of the adapted microflora were determined and compared to that of the native microflora. A marked effect of the selection pressure was observed on the diversity of the microflora, each microflora harboring a major and specific bacterial group. The degradation capacities of the adapted microflora and the occurrence of genes coding for initial hydrocarbon oxidation (alkB, nahAc, cypP450) were also studied. No clear relationship between microflora genes and degradation performances was noted. This seemed to indicate that

  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

    dimensions including radiological, economic, social and environmental aspects. The system of criteria used for evaluating management options, including effectiveness and technical feasibility economic cost, waste generation, social and ethical issues, side effects and factors constraining application are discussed. Rather than a comprehensive analysis of remedial options, the new document gives selected information, describe key issues that are relevant to their implementation based on practical experience, and provide some guidance of their usefulness as part of a remediation strategy. Basic mechanisms behind the effectiveness of most of management options are also described. The document provides recommendations on remediation planning, optimising remediation strategies and available tools for decision making on remediation of different environments. The document specifically collates, and summarises, recent activities relevant to remediation conducted under the auspices of the IAEA, but also refers to relevant studies conducted elsewhere. The text thus capitalises on the knowledge and expertise gained by the many experts involved. In common with previous IAEA documents on remediation, much of the document is relevant for many other situations which may need to be remediated. (authors)

  18. Adsorption-synergic biodegradation of diesel oil in synthetic seawater by acclimated strains immobilized on multifunctional materials.

    Science.gov (United States)

    Wang, Xin; Wang, Xuejiang; Liu, Mian; Bu, Yunjie; Zhang, Jing; Chen, Jie; Zhao, Jianfu

    2015-03-15

    Using enrichment culture technique, three isolates marked as ODB-1, ODB-2 and ODB-3, were selected from oil contaminated seawater. 16S rDNA gene sequencing indicated that ODB-1 affiliated with Pseudomonas sp. while ODB-2 and ODB-3 affiliated with Brevundimonas sp. Subsequently, the bacterial cells were immobilized on the surface of expanded graphite (EG), expanded perlite (EP) and bamboo charcoal (BC). Among the three isolates, ODB-1 showed a strong binding to the bio-carriers through extracellular polysaccharides, while ODB-2 and ODB-3 made the adhesion to bio-carrier through direct physical adsorption. The immobilized bacteria exhibited good salinity tolerance compared with the planktonic bacteria. Their total diesel oil removal rates were more than 85% after 6 days' incubation. Adsorption-biodegradation process played an important role in the oil-pollution remediation. EG-bacteria system was treated as a promising remediation method, which achieved nearly 100% removal of diesel oil. Thereinto, over 83% removal of diesel oil owed to biodegradation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Catalysts for Environmental Remediation

    DEFF Research Database (Denmark)

    Abrams, B. L.; Vesborg, Peter Christian Kjærgaard

    2013-01-01

    on titania (V2O5-WO3/TiO2) as the example catalyst. The main photocatalysts examined for mineralization of organic compounds were TiO2 and MoS2. It is important to obtain insight into the catalyst structure-to-activity relationship in order to understand and locate the active site(s). In this chapter......The properties of catalysts used in environmental remediation are described here through specific examples in heterogeneous catalysis and photocatalysis. In the area of heterogeneous catalysis, selective catalytic reduction (SCR) of NOx was used as an example reaction with vanadia and tungsta...

  20. Biodegradable modified Phba systems

    International Nuclear Information System (INIS)

    Aniscenko, L.; Dzenis, M.; Erkske, D.; Tupureina, V.; Savenkova, L.; Muizniece - Braslava, S.

    2004-01-01

    Compositions as well as production technology of ecologically sound biodegradable multicomponent polymer systems were developed. Our objective was to design some bio plastic based composites with required mechanical properties and biodegradability intended for use as biodegradable packaging. Significant characteristics required for food packaging such as barrier properties (water and oxygen permeability) and influence of γ-radiation on the structure and changes of main characteristics of some modified PHB matrices was evaluated. It was found that barrier properties were plasticizers chemical nature and sterilization with γ-radiation dependent and were comparable with corresponding values of typical polymeric packaging films. Low γ-radiation levels (25 kGy) can be recommended as an effective sterilization method of PHB based packaging materials. Purposely designed bio plastic packaging may provide an alternative to traditional synthetic packaging materials without reducing the comfort of the end-user due to specific qualities of PHB - biodegradability, Biocompatibility and hydrophobic nature

  1. Selective laser-melted fully biodegradable scaffold composed of poly(d,l-lactide) and β-tricalcium phosphate with potential as a biodegradable implant for complex maxillofacial reconstruction: In vitro and in vivo results.

    Science.gov (United States)

    Smeets, Ralf; Barbeck, Mike; Hanken, Henning; Fischer, Horst; Lindner, Markus; Heiland, Max; Wöltje, Michael; Ghanaati, Shahram; Kolk, Andreas

    2017-07-01

    Scaffolds (SC) composed of poly(d,l-lactide) and β-tricalcium phosphate of variable pore structures were manufactured by selective laser melting (SLM), which allowed the production of porous interconnected structures promoting cellular adhesion and vascular proliferation. Biocompatibility, rate of osseointegration and new bone formation (NB) were analyzed. Powder based on the material composition was selective melted by a laser beam allowing layer-by-layer production. Pore size and biocompatibility were tested with mesenchymal stem cells (rMSC) and Saos 2 cells that were cultivated on SCs showing better proliferation, without toxicity, than controls. SCs with a 600- to 700-µm pore diameter proved ideal for fast and reliable cellular and vascular supply throughout the interconnecting pore system. Jaw and calvarial critical-size defects (CSD) with diameters of 5 or 16 mm were drilled in rats and either SLM test SCs (pore diameter 600 µm) or the previously removed autologs bone as controls were (re-) implanted. The SC in vivo led to complete bone ingrowth with minimal inflammatory reaction adjacent to and within the CSD as compared with controls. The SC promoted the differentiation of rMSC into osteoblasts, revealing osteoinductive properties. Promising NB ingrowth of the material was also obtained in the animal study. The SC showed complete bony replacement within 30 days in all rats; this ingrowth was significantly superior to that of controls and revealed no signs of significant foreign body reaction. Because of continuous replacement by bone this material composition is ideal for SCs fitting 3D bone defects. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1216-1231, 2017. © 2016 Wiley Periodicals, Inc.

  2. Biodegradable compounds: Rheological, mechanical and thermal properties

    Science.gov (United States)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  3. Gender, Age and Locus of Control as Correlates of Remedial ...

    African Journals Online (AJOL)

    The study sought to explain remedial learners' attitude towards English language using three variables: gender, age and locus of control. Three properly validated instruments were used to collect data on the relevant variables from 385 remedial English learners randomly selected from 5 remedial education centers in ...

  4. Biodegradation of dissolved humic substances by fungi.

    Science.gov (United States)

    Collado, Sergio; Oulego, Paula; Suárez-Iglesias, Octavio; Díaz, Mario

    2018-04-01

    Humic and fulvic acids constitute humic substances, a complex mixture of many different acids containing carboxyl and phenolate groups, which are not only the principal soil fertility factors but also the main pollutants present in landfill leachates or natural organic matter in water. Due to their low bacterial biodegradability, fungal biodegradation processes are key for their removal. The present study compiles and comments all the available literature on decomposition of aqueous humic substances by fungi or by their extracellular enzymes alone, focusing on the influence of the reaction conditions. The biodegradation extent mainly depends on the characteristics and concentration of the humic compounds, the type of microorganisms selected, the inoculation mode, the C and N sources, the presence of certain chemicals in the medium, the availability of oxygen, the temperature, and the pH.

  5. 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.

  6. 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

  7. Best conditions for biodegradation of diesel oil by chemometric tools

    Directory of Open Access Journals (Sweden)

    Ewa Kaczorek

    2014-01-01

    Full Text Available Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences. These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positive effect of rhamnolipids on hydrocarbon biodegradation was observed. However, rhamnolipids addition did not always have a positive influence on the biodegradation process (e.g. in case of yeast consortia with Stenotrophomonas maltophila KR7. Moreover, particular differences in the degradation pattern were observed for lower and higher alkanes than in the case with C22. Normally, the best conditions for "lower" alkanes are Aeromonas hydrophila KR4 + emulsifier independently from yeasts and e.g. Pseudomonas stutzeri KR7 for C24 alkane.

  8. Best conditions for biodegradation of diesel oil by chemometric tools

    Science.gov (United States)

    Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Héberger, Károly; Kemény, Sándor; Olszanowski, Andrzej; Voelkel, Adam

    2014-01-01

    Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences). These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positive effect of rhamnolipids on hydrocarbon biodegradation was observed. However, rhamnolipids addition did not always have a positive influence on the biodegradation process (e.g. in case of yeast consortia with Stenotrophomonas maltophila KR7). Moreover, particular differences in the degradation pattern were observed for lower and higher alkanes than in the case with C22. Normally, the best conditions for “lower” alkanes are Aeromonas hydrophila KR4 + emulsifier independently from yeasts and e.g. Pseudomonas stutzeri KR7 for C24 alkane. PMID:24948922

  9. 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.

  10. Topical Day on Site Remediation

    International Nuclear Information System (INIS)

    Vandenhove, H.

    1996-01-01

    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

  11. Editorial: Biodegradable Materials

    Directory of Open Access Journals (Sweden)

    Carl Schaschke

    2014-11-01

    Full Text Available This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment.

  12. Remedial action technology - arid

    International Nuclear Information System (INIS)

    Hakonson, T.E.; DePoorter, G.L.; Nyhan, J.W.; Perkins, B.A.; Lane, L.J.

    1982-01-01

    A summary is presented of the low-level waste remedial action program at Los Alamos. The experimental design and progress is described for the experiments on second generation intrusion barriers, subsidence effects on SLB components, moisture cycling effects on chemical transport, and erosion control methodologies. The soil moisture data from the bio-intrusion and moisture cycling experiments both demonstrate the overwhelming importance of vegetation in minimizing infiltration of water through trench covers and backfill. Evaporation, as a water loss component in trench covers, is only effective in reducing soil moisture within 40 cm of the trench cover surface. Moisture infiltrating past the zone of evaporation in unvegetated or poorly vegetated trench covers is in storage and accumulates until drainage out of the soil profile occurs. Judicious selection of vegetation species for revegetating a low-level waste site may prevent infiltration of moisture into the trench and, when coupled with other design features (i.e. trench cover slope, tilling and seeding practice), may greatly reduce problems with erosion. Standard US Department of Agriculture erosion plots, when coupled with a state-of-the-art water balance and erosion model (CREAMS) promises to be highly useful in screening proposed remedial action cover designs for low-level waste sites. The erosion plot configuration allows for complete accounting of the water balance in a soil profile. This feature enables the user to optimize cover designs to minimize erosion and infiltration of water into the trench

  13. 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

  14. Application of terpene-induced cell for enhancing biodegradation of TCE contaminated soil

    Directory of Open Access Journals (Sweden)

    Ekawan Luepromchai

    2004-02-01

    Full Text Available Trichloroethylene (TCE, a chlorinated solvent, is a major water pollutant originating from spillage and inappropriate disposal of dry cleaning agents, degreasing solvents, and paint strippers. Due to its widespread contamination and potential health threat, remediation technology to clean-up TCE is necessary. Aerobic biodegradation of TCE is reported to occur via cometabolism, by which TCE degrading bacteria utilize other compounds such as toluene, phenol, and methane as growth substrate and enzyme inducer. Although toluene is reported to be the most effective inducer, it is regulated as a hazardous material and should not be applied to the environment. The objectives of this study were to identify an alternative enzyme inducer as well as to apply the induced bacteria for degradation of TCE in contaminated soil. We investigated the effect of terpenes, the main components in volatile essential oils of plants, on induction of TCE degradation in Rhodococcus gordoniae P3, a local Gram (+ bacterium. Selected terpenes including cumene, limonene, carvone and pinene at various concentrations were used in the study. Results from liquid culture showed that 25 mg l-1 cumeneinduced R. gordoniae P3 cells resulted in 75% degradation of 10 ppm TCE within 24 hrs. Soil microcosms were later employed to investigate the ability of cumene to enhance TCE biodegradation in the environment. There were two bioremediation treatments studied, including bioaugmentation, the inoculation of cumeneinduced R. gordoniae P3, and biostimulation, the addition of cumene to induce soil indigenous microorganisms to degrade TCE. Bioaugmentation and biostimulation were shown to accelerate TCE reduction significantly more than control treatment at the beginning of study. The results suggest that cumene-induced R. gordoniae P3 and cumene can achieve rapid TCE biodegradation.

  15. Biodegradable Sonobuoy Decelerators

    Science.gov (United States)

    2015-06-01

    agent. Samples were also analyzed for heavy metals which found concentrations below the toxicity threshold, ruling out metals contamination during...unlimited” 13. SUPPLEMENTARY NOTES 14. ABSTRACT In response to environmental concerns regarding nylon decelerators from sonobuoys polluting the oceans...readiness point for technology transition. 15. SUBJECT TERMS biodegrade, decelerator, sonobuoy, polyvinyl alcohol, polyhydroxyalkanoate, marine

  16. Biodegradable Materials for Nonwovens

    Science.gov (United States)

    Demand for nonwovens is increasing globally, particularly in the disposable products area. As the consumption of nonwoven products with short life increases, the burden on waste disposal also rises. In this context, biodegradable nonwovens become more important today and for the future. Several new ...

  17. Almost remediation of saltwater spills at E and P sites

    International Nuclear Information System (INIS)

    Carty, D.J.

    1995-01-01

    At exploration and production (E and P) sites crude spills restricted to topsoil are often self-remediating, but salt spills rarely are. Most soils naturally biodegrade crude. Without appropriate human intervention, brine spills can result in decades of barren land and seriously degrade surface water and aquifers. Servicing the E and P industry are remediation practitioners with a limited array of often expensive remediation concepts and materials which they hope will work, and sometimes do. Unfortunately, many remediation practitioners are unfamiliar with, or disregard, the natural physical, chemical, and biotic complexity of the soil and aquatic media. All too often this results in exacerbating injury to an already damaged ecosystem. Likewise, important cultural factors such as public relations, environmental regulations, property rights, and water rights are also overlooked until after implementation of an ill-advised or illegal remediation design has been initiated. A major issue is determining what constitutes ''successful'' remediation of a brine spill. Environmental managers have long sought one or two universally applicable fast and cheap amendment/treatment protocols for all their diverse multi-state salt affected spill scenarios. This presentation describes aspects of common spill-affected ecosystems which must be considered to achieve ''successful'' remediation

  18. Technologies for remediation of radioactively contaminated sites

    International Nuclear Information System (INIS)

    1999-06-01

    This report presents particulars on environmental restoration technologies (control and treatment) which can be applied to land based, radioactively contaminated sites. The media considered include soils, groundwater, surface water, sediments, air, and terrestrial and aquatic vegetation. The technologies addressed in this report can be categorized as follows: self-attenuation (natural restoration); in-situ treatment; removal of contamination; ex-situ treatment; and transportation and final disposal. The report provides also background information about and a general approach to remediation of radioactively contaminated sites as well as some guidance for the selection of a preferred remediation technology. Examples of remediation experience in Australia and Canada are given it annexes

  19. Water Pollution, and Treatments Part III: Biodegradation of Oil in Refineries Waste Water and Oils Adsorbed in Agricultural Wastes by Selected Strains of Cyanobacteria

    International Nuclear Information System (INIS)

    El-Emary, M.M.; Ali, N.A.; Naguib, M.M.

    2011-01-01

    The main objective of this study is to determine the biological degradation of oil hydrocarbons and sulfur compounds of Marine Balayim crude oil and its refined products by selected indigenous Cyanobacteria strains. The oils used were Marine Balayim crude oil, skimmed oil and some refined products such as gasoline, kerosene, gas oil, fuel oil and petroleum coke. The selected organisms in the current study are the Blue-Green Algae Cyanobacteria, Oscillatoria limentica. This organism was collected from the hyper saline environment of the solar lake in Taba, Sinai, Egypt. The results obtained revealed that the utilization of such strains can be used for the bioremediation of oily waste water.

  20. New perspectives in plastic biodegradation.

    Science.gov (United States)

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Biodegradation of polyethylene by the thermophilic bacterium Brevibacillus borstelensis.

    Science.gov (United States)

    Hadad, D; Geresh, S; Sivan, A

    2005-01-01

    To select a polyethylene-degrading micro-organism and to study the factors affecting its biodegrading activity. A thermophilic bacterium Brevibaccillus borstelensis strain 707 (isolated from soil) utilized branched low-density polyethylene as the sole carbon source and degraded it. Incubation of polyethylene with B. borstelensis (30 days, 50 degrees C) reduced its gravimetric and molecular weights by 11 and 30% respectively. Brevibaccillus borstelensis also degraded polyethylene in the presence of mannitol. Biodegradation of u.v. photo-oxidized polyethylene increased with increasing irradiation time. Fourier Transform Infra-Red (FTIR) analysis of photo-oxidized polyethylene revealed a reduction in carbonyl groups after incubation with the bacteria. This study demonstrates that polyethylene--considered to be inert--can be biodegraded if the right microbial strain is isolated. Enrichment culture methods were effective for isolating a thermophilic bacterium capable of utilizing polyethylene as the sole carbon and energy source. Maximal biodegradation was obtained in combination with photo-oxidation, which showed that carbonyl residues formed by photo-oxidation play a role in biodegradation. Brevibaccillus borstelensis also degraded the CH2 backbone of nonirradiated polyethylene. Biodegradation of polyethylene by a single bacterial strain contributes to our understanding of the process and the factors affecting polyethylene biodegradation.

  2. Policy and Strategies for Environmental Remediation

    International Nuclear Information System (INIS)

    2015-01-01

    out in the policy statement. For its formulation, detailed information is needed on the current situation in the country (organizational, technical and legislative). The technical solutions proposed for the remediation of sites in the country need to be politically, technically and economically feasible. When selecting a set of technological procedures, an appropriate end point must be identified, usually a suitable end state. The steps in formulating and implementing the strategy include selecting the technical procedures, allocating the responsibility for implementing the identified procedures, establishing supervisory mechanisms and developing implementation plans. The policy and strategies may need to be updated because of new national circumstances (legislative changes, plans for new nuclear facilities), new international agreements and/or experience obtained with the original policy and strategies. The lead in making changes is to be taken by the body responsible for the initial formulation of the policy (government) and strategy, but all relevant parties in the country are to be involved and consulted in this process

  3. Biodegradation of Cyanuric Acid

    Science.gov (United States)

    Saldick, Jerome

    1974-01-01

    Cyanuric acid biodegrades readily under a wide variety of natural conditions, and particularly well in systems of either low or zero dissolved-oxygen level, such as anaerobic activated sludge and sewage, soils, muds, and muddy streams and river waters, as well as ordinary aerated activated sludge systems with typically low (1 to 3 ppm) dissolved-oxygen levels. Degradation also proceeds in 3.5% sodium chloride solution. Consequently, there are degradation pathways widely available for breaking down cyanuric acid discharged in domestic effluents. The overall degradation reaction is merely a hydrolysis; CO2 and ammonia are the initial hydrolytic breakdown products. Since no net oxidation occurs during this breakdown, biodegradation of cyanuric acid exerts no primary biological oxygen demand. However, eventual nitrification of the ammonia released will exert its usual biological oxygen demand. PMID:4451360

  4. Absorbable and biodegradable polymers

    CERN Document Server

    Shalaby, Shalaby W

    2003-01-01

    INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

  5. Modeling Biodegradation of Nonylphenol

    International Nuclear Information System (INIS)

    Jahan, Kauser; Ordonez, Raul; Ramachandran, Ravi; Balzer, Shira; Stern, Michael

    2008-01-01

    Nonylphenol is the primary breakdown product of nonylphenol ethoxylates, a certain class of nonionic surfactants. Nonylphenol has been found to be toxic to aquatic organisms and has been suspected of being harmful to humans due to its xenoestrogenic properties. Although there are known releases of nonylphenol to the environment, there is a lack of data describing the extent of biodegradation. This study thus focuses on much needed information on the biodegradation kinetics of nonylphenol. Oxygen uptake, cell growth and nonylphenol removal data were collected using batch reactors in an electrolytic respirometer. Nonylphenol removal, cell growth and substrate removal rates were modeled by the Monod, Haldane, Aiba, Webb, and Yano equations. The differential equations were solved by numerical integration to simulate cell growth, substrate removal, and oxygen uptake as a function of time. All models provided similar results with the Haldane model providing the best fit. The values of the kinetic parameters and the activation energy for nonylphenol were determined. These values can be used for predicting fate and transport of nonylphenol in the environment. The validity of applying each model to the biodegradation of nonylphenol was analyzed by computing the R 2 values of each equation

  6. Biodegradable packaging materials : case: PLA

    OpenAIRE

    Jama, Mohamed

    2017-01-01

    The main aim of this bachelor thesis was to investigate the possibility of biodegradable packaging materials. Plastics and other non-degradable packaging materials have been used for many years and they have a negative impact on the environment since they do not degrade. Different research methods are used to get authentic results, which simplifies using biodegradable packaging materials. There were two biodegradability testing methods, which has been applied to this task:-, testing biode...

  7. 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

  8. 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

  9. 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.

  10. Optimization of BTEX biodegradation in soil using different enhancement methods

    International Nuclear Information System (INIS)

    Kordonska, N.; Biswas, N.; Bewtra, J. K.

    1997-01-01

    Various experiments designed to enhance soil remediation were carried out. Microorganisms, able to utilize benzene, toluene, ethylbenzene and xylene (BTEX) as the sole source of carbon and energy were employed as the inoculum. H-2O 2 was used as a supplemental source of electron acceptor. Nutrients were added to the soil to provide optimum C:N:P. The biodegradation constant was calculated from the BTEX disappearance rate. Results showed that the addition of nutrients improved the rate of biodegradation. When the nutrients were supplemented with additional H 2 O 2 , utilization rate more than doubled. Optimum conditions were created for the biodegradation of all BTEX compounds when an electron acceptor, nutrients and inoculum were added. Under these condition biodegradation increased to almost three times the rate that occurred under natural conditions. Nitrate was successfully used as an alternative electron acceptor by all microorganisms that were able to degrade toluene, ethylbenzene and xylene, however, it was not acceptable as an electron acceptor by degraders of benzene. 9 refs., 3 figs

  11. A model for simultaneous crystallisation and biodegradation of biodegradable polymers.

    Science.gov (United States)

    Han, Xiaoxiao; Pan, Jingzhe

    2009-01-01

    This paper completes the model of biodegradation for biodegradable polymers that was previously developed by Wang et al. (Wang Y, Pan J, Han X, Sinka, Ding L. A phenomenological model for the degradation of biodegradable polymers. Biomaterials 2008;29:3393-401). Crystallisation during biodegradation was not considered in the previous work which is the topic of the current paper. For many commonly used biodegradable polymers, there is a strong interplay between crystallisation and hydrolysis reaction during biodegradation - the chain cleavage caused by the hydrolysis reaction provides an extra mobility for the polymer chains to crystallise and the resulting crystalline phase becomes more resistant to further hydrolysis reaction. This paper presents a complete theory to describe this interplay. The fundamental equations in the Avrami's theory for crystallisation are modified and coupled to the diffusion-reaction equations that were developed in our previous work. The mathematical equations are then applied to three biodegradable polymers for which long term degradation data are available in the literature. It is shown that the model can capture the behavior of the major biodegradable polymers very well.

  12. 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

  13. 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...

  14. Biodegradable Piezoelectric Force Sensor.

    Science.gov (United States)

    Curry, Eli J; Ke, Kai; Chorsi, Meysam T; Wrobel, Kinga S; Miller, Albert N; Patel, Avi; Kim, Insoo; Feng, Jianlin; Yue, Lixia; Wu, Qian; Kuo, Chia-Ling; Lo, Kevin W-H; Laurencin, Cato T; Ilies, Horea; Purohit, Prashant K; Nguyen, Thanh D

    2018-01-30

    Measuring vital physiological pressures is important for monitoring health status, preventing the buildup of dangerous internal forces in impaired organs, and enabling novel approaches of using mechanical stimulation for tissue regeneration. Pressure sensors are often required to be implanted and directly integrated with native soft biological systems. Therefore, the devices should be flexible and at the same time biodegradable to avoid invasive removal surgery that can damage directly interfaced tissues. Despite recent achievements in degradable electronic devices, there is still a tremendous need to develop a force sensor which only relies on safe medical materials and requires no complex fabrication process to provide accurate information on important biophysiological forces. Here, we present a strategy for material processing, electromechanical analysis, device fabrication, and assessment of a piezoelectric Poly-l-lactide (PLLA) polymer to create a biodegradable, biocompatible piezoelectric force sensor, which only employs medical materials used commonly in Food and Drug Administration-approved implants, for the monitoring of biological forces. We show the sensor can precisely measure pressures in a wide range of 0-18 kPa and sustain a reliable performance for a period of 4 d in an aqueous environment. We also demonstrate this PLLA piezoelectric sensor can be implanted inside the abdominal cavity of a mouse to monitor the pressure of diaphragmatic contraction. This piezoelectric sensor offers an appealing alternative to present biodegradable electronic devices for the monitoring of intraorgan pressures. The sensor can be integrated with tissues and organs, forming self-sensing bionic systems to enable many exciting applications in regenerative medicine, drug delivery, and medical devices.

  15. Electrical resistivity tomography to monitor enhanced biodegradation of hydrocarbons with Rhodococcus erythropolis T902.1 at a pilot scale

    Science.gov (United States)

    Masy, Thibaut; Caterina, David; Tromme, Olivier; Lavigne, Benoît; Thonart, Philippe; Hiligsmann, Serge; Nguyen, Frédéric

    2016-01-01

    Petroleum hydrocarbons (HC) represent the most widespread contaminants and in-situ bioremediation remains a competitive treatment in terms of cost and environmental concerns. However, the efficiency of such a technique (by biostimulation or bioaugmentation) strongly depends on the environment affected and is still difficult to predict a priori. In order to overcome these uncertainties, Electrical Resistivity Tomography (ERT) appears as a valuable non-invasive tool to detect soil heterogeneities and to monitor biodegradation. The main objective of this study was to isolate an electrical signal linked to an enhanced bacterial activity with ERT, in an aged HC-contaminated clay loam soil. To achieve this, a pilot tank was built to mimic field conditions. Compared to a first insufficient biostimulation phase, bioaugmentation with Rhodococcus erythropolis T902.1 led to a HC depletion of almost 80% (6900 to 1600 ppm) in 3 months in the center of the contaminated zone, where pollutants were less bioavailable. In the meantime, lithological heterogeneities and microbial activities (growth and biosurfactant production) were successively discriminated by ERT images. In the future, this cost-effective technique should be more and more transferred to the field in order to monitor biodegradation processes and assist in selecting the most appropriate remediation technique.

  16. PREPARATION AND CHARACTERIZATION OF BIODEGRADABLE ...

    African Journals Online (AJOL)

    Dr Abdusalam

    Keywords: Starch, Acetylation, Biodegradation, Poly(vinyl alcohol), Polymer blend. INTRODUCTION. Non-biodegradable polymers, such as polyethene, polypropane, poly(vinylchloride) etc have excellent mechanical properties such as tensile strength, tensile strain, bursting strength and tear strength (Hay and. Sharma.

  17. Thermodynamic Analysis of Biodegradation Pathways

    Science.gov (United States)

    Finley, Stacey D.; Broadbelt, Linda J.

    2014-01-01

    Microorganisms provide a wealth of biodegradative potential in the reduction and elimination of xenobiotic compounds in the environment. One useful metric to evaluate potential biodegradation pathways is thermodynamic feasibility. However, experimental data for the thermodynamic properties of xenobiotics is scarce. The present work uses a group contribution method to study the thermodynamic properties of the University of Minnesota Biocatalysis/Biodegradation Database. The Gibbs free energies of formation and reaction are estimated for 914 compounds (81%) and 902 reactions (75%), respectively, in the database. The reactions are classified based on the minimum and maximum Gibbs free energy values, which accounts for uncertainty in the free energy estimates and a feasible concentration range relevant to biodegradation. Using the free energy estimates, the cumulative free energy change of 89 biodegradation pathways (51%) in the database could be estimated. A comparison of the likelihood of the biotransformation rules in the Pathway Prediction System and their thermodynamic feasibility was then carried out. This analysis revealed that when evaluating the feasibility of biodegradation pathways, it is important to consider the thermodynamic topology of the reactions in the context of the complete pathway. Group contribution is shown to be a viable tool for estimating, a priori, the thermodynamic feasibility and the relative likelihood of alternative biodegradation reactions. This work offers a useful tool to a broad range of researchers interested in estimating the feasibility of the reactions in existing or novel biodegradation pathways. PMID:19288443

  18. Risk evaluation of remedial alternatives for the Hanford Site

    International Nuclear Information System (INIS)

    Clark, S.W.; Lane, N.K.; Swenson, L.

    1994-01-01

    Risk assessment is one of the many tools used to evaluate and select remedial alternatives and evaluate the risk associated with selected remedial alternatives during and after implementation. The risk evaluation of remedial alternatives (RERA) is performed to ensure selected alternatives are protective of human health and the environment. Final remedy selection is promulgated in a record of decision (ROD) and risks of the selected alternatives are documented. Included in the ROD documentation are the risk-related analyses for long-term effectiveness, short-term effectiveness, and overall protection of human health and the environment including how a remedy will eliminate, reduce or control risks and whether exposure will be reduced to acceptable levels. A major goal of RERA in the process leading to a ROD is to provide decision-makers with specific risk information that may be needed to choose among alternatives. For the Hanford Site, there are many considerations that must be addressed from a risk perspective. These include the large size of the Hanford Site, the presence of both chemical and radionuclide contamination, one likelihood of many analogues sites, public and worker health and safety, and stakeholder concern with ecological impacts from site contamination and remedial actions. A RERA methodology has been promulgated to (1) identify the points in the process leading to a ROD where risk assessment input is either required or desirable and (2) provide guidance on how to evaluate risks associated with remedial alternatives under consideration. The methodology and evaluations parallel EPA guidance requiring consideration of short-term impacts and the overall protectiveness of remedial actions for evaluating potential human health and ecological risks during selection of remedial alternatives, implementation of remedial measures, and following completion of remedial action

  19. Biodegradation of used motor oil in soil using organic waste amendments.

    Science.gov (United States)

    Abioye, O P; Agamuthu, P; Abdul Aziz, A R

    2012-01-01

    Soil and surface water contamination by used lubricating oil is a common occurrence in most developing countries. This has been shown to have harmful effects on the environment and human beings at large. Bioremediation can be an alternative green technology for remediation of such hydrocarbon-contaminated soil. Bioremediation of soil contaminated with 5% and 15% (w/w) used lubricating oil and amended with 10% brewery spent grain (BSG), banana skin (BS), and spent mushroom compost (SMC) was studied for a period of 84 days, under laboratory condition. At the end of 84 days, the highest percentage of oil biodegradation (92%) was recorded in soil contaminated with 5% used lubricating oil and amended with BSG, while only 55% of oil biodegradation was recorded in soil contaminated with 15% used lubricating oil and amended with BSG. Results of first-order kinetic model to determine the rate of biodegradation of used lubricating oil revealed that soil amended with BSG recorded the highest rate of oil biodegradation (0.4361 day(-1)) in 5% oil pollution, while BS amended soil recorded the highest rate of oil biodegradation (0.0556 day(-1)) in 15% oil pollution. The results of this study demonstrated the potential of BSG as a good substrate for enhanced remediation of hydrocarbon contaminated soil at low pollution concentration.

  20. Biodegradation of Used Motor Oil in Soil Using Organic Waste Amendments

    Directory of Open Access Journals (Sweden)

    O. P. Abioye

    2012-01-01

    Full Text Available Soil and surface water contamination by used lubricating oil is a common occurrence in most developing countries. This has been shown to have harmful effects on the environment and human beings at large. Bioremediation can be an alternative green technology for remediation of such hydrocarbon-contaminated soil. Bioremediation of soil contaminated with 5% and 15% (w/w used lubricating oil and amended with 10% brewery spent grain (BSG, banana skin (BS, and spent mushroom compost (SMC was studied for a period of 84 days, under laboratory condition. At the end of 84 days, the highest percentage of oil biodegradation (92% was recorded in soil contaminated with 5% used lubricating oil and amended with BSG, while only 55% of oil biodegradation was recorded in soil contaminated with 15% used lubricating oil and amended with BSG. Results of first-order kinetic model to determine the rate of biodegradation of used lubricating oil revealed that soil amended with BSG recorded the highest rate of oil biodegradation (0.4361 day−1 in 5% oil pollution, while BS amended soil recorded the highest rate of oil biodegradation (0.0556 day−1 in 15% oil pollution. The results of this study demonstrated the potential of BSG as a good substrate for enhanced remediation of hydrocarbon contaminated soil at low pollution concentration.

  1. Remediation of metal-contaminated soils with the addition of materials--part I: characterization and viability studies for the selection of non-hazardous waste materials and silicates.

    Science.gov (United States)

    González-Núñez, R; Alba, M D; Orta, M M; Vidal, M; Rigol, A

    2011-11-01

    Contamination episodes in soils require interventions to attenuate their impact. These actions are often based on the addition of materials to increase contaminant retention in the soil and to dilute the contaminant concentration. Here, non-hazardous wastes (such as sugar foam, fly ash and a material produced by the zeolitization of fly ash) and silicates (including bentonites) were tested and fully characterized in the laboratory to select suitable materials for remediating metal-contaminated soils. Data from X-ray fluorescence (XRF), N(2) adsorption/desorption isotherms, X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDX) analyses revealed the chemical composition, specific surface area and the phases appearing in the materials. A pH titration test allowed the calculation of their acid neutralization capacity (ANC). The metal sorption and desorption capacities of the waste materials and silicates were also estimated. Sugar foam, fly ash and the zeolitic material were the best candidate materials. Sugar foam was selected because of its high ANC (17000 meq kg(-1)), and the others were selected because of their larger distribution coefficients and lower sorption reversibilities than those predicted in the contaminated soils. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Sixty years later: Evaluation of passive remediation at an abandoned refinery

    International Nuclear Information System (INIS)

    Senn, R.B.; Gates, M.M.; Gogel, A.J.; Johnson, M.S.

    1992-01-01

    Investigations at old, inactive refineries that have not undergone active remediation may provide valuable data to assist in evaluating cleanup goals. There currently is limited long-term data on remediation programs to efficiently judge the impacts caused by shortcomings in existing technology, particularly at large spill sites. At many refineries the recovery of free phase hydrocarbons has been on-going for many years without addressing the issue of ground-water or residual soil contamination. As a result, regulators have very little to base their technical judgements on when contemplating enforcement actions or compliance time frames. Realistic refinery cleanup goals can better be understood by evaluating the results of passive or natural processes that have been affecting petroleum hydrocarbons at abandoned refineries. A comprehensive study was conducted at a refinery abandoned since the early 1930's. The presence of hydrocarbon staining in the vados zone was very prominant, providing evidence that a hydrocarbon plume had been present. However, analytical data reveal that the majority of the hydrocarbon components are no longer present at the site. Results of the study indicate that the petroleum hydrocarbons which were once present in the capillary fringe have been attenuated by various natural processes. The possible list of such processes includes dispersion, dilution, sorption, volatilization, and biodegradation. Bacteriological evaluation results from selected samples indicate the naturally occurring bacteria have been exposed to hydrocarbons and have adapted to degrade many of these compounds. The results of this investigation, and others like it, may provide guidelines for scoping remediation programs at sites with similar characteristics

  3. Biodegradation of Polypropylene Nonwovens

    Science.gov (United States)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma

  4. In situ Remediation Technologies

    NARCIS (Netherlands)

    Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2011-01-01

    A summary of two decades of developments of In Situ remediation is presented in this chapter. The basic principles of In Situ technology application are addressed, such as equilibrium relations between contaminant phases, factors controlling biological and geochemical processes, contaminant

  5. Cleanup and biodegradation of a crude-oil spill at Prudhoe Bay, Alaska

    International Nuclear Information System (INIS)

    Jorgenson, M.T.; Cater, T.C.; Joyce, M.R.; Ronzio, S.

    1992-01-01

    A crude oil spill occurred at an exploratory well site near Prudhoe Bay, Alaska during drilling in the winter of 1969-70. The oil infiltrated a portion of the gravel pad and flowed onto the adjacent tundra. Although some attempts were made to clean up the site at the time, a large area of contaminated gravel and tundra remained in 1990. Based on a detailed site assessment, 2.2 hectares had such high total petroleum hydrocarbon (TPH) concentrations that excavation and incineration were selected as the most appropriate remedial actions. In the remaining less-contaminated areas that were not excavated and in subsurface soil horizons, bioremediation was selected. During the winter of 1991, an estimated 19,000 m 3 of soil was excavated and incinerated in a rotary kiln. During summer 1991, biodegradation of the TPH in the remaining soil was promoted by tilling, watering and draining, and fertilizing. Excavation of the heavily contaminated soil reduced mean TPH concentrations by 89% at the tundra surface. Bioremediation for 53 days reduced mean TPH concentrations by 74%. Hydrocarbon-degrading bacteria and soil and groundwater properties important to microbial growth were also monitored. Two strains of Pseudomonas species showed a good ability to degrade crude oil and probably were responsible for the large reduction in TPH concentrations observed after one summer. 5 refs., 5 figs

  6. 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

  7. Selective divalent cobalt ions detection using Ag2O3-ZnO nanocones by ICP-OES method for environmental remediation.

    Science.gov (United States)

    Rahman, Mohammed M; Khan, Sher Bahadar; Marwani, Hadi M; Asiri, Abdullah M

    2014-01-01

    Here, we have synthesized Ag2O3-ZnO nanocones (NCs) by a wet-chemical route using reducing agents at low temperature. The structural, optical and morphological properties of Ag2O3-ZnO NCs were investigated by several conventional techniques such as powder XRD, XPS, FESEM, XEDS, FTIR and UV/vis. spectroscopy. The analytical parameters of prepared NCs were also calculated for a selective detection of divalent cobalt [Co(II)] prior to its determination by inductively coupled plasma-optical emission spectrometry (ICP-OES). The selectivity of NCs toward various metal ions, including Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Ni(II), and Zn(II) was studied. Results of the selectivity study demonstrated that Ag2O3-ZnO NC phase was the most selective towards Co(II) ion. The uptake capacity for Co(II) ion was experimentally calculated to be ∼76.69 mgg-1. Moreover, adsorption isotherm data provided that the adsorption process was mainly monolayer on homogeneous adsorbent surfaces of Ag2O3-ZnO NCs. Kinetic study revealed that the adsorption of Co(II) on Ag2O3-ZnO NCs phase followed the pseudo-second-order kinetic model. In addition, thermodynamic results provided that the adsorption mechanism of Co(II) ions on Ag2O3-ZnO NCs was a spontaneous process and thermodynamically favorable. Finally, the proposed method was validated by applying it to real environmental water samples with reasonable results.

  8. Biodegradation of gallotannins and ellagitannins.

    Science.gov (United States)

    Li, Mingshu; Kai, Yao; Qiang, He; Dongying, Jia

    2006-01-01

    Nowadays, many researches have been made on gallotannin biodegradation and have gained great success in further utilization. Some of industrial applications of these findings are in the production of tannase, the biotransformation of tannic acid to gallic acid or pyrogallol and detannification of food and fodder. Although ellagitannins have the typical C-C bound which is more difficult to be degraded than gallotannins, concerted efforts are still in progress to improve ellagitannin degradation and utilization. Currently, more attention is mainly focused on intestinal microflora biodegradation of tannins especially ellagitannins which can contribute to the definition of their bioavailability for both human beings and ruminants. Also there have been endeavours to utilize the tannin-degrading activity of different fungi for ellagitannin-rich biomass, which will facilitate application of tannin-degrading enzymes in strategies for improving industrial and livestock production. Due to the complicated structures of complex tannins and condensed tannins, the biodegradation of them is much more difficult and there are fewer researches on them. Therefore, the researches on the mechanisms of gallotannin and ellagitannin biodegradation can result in the overall understanding to the biodegradation of complex tannins and condensed tannins. Biodegradation of tannins is in an incipient stage and further studies have to be carried out to exploit the potential of various tannins for largescale applications in food, fodder, medicine and tannery effluent treatment. ((c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

  9. Transformation and biodegradation of 1,2,3-trichloropropane (TCP).

    Science.gov (United States)

    Samin, Ghufrana; Janssen, Dick B

    2012-09-01

    1,2,3-Trichloropropane (TCP) is a persistent groundwater pollutant and a suspected human carcinogen. It is also is an industrial chemical waste that has been formed in large amounts during epichlorohydrin manufacture. In view of the spread of TCP via groundwater and its toxicity, there is a need for cheap and efficient technologies for the cleanup of TCP-contaminated sites. In situ or on-site bioremediation of TCP is an option if biodegradation can be achieved and stimulated. This paper presents an overview of methods for the remediation of TCP-contaminated water with an emphasis on the possibilities of biodegradation. Although TCP is a xenobiotic chlorinated compound of high chemical stability, a number of abiotic and biotic conversions have been demonstrated, including abiotic oxidative conversion in the presence of a strong oxidant and reductive conversion by zero-valent zinc. Biotransformations that have been observed include reductive dechlorination, monooxygenase-mediated cometabolism, and enzymatic hydrolysis. No natural organisms are known that can use TCP as a carbon source for growth under aerobic conditions, but anaerobically TCP may serve as electron acceptor. The application of biodegradation is hindered by low degradation rates and incomplete mineralization. Protein engineering and genetic modification can be used to obtain microorganisms with enhanced TCP degradation potential.

  10. Enhanced TEX biodegradation in nutrient briquet-peat barrier system

    International Nuclear Information System (INIS)

    Kao, C.M.; Borden, R.C.

    1997-01-01

    A two-layer barrier system has been developed to remediate gasoline-contaminated ground water. This system consists of a nutrient briquet layer to continuously supply nitrate as the electron acceptor for contaminant biodegradation and a peat layer to remove residual nitrate via biological denitrification and residual contaminants by sorption. Nitrate release rates from three different sizes of concrete briquets were used to estimate parameters for modeling solute diffusion in aggregated porous media with mobile and stagnant porewater regions. Toluene, ethylbenzene, and xylene (TEX) biodegradation rates in denitrifying microcosms at pH 8 and 9 were lower than in microcosms at pH 7.4. No degradation was observed at pH 10 under denitrifying conditions. A laboratory-scale, permeable barrier system was developed to evaluate TEX removal and to identify any operational problems. Average removal efficiencies were 86% for toluene, 71% for ethylbenzene, 43% for m-xylene, and 28% for o-xylene in the nutrient briquet and downstream soil column over a 45-day operating period. There was no evidence of benzene biodegradation under denitrifying conditions in the batch microcosms or continuous-flow columns

  11. In-situ biodegradation of ethanolamine in low permeability soils

    International Nuclear Information System (INIS)

    Lunn, S. R. D.; McLay, K. H.; McGregor, S. E.; Goodman, R. H.; Drummond, N. W.; Armstrong, J. E.

    1999-01-01

    A research program to investigate whether ethanolamine is susceptible to biodegradation is described. The project was undertaken at a former Edmonton area gas plant site to demonstrate in-situ site remediation techniques. A horizontal well was drilled at a depth of four metres below ground surface and hydraulically fractured to increase permeability of the glacial till soils. A sand propant was used to prevent the subsequent closure of the water-based slurry used in fracturing the soil, with phosphoric acid added to provide a source of phospate to stimulate bacterial growth. A network of monitoring wells was installed along the horizontal wells to monitor bacterial respiration. Field test results showed oxygen depletion and carbon dioxide production. Bioventing was restricted as a result of unexpectedly high water levels, but in a subsequent dewatering bioventing program the ethanolamine levels in groundwater extracted from the monitoring wells showed an overall decline in concentration. There were no changes in ammonia levels. Since ammonia is a breakdown product of amines its increase in the groundwater would have provided positive proof of biodegradation. However, the fact that there was no change, is not taken as an indication of the total absence of biodegradation. Rather, it is suspected that the concentration of the ammonia in the groundwater is at a level that it exerts a a toxic influence on the soil bacteria, thus preventing additional degradation. 14 refs., 4 tabs.7 figs

  12. Characterisation and biodegradation of settleable organic matter for ...

    African Journals Online (AJOL)

    Biodegradation of settled COD is studied by evaluating the associated OUR profile obtained in an aerated batch reactor. Hydrolysis was selected, as in current modelling, as the rate-limiting step for O2 consumption. Settled COD was found to incorporate a significant fraction of active biomass that needs to be accounted for ...

  13. A field evaluation of coated urea with biodegradable materials and ...

    African Journals Online (AJOL)

    Urease inhibitor and biodegradable polymer coatings are two most suitable startegies to increase urea fertilizer efficiency. Coating of urea with selected inhibitors can increase the crop production by slowing down the hydrolysis process of urea in the soil. For this purpose, a field experiment was conducted to evaluate the ...

  14. Biodegradation of premium motor spirit (PMS) by lipase from ...

    African Journals Online (AJOL)

    Biodegradation of premium motor spirit (PMS) by lipase from Bacillus thuringiensis and Lysinibacillus sphaericus. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to ...

  15. Chloroethene Biodegradation Potential, ADOT/PF Peger Road Maintenance Facility, Fairbanks, Alaska

    Science.gov (United States)

    Bradley, Paul M.; Chapelle, Frances H.

    2004-01-01

    A series of 14C-radiotracer-based microcosm experiments were conducted to assess: 1) the extent, rate and products of microbial dechlorination of trichloroethene (TCE), cis-dichloroethene (cis-DCE) and vinyl chloride (VC) in sediments at the Peger Road site; 2) the effect of three electron donor amendments (molasses, shrimp and crab chitin, and 'Hydrogen Release Compound' (HRC)) on microbial degradation of TCE in three Peger Road sediments; and 3) the potential significance at the site of chloroethene biodegradation processes other than reductive dechlorination. In these experiments, TCE biodegradation yielded the reduced products, DCE and VC, and the oxidation product CO 2. Biodegradation of DCE and VC involved stoichiometric oxidation to CO 2. Both laboratory microcosm study and field redox assessment results indicated that the predominant terminal electron accepting process in Peger Road plume sediments under anoxic conditions was Mn/Fe-reduction. The rates of chloroethene biodegradation observed in Peger Road sediment microcosms under low temperature conditions (4?C) were within the range of those observed in sediments from temperate (20?C) aquifer systems. This result confirmed that biodegradation can be a significant mechanism for in situ contaminant remediation even in cold temperature aquifers. The fact that CO2 was the sole product of cis-DCE and VC biodegradation detected in Peger Road sediments indicated that a natural attenuation assessment based on reduced daughter product accumulation may significantly underestimate the potential for DCE and VC biodegradation at the Peger Road. Neither HRC nor molasses addition stimulated TCE reductive dechlorination. The fact that molasses and HRC amendment did stimulate Mn/Fe-reduction suggests that addition of these electron donors favored microbial Mn/Fe-reduction to the detriment of microbial TCE dechlorinating activity. In contrast, amendment of sediment microcosms with shrimp and crab chitin resulted in the

  16. Technology development activities supporting tank waste remediation

    International Nuclear Information System (INIS)

    Bonner, W.F.; Beeman, G.H.

    1994-06-01

    This document summarizes work being conducted under the U.S. Department of Energy's Office of Technology Development (EM-50) in support of the Tank Waste Remediation System (TWRS) Program. The specific work activities are organized by the following categories: safety, characterization, retrieval, barriers, pretreatment, low-level waste, and high-level waste. In most cases, the activities presented here were identified as supporting tank remediation by EM-50 integrated program or integrated demonstration lead staff and the selections were further refined by contractor staff. Data sheets were prepared from DOE-HQ guidance to the field issued in September 1993. Activities were included if a significant portion of the work described provides technology potentially needed by TWRS; consequently, not all parts of each description necessarily support tank remediation

  17. Progress of biodegradable metals

    Directory of Open Access Journals (Sweden)

    Huafang Li

    2014-10-01

    Full Text Available Biodegradable metals (BMs are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompatibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  18. Treatment of biodegradable material

    Energy Technology Data Exchange (ETDEWEB)

    Pannell, S.D.; Greenshields, R.N.

    1981-05-13

    Biodegradable effluents, e.g. containing carbohydrates and/or proteins, were treated by passing up a tower fermenter tapered at the top and with an aspect ratio of greater than or equal to 3:1. A flocculant microorganism aerobically digested the effluent in the tower and the mixture of treated medium, gas, and surplus microorganism was discharged through an inverted-U-shaped outlet at the top. After separation of the biomass, which could be used as an animal feed, the purified effluent could be discharged. A milk-processing effluent (2.5 g solids/l, of which 65% was sucrose and 35% milk solids) was treated in a fermentation tower (aspect ratio 10:1). Aspergillus niger in the tower readily digested sucrose and at least some lactose as air and NH/sub 4/NO/sub 3/ were added. At least 90% of the casein was trapped by the microorganisms and discharged with them from the tower. The microrganisms were separated with a vibrating sieve giving a final discharged liquid containing 0.2 g solids/l.

  19. The freshwater biodegradation potential of nine Alaskan oils

    International Nuclear Information System (INIS)

    Blenkinsopp, S.; Segy, G.

    1997-01-01

    Nine Alaskan representative crude oils and oil products with freshwater spill potential were collected, aged, and incubated in the presence of the standard freshwater inoculum for 28 days at 10 degrees C. Detailed analytical chemistry was performed on all samples to quantify compositional changes. All of the samples tested exhibited measurable hydrocarbon loss as a result of incubation with the freshwater inoculum. Total saturate and total n-alkane biodegradation were greatly enhanced when nutrients were present. The oil products Jet B Fuel and Diesel No. 2 appear to be more biodegradable than the Alaska North Slope and Cook Inlet crude oils tested, while the Bunker C/Diesel mixture appears to be less biodegradable than these crude oils. These results suggest that the screening procedures described here can provide useful information when applying bioremediation technology to the cleanup of selected oiled freshwater environments. 10 refs., 5 tabs., 13 figs

  20. DEVELOPMENT OF ACTIVE AND BIODEGRADABLES CONTAINERS FOR AGRICULTURAL CROPS

    Directory of Open Access Journals (Sweden)

    Franco Poggio

    2016-06-01

    Full Text Available In this paper, the development of biodegradable containers for crops that could be transplanted directly and act as fertilizers is proposed. Bovine gelatin was chosen as the base material, which was processed in a mini-injector mixer with a concentrated urea solution acted as a plasticizer. Rheological and tensile tests were performed in order to evaluate the injection of gelatin based formulations and mechanical properties related to the proposed application. Taking into account that biodegradable materials have a low water resistance, the increment of container stability was proposed using a surface coating. In addition, the influence of moisture content, the soluble matter and swelling were studied and analyzed. It was observed that coated samples were significantly more stable than the control ones, which guarantees the feasibility of the selected system and its potential development of biodegradable containers.

  1. Electrodialytic Soil Remediation

    DEFF Research Database (Denmark)

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

    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...

  2. Solutions Remediate Contaminated Groundwater

    Science.gov (United States)

    2010-01-01

    During the Apollo Program, NASA workers used chlorinated solvents to clean rocket engine components at launch sites. These solvents, known as dense non-aqueous phase liquids, had contaminated launch facilities to the point of near-irreparability. Dr. Jacqueline Quinn and Dr. Kathleen Brooks Loftin of Kennedy Space Center partnered with researchers from the University of Central Florida's chemistry and engineering programs to develop technology capable of remediating the area without great cost or further environmental damage. They called the new invention Emulsified Zero-Valent Iron (EZVI). The groundwater remediation compound is cleaning up polluted areas all around the world and is, to date, NASA's most licensed technology.

  3. Emplacement of zero-valent metal for remediation of deep contaminant plumes

    International Nuclear Information System (INIS)

    Hubble, D.W.; Gillham, R.W.; Cherry, J.A.

    1997-01-01

    Some groundwater plumes containing chlorinated solvent contaminants are found to be so deep that current in situ remediation technologies cannot be economically applied. Also, source zones are often found to be too deep for removal or inaccessible due to surface features. Plumes emanating from these sources require containment or treatment. Containment technologies are available for shallow sites (< 15 m) and are being developed for greater depths. However, it is important to advance the science of reactive treatment - both for cut off of plumes and to contain and treat source zones. Zero-valent metal technology has been used for remediation of solvent plumes at sites in Canada, the UK and at several industrial and military sites in the USA. To date, all of the plumes treated with zero-valent metal (granular iron) have been at depths less than 15 m. This paper gives preliminary results of research into methods to emplace granular iron at depths in the range of 15 to 60 m. The study included review of available and emerging methods of installing barrier or reactive material and the selection, preliminary design and costing of several methods. The design of a treatment system for a 122 m wide PCE plume that, immediately down gradient from its source, extends from a depth of 24 to 37 m below the ground surface is used as a demonstration site. Both Permeable Reactive Wall and Funnel-and-Gate trademark systems were considered. The emplacement methods selected for preliminary design and costing were slurry wall, driven/vibrated beam, deep soil mixing and hydrofracturing injection. For each of these methods, the iron must be slurried for ease of pumping and placement using biodegradable polymer viscosifiers that leave the iron reactive

  4. Mitigation action plan for 300-FF-1 remedial action

    International Nuclear Information System (INIS)

    Weiss, S.G.

    1996-10-01

    A record of decision was issued (dated July 1996), for remediation of waste sites in the 300-FF-1 Operable Unit in the 300 Area of the Hanford Site. The selected remedies for the 300-FF-1 and 300-FF-5 waste sites include selective excavation and disposal of contaminated soil and debris from the process waste units, excavation and removal of the 618-4 Burial Ground, and institutional controls for groundwater. This mitigation action plan explains how cultural resources will be managed and how revegetation for these remedial activities will be planned

  5. Supramolecular Phase-Selective Gelation by Peptides Bearing Side-Chain Azobenzenes: Effect of Ultrasound and Potential for Dye Removal and Oil Spill Remediation

    Science.gov (United States)

    Bachl, Jürgen; Oehm, Stefan; Mayr, Judith; Cativiela, Carlos; Marrero-Tellado, José Juan; Díaz Díaz, David

    2015-01-01

    Phase selective gelation (PSG) of organic phases from their non-miscible mixtures with water was achieved using tetrapeptides bearing a side-chain azobenzene moiety. The presence of the chromophore allowed PSG at the same concentration as the minimum gelation concentration (MGC) necessary to obtain the gels in pure organic phases. Remarkably, the presence of the water phase during PSG did not impact the thermal, mechanical, and morphological properties of the corresponding organogels. In the case of miscible oil/water mixtures, the entire mixture was gelled, resulting in the formation of quasi-hydrogels. Importantly, PSG could be triggered at room temperature by ultrasound treatment of the mixture or by adding ultrasound-aided concentrated solution of the peptide in an oil-phase to a mixture of the same oil and water. Moreover, the PSG was not affected by the presence of salts or impurities existing in water from natural sources. The process could be scaled-up, and the oil phases (e.g., aromatic solvents, gasoline, diesel fuel) recovered almost quantitatively after a simple distillation process, which also allowed the recovery and reuse of the gelator. Finally, these peptidic gelators could be used to quantitatively remove toxic dyes from aqueous solutions. PMID:26006247

  6. Selective remediation of reversal learning deficits in the neurodevelopmental MAM model of schizophrenia by a novel mGlu5 positive allosteric modulator.

    Science.gov (United States)

    Gastambide, Francois; Cotel, Marie-Caroline; Gilmour, Gary; O'Neill, Michael J; Robbins, Trevor W; Tricklebank, Mark D

    2012-03-01

    Based on the glutamatergic hypothesis of schizophrenia we assessed the effects of a novel mGlu5 positive allosteric modulator, LSN2463359 [N-(1-methylethyl)-5-(pyridin-4-ylethynyl)pyridine-2-carboxamide] on deficits in cognitive flexibility in two distinct rodent models of schizophrenia, the neurodevelopmental MAM E17 model and the acute PCP model. Cognitive flexibility was measured with the intra-dimensional and extra-dimensional set-shifting and reversal learning digging paradigm. Regional effects of MAM on the expression of parvalbumin-positive cells (PV) and mGlu5 receptors were also examined, to further characterize the model. Results showed that LSN2463359 selectively attenuated reversal learning deficits in the MAM but not acute PCP model. Whilst both models led to deficits in reversal learning and extra-dimensional set-shifting, the reversal impairments were qualitatively distinct, with MAM increasing perseverative responding, whereas the PCP deficit was mainly due to the inability of rats to maintain reinforced choice behavior. Reduction of PV and mGlu5 expression was found in the MAM model in several regions of importance in schizophrenia, such as the orbitofrontal and medial prefrontal cortex, which also mediate reversal learning and extra-dimensional set-shifting. The present findings confirm that the positive modulation of mGlu5 receptors may have beneficial effects in the treatment of certain aspects of cognitive impairment associated with schizophrenia. This study also illustrates the importance of studying putative cognitive enhancing drug effects in a number of models which may have implications for the future development of the compound.

  7. Remediation for contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Kivekaes, L. [Lohja Envirotec, Helsinki (Finland)

    2000-07-01

    A versatile remediation centre for contaminated soils has operated at Virkkala close to Helsinki since 1998. It is the first regional soil remediation centre in Finland and serves a large area in south- western Finland. Contaminated soils are collected from tens of small and large sites each year and transported to Virkkala for a very high class and environmentally safe treatment under controlled conditions. The centre consists of a 2 ha large hall for storage and treatment of the soils, a 1 ha outside bio-remediation field and a service and truck washing hall. Three treatment technologies are available at the centre: Stabilization/solidification, washing and bio-remediation. With these methods all the most common types of contamination can be treated: Heavy metals, oils, PAHs, creosotes and chlorophenols. Special care has been taken with prevention of environmental emissions, because the centre is located close to a housing area and on a lake-front. All the storage and treatment areas are covered with a double or triple bottom liner system and all environmental emissions are being monitored constantly. EU's Life Environment -fund has supported the project. (orig.)

  8. Trade Remedies: A Primer

    National Research Council Canada - National Science Library

    Jones, Vivian C

    2006-01-01

    The United States and many of its trading partners use laws known as trade remedies to mitigate the adverse impact of various trade practices on domestic industries and workers. U.S. antidumping laws (19 U.S.C. 1673 et seq...

  9. Evaluation of the effects of nanoscale zero-valent iron (nZVI) dispersants on intrinsic biodegradation of trichloroethylene (TCE).

    Science.gov (United States)

    Chang, Y C; Huang, S C; Chen, K F

    2014-01-01

    In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) > polyoxyethylene (20) sorbitan monolaurate (Tween 20) > polyacrylic acid (PAA) under aerobic conditions, and PV3A > Tween 20 > PAA under anaerobic conditions. Natural biodegradation of TCE was observed under both aerobic and anaerobic conditions. No significant effects were observed on the intrinsic biodegradation of TCE under aerobic conditions with the presence of the dispersants. The addition of PAA seemed to have a slightly adverse impact on anaerobic TCE biodegradation. Higher accumulation of the byproducts of anaerobic TCE biodegradation was detected with the addition of PV3A and Tween 20. The diversity of the microbial community was enhanced under aerobic conditions with the presence of more biodegradable PV3A and Tween 20. The results of this study indicate that it is necessary to select an appropriate dispersant for nZVI to prevent a residual of the dispersant in the subsurface. Additionally, the effects of the dispersant on TCE biodegradation and the accumulation of TCE biodegrading byproducts should also be considered.

  10. Biodegradable Peptide-Silica Nanodonuts.

    Science.gov (United States)

    Maggini, Laura; Travaglini, Leana; Cabrera, Ingrid; Castro-Hartmann, Pablo; De Cola, Luisa

    2016-03-07

    We report hybrid organosilica toroidal particles containing a short peptide sequence as the organic component of the hybrid systems. Once internalised in cancer cells, the presence of the peptide allows for interaction with peptidase enzymes, which attack the nanocarrier effectively triggering its structural breakdown. Moreover, these biodegradable nanovectors are characterised by high cellular uptake and exocytosis, showing great potential as biodegradable drug carriers. To demonstrate this feature, doxorubicin was employed and its delivery in HeLa cells investigated. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. ANAEROBIC BIODEGRADATION OF A BIODEGRADABLE MATERIAL UNDER ANAEROBIC - THERMOPHILIC DIGESTION

    Directory of Open Access Journals (Sweden)

    RICARDO CAMACHO-MUÑOZ

    2014-12-01

    Full Text Available This paper dertermined the anaerobic biodegradation of a polymer obtained by extrusion process of native cassava starch, polylactic acid and polycaprolactone. Initially a thermophilic - methanogenic inoculum was prepared from urban solid waste. The gas final methane concentration and medium’s pH reached values of 59,6% and 7,89 respectively. The assay assembly was carried out according ASTM D5511 standard. The biodegradation percent of used materials after 15 day of digestion were: 77,49%, 61,27%, 0,31% for cellulose, sample and polyethylene respectively. Due cellulose showed biodegradation levels higher than 70% it’s deduced that the inoculum conditions were appropriate. A biodegradation level of 61,27%, 59,35% of methane concentration in sample’s evolved gas and a medium’s finale pH of 7,71 in sample’s vessels, reveal the extruded polymer´s capacity to be anaerobically degraded under thermophilic- high solid concentration conditions.

  12. Enhanced aerobic biodegradation of some toxic hydrocarbon pollutants

    International Nuclear Information System (INIS)

    Elshahawy, M.R.M.

    2007-01-01

    samples were collected from the same location in Suez Gulf during the period from June, 2004 to April 2006 then microbiologically and chemically analyzed . the TPH levels ranged from 55 to 86 ppm and exceeded the known permissible limits referring to a settled situation of chronic hydrocarbon pollution in the studied area. on the other hand the biodegrading bacterial counts cfu clearly reflected the great adaptation of endogenous bacteria to use hydrocarbons as a sole source of carbon . the ratio of biodegrading bacteria to heterotrophic ones ranged between 26 and 50% over the period of collection. the biodegradation potentials of suez gulf consortia were studied at different concentrations of phenanthrene as a sole carbon source. it was found that the degradation kinetics of phenanthrene either due to biotic or abiotic factors is affected with the initial concentration of PAHs. twenty PAHs degraders were isolated from Suez Gulf consortia after different adaptation periods on phenanthrene.ten isolates were selected to be promising due to their ability to tolerate high base oil concentrations, grow at wide range of temperatures and their short incubation period on MSO. the biodegradation kinetics of 200 ppm phenanthrene by the selected isolates was monitored by HPLC

  13. Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

    International Nuclear Information System (INIS)

    McCarty, P. L.; Spormann, Alfred M.; Criddle, Craig S.

    2003-01-01

    Chlorinated solvents are among the most widespread groundwater contaminants in the country, contamination which is also among the most difficult and expensive for remediation. These solvents are biodegradable in the absence of oxygen, but this biodegradation requires both a food source for the organisms (electron donor) and the presence of chlorinated solvent biodegrading organisms. These two requirements are present naturally at some contamination sites, leading to natural attenuation of the solvents. If one or both requirements are absent, then engineered bioremediation either through addition of an external electron donor or through bioaugmentation with appropriate microorganisms, or both, may be used for site remediation. The most difficult case for cleanup is when a large residual of undissolved chlorinated solvents are present, residing as dense -non-aqueous-phase- liquid ( DNAPL). A major focus of this study was on the potential for biodegradation of the solvents when pre sent as DNAPL where concentrations are very high and potential for toxicity to microorganisms exist. Another focus was on a better understanding of the biological mechanisms involved in chlorinated solvent biodegradation . These studies were directed towards the chlorinated solvents, trichloroethene (TCE), tetrachloroethene or perchloroethene (PCE), and carbon tetrachloride (CT). The potential for biodegradation of TCE and PCE DNAPL was clearly demonstrated in this research. From column soil studies and batch studies we found there to be a clear advantage in focusing efforts at bioremediation near the DNAPL. Here, chlorinated solvent concentrations are the highest, both because of more favorable reaction kinetics and because such high solvent concentrations are toxic to microorganisms, such as methanogens, which compete with dehalogenators for the electron donor. Additionally, biodegradation near a PCE DNAPL results in an enhanced dissolution rate for the chlorinated solvent, by factors of

  14. Biodegradation kinetics for pesticide exposure assessment.

    Science.gov (United States)

    Wolt, J D; Nelson, H P; Cleveland, C B; van Wesenbeeck, I J

    2001-01-01

    Understanding pesticide risks requires characterizing pesticide exposure within the environment in a manner that can be broadly generalized across widely varied conditions of use. The coupled processes of sorption and soil degradation are especially important for understanding the potential environmental exposure of pesticides. The data obtained from degradation studies are inherently variable and, when limited in extent, lend uncertainty to exposure characterization and risk assessment. Pesticide decline in soils reflects dynamically coupled processes of sorption and degradation that add complexity to the treatment of soil biodegradation data from a kinetic perspective. Additional complexity arises from study design limitations that may not fully account for the decline in microbial activity of test systems, or that may be inadequate for considerations of all potential dissipation routes for a given pesticide. Accordingly, kinetic treatment of data must accommodate a variety of differing approaches starting with very simple assumptions as to reaction dynamics and extending to more involved treatments if warranted by the available experimental data. Selection of the appropriate kinetic model to describe pesticide degradation should rely on statistical evaluation of the data fit to ensure that the models used are not overparameterized. Recognizing the effects of experimental conditions and methods for kinetic treatment of degradation data is critical for making appropriate comparisons among pesticide biodegradation data sets. Assessment of variability in soil half-life among soils is uncertain because for many pesticides the data on soil degradation rate are limited to one or two soils. Reasonable upper-bound estimates of soil half-life are necessary in risk assessment so that estimated environmental concentrations can be developed from exposure models. Thus, an understanding of the variable and uncertain distribution of soil half-lives in the environment is

  15. Biodegradable congress 2012; Bioschmierstoff-Kongress 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Within the Guelzower expert discussions at 5th and 6th June, 2012 in Oberhausen (Federal Republic of Germany) the following lectures were held: (1) Promotion of biodegradable lubricants by means of research and development as well as public relations (Steffen Daebeler); (2) Biodegradable lubricants - An overview of the advantages and disadvantages of the engaged product groups (Hubertus Murrenhoff); (3) Standardization of biodegradable lubricants - CEN/DIN standard committees - state of the art (Rolf Luther); (4) Market research for the utilization of biodegradable lubricants and means of proof of sustainability (Norbert Schmitz); (5) Fields of application for high performance lubricants and requirements upon the products (Gunther Kraft); (6) Investigations of biodegradable lubricants in rolling bearings and gears (Christoph Hentschke); (7) Biodegradable lubricants in central lubrication systems Development of gears and bearings of offshore wind power installations (Reiner Wagner); (8) Investigations towards environmental compatibility of biodegradable lubricants used in offshore wind power installations (Tolf Schneider); (9) Development of glycerine based lubricants for the industrial metalworking (Harald Draeger); (10) Investigations and utilization of biodegradable oils as electroinsulation oils in transformers (Stefan Tenbohlen); (11) Operational behaviour of lubricant oils in vegetable oil operation and Biodiesel operation (Horst Hamdorf); (12) Lubrication effect of lubricating oil of the third generation (Stefan Heitzig); (13) Actual market development from the view of a producer of biodegradable lubricants (Frank Lewen); (14) Utilization of biodegradable lubricants in forestry harvesters (Guenther Weise); (15) New biodegradable lubricants based on high oleic sunflower oil (Otto Botz); (16) Integrated fluid concept - optimized technology and service package for users of biodegradable lubricants (Juergen Baer); (17) Utilization of a bio oil sensor to control

  16. Biodegradable polymeric prodrugs of naltrexone

    NARCIS (Netherlands)

    Bennet, D.B.; Li, X.; Adams, N.W.; Kim, S.W.; Hoes, C.J.T.; Hoes, C.J.T.; Feijen, Jan

    1991-01-01

    The development of a biodegradable polymeric drug delivery system for the narcotic antagonist naltrexone may improve patient compliance in the treatment of opiate addiction. Random copolymers consisting of the ¿-amino acids N5-(3-hydroxypropyl--glutamine and -leucine were synthesized with equimolar

  17. Biodegradable poly(lactic acid)

    Indian Academy of Sciences (India)

    The fabrication of biodegradable poly(lactic acid) (PLA) microspheres containing total alkaloids of Caulis sinomenii was investigated. The formation, diameter, morphology and properties of the microspheres were characterized using Fourier transform infrared spectroscopy (FT–IR), laser particle size analyser and scanning ...

  18. A proactive approach can make site remediation less expensive.

    Science.gov (United States)

    Bage, Gontran F; Samson, Réjean; Sinclair-Desgagné, Bernard

    2004-10-01

    Without any incentive to clean up a contaminated site, remediation is often delayed until the site owner is compelled to act by regulatory agencies. In such a context, the selected technology is typically the one that will reach the remediation goals as quickly as possible. Unfortunately, this criterion is often met by overly expensive technologies, resulting in high and sometimes unaffordable total remediation costs, leading to a remediation with a negative net benefit. This study examines the effects of time constraint and benefit value on the optimal remediation strategy for a diesel-contaminated site. This strategy is developed using the technico-economic model METEORS, which takes into account the technology's effectiveness, the uncertainty of the level of contamination, and the possibility of reducing this uncertainty through either an additional characterization (before selecting and applying a technology) or the monitoring of the remediation technology (during its use). Results of simulations with both economic and temporal constraints support a proactive approach to site remediation.

  19. Evaluation of Bioaugmentation with Entrapped Degrading Cells as a Soil Remediation Technology

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Dechesne, Arnaud; Binning, Philip John

    2010-01-01

    Soil augmentation with microbial degraders immobilized on carriers is evaluated as a potential remediation technology using a mathematical model that includes degradation within spatially distributed carriers and diffusion or advectiondispersion as contaminant mass transfer mechanisms. The total...... degraders have low intrinsic degradation rates and that only limited carrier to soil volume ratios are practically feasible, bioaugmented soils are characterized by low effective degradation ratesandcanbeconsidered fully mixed. A simple exponential model is then sufficient to predict biodegradation...

  20. Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions

    International Nuclear Information System (INIS)

    Zembrzuska, Joanna; Budnik, Irena; Lukaszewski, Zenon

    2016-01-01

    Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C 12 E 9 having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C 12 E 9 as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C 12 E 9 and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C 12 E 9 , C 12 E 8 , C 12 E 7 and C 12 E 6 . Apart from the substrate, the homologues C 12 E 8 , C 12 E 7 and C 12 E 6 , being metabolites of C 12 E 9 biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C 12 E 8 COOH, C 12 E 7 COOH, C 12 E 6 COOH and C 12 E 5 COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C 12 E 9 and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a single unit. - Highlights: • Two parallel biodegradation pathways of alcohol ethoxylates have been discovered. • Apart from central

  1. Additional Equipment for Soil Biodegradation

    Science.gov (United States)

    Vondráčková, Terezie; Kraus, Michal; Šál, Jiří

    2017-12-01

    Intensification of industrial production, increasing citizens’ living standards, expanding the consumer assortment mean in the production - consumption cycle a constantly increasing occurrence of waste material, which by its very nature must be considered as a source of useful raw materials in all branches of human activity. In addition to strict legislative requirements, a number of circumstances characterize waste management. It is mainly extensive transport associated with the handling and storage of large volumes of substances with a large assortment of materials (substances of all possible physical and chemical properties) and high demands on reliability and time coordination of follow-up processes. Considerable differences in transport distances, a large number of sources, processors and customers, and not least seasonal fluctuations in waste and strong price pressures cannot be overlooked. This highlights the importance of logistics in waste management. Soils that are contaminated with oil and petroleum products are hazardous industrial waste. Methods of industrial waste disposal are landfilling, biological processes, thermal processes and physical and chemical methods. The paper focuses on the possibilities of degradation of oil pollution, in particular biodegradation by bacteria, which is relatively low-cost among technologies. It is necessary to win the fight with time so that no ground water is contaminated. We have developed two additional devices to help reduce oil accident of smaller ranges. In the case of such an oil accident, it is necessary to carry out the permeability test of contaminated soil in time and, on this basis, to choose the technology appropriate to the accident - either in-sit biodegradation - at the site of the accident, or on-sit - to remove the soil and biodegrade it on the designated deposits. A special injection drill was developed for in-sit biodegradation, tossing and aeration equipment of the extracted soil was developed for

  2. Risk evaluation of remedial alternatives for the Hanford Site

    International Nuclear Information System (INIS)

    1994-09-01

    This document provides guidance on the process of risk evaluation of remedial alternatives (RERA) at the Hanford Site. Remediation activities at the Hanford Site are being conducted pursuant to the Comprehensive Environmental Restoration, Compensation, and Liability Act and the Resource Conservation and Recovery Act. This document identifies points in the remedial alternative selection process where risk assessment input is either required or desirable. For each of these points of application, the document identifies issues to consider and address, and suggests possible approaches, techniques, and appropriate levels of detail. The level of detail of a RERA is driven by the need to use risk as a criterion for selecting a remedial alternative. Such a document is needed to ensure that RERA is conducted in a consistent manner, and to prevent restating or creating guidance within each RERA

  3. Remediation of SRS Basins by In Situ Stabilization/Solidification

    International Nuclear Information System (INIS)

    Ganguly, A.

    1999-01-01

    In the late summer of 1998, the Savannah River Site began remediation of two radiologically contaminated basins using in situ stabilization. These two high-risk, unlined basins contain radiological contaminants, which potentially pose significant risks to human health and the environment. The selected remedy involves in situ stabilization/solidification of the contaminated wastes (basin and pipeline soils, pipelines, vegetation, and other debris) followed by installation of a low permeability soil cover

  4. Is Sustainable Remediation Now a Self-Sustaining Process? an International Progress Report

    Science.gov (United States)

    Smith, J. W. N.

    2014-12-01

    Sustainable remediation - the consideration of environmental, social and economic factors associated with soil and groundwater risk-management options, to help select the best overall solution - has been a rapidly evolving topic in recent years. The first published reference[1] to 'sustainable remediation' was in the title of a 1999 conference paper by Kearney et al., (1999), but activity really accelerated in the middle-late 2000's, with establishment of a number of collaborative sustainable remediation groups and fora, and increased publication rates in the peer reviewed literature (Fig 1). Figure 1. Journal paper publications with search term 'sustainable remediation' (SCOPUS survey, 17 July 2014) This presentation will review the international progress of sustainable remediation concept development and application in regulatory and corporate decision-making processes. It will look back at what has already been achieved, provide an update on the latest initiatives and developments, and look forward to what the future of sustainable remediation might look like. Specifically it will describe: Sustainable remediation frameworks: synergies and international collaboration; Latest guidance and tools developed by the various sustainable remediation organisations (SuRFs), including the SuRF-UK Best Management Practices and Tier 1 Briefcase; Best practice standard development by ASTM and ISO; Regulatory acceptance of sustainable remediation, including incorporation into legislation, and the NICOLE - Common Forum Joint statement on 'risk-informed and sustainable remediation' in Europe; Examples of corporate adoption of sustainable remediation principles. The presentation will conclude with a look forward to a vision of sustainable remediation in 2020.

  5. 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

  6. Biodegradable polymeric nanocarriers for pulmonary drug delivery.

    Science.gov (United States)

    Rytting, Erik; Nguyen, Juliane; Wang, Xiaoying; Kissel, Thomas

    2008-06-01

    Pulmonary drug delivery is attractive for both local and systemic drug delivery as a non-invasive route that provides a large surface area, thin epithelial barrier, high blood flow and the avoidance of first-pass metabolism. Nanoparticles can be designed to have several advantages for controlled and targeted drug delivery, including controlled deposition, sustained release, reduced dosing frequency, as well as an appropriate size for avoiding alveolar macrophage clearance or promoting transepithelial transport. This review focuses on the development and application of biodegradable polymers to nanocarrier-based strategies for the delivery of drugs, peptides, proteins, genes, siRNA and vaccines by the pulmonary route. The selection of natural or synthetic materials is important in designing particles or nanoparticle clusters with the desired characteristics, such as biocompatibility, size, charge, drug release and polymer degradation rate.

  7. Biobased and biodegradable polymer nanocomposites

    Science.gov (United States)

    Qiu, Kaiyan

    In this dissertation, various noncrosslinked and crosslinked biobased and biodegradable polymer nanocomposites were fabricated and characterized. The properties of these polymer nanocomposites, and their relating mechanisms and corresponding applications were studied and discussed in depth. Chapter 1 introduces the research background and objectives of the current research. Chapter 2 presents the development of a novel low cost carbon source for bacterial cellulose (BC) production and fabrication and characterization of biobased polymer nanocomposites using produced BC and soy protein based resins. The carbon source, soy flour extract (SFE), was obtained from defatted soy flour (SF) and BC yield achieved using SFE medium was high. The results of this study showed that SFE consists of five sugars and Acetobacter xylinum metabolized sugars in a specific order. Chapter 3 discusses the fabrication and characterization of biodegradable polymer nanocomposites using BC and polyvinyl alcohol (PVA). These polymer nanocomposites had excellent tensile and thermal properties. Crosslinking of PVA using glutaraldehyde (GA) not only increased the mechanical and thermal properties but the water-resistance. Chapter 4 describes the development and characterization of microfibrillated cellulose (MFC) based biodegradable polymer nanocomposites by blending MFC suspension with PVA. Chemical crosslinking of the polymer nanocomposites was carried out using glyoxal to increase the mechanical and thermal properties as well as to make the PVA partially water-insoluble. Chapter 5 reports the development and characterization of halloysite nanotube (HNT) reinforced biodegradable polymer nanocomposites utilizing HNT dispersion and PVA. Several separation techniques were used to obtain individualized HNT dispersion. The results indicated uniform dispersion of HNTs in both PVA and malonic acid (MA) crosslinked PVA resulted in excellent mechanical and thermal properties of the materials, especially

  8. 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

  9. 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.

  10. Remediation of soil co-contaminated with petroleum and heavy metals by the integration of electrokinetics and biostimulation.

    Science.gov (United States)

    Dong, Zhi-Yong; Huang, Wen-Hui; Xing, Ding-Feng; Zhang, Hong-Feng

    2013-09-15

    Successful remediation of soil co-contaminated with high levels of organics and heavy metals is a challenging task, because that metal pollutants in soil can partially or completely suppress normal heterotrophic microbial activity and thus hamper biodegradation of organics. In this study, the benefits of integrating electrokinetic (EK) remediation with biodegradation for decontaminating soil co-contaminated with crude oil and Pb were evaluated in laboratory-scale experiments lasting for 30 days. The treated soil contained 12,500 mg/kg of total petroleum hydrocarbons (TPH) and 450 mg/kg Pb. The amendments of EDTA and Tween 80, together with a regular refreshing of electrolyte showed the best performance to remediate this contaminated soil. An important function of EDTA-enhanced EK treatment was to eliminate heavy metal toxicity from the soil, thus activating microbial degradation of oil. Although Tween 80 reduced current, it could serve as a second substrate for enhancing microbial growth and biodegradation. It was found that oil biodegradation degree and microbial numbers increased toward the anode and cathode. Microbial metabolism was found to be beneficial to metal release from the soil matrix. Under the optimum conditions, the soil Pb and TPH removal percentages after 30 days of running reached 81.7% and 88.3%, respectively. After treatment, both the residual soil Pb and TPH concentrations met the requirement of the Chinese soil environmental quality standards. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. The Remediation of Nosferatu

    DEFF Research Database (Denmark)

    Ghellal, Sabiha; Morrison, Ann; Hassenzahl, Marc

    2014-01-01

    In this paper we present The Remediation of Nosferatu, a location based augmented reality horror adventure. Using the theory of fictional universe elements, we work with diverse material from Nosferatu’s horror genre and vampire themes as a case study. In this interdisciplinary research we...... intertwine traditional storytelling and scriptwriting skills with interaction design methods. For the game setting, we create hybrid spaces merging the fictional universe and the physical environment into one pervasive experience, centering around a variety of augmented reality activities played out...

  12. Saxton soil remediation project

    International Nuclear Information System (INIS)

    Holmes, R.D.

    1995-01-01

    The Saxton Nuclear Experimental Facility (SNEF) consists of a 23-MW(thermal) pressurized light water thermal reactor located in south central Pennsylvania. The Saxton Nuclear Experimental Corporation (SNEC), a wholly owned subsidiary of the General Public Utilities (GPU) Corporation, is the licensee for the SNEF. Maintenance and decommissioning activities at the site are conducted by GPU Nuclear, also a GPU subsidiary and operator of the Three Mile Island and Oyster Creek nuclear facilities. The remediation and radioactive waste management of contaminated soils is described

  13. Biodegradation of Ochratoxin A for Food and Feed Decontamination

    Directory of Open Access Journals (Sweden)

    Luís Abrunhosa

    2010-05-01

    Full Text Available Ochratoxin A (OTA is one of the most important mycotoxins that is found in food and feed products. It has proven toxic properties, being primarily known for its nephrotoxicity and carcinogenicity to certain animal species. OTA is produced by several species of Aspergillus and Penicillium that can be found in a wide variety of agricultural products, which makes the presence of OTA in these products common. Many countries have statutory limits for OTA, and concentrations need to be reduced to as low as technologically possible in food and feed. The most important measures to be taken to control OTA are preventive in order to avoid fungal growth and OTA production. However, these measures are difficult to implement in all cases with the consequence of OTA remaining in agricultural commodities. Remediation processes are often used to eliminate, reduce or avoid the toxic effects of OTA. Biological methods have been considered increasingly as an alternative to physical and chemical treatments. However, examples of practical applications are infrequent. This review will focus on the (i known microorganisms and enzymes that are able to biodegrade OTA; (ii mode of action of biodegradation and (iii current applications. A critical discussion about the technical applicability of these strategies is presented.

  14. Toxicity and biodegradation of PCBs in contaminated sediments

    International Nuclear Information System (INIS)

    Dercova, K.; Cicmanova, J.; Lovecka, P.; Demnerova, K.; Mackova, M.; Hucko, P.; Kusnir, P.

    2006-01-01

    PCBs represent a serious ecological problem due to their low degradability, high toxicity, and strong bioaccumulation. Because of many environmental and economical problems, there are efforts to develop bio-remediation technologies for decontamination of the PCB-polluted areas. PCB were used by storage of spent nuclear fuel in nuclear power plants Jaslovske Bohunice. In the locality of the former producer of PCB - Chemko Strazske a. s. - big amount of these substances is still persisting in sediments and soil. The goal of this study was to analyze the contaminated sediments from Strazsky canal and Zemplinska Sirava water reservoir from several points of view. The study of eco-toxicity confirmed that both sediments were toxic for various tested organisms. The genotoxicity test has not proved the mutagenic effect. The subsequent step included microbiological analysis of the contaminated sediments and isolation of pure bacterial cultures capable of degrading PCBs. In order to determine the genetic potential for their biodegradability, the gene bphA1 was identified using PCR technique in their genomes. This gene codes the enzyme biphenyl-dioxygenase, which is responsible for PCB degradation. The final goal was to perform aerobic biodegradation of PCBs in the sediments. The bacteria present in both sediments are able to degrade certain low chlorinated congeners. The issue of biodiversity is still open and has to be studied to reveal the real cooperation between bacteria. (authors)

  15. Citrate biodegradation. Mid-year status report, [January 1994--June 1994

    International Nuclear Information System (INIS)

    Francis, A.J.; Dodge, C.J.; Chatterjee, S.; Landry, M.F.

    1994-07-01

    The Uranium Soils Integrated Demonstration (USID) Program was established to demonstrate advanced technologies for the remediation of uranium contaminated soils. This program, managed by the Fernald Environmental Restoration Management Corporation (FERMCO), focuses on the development and demonstration of new soil remediation processes which are faster, safer, and more economical for use at the Fernald site and throughout the DOE complex for cleanup of similar contaminants. Brookhaven National Laboratory (BNL) has developed a process which uses citric acid to treat contaminated soils and wastes with the subsequent recovery of toxic metals and uranium. Citric acid, a naturally occurring organic chelating agent, forms multidentate stable complexes with the transition metals and actinides, and has been effectively used to extract uranium and other metals from solid wastes via the formation of soluble metal citrate complexes. Further studies have also shown that several of the metal citrate complexes are readily biodegraded by microorganisms. During this process, the metals form a precipitate or become associated with the biomass and are recovered at the end of the biodegradation. Although uranyl citrate is recalcitrant to biodegradation, upon exposure to visible light it undergoes photochemical degradation resulting in the formation of an insoluble, stable polymeric form of uranium

  16. 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…

  17. Lasagna trademark soil remediation

    International Nuclear Information System (INIS)

    1996-04-01

    Lasagna trademark is an integrated, in situ remediation technology being developed which remediates soils and soil pore water contaminated with soluble organic compounds. Lasagna trademark is especially suited to sites with low permeability soils where electroosmosis can move water faster and more uniformly than hydraulic methods, with very low power consumption. The process uses electrokinetics to move contaminants in soil pore water into treatment zones where the contaminants can be captured and decomposed. Initial focus is on trichloroethylene (TCE), a major contaminant at many DOE and industrial sites. Both vertical and horizontal configurations have been conceptualized, but fieldwork to date is more advanced for the vertical configuration. Major features of the technology are electrodes energized by direct current, which causes water and soluble contaminants to move into or through the treatment layers and also heats the soil; treatment zones containing reagents that decompose the soluble organic contaminants or adsorb contaminants for immobilization or subsequent removal and disposal; and a water management system that recycles the water that accumulates at the cathode (high pH) back to the anode (low pH) for acid-base neutralization. Alternatively, electrode polarity can be reversed periodically to reverse electroosmotic flow and neutralize pH

  18. Radiation effects on biodegradable polyesters

    International Nuclear Information System (INIS)

    Hiroshi Mitomo; Darmawan Darwis; Fumio Yoshii; Keizo Makuuchi

    1999-01-01

    Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

  19. Biodegradation of di(2-ethylhexyl)phthalate in a typical tropical soil

    Energy Technology Data Exchange (ETDEWEB)

    Castelo de Moura Carrara, Silvia Marta; Morita, Dione Mari [Polytechnic School, University of Sao Paulo (Brazil); Boscov, Maria Eugenia Gimenez, E-mail: meboscov@usp.br [Polytechnic School, University of Sao Paulo (Brazil)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Scarce literature on contamination of tropical soils by phthalates. Black-Right-Pointing-Pointer Investigation of mobility of DEHP in a tropical soil by infiltration tests showed that DEHP is retained in the upper layer of the soil. Black-Right-Pointing-Pointer Low air and water permeability indicate that in situ bioremediation is not feasible for this soil. Black-Right-Pointing-Pointer Respirometric tests were inadequate to investigate biodegradation because tropical soils are acidic. Black-Right-Pointing-Pointer Slurry-phase reactor with cement mixer provided significant biodegradation (99% in 49 days). - Abstract: The aim of this research was to evaluate the possibility of biodegradation of di(2-ethylhexyl)phthalate (DEHP), widely used as an industrial plasticizer and considered an endocrine-disrupting chemical included in the U.S. Environmental Protection Agency priority list, in a Brazilian tropical soil, which has not been previously reported in the literature, despite the geographic importance of tropical soils. Preliminary laboratory testing comprised respirometric, air and water permeability, and pilot scale infiltration tests. Standard respirometric tests were found inadequate for studying biodegradation in tropical contaminated soils, due to the effect of the addition of significant amounts of calcium carbonate, necessary to adjust soil pH. Pilot scale infiltration tests performed for 5 months indicated that DEHP was retained in the superficial layer of the soil, barely migrating downwards, whereas air and water permeability tests discarded in situ bioremediation. However, ex situ bioremediation was possible, using a slurry-phase reactor with acclimated microorganisms, in pilot scale tests conducted to remediate a total mass of 150 kg of contaminated soil with 100 mg DEHP/kg. The removal of DEHP in the slurry-phase reactor achieved the percentage of 99% in 49 days, with biodegradation following a first

  20. Preliminary experience with biodegradable implants for fracture fixation

    Directory of Open Access Journals (Sweden)

    Dhillon Mandeep

    2008-01-01

    Full Text Available Background: Biodegradable implants were designed to overcome the disadvantages of metal-based internal fixation devices. Although they have been in use for four decades internationally, many surgeons in India continue to be skeptical about the mechanical strength of biodegradable implants, hence this study. Materials and Methods: A prospective study was done to assess the feasibility and surgeon confidence level with biodegradable implants over a 12-month period in an Indian hospital. Fifteen fractures (intra-articular, metaphyseal or small bone fractures were fixed with biodegradable implants. The surgeries were randomly scheduled so that different surgeons with different levels of experience could use the implants for fixation. Results: Three fractures (one humeral condyle, two capitulum, were supplemented by additional K-wires fixation. Trans-articular fixator was applied in two distal radius and two pilon fractures where bio-pins alone were used. All fractures united, but in two cases the fracture displaced partially during the healing phase; one fibula due to early walking, and one radius was deemed unstable even after bio-pin and external fixator. Conclusions: Biodegradable -implants are excellent for carefully selected cases of intra-articular fractures and some small bone fractures. However, limitations for use in long bone fractures persist and no great advantage is gained if a "hybrid" composite is employed. The mechanical properties of biopins and screws in isolation are perceived to be inferior to those of conventional metal implants, leading to low confidence levels regarding the stability of reduced fractures; these implants should be used predominantly in fracture patterns in which internal fixation is subjected to minimal stress.

  1. A survey of ethnoveterinary botanical remedies in Ogun State and ...

    African Journals Online (AJOL)

    Twenty four villages were visited during a cross sectional survey of ethno veterinary botanical remedies used for the management of animal diseases in four local government areas randomly selected cutting across the four geopolitical zones in Ogun State. A total of 323 households were purposively selected and ...

  2. Remediating sites contaminated with heavy metals

    International Nuclear Information System (INIS)

    Swartzbaugh, J.; Sturgill, J.; Cormier, B.; Williams, H.D.

    1992-01-01

    This article is intended to serve as a reference for decision makers who must choose an approach to remediate sites contaminated with heavy metals. Its purpose is to explain pertinent chemical and physical characteristics of heavy metals, how to use these characteristics to select remedial technologies, and how to interpret and use data from field investigations. Different metal species are typically associated with different industrial processes. The contaminant species behave differently in various media (i.e., groundwater, soils, air), and require different technologies for containment and treatment. We focus on the metals that are used in industries that generate regulated waste. These include steelmaking, paint and pigment manufacturing, metal finishing, leather tanning, papermaking, aluminum anodizing, and battery manufacturing. Heavy metals are also present in refinery wastes as well as in smelting wastes and drilling muds

  3. The influence of the remedy with diesel oil in impacted environment; A influencia da remediacao em ambiente impactado com oleo diesel

    Energy Technology Data Exchange (ETDEWEB)

    Bento, Douglas M.; Baisch, Paulo; Machado, Maria I.; Costa, Jorge A.V.; Martins, Vilasia [Fundacao Universidade Federal do Rio Grande (FURG), RS (Brazil)

    2004-07-01

    The conventional techniques of cleaning can be complemented with the remediation, for the use of chemical surfactant or of bio surfactant. The bioremediation minimizes the impact of recalcitrant substances in the atmosphere. The chemical surfactant can promote the fastest biodegradation of the oil, but its application should always be evaluated by professionals specialized in environment, since she can be seen as a deliberated introduction of a pollutant. The present work evaluated the influence of the use of a chemical surfactant and of a of bio surfactant (produced by the fungus Aspergillus fumigatus), in controlled spill of oil diesel, happened in at spring/2003 in the Island of the Horses located in the estuary of the Patos Lagoon. The atmosphere was monitored for 6 months, being selected a place with oil diesel, another with oil diesel and chemical surfactant and another with oil diesel and of bio surfactant. The following chemical parameters were analyzed: organic carbon, nitrogen and total match of the sediment. The statistical treatment consisted of the variance analysis (ANOVA) and in the test of Tukey (p <0,01), for the analyzed nutrients. The coming hydrocarbons of the degradation of the oil diesel will be later on certain for GC-MS. The results showed that the best environmental conditions were verified where the remediation was used. (author)

  4. 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

  5. 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 ...

  6. 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...

  7. Anaerobic biodegradation of fluoranthene under methanogenic conditions in presence of surface-active compounds

    DEFF Research Database (Denmark)

    Fuchedzhieva, Nadezhda; Karakashev, Dimitar Borisov; Angelidaki, Irini

    2008-01-01

    Bacillus cereus isolated from municipal wastewater treatment plant was used as a model strain to assess the efficiency of two anionic surfactants, a chemical surfactant and a biosurfactant during fluoranthene biodegradation under anaerobic methanogenic conditions. The surfactants selected...... for the study were linear alkyl benzene sulphonates (LAS) and rhamnolipid-biosurfactant complex from Pseudomonas sp. PS-17. Biodegradation of fluoranthene was monitored by GC/MS for a period up to 12th day. No change in the fluoranthene concentration was registered after 7th day. The presence of LAS enhanced...... the cell growth as well as the fluoranthene biodegradation. The rhamnolipid-biosurfactant at both used concentrations inhibited the cell growth and had no effect on the biodegradation rate. It was shown that LAS did not affect the microbial cell permeability and its positive effect on fluoranthene...

  8. Enhanced biodegradation of TPH and PAHs in diesel contaminated soils through bioventing

    International Nuclear Information System (INIS)

    Nickerson, D.A.; Baker, J.N.

    1995-01-01

    A bioventing system was designed and installed to enhance the natural biodegradation of diesel fuel residuals in soils at an underground storage tank (UST) facility in Pittsburgh, Pennsylvania. This system was designed to operate in conjunction with a groundwater pump and treatment system which exposes the more heavily contaminated soils at the capillary fringe to ambient air supplied to the subsurface at a low flow rate from a single vertical injection point. Results of a pilot study conducted at the facility indicated that an initial average biodegradation rate of 2,100 milligrams of total petroleum hydrocarbons (TPH) per kilogram of soil per year could be achieved, making enhanced in situ biodegradation a feasible and cost-effective remedial alternative for soil cleanup. Oxygen (O 2 ), carbon dioxide (CO 2 ), and hydrocarbon vapor concentrations and pressure responses were measured in vapor monitoring points constructed at various depth intervals and varying distances from the central air injection point. Results indicate that the system is capable of providing sufficient oxygen to maintain microbial biodegradation of residual petroleum hydrocarbons within a radius of 70 feet of the injection point. Soil samples were collected during the installation of the vapor monitoring points and analyzed for TPH and PAH (Polynuclear Aromatic Hydrocarbon) concentrations to provide baseline analytical data from the areas of highest known contamination. A soil sampling program will be implemented to independently confirm the amount of TPH and PAH reduction that has occurred after the initial six-months of full-scale bioventing operation

  9. Biodegradation and ecotoxicity of soil contaminated by pentachlorophenol applying bioaugmentation and addition of sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Zuzana, S.; Katarina, D.; Livia, T. [Slovak Technical University Bratislava, Bratislava (Slovakia). Dept. of Biochemical Technology

    2009-02-15

    Biodegradation of pentachlorophenol (PCP) in soil by autochthonous microorganisms and in soil bioaugmented by the bacterial strain Comamonas testosteroni CCM 7530 was studied. Subsequent addition of organomineral complex (OMC) or lignite as possible sorbents for PCP immobilization has been investigated as well. The OMC was prepared from humic acids (HAs) isolated from lignite by binding them onto zeolite. Biodegradation of PCP and number of colony forming units (CFUs) were determined in the three types of soil, Chernozem, Fluvisol, and Regosol, freshly spiked with PCP and amended separately with tested sorbents. The enhancing effect of sorbent addition and bioaugmentation on PCP biodegradation depended mainly on the soil type and the initial PCP concentration. Microbial activity resulted in biotransformation of PCP into certain toxic substances, probably lower chlorinated phenols that are more soluble than PCP, and therefore more toxic to present biota. Therefore, it was necessary to monitor soil ecotoxicity during biodegradation. Addition of the OMC resulted in a more significant decrease of soil toxicity in comparison with addition of lignite. Lignite and OMC appear to be good traps for PCP with potential application in remediation technology.

  10. Optimizing BTEX biodegradation under denitrifying conditions

    International Nuclear Information System (INIS)

    Hutchins, S.R.

    1991-01-01

    Leaking underground storage tanks are a major source of ground water contamination by petroleum hydrocarbons. Gasoline and other fuels contain benzene, toluene, ethylbenzene, and xylenes (collectively known as BTEX), which are hazardous compounds, regulated by the U.S. Environmental Protection Agency (EPA). Laboratory tests were conducted to determine optimum conditions for benzene, toluene, ethylbenzene, and xylene (collectively known as BTEX) biodegradation by aquifer microorganisms under denitrifying conditions. Microcosms, constructed with aquifer samples from Traverse City, Michigan, were amended with selected concentrations of nutrients and one or more hydrocarbons. Toluene, ethylbenzene, m-xylene, and p-xylene, were degraded to below 5 micrograms/L when present as sole source substrates; stoichiometric calculations indicated that nitrate removal was sufficient to account for 70 to 80% of the compounds being mineralized. o-Xylene was recalcitrant when present as a sole source substrate, but was slowly degraded in the presence of the other hydrocarbons. Benzene was not degraded within one year, regardless of whether it was available as a sole source substrate or in combination with toluene, phenol, or catechol. Pre-exposure to low levels of BTEX and nutrients had variable effects, as did the addition of different concentrations of ammonia and phosphate. Nitrate concentrations as high as 500 mg/L NO3-N were slightly inhibitory. These data indicate that nitrate-mediated biodegradation of BTEX at Traverse City can occur under a variety of environmental conditions with rates relatively independent of nutrient concentrations. However, the data reaffirm that benzene is recalcitrant under strictly anaerobic conditions in these samples

  11. Cognitive Remediation in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Joana Vieira

    2014-06-01

    Full Text Available Several reviews of the literature support the idea that cognitive deficits observed in a large percentage of patients with schizophrenia are responsible for the cognitive performance deficit and functional disability associated with the disease. The grow- ing importance of neurocognition in Psychiatry, especially with regard to planning strategies and rehabilitative therapies to improve the prognosis of patients contrib- utes to the interest of achieving this literature review on cognitive rehabilitation in schizophrenia. In this work, drawn from research in the areas of schizophrenia, cog- nition, cognitive rehabilitation and cognitive remediation (2000-2012 through PubMed and The Cochrane Collaboration, it is intended, to describe the types of psychological and behavioral therapies recommended in the treatment of cognitive disabilities in patients diagnosed with schizophrenia. This review will also highlight the clinical and scientific evidence of each of these therapies, as their effect on cognitive performance, symptoms and functionality in patients with schizophrenia.

  12. Biodegradable polymers in Quebec; Les polymeres biodegradables au Quebec

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Poly-hydroxy-alkanoates (PHA) are natural polymers made from renewable resources and are easily recyclable, hydrolyzable and biodegradable. Thanks to genetic technologies, PHA can be synthesized from plants or bacteria and can be used in various domains ranging from the manufacturing of packing materials to medical applications. Moreover, their properties make them good substitutes of equivalent petroleum-derived compounds. This report makes a status of Quebec's research work on PHAs and presents the three main research centers in which such studies are carried out: the biotechnology research institute, the Mc Gill university and the Polytechnique school of Montreal. (J.S.)

  13. Biodegradability and biodegradation pathways of endosulfan and endosulfan sulfate.

    Science.gov (United States)

    Kataoka, Ryota; Takagi, Kazuhiro

    2013-04-01

    Endosulfan and endosulfan sulfate are persistent organic pollutants that cause serious environmental problems. Although these compounds are already prohibited in many countries, residues can be detected in soils with a history of endosulfan application. Endosulfan is transformed in the environment into endosulfan sulfate, which is a toxic and persistent metabolite. However, some microorganisms can degrade endosulfan without producing endosulfan sulfate, and some can degrade endosulfan sulfate. Therefore, biodegradation has the potential to clean up soil contaminated with endosulfan. In this review, we provide an overview of aerobic endosulfan degradation by bacteria and fungi, and a summary of recent advances and prospects in this research field.

  14. Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review

    Energy Technology Data Exchange (ETDEWEB)

    Haritash, A.K., E-mail: akharitash@gmail.com [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar, Haryana (India); Kaushik, C.P. [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar, Haryana (India)

    2009-09-30

    and the rate can be enhanced by physical/chemical pretreatment of contaminated soil. Addition of biosurfactant-producing bacteria and light oils can increase the bioavailability of PAHs and metabolic potential of the bacterial community. The supplementation of contaminated soils with compost materials can also enhance biodegradation without long-term accumulation of extractable polar and more available intermediates. Wetlands, too, have found an application in PAH removal from wastewater. The intensive biological activities in such an ecosystem lead to a high rate of autotrophic and heterotrophic processes. Aquatic weeds Typha spp. and Scirpus lacustris have been used in horizontal-vertical macrophyte based wetlands to treat PAHs. An integrated approach of physical, chemical, and biological degradation may be adopted to get synergistically enhanced removal rates and to treat/remediate the contaminated sites in an ecologically favorable process.

  15. Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review

    International Nuclear Information System (INIS)

    Haritash, A.K.; Kaushik, C.P.

    2009-01-01

    be enhanced by physical/chemical pretreatment of contaminated soil. Addition of biosurfactant-producing bacteria and light oils can increase the bioavailability of PAHs and metabolic potential of the bacterial community. The supplementation of contaminated soils with compost materials can also enhance biodegradation without long-term accumulation of extractable polar and more available intermediates. Wetlands, too, have found an application in PAH removal from wastewater. The intensive biological activities in such an ecosystem lead to a high rate of autotrophic and heterotrophic processes. Aquatic weeds Typha spp. and Scirpus lacustris have been used in horizontal-vertical macrophyte based wetlands to treat PAHs. An integrated approach of physical, chemical, and biological degradation may be adopted to get synergistically enhanced removal rates and to treat/remediate the contaminated sites in an ecologically favorable process.

  16. Rail transportation of Fernald remediation waste

    International Nuclear Information System (INIS)

    Fellman, R.T.; Lojek, D.A.; Motl, G.P.; Weddendorf, W.K.

    1995-01-01

    Remediation of the Department of Energy (DOE) Fernald site located north of Cincinnati will generate large quantities of low-level radwaste. This volume includes approximately 1,050,000 tons of material to be removed from eight waste pits comprising Operable Unit 1 (OU-1). The remedial alternative selected includes waste material excavation, drying and transportation by rail to a burial site in the arid west for disposal. Rail transportation was selected not only because rail transportation is safer than truck transportation, but also because of the sheer magnitude of the project and the availability of bulk rail car unloading facilities at a representative disposal site. Based upon current waste quantity estimates as presented in the Feasibility Study for OUI, a fully-loaded 47-car unit train would depart the Fernald site weekly for five years. This paper illustrates the steps taken to obtain agency and public acceptance of the Record of Decision for the remedy which hinged on rail transportation. A preliminary, but detailed, rail transportation plan was prepared for the project to support a series of CERCLA public meetings conducted in late 1994. Some of the major issues addressed in the plan included the following: (1) Scope of project leading to selection of rail transportation; (2) Waste classification; (3) Rail Company overview; (4) Train configuration and rail car selection; (5) Routing; (6) Safety; (7) Prior Notification Requirements (8) Emergency Response. A series of three public meetings identified a number of issues of prime concern to Fernald stakeholders. Following resolution of these issues during the public comment period, a Record of Decision (ROD) approving implementation of the rail transportation strategy was approved pending incorporation of EPA and State of Ohio comments on December 22, 1994

  17. Remedial Action Plan and Site design for stabilization of the inactive Uranium Mill Tailings sites at Slick Rock, Colorado: Revision 1. Remedial action selection report, Attachment 2, geology report, Attachment 3, ground water hydrology report, Attachment 4, water resources protection strategy. Final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The Slick Rock uranium mill tailings sites are located near the small community of Slick Rock, in San Miguel County, Colorado. There are two designated Uranium Mill Tailings Remedial Action (UMTRA) Project sites at Slick Rock: the Union Carbide site and the North Continent site. Both sites are adjacent to the Dolores River. The sites contain former mill building concrete foundations, tailings piles, demolition debris, and areas contaminated by windblown and waterborne radioactive materials. The total estimated volume of contaminated materials is approximately 621,000 cubic yards (475,000 cubic meters). In addition to the contamination at the two processing site areas, 13 vicinity properties were contaminated. Contamination associated with the UC and NC sites has leached into ground water. Pursuant to the requirements of the Uranium Mill Tailings Radiation Control Act (UMTRCA) (42 USC {section}7901 et seq.), the proposed remedial action plan (RAP) will satisfy the final US Environmental Protection Agency (EPA) standards in 40 CFR Part 192 (60 FR 2854) for cleanup, stabilization, and control of the residual radioactive material (RRM) (tailings and other contaminated materials) at the disposal site at Burro Canyon. The requirements for control of the RRM (Subpart A) will be satisfied by the construction of an engineered disposal cell. The proposed remedial action will consist of relocating the uranium mill tailings, contaminated vicinity property materials, demolition debris, and windblown/weaterborne materials to a permanent repository at the Burro Canyon disposal site. The site is approximately 5 road mi (8 km) northeast of the mill sites on land recently transferred to the DOE by the Bureau of Land Management.

  18. Remedial Action Plan and Site design for stabilization of the inactive Uranium Mill Tailings sites at Slick Rock, Colorado: Revision 1. Remedial action selection report, Attachment 2, geology report, Attachment 3, ground water hydrology report, Attachment 4, water resources protection strategy. Final

    International Nuclear Information System (INIS)

    1995-09-01

    The Slick Rock uranium mill tailings sites are located near the small community of Slick Rock, in San Miguel County, Colorado. There are two designated Uranium Mill Tailings Remedial Action (UMTRA) Project sites at Slick Rock: the Union Carbide site and the North Continent site. Both sites are adjacent to the Dolores River. The sites contain former mill building concrete foundations, tailings piles, demolition debris, and areas contaminated by windblown and waterborne radioactive materials. The total estimated volume of contaminated materials is approximately 621,000 cubic yards (475,000 cubic meters). In addition to the contamination at the two processing site areas, 13 vicinity properties were contaminated. Contamination associated with the UC and NC sites has leached into ground water. Pursuant to the requirements of the Uranium Mill Tailings Radiation Control Act (UMTRCA) (42 USC section 7901 et seq.), the proposed remedial action plan (RAP) will satisfy the final US Environmental Protection Agency (EPA) standards in 40 CFR Part 192 (60 FR 2854) for cleanup, stabilization, and control of the residual radioactive material (RRM) (tailings and other contaminated materials) at the disposal site at Burro Canyon. The requirements for control of the RRM (Subpart A) will be satisfied by the construction of an engineered disposal cell. The proposed remedial action will consist of relocating the uranium mill tailings, contaminated vicinity property materials, demolition debris, and windblown/weaterborne materials to a permanent repository at the Burro Canyon disposal site. The site is approximately 5 road mi (8 km) northeast of the mill sites on land recently transferred to the DOE by the Bureau of Land Management

  19. Innovative vitrification for soil remediation

    International Nuclear Information System (INIS)

    Jetta, N.W.; Patten, J.S.; Hnat, 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 I 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

  20. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    2000-01-01

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization...... in the order of 200 days. Higher concentrations of 2,4-D resulted in a grossly overestimate of the actual degradation rate for concentrations characteristic for Danish found in groundwater....

  1. Evaluation of biodegradation and biocompatibility of collagen ...

    Indian Academy of Sciences (India)

    ing material in tissue engineering applications owing to its excellent biocompatibility and biodegradability [2]. How- ever, its fast biodegradation and low mechanical strength are the foremost issues that limit the further uses of this material. Another extensively studied material is chitosan, a linear polysaccharide derived by ...

  2. Enhancing the biodegradation process of cassava ( Manihot ...

    African Journals Online (AJOL)

    Cassava (Manihot esculenta Crantz) peels have been implicated in serious environmental pollution. This study was aimed at investigating the effect of N.P.K (15:15:15) and microbial inoculants on the biodegradation process of cassava peels. Fresh cassava peels were subjected to biodegradation process for twenty weeks.

  3. Biodegradation of phenol by Pseudomonas pictorum on ...

    African Journals Online (AJOL)

    Biodegradation of phenol using Pseudomonas pictorum (ATCC 23328) a potential biodegradant of phenol was investigated under different operating conditions. Chitin was chosen as a support material and then partially characterized physically and chemically. The pH of the solution was varied over a range of 7 – 9.

  4. Biodegradation of dodecylbenzene solfonate sodium by ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-01-04

    Jan 4, 2010 ... Key words: Branched anionic surfactants, biofilm, biodegradation, silanization. ... polymers, pesticides, oil recovery, textiles and paper ... surfactants are not degraded by microorganisms in the environment. Because of its low biodegradation ability and toxic effects on environment, BAS was forbidden in.

  5. Biodegradation of phenol with immobilized Pseuodomonas putida ...

    African Journals Online (AJOL)

    Biodegradation of phenol with immobilized Pseuodomonas putida activated carbon packed bio-filter tower. ... Comparative study on adsorption and simultaneous adsorption and biodegradation (SAB) of phenol using Pseuodomonas putida (MTCC 1194) in a biofilter tower packed with fresh granular activated carbon (GAC) ...

  6. Nylon biodegradation by lignin-degrading fungi.

    Science.gov (United States)

    Deguchi, T; Kakezawa, M; Nishida, T

    1997-01-01

    The biodegradation of nylon by lignin-degrading fungi was investigated. The fungus IZU-154 significantly degraded nylon-66 membrane under ligninolytic conditions. Nuclear magnetic resonance analysis showed that four end groups, CHO, NHCHO, CH3, and CONH2, were formed in the biodegraded nylon-66 membranes, suggesting that nylon-66 was degraded oxidatively. PMID:8979361

  7. Nylon biodegradation by lignin-degrading fungi.

    OpenAIRE

    Deguchi, T; Kakezawa, M; Nishida, T

    1997-01-01

    The biodegradation of nylon by lignin-degrading fungi was investigated. The fungus IZU-154 significantly degraded nylon-66 membrane under ligninolytic conditions. Nuclear magnetic resonance analysis showed that four end groups, CHO, NHCHO, CH3, and CONH2, were formed in the biodegraded nylon-66 membranes, suggesting that nylon-66 was degraded oxidatively.

  8. Biodegradability of electrostatic photocopier toners | Odokuma ...

    African Journals Online (AJOL)

    Biodegradation was monitored over a 28-day period using changes total organic carbon (TOC), Dissolved organic carbon (DOC) ratio of DOC to TOC (Primary biodegradation) and Biochemical Oxygen Demand (BOD) measurements. At day 0 the BOD for Fresh Sharp, Reused Sharp, Fresh Minolta and Reused Minolta ...

  9. Formulation and Characterization of Biodegradable Medicated ...

    African Journals Online (AJOL)

    (TPA), biodegradation, in vitro drug release using a modified chewing apparatus, and sensory properties. Result: Formulations code MCG-5 and MCG-9 which incorporated glyceryl triacetate and castor oil as plasticizers, respectively, showed a biodegradation score of 2 and 1, respectively, indicating significant.

  10. Simultaneous adsorption and biodegradation of synthetic melanoidin

    African Journals Online (AJOL)

    Being an antioxidant, melanoidin removal through purely biodegradation has been inadequate. Consequently, in the current study, simultaneous adsorption and biodegradation (SAB) was employed in a stirred tank system to remove melanoidin from synthetic wastewater. Mixed microbial consortium was immobilized onto ...

  11. 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)

  12. Dissolution Coupled Biodegradation of Pce by Inducing In-Situ Biosurfactant Production Under Anaerobic Conditions

    Science.gov (United States)

    Dominic, J.; Nambi, I. M.

    2013-12-01

    Biosurfactants have proven to enhance the bioavailability and thereby elevate the rate of degradation of Light Non Aqueous Phase Liquids (LNAPLs) such as crude oil and petroleum derivatives. In spite of their superior characteristics, use of these biomolecules for remediation of Dense Non Aqueous Phase Liquids (DNAPLs) such as chlorinated solvents is still not clearly understood. In this present study, we have investigated the fate of tetrachloroethylene (PCE) by inducing in-situ biosurfactants production, a sustainable option which hypothesizes increase in bioavailability of LNAPLs. In order to understand the effect of biosurfactants on dissolution and biodegradation under the inducement of in-situ biosurfactant production, batch experiments were conducted in pure liquid media. The individual influence of each process such as biosurfactant production, dissolution of PCE and biodegradation of PCE were studied separately for getting insights on the synergistic effect of each process on the fate of PCE. Finally the dissolution coupled biodegradation of non aqueous phase PCE was studied in conditions where biosurfactant production was induced by nitrate limitation. The effect of biosurfactants was differentiated by repeating the same experiments were the biosurfactant production was retarded. The overall effect of in-situ biosurfactant production process was evaluated by use of a mathematical model. The process of microbial growth, biosurfactant production, dissolution and biodegradation of PCE were translated as ordinary differential equations. The modelling exercise was mainly performed to get insight on the combined effects of various processes that determine the concentration of PCE in its aqueous and non-aqueous phases. Model simulated profiles of PCE with the kinetic coefficients evaluated earlier from individual experiments were compared with parameters fitted for observations in experiments with dissolution coupled biodegradation process using optimization

  13. Biodegradable polymers for electrospinning: towards biomedical applications.

    Science.gov (United States)

    Kai, Dan; Liow, Sing Shy; Loh, Xian Jun

    2014-12-01

    Electrospinning has received much attention recently due to the growing interest in nano-technologies and the unique material properties. This review focuses on recent progress in applying electrospinning technique in production of biodegradable nanofibers to the emerging field of biomedical. It first introduces the basic theory and parameters of nanofibers fabrication, with focus on factors affecting the morphology and fiber diameter of biodegradable nanofibers. Next, commonly electrospun biodegradable nanofibers are discussed, and the comparison of the degradation rate of nanoscale materials with macroscale materials are highlighted. The article also assesses the recent advancement of biodegradable nanofibers in different biomedical applications, including tissue engineering, drug delivery, biosensor and immunoassay. Future perspectives of biodegradable nanofibers are discussed in the last section, which emphasizes on the innovation and development in electrospinning of hydrogels nanofibers, pore size control and scale-up productions. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Biodegradation of bioplastics in natural environments.

    Science.gov (United States)

    Emadian, S Mehdi; Onay, Turgut T; Demirel, Burak

    2017-01-01

    The extensive production of conventional plastics and their use in different commercial applications poses a significant threat to both the fossil fuels sources and the environment. Alternatives called bioplastics evolved during development of renewable resources. Utilizing renewable resources like agricultural wastes (instead of petroleum sources) and their biodegradability in different environments enabled these polymers to be more easily acceptable than the conventional plastics. The biodegradability of bioplastics is highly affected by their physical and chemical structure. On the other hand, the environment in which they are located, plays a crucial role in their biodegradation. This review highlights the recent findings attributed to the biodegradation of bioplastics in various environments, environmental conditions, degree of biodegradation, including the identified bioplastic-degrading microorganisms from different microbial communities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Chaos and remedial investigations

    International Nuclear Information System (INIS)

    Galbraith, R.M.

    1991-01-01

    Current research into the nature of chaos indicates that even for systems that are well known and easily modeled, slight changes in the scale used to measure the input have unpredictable results in the model output. The conduct of a remedial investigation (RI) is dictated by well-established rules of investigation and management, yet small changes in project orientation, regulatory environment, or site conditions have unpredictable consequences to the project. The consequences can lead to either brilliant success or utter failure. The chaotic effect of a change in scale is most often illustrated by an exercise in measuring the length of the coast of Great Britain. If a straight ruler 10-kilometers long is used, the sum of the 10-kilometer increments gives the length of the coast. If the ruler is changed to five kilometers long and the exercise is repeated, the sum of the five-kilometer increments will not be the same as the sum of the 10-kilometer increments. Nor is there a way to predict what the length of the coast will be using any other scale. Several examples from the Fernald Project RI are used to illustrate open-quotes changes in scaleclose quotes in both technical and management situations. Given that there is no way to predict the outcome of scale changes in a RI, technical and project management must be alert to the fact that a scale has changed and the investigation is no longer on the path it was thought to be on. The key to success, therefore, is to develop specific units of measure for a number of activities, in addition to cost and schedule, and track them regularly. An example for tracking a portion of the field investigation is presented. The determination of effective units of measure is perhaps the most difficult aspect of any project. Changes in scale sometimes go unnoticed until suddenly the budget is expended and only a portion of the work is completed. Remedial investigations on large facilities provide new and complex challenges

  16. Assessment of international remedial technologies for application to Superfund sites

    International Nuclear Information System (INIS)

    Sanning, D.E.

    1990-01-01

    This paper presents some of the logical arguments for conducting research on remedial technologies for contaminated land and groundwater at an international level. It gives information on many of the international organizations that are involved in environmental programs, but it especially gives emphasis to the NATO-CCMS pilot study on Demonstration of Remedial Action Technologies for Contaminated Land and Groundwater. The purpose of the study is to field demonstrate and evaluate new/innovative technologies for remedial action at uncontrolled hazardous waste sites. This study is a logical international extension of the US EPA SITE program. It offers the opportunity to obtain a multiple data base on various remedial action unit processes without any single country having to commit a disproportionate amount of its internal resources to any specific activity. Each participating country provides the necessary resources for those demonstrations which they are contributing to the study. Sites are selected by a majority vote of all participating countries (no country is permitted to vote for its own sites). The study is a 5 year program with participants from Canada, Denmark, Federal Republic of Germany, France, Greece, Italy, Japan, the Netherlands, Norway, Spain, and the US. The need for cost-effective remedial action technologies for hazardous waste sites is a problem of all industrialized countries. The need to build a knowledge base of emerging remedial technologies was the impetus behind the USEPA's lead role and commitment to this pilot study

  17. Air sparging and soil vapor extraction to remediate ground water

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, T.P.; Finkbeiner, J.A.; Warmus, P.J. [ATEC Associates, Inc., Raleigh, NC (United States)

    1994-12-31

    An Air Sparging and Soil Vapor Extraction System was chosen to remediate petroleum impacted ground water over traditional remedial alternatives, such as ``pump and treat``, to expedite site closure. Field pilot testing, computer modeling and cost benefit analyses performed for several alternatives. Air Sparging and Soil Vapor Extraction pilot studies proved this technology to be the most effective with respect to remedial and economic concerns. Underground Storage Tanks (USTs) were closed at the facility located in North Eastern North Carolina in August of 1992. During UST closure, petroleum impacted ground water and soils were encountered. ATEC performed a Comprehensive Site assessment to delineate the impacted soil and ground water plume. Following completion of the site assessment, a Corrective Action Plan was prepared. As part of the Corrective Action Plan preparation, field pilot testing was performed to evaluate remedial alternatives and provide information for full scale design. The full scale treatment system was installed and started in January 1994. This effective Remedial System was selected over other options due to successful pilot testing results with site closure petitioning scheduled within 12 to 14 months after start up. The Air Sparging System, properly applied, is an effective and ``quick`` remedial option with no generation of ground water for disposal and permitting. This paper concentrates on the Air Sparging application applied at this North Carolina site. Although Vapor extraction was also implemented, this presentation does not elaborate on vapor extraction design or implementation and only discusses vapor extraction where it is directly related to the Air Sparging System.

  18. Respirometric evaluation of biodegradation characteristics of dairy wastewater for organic carbon removal.

    Science.gov (United States)

    Ubay Cokgör, E; Sözen, S; Insel, G; Orhon, D

    2009-10-01

    This study evaluates the biodegradation kinetics of an integrated dairy wastewater, with the main purpose of defining the experimental basis for modelling of the activated sludge process. Besides conventional characterization, the experiments involved detailed chemical oxygen demand (COD) fractionation and assessment of major kinetic and stoichiometric coefficients, by using respirometric methods. A multi-component model based on the endogenous decay concept was used for the kinetic interpretation. The results of conventional analyses and respirometric evaluations together with the assessment of residual components showed that the organic carbon content of the dairy wastewater was mostly soluble and biodegradable. The soluble, slowly biodegradable COD was the major COD fraction, representing around 50% of the total COD. Model calibration of the oxygen uptake rate profiles were consistent and revealed the existence of dual hydrolysis kinetics for soluble and particulate COD components. The hydrolysis rate associated with the main COD component--the soluble, slowly biodegradable COD fraction--was found to be 1.2 d(-1), which is quite low and underlines the role of this COD fraction as the rate-limiting factor for effluent quality. Simulation of process efficiency by the adopted model, calibrated with the experimentally determined parameters, indicated that effective control of the biodegradation of the soluble biodegradable COD components could be done by selection of appropriate values for the sludge age and hydraulic retention time. In this way, the total effluent soluble COD level could be lowered to 30-40 mg L(-1) range, in conformity with effluent limitations.

  19. Biodegradation and attenuation of steroidal hormones and alkylphenols by stream biofilms and sediments

    Science.gov (United States)

    Writer, Jeffrey; Barber, Larry B.; Ryan, Joseph N.; Bradley, Paul M.

    2011-01-01

    Biodegradation of select endocrine-disrupting compounds (17β-estradiol, estrone, 17α-ethynylestradiol, 4-nonylphenol, 4-nonylphenolmonoexthoylate, and 4-nonylphenoldiethoxylate) was evaluated in stream biofilm, sediment, and water matrices collected from locations upstream and downstream from a wastewater treatment plant effluent discharge. Both biologically mediated transformation to intermediate metabolites and biologically mediated mineralization were evaluated in separate time interval experiments. Initial time intervals (0–7 d) evaluated biodegradation by the microbial community dominant at the time of sampling. Later time intervals (70 and 185 d) evaluated the biodegradation potential as the microbial community adapted to the absence of outside energy sources. The sediment matrix was more effective than the biofilm and water matrices at biodegrading 4-nonylphenol and 17β-estradiol. Biodegradation by the sediment matrix of 17α-ethynylestradiol occurred at later time intervals (70 and 185 d) and was not observed in the biofilm or water matrices. Stream biofilms play an important role in the attenuation of endocrine-disrupting compounds in surface waters due to both biodegradation and sorption processes. Because sorption to stream biofilms and bed sediments occurs on a faster temporal scale (185 d), these compounds can accumulate in stream biofilms and sediments.

  20. Kinetics of Organic Matter Biodegradation in Leachate from Tobacco Waste

    Directory of Open Access Journals (Sweden)

    Briški, F.

    2012-09-01

    initial substrate concentrations on biomass growth rate in comparison with Monod model are presented in Figs. 3 and 4. These results suggest that selected model de scribes well the biodegradation process of leachate in batch reactor. Microscopic examination of activated sludge showed that flocs were healthy and compact, with simultaneous formation of young flocs (Table 3, Figs. 5a and 5b. Figure 6 presents the decrease in organic matter in the leachate and increase in activated sludge concentration within two days of biodegradation during which activated sludge showed strong ability to degrade organic matter, while process efficiency (Fig. 7 was approximately 80.3 %.

  1. Opium the Best Remedy

    Directory of Open Access Journals (Sweden)

    Harold Merskey

    2004-01-01

    Full Text Available Sydenham was the leading English physician of the 17th century and probably to the present time. He was using a well tried remedy. It had been known by then for about 4000 years, frequently mentioned by Hippocrates, and recognized in use in medieval Europe where it probably came through Arabic traders and was well established in use in Paris by the 12th century (2. Professional concerns up to the time of Sydenham were not about addiction. As can be seen from his text, they were about whether the drug was available in adequate preparations, whether there was any difference between opium and other narcotics, particularly comparing the natural juice with "its artificial preparations" (1 (all of which he thought to be about equal in effect, whether it was stimulant or restorative and invigorating, and whether it was being properly used for all the conditions in which it could be helpful. Addiction, dependence and insanity are not mentioned, although the fact that it could occasionally promote excitement ("frenzy" was known.

  2. A responsible remediation strategy

    International Nuclear Information System (INIS)

    Knowles, C.R.

    1992-01-01

    This paper deals with an approach to cleaning up the residue of 150 years of intense urban and industrial development in the United States. The discussion focuses on several choices and strategies that business can adopt given the existing environmental laws and the socio-economic trends of the 1990's. The thesis of this paper is that the best business strategy for dealing with environmental liabilities is to act affirmatively and aggressively. An aggressive, pro-active approach to environmental remediation liabilities makes good business sense. It allows a company to learn the true size of the problem early. Early assessment and prioritization allows one to control the course and conduct of the cleanup. Early voluntary action is always viewed favorably by agencies. It gives one control over spending patterns which has value in and of itself. Voluntary cleanups are certainly faster and invariably more efficient. And they attain clearly acceptable standards. The volunteering company that takes the lead in a multi-party site finds that the courts are supportive in helping the volunteer collect from recalcitrant polluters. All of these pluses have a direct and positive impact on the bottom line and that means that the aggressive approach is the right thing to do for both stockholders and the communities where a business exists

  3. 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.

  4. Honey: An Effective Cough Remedy?

    Science.gov (United States)

    ... cough remedy? Is it true that honey calms coughs better than cough medicine does? Answers from James M. Steckelberg, M. ... throat. But honey alone may be an effective cough suppressant, too. In one study, children age 2 ...

  5. The Role of Attached and Free-Living Bacteria in Biodegradation in Karst Aquifers

    Directory of Open Access Journals (Sweden)

    Ahmad Kheder

    2011-12-01

    Full Text Available Natural attenuation of groundwater contamination occurs at some level for all aquifers impacted with organic contaminants. The issues regarding natural attenuation are whether it takes place at a sufficient rate to be protective of human health and the environment. Implementation of a Monitored Natural Attenuation (MNA remedial alternative for groundwater requires parties responsible for the contamination to demonstrate to regulators and the public that MNA is protective at a given site. Analysis of MNA for remediation of karst aquifers is hampered by a lack of understanding of biodegradation in karst environments. The lack of studies examining biodegradation in karst aquifers may in large part be due to the widespread perception that contaminants are rapidly flushed out of karst aquifers resulting in insufficient residence times for contaminants to biodegrade. In highly developed and well-connected conduit systems, the rate of contaminant migration is perceived to be much faster than the rate of biodegradation. This perception of contaminant transport is largely incorrect. Tracer studies for karst aquifers often indicate that these aquifers are characterized by diverse flow regimes and storage capabilities. Additionally, it is also believed that if bioremediation in bedrock aquifers is dependent upon contact between surface-attached bacteria and contaminants, then bioremediation would be limited by the low surface-area-to-volume ratio (SA/V of karst aquifers. A quantitative basis, however, for accepting or rejecting the assumption that attached bacteria dominate the biodegradation process in karst conduits has not been shown. The objective of this research was to determine if free-living karst bacteria from contributed as much to toluene biodegradation as attached bacteria. This is an important area of research. Research indicates bacteria are both attached and free-living in karst aquifers and it is unrealistic to think that only the attached

  6. Tank Waste Remediation System optimized processing strategy

    International Nuclear Information System (INIS)

    Slaathaug, E.J.; Boldt, A.L.; Boomer, K.D.; Galbraith, J.D.; Leach, C.E.; Waldo, T.L.

    1996-03-01

    This report provides an alternative strategy evolved from the current Hanford Site Tank Waste Remediation System (TWRS) programmatic baseline for accomplishing the treatment and disposal of the Hanford Site tank wastes. This optimized processing strategy performs the major elements of the TWRS Program, but modifies the deployment of selected treatment technologies to reduce the program cost. The present program for development of waste retrieval, pretreatment, and vitrification technologies continues, but the optimized processing strategy reuses a single facility to accomplish the separations/low-activity waste (LAW) vitrification and the high-level waste (HLW) vitrification processes sequentially, thereby eliminating the need for a separate HLW vitrification facility

  7. Automated remedial assessment methodology software system

    International Nuclear Information System (INIS)

    Whiting, M.; Wilkins, M.; Stiles, D.

    1994-11-01

    The Automated Remedial Analysis Methodology (ARAM) software system has been developed by the Pacific Northwest Laboratory to assist the U.S. Department of Energy (DOE) in evaluating cleanup options for over 10,000 contaminated sites across the DOE complex. The automated methodology comprises modules for decision logic diagrams, technology applicability and effectiveness rules, mass balance equations, cost and labor estimating factors and equations, and contaminant stream routing. ARAM is used to select technologies for meeting cleanup targets; determine the effectiveness of the technologies in destroying, removing, or immobilizing contaminants; decide the nature and amount of secondary waste requiring further treatment; and estimate the cost and labor involved when applying technologies

  8. A Simple and Effective Remedial Learning System with a Fuzzy Expert System

    Science.gov (United States)

    Lin, C.-C.; Guo, K.-H.; Lin, Y.-C.

    2016-01-01

    This study aims at implementing a simple and effective remedial learning system. Based on fuzzy inference, a remedial learning material selection system is proposed for a digital logic course. Two learning concepts of the course have been used in the proposed system: number systems and combinational logic. We conducted an experiment to validate…

  9. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lihui [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Zhang, Yongming, E-mail: zhym@shnu.edu.cn [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Bai, Qi; Yan, Ning; Xu, Hua [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Rittmann, Bruce E. [Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, AZ 85287-5701 (United States)

    2015-04-28

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.

  10. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    International Nuclear Information System (INIS)

    Yang, Lihui; Zhang, Yongming; Bai, Qi; Yan, Ning; Xu, Hua; Rittmann, Bruce E.

    2015-01-01

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA

  11. Biodegradation of bituminous products from processing liquid radioactive wastes

    International Nuclear Information System (INIS)

    Tibensky, L.; Krejci, F.; Hladky, E.; Halama, D.

    1988-01-01

    One of the possible ways of disturbing the stability of bituminous products from liquid radioactive waste processing, is biodegradation caused by common microorganisms. Pseudomonas bacteria and a Bacillus cereus culture were selected for experimental study of cultivation of microorganisms. Experiments with mixed cultures were also performed. Pitches, ajatin and imidazoline were used as inhibitors. The thin layer and the emulsion methods were used in assessing biological corrosion. The results of the experiments are discussed with respect to the dependence of bacterial growth on bitumen biodegradation, the effect of pH on bitumen degradation and the effect of inhibitors on bitumen biodegradation. The salts contained in bituminous products were not found to significantly affect the rate of destruction. The degree of degradation was found to mainly depend on the bitumen, its chemical composition, and on the conditions of storage. It was also found that inhibitor additions in some cases modified the properties of the matrix such that it became more liquid. The coefficient of extractibility thus increased of matrix salts. The recultivation of bacteria on a full-value medium resulted in the loss of the inhibitory effect. In some cases, the inhibitor even stimulated the growth of microorganisms. The use of inhibitors in an effort to achieve biostability of bituminous products thus did not solve the problem. (Z.M.). 2 tabs., 9 refs

  12. Biodegradation of Petroleum Hydrocarbon Vapors In Unsaturated Alluvial Sand

    Science.gov (United States)

    Höhener, P.; Duwig, C.; Pasteris, G.; Dakhel, N.; Kaufmann, K.; Werner, D.

    Biodegradation rates are critical parameters in models aimed at predicting the nat- ural attenuation of volatile organic compounds (VOCs) in the unsaturated zone. In this study the kinetic rate laws for the aerobic biodegradation of selected petroleum hydrocarbons and MTBE were investigated in unsaturated alluvial sand exposed to the vapors from a fuel mixture. Laboratory column and batch experiments were per- formed at room temperature under aerobic conditions. An analytical reactive transport model for VOC vapors in soil based on Monod kinetics is used for data interpretation. In the column experiment, steady-state diffusive vapor transport was reached after 23 days. Monod kinetic parameters were derived from the column profiles for toluene, m-xylene, octane and hexane. The degradation of cyclic alkanes, isooctane, and 1,2,4- trimethylbenzene was best described by first-order kinetics. MTBE, pentane and chlo- rofluorocarbons were recalcitrant. Batch experiments suggested first-order disappear- ance rate laws for all VOCs except octane, which followed zero-order kinetics. For some compounds including MTBE, disappearance rates in abiotic batch experiments were as high as in live batches. Abiotic disappearance is explained by slow intraparti- cle diffusion and sorption. It is concluded that the column approach is preferable for determining biodegradation rate parameters to be used in risk assessment models.

  13. Primary biodegradation and mineralization of hair shampoos in ...

    African Journals Online (AJOL)

    Two methods, the methylene blue active stain (MBAS) river die away method for monitoring primary biodegradation of surfactants and the ultimate biodegradability method for monitoring mineralization of the total biodegradable organic component in a compound were employed to determine the biodegradability of three ...

  14. Microbial Enzymatic Degradation of Biodegradable Plastics.

    Science.gov (United States)

    Roohi; Bano, Kulsoom; Kuddus, Mohammed; Zaheer, Mohammed R; Zia, Qamar; Khan, Mohammed F; Ashraf, Ghulam Md; Gupta, Anamika; Aliev, Gjumrakch

    2017-01-01

    The renewable feedstock derived biodegradable plastics are important in various industries such as packaging, agricultural, paper coating, garbage bags and biomedical implants. The increasing water and waste pollution due to the available decomposition methods of plastic degradation have led to the emergence of biodegradable plastics and biological degradation with microbial (bacteria and fungi) extracellular enzymes. The microbes utilize biodegradable polymers as the substrate under starvation and in unavailability of microbial nutrients. Microbial enzymatic degradation is suitable from bioremediation point of view as no waste accumulation occurs. It is important to understand the microbial interaction and mechanism involved in the enzymatic degradation of biodegradable plastics under the influence of several environmental factors such as applied pH, thermo-stability, substrate molecular weight and/or complexity. To study the surface erosion of polymer film is another approach for hydrolytic degradation characteristion. The degradation of biopolymer is associated with the production of low molecular weight monomer and generation of carbon dioxide, methane and water molecule. This review reported the degradation study of various existing biodegradable plastics along with the potent degrading microbes (bacteria and fungi). Patents available on plastic biodegradation with biotechnological significance is also summarized in this paper. This paper assesses that new disposal technique should be adopted for the degradation of polymers and further research is required for the economical production of biodegradable plastics along with their enzymatic degradation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. 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.

  16. Plant aided biopile for remediation of soil contaminated by petroleum hydrocarbons

    Science.gov (United States)

    Chang, Y.; Kim, K.; Sung, K.; Lee, C.

    2003-04-01

    As a more innovative technique, plant aided biopile has been developed to enhance the remediation efficiency of biopile, known as one of the remediation methods for soil contaminated by petroleum hydrocarbons. Plant effects were added to the conventional biopile and its potential application was tested by comparing remediation efficiency at artificially diesel contaminated soil. The treatments were a biopile treatment, a plant (alfalfa) aided biopile treatment, and a control treatment. Removal of petroleum hydrocarbons and changes of soil microbial activity, soil organic matter content and pH were investigated at large box lysimeters (1.0m x 1.0m x 1.0 m). Both the removal efficiency of diesel and the microbial activity were the highest in the plant aided biopile treatment. It was suggested that plant formed the root zone at contaminated soil, stimulated microbial activity by plant root exudates, and played an important role in enhanced biodegradation of hydrocarbon compounds. Periodic air injection provided oxygen that was necessary for microorganisms and thus could compensate for the oxygen limitation due to increased microbial activity at the root zone. The results showed that plant aided biopile could enhance the remediation efficiency of conventional biopile. At the same time, utilization of natural substances released by the plant roots resulted in the reduction of expenses for substrate provision in the biopile application. Plant aided biopile may be new environmental friendly remediation alternative for petroleum hydrocarbon contaminated soil.

  17. Self-Remediating Energetic Fills Based on Cyclic Dinitroureas

    Science.gov (United States)

    2016-12-01

    moderate mobility in soil, and its natural (aerobic) biodegradation is very slow. As a potential solution to the persistent environmental problems of...energetic sample to initiation by friction. The test is conducted using a pendulum drop angle of 90 degrees. This imparts an initial velocity of 8 feet...a selected force obtained by means of a hydraulic ram. The plate is free to slide exactly 1 inch after being struck by the pendulum and the sample

  18. Biodegradable and compostable alternatives to conventional plastics.

    Science.gov (United States)

    Song, J H; Murphy, R J; Narayan, R; Davies, G B H

    2009-07-27

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all 'good' or petrochemical-based products are all 'bad'. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated 'home' composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.

  19. Biodegradable and compostable alternatives to conventional plastics

    Science.gov (United States)

    Song, J. H.; Murphy, R. J.; Narayan, R.; Davies, G. B. H.

    2009-01-01

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated ‘home’ composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted. PMID:19528060

  20. Biodegradable Metals From Concept to Applications

    CERN Document Server

    Hermawan, Hendra

    2012-01-01

    This book in the emerging research field of biomaterials covers biodegradable metals for biomedical applications. The book contains two main parts where each of them consists of three chapters. The first part introduces the readers to the field of metallic biomaterials, exposes the state of the art of biodegradable metals, and reveals its application for cardiovascular implants. It includes some fundamental aspects to give basic understanding on metals for further review on the degradable ones is covered in chapter one. The second chapter introduces the concept of biodegradable metals, it's st

  1. Engineered biosynthesis of biodegradable polymers.

    Science.gov (United States)

    Jambunathan, Pooja; Zhang, Kechun

    2016-08-01

    Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers.

  2. Biodegradable polyesters from renewable resources.

    Science.gov (United States)

    Tsui, Amy; Wright, Zachary C; Frank, Curtis W

    2013-01-01

    Environmental concerns have led to the development of biorenewable polymers with the ambition to utilize them at an industrial scale. Poly(lactic acid) and poly(hydroxyalkanoates) are semicrystalline, biorenewable polymers that have been identified as the most promising alternatives to conventional plastics. However, both are inherently susceptible to brittleness and degradation during thermal processing; we discuss several approaches to overcome these problems to create a balance between durability and biodegradability. For example, copolymers and blends can increase ductility and the thermal-processing window. Furthermore, chain modifications (e.g., branching/crosslinking), processing techniques (fiber drawing/annealing), or additives (plasticizers/nucleating agents) can improve mechanical properties and prevent thermal degradation during processing. Finally, we examine the impacts of morphology on end-of-life degradation to complete the picture for the most common renewable polymers.

  3. Remedies for Discrimination in Supervisorial and Managerial Jobs.

    Science.gov (United States)

    Newman, Robert

    1978-01-01

    The thesis of this article is that court reliance on objective job criteria as a basis for decisions in discrimination suits involving supervisorial or managerial employees is misplaced. Alternative remedies to the discriminatory use of subjective criteria in the selection and promotion of supervisorial and managerial employees are suggested.…

  4. Biogeochemical Considerations Related To The Remediation Of I-129 Plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D. I. [Savannah River Site (SRS), Aiken, SC (United States); Yeager, C. [Los Alamos National Laboratory , Los Alamos, NM (United States); Denham, M. E. [Savannah River Site (SRS), Aiken, SC (United States); Zhang, S. [Texas A& amp; M University, Galveston, TX (United States); Xu, C. [Texas A& amp; M University, Galveston, TX (United States); Schwehr, K. A. [Texas A& amp; M University, Galveston, TX (United States); Li, H. P. [Texas A& amp; M University, Galveston, TX (United States); Brinkmeyer, R. [Texas A& amp; M University, Galveston, TX (United States); Santschi, P. H. [Texas A& amp; M University, Galveston, TX (United States)

    2012-09-24

    The objectives of this report were to: provide a current state of the science of radioiodine biogeochemistry relevant to its fate and transport at the Hanford Site; conduct a review of Hanford Site data dealing with groundwater {sup 129}I; and identify critical knowledge gaps necessary for successful selection, implementation, and technical defensibility in support of remediation decisions.

  5. Soil slurry reactors for the assessment of contaminant biodegradation

    Science.gov (United States)

    Toscano, G.; Colarieti, M. L.; Greco, G.

    2012-04-01

    Slurry reactors are frequently used in the assessment of feasibility of biodegradation in natural soil systems. The rate of contaminant removal is usually quantified by zero- or first-order kinetics decay constants. The significance of such constants for the evaluation of removal rate in the field could be questioned because the slurry reactor is a water-saturated, well-stirred system without resemblance with an unsaturated fixed bed of soil. Nevertheless, a kinetic study with soil slurry reactors can still be useful by means of only slightly more sophisticated kinetic models than zero-/first-order decay. The use of kinetic models taking into account the role of degrading biomass, even in the absence of reliable experimental methods for its quantification, provides further insight into the effect of nutrient additions. A real acceleration of biodegradation processes is obtained only when the degrading biomass is in the growth condition. The apparent change in contaminant removal course can be useful to diagnose biomass growth without direct biomass measurement. Even though molecular biology techniques are effective to assess the presence of potentially degrading microorganism in a "viable-but-nonculturable" state, the attainment of conditions for growth is still important to the development of enhanced remediation techniques. The methodology is illustrated with reference to data gathered for two test sites, Oslo airport Gardermoen in Norway (continuous contamination by aircraft deicing fluids) and the Trecate site in Italy (aged contamination by crude oil spill). This research is part of SoilCAM project (Soil Contamination, Advanced integrated characterisation and time-lapse Monitoring 2008-2012, EU-FP7).

  6. Biodegradation of thiocyanate in mining-contaminated groundwater

    Science.gov (United States)

    Spurr, L. P.; Watts, M. P.; Moreau, J. W.

    2015-12-01

    In-situ SCN- biodegradation as a strategy for remediating contaminated groundwater remains largely unproven. This study aimed to culture and characterise a community of SCN--degrading microbes from mining-contaminated groundwater, and to optimize the efficiency of this process under varied geochemical conditions. A gold ore processing plant in Victoria, Australia, has generated high amounts of thiocyanate (SCN-)-contaminated waste effluent. This effluent collects in a tailings storage facility (TSF) on site and seepage has contaminated local groundwater. This SCN- plume recently escaped the mine lease in a plume flowing partly through a confined aquifer and partly along buried paleochannel gravels. Groundwater samples were collected using a low-flow pump from two bores near the TSF. The pH of the SCN- contaminated groundwater typically varies between 4 and 6, and dissolved O2 varies between 1 and 40 ppm. SCN- concentrations in off-lease groundwater have increased from 10 ppm in 2010 to over 150 ppm in 2015. Cultures were inoculated directly from the groundwater, and filtered groundwater was used with amendments as the basal growth medium Cultures were subjected to geochemical amendments including changes in dissolved O2, pH, SCN- concentration and additions of organic carbon, phosphate or both. The enriched microbial consortia could not degrade thiocyanate under anoxic conditions, but some could completely degrade high concentrations of SCN- (>800mg L-1) under oxic conditions. Biodegradation accelerated with the addition of phosphate, while the addition of organic carbon actually limited the rate. SCN- degrading cultures are undergoing DNA sequencing for species identification and comparison to SCN--degrading cultures inoculated from surface waters in the TSF.

  7. A biodegradation study of forest biomass by Aspergillus niger F7: correlation between enzymatic activity, hydrolytic percentage and biodegradation index.

    Science.gov (United States)

    Sharma, Nivedita; Kaushal, Richa; Gupta, Rakesh; Kumar, Sanjeev

    2012-04-01

    Aspergillus niger F7 isolated from soil was found to be the potent producer of cellulase and xylanase. The residue of forest species Toona ciliata, Celtris australis, Cedrus deodara and Pinus roxburghii was selected as substrate for biodegradation study due to its easy availability and wide use in industry. It was subjected to alkali (sodium hydroxide) treatment for enhancing its degradation. Biodegradation of forest waste by hydrolytic enzymes (cellulase and xylanase) secreted by A. niger under solid state fermentation (SSF) was explored. SSF of pretreated forest biomass was found to be superior over untreated forest biomass. Highest extracellular enzyme activity of 2201±23.91 U/g by A. niger was shown in pretreated C. australis wood resulting in 6.72±0.20 percent hydrolysis and 6.99±0.23 biodegradation index (BI). The lowest BI of 1.40±0.08 was observed in untreated saw dust of C. deodara having the least enzyme activity of 238±1.36 U/g of dry matter. Biodegradation of forest biomass under SSF was increased many folds when moistening agent i.e. tap water had been replaced with modified basal salt media (BSM). In BSM mediated degradation of forest waste with A. niger, extracellular enzyme activity was increased up to 4089±67.11 U/g of dry matter in turn resulting in higher BI of 15.4±0.41 and percent hydrolysis of 19.38±0.81 in pretreated C. australis wood. A. niger exhibited higher enzyme activity on pretreated biomass when moistened with modified BSM in this study. Statistically a positive correlation has been drawn between these three factors i.e. enzyme activity, BI and percent hydrolysis of forest biomass thus proving their direct relationship with each other.

  8. A biodegradation study of forest biomass by Aspergillus niger F7: correlation between enzymatic activity, hydrolytic percentage and biodegradation index

    Directory of Open Access Journals (Sweden)

    Nivedita Sharma

    2012-06-01

    Full Text Available Aspergillus niger F7 isolated from soil was found to be the potent producer of cellulase and xylanase. The residue of forest species Toona ciliata, Celtris australis, Cedrus deodara and Pinus roxburghii was selected as substrate for biodegradation study due to its easy availability and wide use in industry. It was subjected to alkali (sodium hydroxide treatment for enhancing its degradation. Biodegradation of forest waste by hydrolytic enzymes (cellulase and xylanase secreted by A. niger under solid state fermentation (SSF was explored. SSF of pretreated forest biomass was found to be superior over untreated forest biomass. Highest extracellular enzyme activity of 2201±23.91 U/g by A. niger was shown in pretreated C. australis wood resulting in 6.72±0.20 percent hydrolysis and 6.99±0.23 biodegradation index (BI. The lowest BI of 1.40±0.08 was observed in untreated saw dust of C. deodara having the least enzyme activity of 238±1.36 U/g of dry matter. Biodegradation of forest biomass under SSF was increased many folds when moistening agent i.e. tap water had been replaced with modified basal salt media (BSM. In BSM mediated degradation of forest waste with A. niger, extracellular enzyme activity was increased up to 4089±67.11 U/g of dry matter in turn resulting in higher BI of 15.4±0.41 and percent hydrolysis of 19.38±0.81 in pretreated C. australis wood. A. niger exhibited higher enzyme activity on pretreated biomass when moistened with modified BSM in this study. Statistically a positive correlation has been drawn between these three factors i.e. enzyme activity, BI and percent hydrolysis of forest biomass thus proving their direct relationship with each other.

  9. Electrospun biodegradable polymers loaded with bactericide agents

    Directory of Open Access Journals (Sweden)

    Ramaz Katsarava

    2016-03-01

    Full Text Available Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrospinning, co-electrospinning, coaxial electrospinning, and miniemulsion electrospinning can be obtained to influence the ability to load agents with different characteristics and stability and to modify the release behaviour. Furthermore, antimicrobial agents can be loaded during the electrospinning process or by a subsequent coating process. In order to the mitigate burst release effect, it is possible to encapsulate the selected drug into inorganic nanotubes and nanoparticles, as well as in organic cyclodextrine polysaccharides. In the same way, processes that involve covalent linkage of bactericide agents during surface treatment of electrospun samples may also be considered. The present review is focused on more recent works concerning the electrospinning of antimicrobial polymers. These include chitosan and common biodegradable polymers with activity caused by the specific load of agents such as metal and metal oxide particles, quaternary ammonium compounds, hydantoin compounds, antibiotics, common organic bactericides, and bacteriophages.

  10. Acceleration of biodegradation by ultraviolet femtosecond laser irradiation to biodegradable polymer

    Science.gov (United States)

    Shibata, Akimichi; Yada, Shuhei; Kondo, Naonari; Terakawa, Mitsuhiro

    2017-02-01

    Biodegradability is a key property of biodegradable polymers for tissue scaffold applications. Among the methods to control biodegradability, laser processing is a simple technique, which enables the alteration of biodegradability even after molding. Since ultrafast laser processing realizes precise processing of biodegradable polymer with less heat affected zone, ultrafast laser processing has the potential to fabricate tissue scaffolds and to control its biodegradability. In this study, we investigate the effect of femtosecond laser wavelength on the biodegradability of PLGA. We evaluated the biodegradability of PLGA irradiated with femtosecond laser pulses at the wavelength of 800, 400, 266 nm by the measurement of the change in mass of PLGA during water immersion. The results of degradation tests indicate that PLGA irradiated with the shorter wavelength show faster water absorption as well as rapid mass decrease. Since the results of X-ray photoelectron spectroscopy analysis indicate that the chemical bonds of PLGA irradiated with the shorter wavelength are dissociated more significantly, the acceleration of the biodegradation could be attributable to the decrease in molecular weight by chemical bond breaking.

  11. Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zembrzuska, Joanna, E-mail: Joanna.Zembrzuska@put.poznan.pl; Budnik, Irena, E-mail: Irena.Budnik@gmail.com; Lukaszewski, Zenon, E-mail: zenon.lukaszewski@put.poznan.pl

    2016-07-01

    Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C{sub 12}E{sub 9} having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C{sub 12}E{sub 9} as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C{sub 12}E{sub 9} and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C{sub 12}E{sub 9}, C{sub 12}E{sub 8}, C{sub 12}E{sub 7} and C{sub 12}E{sub 6}. Apart from the substrate, the homologues C{sub 12}E{sub 8}, C{sub 12}E{sub 7} and C{sub 12}E{sub 6}, being metabolites of C{sub 12}E{sub 9} biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C{sub 12}E{sub 8}COOH, C{sub 12}E{sub 7}COOH, C{sub 12}E{sub 6}COOH and C{sub 12}E{sub 5}COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C{sub 12}E{sub 9} and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a

  12. Perspectives on nanofiber dressings for the localized delivery of botanical remedies in wound healing

    Directory of Open Access Journals (Sweden)

    Sukhwinder K. Bhullar

    2017-02-01

    Full Text Available Based on their antiseptic and anti-inflammatory properties, plant-derived remedies and herbal products have been used since ancient times for wound and burn cure as well as for treating chronic skin diseases like dermatitis and eczema. Biocompatible and biodegradable polymer nanofiber devices are currently fabricated using sophisticated engineering techniques. Such nanofiber structures have proven efficacious for the localized delivery of therapeutic agents for the treatment of wounds due to their unique physical-chemical properties such as large surface-area-to-volume ratio, high porosity, improved cell adherence, cellular proliferation and migration, as well as controlled in vivo biodegradation rates. The remit of this communication is to highlight the methodology used for the fabrication of nanofiber mats and dressings for the localised delivery of herbal products and plant-derived ingredients for wound healing.

  13. HANFORD GROUNDWATER REMEDIATION

    Energy Technology Data Exchange (ETDEWEB)

    CHARBONEAU, B; THOMPSON, M; WILDE, R.; FORD, B.; GERBER, M.S.

    2006-02-01

    geographically dispersed community is united in its desire to protect the Columbia River and have a voice in Hanford's future. This paper presents the challenges, and then discusses the progress and efforts underway to reduce the risk posed by contaminated groundwater at Hanford. While Hanford groundwater is not a source of drinking water on or off the Site, there are possible near-shore impacts where it flows into the Columbia River. Therefore, this remediation is critical to the overall efforts to clean up the Site, as well as protect a natural resource.

  14. 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

  15. 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)

  16. Engineered wetlands for on-site groundwater remediation

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, S.; Davis, B.M. [Jacques Whitford NAWE Inc., White Bear Lake, MN (United States)

    2008-07-01

    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{sup 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.

  17. Biodegradation of VX/Water Hydrolysate

    National Research Council Canada - National Science Library

    DeFrank, Joseph

    1997-01-01

    ...-(diisopropylaminoethyl) methyl phosphonothioate was neutralization followed by biodegradation. The treatment of VX with an equimolar amount of water results in the slow, but complete hydrolysis of the phosphorus-sulfur bond...

  18. Biodegradable lubricants - ''the solution for future?''

    International Nuclear Information System (INIS)

    Jahan, A.

    1997-01-01

    The environmental impact of lubricants use concern the direct effects from spills but also the indirect effects such as their lifetime and the emissions from thermal engines. The biodegradable performances and the toxicity are the environmental criteria that must be taken into account in the development and application of lubricants together with their technical performances. This paper recalls first the definition of biodegradable properties of hydrocarbons and the standardized tests, in particular the CEC and AFNOR tests. Then, the biodegradable performances of basic oils (mineral, vegetal, synthetic esters, synthetic hydrocarbons etc..), finite lubricants (hydraulic fluids..) and engine oils is analyzed according to these tests. Finally, the definition of future standards would take into account all the environmental characteristics of the lubricant: biodegradable performances, energy balance (CO 2 , NOx and Hx emissions and fuel savings), eco-toxicity and technical performances (wearing and cleanliness). (J.S.)

  19. Biodegradability and treatability of caprolactam waste

    Energy Technology Data Exchange (ETDEWEB)

    Patel, M.D.; Patel, D.R.

    1977-01-01

    Studies were conducted on the biodegradability and treatment of wastewaters from a plant manufacturing caprolactam. Two-stage biological treatment, with preliminary aeration followed by an oxidation channel, gave an effluent of the desired quality.

  20. MOLECULAR BASIS OF BIODEGRADATION OF CHLOROAROMATIC COMPOUNDS

    Science.gov (United States)

    Chlorinated aromatic hydrocarbons are widely used in industry and agriculture, and comprise the bulk of environmental pollutants. Although simple aromatic compounds are biodegradable by a variety of degradative pathways, their halogenated counterparts are more resistant to bacter...

  1. Formulation and Characterization of Biodegradable Medicated ...

    African Journals Online (AJOL)

    PEG)-600, tributyl citrate, PEG-200, PEG-300, PEG-400, PEG-4000, triethyl citrate and castor oil. The gum formulations were characterized for the following parameters: texture profile analysis (TPA), biodegradation, in vitro drug release using a ...

  2. Bioventing in the subarctic: Field scale implementation of soil heating to allow in situ vadose zone biodegradation throughout the year

    International Nuclear Information System (INIS)

    Oram, D.E.; Winters, A.T.; Winsor, T.R.

    1994-01-01

    Bioventing is a technique of in situ bioremediation of contaminants in unsaturated zone soils that has advantages over other technologies such as soil vapor extraction. At locations where off-gas treatment would be required, bioventing can be a more cost-effective method of remediation. Using bioventing to remediate petroleum hydrocarbons in the vadose zone soils in extremely cold climates may be augmented by heating the subsurface soils. The US Air Force has conducted a bioventing feasibility study at Eielson Air Force Base since 1991. The feasibility study evaluated different methods of heating soils to maintain biodegradation rates through the winter. Results from this study were used to optimize the design of a full-scale bioventing system that incorporated a soil heating system. The system installed consists of the typical components of a bioventing system including an air injection blower, a system to distribute air in the vadose zone, and a monitoring system. To maintain biodegradation at a constant rate throughout the year, soil heating and temperature monitoring systems were also installed. Results to date indicate that summer soil temperatures and biodegradation of hydrocarbons have been maintained through the winter

  3. Comparison of approaches for assessing sustainable remediation of contaminated sites

    DEFF Research Database (Denmark)

    Søndergaard, Gitte Lemming; Binning, Philip John; Bjerg, Poul Løgstrup

    2017-01-01

    from amongst a number of defined remedial scenarios. Results of the review show that most approaches use multi-criteria assessment methods (MCA) to structure a decision support process because it allows the combined assessment of criteria which may be either quantitatively or qualitatively assessed......, is conducted in various ways. Some approaches involve stakeholders directly in the evaluation or weighting of criteria, whereas other approaches only indirectly consider stakeholder preferences. This study has reviewed available methods for assessing and comparing the sustainability of contaminated site...... remediation alternatives. It is concluded that MCA methods are very useful when comparing remediation alternatives, since they allow for a joint assessment of many types of indicators; however the available tools and methods differ substantially, for instance in their selection of indicators, criteria...

  4. Biodegradation behaviors of cellulose nanocrystals -PVA nanocomposites

    Directory of Open Access Journals (Sweden)

    Mahdi Rohani

    2014-11-01

    Full Text Available In this research, biodegradation behaviors of cellulose nanocrystals-poly vinyl alcohol nanocomposites were investigated. Nanocomposite films with different filler loading levels (3, 6, 9 and 12% by wt were developed by solvent casting method. The effect of cellulose nanocrystals on the biodegradation behaviors of nanocomposite films was studied. Water absorption and water solubility tests were performed by immersing specimens into distilled water. The characteristic parameter of diffusion coefficient and maximum moisture content were determined from the obtained water absorption curves. The water absorption behavior of the nanocomposites was found to follow a Fickian behavior. The maximum water absorption and diffusion coefficients were decreased by increasing the cellulose nanocrystals contents, however the water solubility decrease. The biodegradability of the films was investigated by immersing specimens into cellulase enzymatic solution as well as by burial in soil. The results showed that adding cellulose nanocrystals increase the weight loss of specimens in enzymatic solution but decrease it in soil media. The limited biodegradability of specimens in soil media attributed to development of strong interactions with solid substrates that inhibit the accessibility of functional groups. Specimens with the low degree of hydrolysis underwent extensive biodegradation in both enzymatic and soil media, whilst specimens with the high degree of hydrolysis showed recalcitrance to biodegradation under those conditions.

  5. Biodegradation of acrylic based resins: A review.

    Science.gov (United States)

    Bettencourt, Ana F; Neves, Cristina B; de Almeida, Marise S; Pinheiro, Lídia M; Oliveira, Sofia Arantes e; Lopes, Luís P; Castro, Matilde F

    2010-05-01

    The development of different types of materials with application in dentistry is an area of intense growth and research, due to its importance in oral health. Among the different materials there are the acrylic based resins that have been extensively used either in restorations or in dentures. The objective of this manuscript was to review the acrylic based resins biodegradation phenomena. Specific attention was given to the causes and consequences of materials degradation under the oral environment. Information from scientific full papers, reviews or abstracts published from 1963 to date were included in the review. Published material was searched in dental literature using general and specialist databases, like the PubMED database. Published studies regarding the description of biodegradation mechanisms, in vitro and in vivo release experiments and cell based studies conducted on acrylic based resins or their components were evaluated. Studies related to the effect of biodegradation on the physical and mechanical properties of the materials were also analyzed. Different factors such as saliva characteristics, chewing or thermal and chemical dietary changes may be responsible for the biodegradation of acrylic based resins. Release of potential toxic compounds from the material and change on their physical and mechanical properties are the major consequences of biodegradation. Increasing concern arises from potential toxic effects of biodegradation products under clinical application thus justifying an intensive research in this area. 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Use of a horizontal air-dispersion system to enhance biodegradation of diesel fuel contaminated soils

    International Nuclear Information System (INIS)

    Baker, J.N.; Nickerson, D.A.; Guest, P.R.; Portele, T.E.

    1993-01-01

    A horizontal air-dispersion system was designed and installed to enhance the natural biodegradation of residual diesel fuel contaminated soils at an underground storage tank (UST) facility in Seattle, Washington. This system was designed to operate in conjunction with an existing free-product recovery system which exposes more heavily contaminated soils at the capillary fringe to injected air. Results of a pilot study conducted at the facility indicate that an initial biodegradation rate of 2,200 mg of total petroleum hydrocarbons (TPH) per kg of soil per year will be achieved, making in-situ biodegradation a feasible remedial alternative for contaminated site soils. Oxygen, carbon dioxide, and hydrocarbon vapor concentrations have been monitored since full-scale startup in September 1992, using a series of vapor monitoring points (VMPs) installed in the vicinity of the aerated beds and around the perimeter of the facility. Recent monitoring data indicate that the system is capable of aerating soils at distances greater than 80 feet from the aerated beds. Oxygen utilization and carbon dioxide production measured during post-startup respiration tests indicate microbial activity has increased as a result of seven months of full-scale system operation

  7. Remediation of copper in vineyards – A mini review

    International Nuclear Information System (INIS)

    Mackie, K.A.; Müller, T.; Kandeler, E.

    2012-01-01

    Viticulturists use copper fungicide to combat Downy Mildew. Copper, a non-degradable heavy metal, can accumulate in soil or leach into water sources. Its accumulation in topsoil has impacted micro and macro organisms, spurring scientists to research in situ copper removal methods. Recent publications suggest that microorganism assisted phytoextraction, using plants and bacteria to actively extract copper, is most promising. As vineyards represent moderately polluted sites this technique has great potential. Active plant extraction and chelate assisted remediation extract too little copper or risk leaching, respectively. However, despite interesting pot experiment results using microorganism assisted phytoextraction, it remains a challenge to find plants that primarily accumulate copper in their shoots, a necessity in vineyards where whole plant removal would be time consuming and financially cumbersome. Vineyard remediation requires a holistic approach including sustainable soil management, proper plant selection, increasing biodiversity and microorganisms. - Highlights: ► We describe copper distribution and availability in vineyards. ► We explain the environmental impact of copper on organisms, plants and processes. ► We detail possible remediation methods within vineyards. ► Microbially assisted phytoremediation is the most promising remediation method. ► A solution requires an interdisciplinary approach between plants, soil and vines. - This review is significant because it highlights prospective remediation methods usable in copper contaminated vineyards.

  8. Remediation plan for fluorescent light fixtures containing polychlorinated biphenyls (PCBs)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-04-30

    This report describes the remedial action to achieve compliance with 29 CFR 1910 Occupational Safety and Health Administration (OSHA) requirements of fluorescent light fixtures containing PCBs at K-25 site. This remedial action is called the Remediation Plan for Fluorescent Light Fixtures Containing PCBs at the K-25 Site (The Plan). The Plan specifically discusses (1) conditions of non-compliance, (2) alternative solutions, (3) recommended solution, (4) remediation plan costs, (5) corrective action, (6) disposal of PCB waste, (7) training, and (8) plan conclusions. The results from inspections by Energy Systems personnel in 2 buildings at K-25 site and statistical extension of this data to 91 selected buildings at the K-25 site indicates that there are approximately 28,000 fluorescent light fixtures containing 47,036 ballasts. Approximately 38,531 contain PCBs and 2,799 of the 38,531 ballasts are leaking PCBs. Review of reportable occurrences at K-25 for the 12 month period of September 1990 through August 1991 shows that Energy Systems personnel reported 69 ballasts leaking PCBs. Each leaking ballast is in non-compliance with 29 CFR 1910 - Table Z-1-A. The age of the K-25 facilities indicate a continued and potential increase in ballasts leaking PCBs. This report considers 4 alternative solutions for dealing with the ballasts leaking PCBs. The advantages and disadvantages of each alternative solution are discussed and ranked using cost of remediation, reduction of health risks, and compliance with OSHA as criteria.

  9. Remediation Technologies Eliminate Contaminants

    Science.gov (United States)

    2012-01-01

    groundwater tainted by chlorinated solvents once used to clean rocket engine components. The award-winning innovation (Spinoff 2010) is now NASA s most licensed technology to date. PCBs in paint presented a new challenge. Removing the launch stand for recycling proved a difficult operation; the toxic paint had to be fully stripped from the steel structure, a lengthy and costly process that required the stripped paint to be treated before disposal. Noting the lack of efficient, environmentally friendly options for dealing with PCBs, Quinn and her colleagues developed the Activated Metal Treatment System (AMTS). AMTS is a paste consisting of a solvent solution containing microscale particles of activated zero-valent metal. When applied to a painted surface, the paste extracts and degrades the PCBs into benign byproducts while leaving the paint on the structure. This provides a superior alternative to other methods for PCB remediation, such as stripping the paint or incinerating the structure, which prevents reuse and can release volatized PCBs into the air. Since its development, AMTS has proven to be a valuable solution for removing PCBs from paint, caulking, and various insulation and filler materials in older buildings, naval ships, and former munitions facilities where the presence of PCBs interferes with methods for removing trace explosive materials. Miles of potentially toxic caulking join sections of runways at airports. Any of these materials installed before 1979 potentially contain PCBs, Quinn says. "This is not just a NASA problem," she says. "It s a global problem."

  10. A remedial alternative prioritization method

    International Nuclear Information System (INIS)

    Richter, S.A.; Travis, C.C.

    1987-01-01

    This study develops and tests a technique for evaluating and prioritizing alternative remedial actions for hazardous waste sites. The method is based on criteria involving risk, benefit and cost, and identifies the most cost-effective solution to a given remedial problem. Four sites on the Department of Energy's Oak Ridge National Laboratory (ORNL) property in Oak Ridge, Tennessee, were used in a case study to develop and test the method. Results of the case study indicate that even if the cap providing in situ containment must be replaced every 10 years, it is a superior alternative to total excavation of the waste sites

  11. The ecotoxicity and the biodegradability of lactic acid, alkyl lactate esters and lactate salts

    NARCIS (Netherlands)

    Bowmer, C.T.; Hooftman, R.N.; Hanstveit, A.O.; Venderbosch, P.W.M.; Hoeven, N. van der

    1998-01-01

    The ecotoxicity of lactic acid, its alkyl esters and selected metal salts was studied experimentally with the micro alga Selenastrum capricornutum, the crustacean Daphnia magna and the fish species Brachydanio rerio and Pimephales promelas. In addition, the biodegradation of lactate esters was also

  12. Biodegradability and biodegradation rate of poly(caprolactone)-starch blend and poly(butylene succinate) biodegradable polymer under aerobic and anaerobic environment.

    Science.gov (United States)

    Cho, H S; Moon, H S; Kim, M; Nam, K; Kim, J Y

    2011-03-01

    The biodegradability and the biodegradation rate of two kinds biodegradable polymers; poly(caprolactone) (PCL)-starch blend and poly(butylene succinate) (PBS), were investigated under both aerobic and anaerobic conditions. PCL-starch blend was easily degraded, with 88% biodegradability in 44 days under aerobic conditions, and showed a biodegradation rate of 0.07 day(-1), whereas the biodegradability of PBS was only 31% in 80 days under the same conditions, with a biodegradation rate of 0.01 day(-1). Anaerobic bacteria degraded well PCL-starch blend (i.e., 83% biodegradability for 139 days); however, its biodegradation rate was relatively slow (6.1 mL CH(4)/g-VS day) compared to that of cellulose (13.5 mL CH(4)/g-VS day), which was used as a reference material. The PBS was barely degraded under anaerobic conditions, with only 2% biodegradability in 100 days. These results were consistent with the visual changes and FE-SEM images of the two biodegradable polymers after the landfill burial test, showing that only PCL-starch blend had various sized pinholes on the surface due to attack by microorganisms. This result may be use in deciding suitable final disposal approaches of different types of biodegradable polymers in the future. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Integrating biodegradation and electroosmosis for the enhanced removal of polycyclic aromatic hydrocarbons from creosote-polluted soils.

    Science.gov (United States)

    Niqui-Arroyo, José-Luis; Ortega-Calvo, José-Julio

    2007-01-01

    This paper presents a hybrid technology of soil remediation based on the integration of biodegradation and electroosmosis. We employed soils with different texture (clay soil and loamy sand) containing a mixture of polycyclic aromatic hydrocarbons (PAH) present in creosote, and inoculation with a representative soil bacterium able to degrade fluorene, phenanthrene, fluoranthene, pyrene, anthracene, and benzo[a]pyrene. Two different modes of treatment were prospected: (i) inducing in soil the simultaneous occurrence of biodegradation and electroosmosis in the presence of a biodegradable surfactant, and (ii) treating the soils sequentially with electrokinetics and bioremediation. Losses of PAH due to simultaneous biodegradation and electroosmosis (induced by a continuous electric field) were significantly higher than in control cells that contained the surfactant but no biological activity or no current. The method was especially successful with loamy sand. For example, benzo[a]pyrene decreased its concentration by 50% after 7 d, whereas 22 and 17% of the compound had disappeared as a result of electrokinetic flushing and bioremediation alone, respectively. The use of periodical changes in polarity and current pulses increased by 16% in the removal of total PAH and in up to 30% of specific compounds, including benzo[a]pyrene. With the aim of reaching lower residual levels through bioremediation, an electrokinetic pretreatment was also evaluated as a way to mobilize the less bioaccessible fraction of PAH. Residual concentrations of total biodegradable PAH, remaining after bioremediation in soil slurries, were twofold lower in electrokinetically pretreated soils than in untreated soils. The results indicate that biodegradation and electroosmosis can be successfully integrated to promote the removal of PAH from soil.

  14. A model framework to describe growth-linked biodegradation of trace-level pesticides in the presence of coincidental carbon substrates and microbes

    DEFF Research Database (Denmark)

    Liu, Li; Helbling, Damian E.; Kohler, Hans-Peter E.

    2014-01-01

    , challenges remain in developing engineered remediation strategies for pesticide-contaminated environments because the fundamental processes that regulate growth-linked biodegradation of pesticides in natural environments remain poorly understood. In this research, we developed a model framework to describe......Pollutants such as pesticides and their degradation products occur ubiquitously in natural aquatic environments at trace concentrations (μg L–1 and lower). Microbial biodegradation processes have long been known to contribute to the attenuation of pesticides in contaminated environments. However...... growth-linked biodegradation of pesticides at trace concentrations. We used experimental data reported in the literature or novel simulations to explore three fundamental kinetic processes in isolation. We then combine these kinetic processes into a unified model framework. The three kinetic processes...

  15. The studies on waste biodegradation by Tenebrio molitor

    Directory of Open Access Journals (Sweden)

    Bożek Magdalena

    2017-01-01

    Full Text Available As cities are growing in size with a rise in the population, the amount of plastic waste generated is increasing and becoming unmanageable. The treatment and disposal of plastic waste is an urgent need of our present and future. It has been proved recently that mealworms, the larvae of Tenebrio molitor Linnaeus, are able eat styrofoam, a common polystyrene product. Polystyrene is one of the most widely used plastics, the scale of its production being several million tons per year. Tenebrio molitor is one of the largest pests found in stored-grain products. The insect is indigenous to Europe, but is currently cosmopolitan in distribution. The styrofoam is efficiently degraded in the larval gut by microorganisms. We have used the larvae of T. molitor to biodegrade three types of food packaging plastics: polystyrene (PS, polyvinyl chloride (PVC and polylactide (PLA. PVC is a thermoplastic made of 57% chlorine (derived from industrial grade salt and 43% carbon (derived predominantly from oil /gas via ethylene. It is the world's third-most widely produced synthetic plastic polymer, which is not biodegradable easily. On the other hand, PLA is an easily biodegradable and bioactive thermoplastic aliphatic polyester derived from corn and tapioca starch or sugarcane. Three groups of larvae were fed selected types of polymers as an only food, while a control population was fed on oatmeal. The mass loss, dry matter content and biochemical composition of mealworms were assessed in the performed laboratory experiments. The protein concentration in homogenates of the larvae was determined by the Bradford method. To determine the level of hydrolized carbohydrates we used anthrone method. The classical sulfo-phospho-vanillin assay (SPVA was used to quantitate total lipids in mealworms. The results allowed to compare the decomposition efficiency of selected polymer materials by mealworms and to recognize the mechanism of decomposition contributing to the future

  16. Use Of Biodegradation Ratios In Monitoring Trend Of Biostimulated Biodegradation In Crude Oil Polluted Soils

    Directory of Open Access Journals (Sweden)

    Okorondu

    2017-03-01

    Full Text Available This study deals with biodegradation experiment on soil contaminated with crude oil. The soil sample sets A BC D E F G were amended with inorganic fertilizer to enhance microbial growth and hydrocarbon degradation moisture content of some of the sets were as well varied. Biodegradation ratios nC17Pr nC18Ph and nC17nC18PrPh were used to monitor biodegradation of soil sets A BC D E F G for a period of 180. The soil samples were each contaminated with the same amount of crude oil and exposed to specific substrate treatment regarding the amount of nutrients and water content over the same period of time. The trend in biodegradation of the different soil sample sets shows that biodegradation ratio nC17nC18PrPh was more reflective of and explains the biodegradation trend in all the sample sets throughout the period of the experiment hence a better parameter ratio for monitoring trend of biostimulated biodegradation. The order of preference of the biodegradation ratios is expressed as nC18Ph nC17Pr nC17nC18 PrPh. This can be a relevant support tool when designing bioremediation plan on field.

  17. 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

  18. Behavior of solid carbon sources for biological denitrification in groundwater remediation.

    Science.gov (United States)

    Zhang, Jianmei; Feng, Chuanping; Hong, Siqi; Hao, Huiling; Yang, Yingnan

    2012-01-01

    The present study was conducted to compare the behavior of wheat straw, sawdust and biodegradable plastic (BP) as potential carbon sources for denitrification in groundwater remediation. The results showed that a greater amount of nitrogen compounds were released from wheat straw and sawdust than from BP in leaching experiments. In batch experiments, BP showed higher nitrate removal efficiency and longer service life than wheat straw and sawdust, which illustrated that BP is the most appropriate carbon source for stimulation of denitrification activity. In column experiments, BP was able to support complete denitrification at influent nitrate concentrations of 50, 60, 70, 80, and 90 mg NO(3)(-)-N/L, showing corresponding denitrification rates of 0.12, 0.14, 0.17, 0.19, and 0.22 mg NO(3)(-)-N.L(-1).d(-1).g(-1), respectively. These findings indicate that BP is applicable for use as a carbon source for nitrate-polluted groundwater remediation.

  19. Applications of Biosurfactants in the Petroleum Industry and the Remediation of Oil Spills

    Directory of Open Access Journals (Sweden)

    Rita de Cássia F. S. Silva

    2014-07-01

    Full Text Available Petroleum hydrocarbons are important energy resources. However, petroleum is also a major pollutant of the environment. Contamination by oil and oil products has caused serious harm, and increasing attention has been paid to the development and implementation of innovative technologies for the removal of these contaminants. Biosurfactants have been extensively used in the remediation of water and soil, as well as in the main stages of the oil production chain, such as extraction, transportation, and storage. This diversity of applications is mainly due to advantages such as biodegradability, low toxicity and better functionality under extreme conditions in comparison to synthetic counterparts. Moreover, biosurfactants can be obtained with the use of agro-industrial waste as substrate, which helps reduce overall production costs. The present review describes the potential applications of biosurfactants in the oil industry and the remediation of environmental pollution caused by oil spills.

  20. Applications of biosurfactants in the petroleum industry and the remediation of oil spills.

    Science.gov (United States)

    de Cássia F S Silva, Rita; Almeida, Darne G; Rufino, Raquel D; Luna, Juliana M; Santos, Valdemir A; Sarubbo, Leonie Asfora

    2014-07-15

    Petroleum hydrocarbons are important energy resources. However, petroleum is also a major pollutant of the environment. Contamination by oil and oil products has caused serious harm, and increasing attention has been paid to the development and implementation of innovative technologies for the removal of these contaminants. Biosurfactants have been extensively used in the remediation of water and soil, as well as in the main stages of the oil production chain, such as extraction, transportation, and storage. This diversity of applications is mainly due to advantages such as biodegradability, low toxicity and better functionality under extreme conditions in comparison to synthetic counterparts. Moreover, biosurfactants can be obtained with the use of agro-industrial waste as substrate, which helps reduce overall production costs. The present review describes the potential applications of biosurfactants in the oil industry and the remediation of environmental pollution caused by oil spills.

  1. 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

  2. Electrokinetic remediation of copper mine tailings

    DEFF Research Database (Denmark)

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

    2007-01-01

    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......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...

  3. Syntrophic biodegradation of hydrocarbon contaminants.

    Science.gov (United States)

    Gieg, Lisa M; Fowler, S Jane; Berdugo-Clavijo, Carolina

    2014-06-01

    Anaerobic environments are crucial to global carbon cycling wherein the microbial metabolism of organic matter occurs under a variety of redox conditions. In many anaerobic ecosystems, syntrophy plays a key role wherein microbial species must cooperate, essentially as a single catalytic unit, to metabolize substrates in a mutually beneficial manner. Hydrocarbon-contaminated environments such as groundwater aquifers are typically anaerobic, and often methanogenic. Syntrophic processes are needed to biodegrade hydrocarbons to methane, and recent studies suggest that syntrophic hydrocarbon metabolism can also occur in the presence of electron acceptors. The elucidation of key features of syntrophic processes in defined co-cultures has benefited greatly from advances in 'omics' based tools. Such tools, along with approaches like stable isotope probing, are now being used to monitor carbon flow within an increasing number of hydrocarbon-degrading consortia to pinpoint the key microbial players involved in the degradative pathways. The metagenomic sequencing of hydrocarbon-utilizing consortia should help to further identify key syntrophic features and define microbial interactions in these complex communities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Effect of modified montmorillonites on the biodegradation and adsorption of biomarkers such as hopanes, steranes and diasteranes.

    Science.gov (United States)

    Ugochukwu, Uzochukwu C; Head, Ian M; Manning, David A C

    2013-12-01

    The effect of modified montmorillonites on the biodegradation and adsorption of selected steranes, diasteranes and hopanes was investigated in aqueous clay/oil microcosm experiments with a hydrocarbon degrading microorganism community. The unmodified montmorillonite was treated with didecyldimethylammonium bromide, hydrochloric acid and the relevant metallic chloride to produce organomontmorillonite, acid activated montmorillonite and homoionic montmorillonite respectively which were used in this study. The study indicated that organomontmorillonite, acid activated montmorillonite and potassium montmorillonite did not support the biodegradation of the selected steranes, diasteranes and hopanes as alteration of the biomarkers via biodegradation varied from a paltry 2-6 %. The adsorption of the selected biomarkers on acid activated montmorillonite and organomontmorillonite was also poor. However, adsorption of the biomarkers on potassium montmorillonite was relatively high. Sodium montmorillonite and unmodified montmorillonite appear to stimulate the biodegradation of the selected biomarkers moderately (30-35 %) with adsorption occurring at low level. Calcium montmorillonite and ferric montmorillonite effected significant biodegradation (51-60 %) of the selected biomarkers.

  5. Influence of adhesion on aerobic biodegradation and bioremediation of liquid hydrocarbons.

    Science.gov (United States)

    Abbasnezhad, Hassan; Gray, Murray; Foght, Julia M

    2011-11-01

    Biodegradation of poorly water-soluble liquid hydrocarbons is often limited by low availability of the substrate to microbes. Adhesion of microorganisms to an oil-water interface can enhance this availability, whereas detaching cells from the interface can reduce the rate of biodegradation. The capability of microbes to adhere to the interface is not limited to hydrocarbon degraders, nor is it the only mechanism to enable rapid uptake of hydrocarbons, but it represents a common strategy. This review of the literature indicates that microbial adhesion can benefit growth on and biodegradation of very poorly water-soluble hydrocarbons such as n-alkanes and large polycyclic aromatic hydrocarbons dissolved in a non-aqueous phase. Adhesion is particularly important when the hydrocarbons are not emulsified, giving limited interfacial area between the two liquid phases. When mixed communities are involved in biodegradation, the ability of cells to adhere to the interface can enable selective growth and enhance bioremediation with time. The critical challenge in understanding the relationship between growth rate and biodegradation rate for adherent bacteria is to accurately measure and observe the population that resides at the interface of the hydrocarbon phase. © Springer-Verlag 2011

  6. Effect of Gamma Irradiation on the Biodegradation Process of some Organic Pollutants

    International Nuclear Information System (INIS)

    El-Shahawy, M.R.

    2014-01-01

    Water samples were collected from Ras Gemsa on western coast of Suez Gulf, then microbiologically and chemically analyzed. The total petroleum hydrocarbons (TPH) was at concentration of 357 ppm and exceeded the known permissible limits ranged from 5 to 100 ppm according to the receiving water bulk. On the other hand the biodegrading bacterial counts ( CFU ) clearly reflected the great adaptation of endogenous bacteria to use hydrocarbons as a sole source of carbon. The ratio of biodegrading bacteria to heterotrophic ones was about 3.3%. Five hydrocarbon degrading bacteria were isolated from Suez Gulf Consortia. One isolate HD1 were selected to be promising due to its capacity of hydrocarbon degradation, this promising isolate was characterized and identified by API system as Bacillus subtilis. The biodegradation kinetics of radiated polluted water samples by B. subtilis and the Suez Gulf consortium was monitored gravimetrically. The results showed that The Suez Gulf consortium had more biodegradation capacity than the single isolate B. subtilis overall radiation doses applied and non-radiated polluted water sample. The data showed a significant increase of the biodegradability with increase of radiation doses used

  7. Environmental Modelling of Remediation of Urban Contaminated Areas. Report of the Urban Remediation Working Group of EMRAS Theme 2

    International Nuclear Information System (INIS)

    2012-01-01

    obtained in Ukraine following the Chernobyl accident. This exercise provided an opportunity to model large-scale contamination events such as the result of a nuclear accident. The exercise was designed to permit intercomparison of model results from different participants as well as, for some endpoints, comparison of model results with actual measurements. The third area was a modelling exercise based on a hypothetical situation involving a point-release of a radionuclide in an urban setting, specifically a release resulting from a radiological dispersal device involving an explosion. This exercise was intended to provide an opportunity for intercomparison of model results among participants. For both modelling exercises, the intent was to model the radiological situation over time in the absence of any remediation and with the effects of selected remedial measures. This approach was intended to permit comparison of the effects of various remedial measures in terms of their short- or long-term effect on dose rates and resulting doses in the areas of interest, for the purpose of aiding decisions about when to remediate and which remedial measures to use. The Urban Remediation Working Group's final report includes an overview and discussion of the major modelling approaches and computer models presently available for use in assessing urban contamination situations. The models actually used in the Working Group's exercises are described in detail, including the parameterization for each of the exercises. Basic considerations in characterizing an urban environment have been summarized. The application of computer models to assess potential countermeasures or remediation measures is less well developed; therefore, the Working Group has summarized the available literature on countermeasures and their effectiveness and has developed some guidance for implementing countermeasures or remediation measures in computer models. An important caveat is that much of the information base

  8. Green Chemistry and Environmental Remediation

    Science.gov (United States)

    Abstract: Nutrient remediation and recovery is a growing concern for two key reasons: (i) the prevention of harmful algal bloom proliferation, and (ii) the recycling of nutrients (e.g., phosphates) as they are non-renewable resources which are quickly being depleted. A wide range...

  9. 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....

  10. 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.

  11. WATER AS A REAGENT FOR SOIL REMEDIATION

    Energy Technology Data Exchange (ETDEWEB)

    Indira S. Jayaweera; Jordi Diaz-Ferraro

    2000-02-28

    SRI International is conducting experiments to develop and evaluate hydrothermal extraction technology for remediating petroleum-contaminated soils. Most current remediation practices generally fail (or are cost prohibitive) to remove the polycyclic aromatic hydrocarbons (PAHs) found in petroleum-contaminated sites or they require the use of organic solvents to achieve removal, at the expense of additional contamination and with the added cost of recycling solvents. Hydrothermal extraction offers the promise of efficiently extracting PAHs and other kinds of organics from contaminated soils at moderate temperatures and pressures, using only water and inorganic salts such as carbonate. Initial work is being conducted at SRI to measure the solubility and rate of solubilization of selected PAHs (anthracene, fluoranthene, pyrene, and chrysene) in water, using SRI's hydrothermal optical cell with the addition of varying amounts of sodium carbonate to evaluate the efficiency of the technology for removing PAHs from the soil. Preliminary results with pyrene and fluoranthene in water clearly indicate a significant enhancement of solubility with increase in temperature. During this quarter, we conducted experiments with pyrene in the temperature range 200 to 300 C and observed a great enhancement in solubility with an increase in temperature. We also started experiments with real-world soil samples purchased from the subcontractor.

  12. DoD Green Remediation Policy Update

    Science.gov (United States)

    2011-05-11

    decisions and practices  Green remediation is the practice of considering all environmental effects of remedy implementation and incorporating... reforestation irrigation – More than 30,000 tons of soil remediated and 270 tons of lead bullet fragments were reclaimed for recycling  Footprint Reduction

  13. 40 CFR 92.705 - Remedial plan.

    Science.gov (United States)

    2010-07-01

    ... POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Recall Regulations § 92.705 Remedial plan. (a) When any... repair under the remedial plan to affix a label to each locomotive or locomotive engine repaired or, when... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Remedial plan. 92.705 Section 92.705...

  14. 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…

  15. Pyrene biodegradation with layer-by-layer assembly bio-microcapsules.

    Science.gov (United States)

    Deng, Fucai; Zhang, Zhengfang; Yang, Chen; Guo, Chuling; Lu, Guining; Dang, Zhi

    2017-04-01

    Biotechnology is considered as a promising technology for the removal of polycyclic aromatic hydrocarbons from the environment. Free bacteria are often sensitive to some biotic and abiotic factors in the environment to the extent that their ability to effect biodegradation of organic pollutants, such as polycyclic aromatic hydrocarbons, is hampered. Consequently, it is imperative to carry out investigations into biological systems that will obviate or aid tolerance of bacteria to harsh environmental conditions. Chitosan/alginate bio-microcapsules produced using layer-by-layer (LBL) assembly method were tested for pyrene (PYR) biodegradation under harsh environmental conditions. Morphology observation indicated that the flake bio-microcapsules could be successfully prepared through LBL assembly method. Surface analysis showed that the bio-microcapsules had large fractions of mesopores. The results of the biodegradation experiments revealed that the 95% of 10mgL -1 PYR could be removed by the bacteria encapsulated chitosan/alginate bio-microcapsules in 3 days, which was higher than that of the free bacteria (59%). Compared to the free cells, the bacteria encapsulated chitosan/alginate bio-microcapsules produced 1-6 times higher PYR biodegradation rates at a high initial PYR concentration (50mgL -1 ) and extremely low pH values (pH =3) or temperatures (10°C or 40°C), as well as high salt stress. The results indicated that bacteria in microcapsules treatment gained a much higher tolerance to environmental stress and LBL bio-microcapsule could be promising candidate for remediating the organic pollutants. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Soil Contamination and Remediation Strategies. Current research and future challenge

    Science.gov (United States)

    Petruzzelli, G.

    2012-04-01

    Soil contamination: the heritage of industrial development Contamination is only a part of a whole set of soil degradation processes, but it is one of paramount importance since soil pollution greatly influences the quality of water, food and human health. Soil contamination has been identified as an important issue for action in the European strategy for soil protection, it has been estimated that 3.5 million of sites are potentially contaminated in Europe. Contaminated soils have been essentially discovered in industrial sites landfills and energy production plants, but accumulation of heavy metals and organic compounds can be found also in agricultural land . Remediation strategies. from incineration to bioremediation The assessment of soil contamination is followed by remedial action. The remediation of contaminated soils started using consolidates technologies (incineration inertization etc.) previously employed in waste treatment,. This has contributed to consider a contaminated soil as an hazardous waste. This rough approximation was unfortunately transferred in many legislations and on this basis soil knowledge have been used only marginally in the clean up procedures. For many years soil quality has been identified by a value of concentration of a contaminant and excavation and landfill disposal of soil has been largely used. In the last years the knowledge of remediation technology has rapidly grown, at present many treatment processes appear to be really feasible at field scale, and soil remediation is now based on risk assessment procedures. Innovative technologies, largely dependent on soil properties, such as in situ chemical oxidation, electroremediation, bioventing, soil vapor extraction etc. have been successfully applied. Hazardous organic compounds are commonly treated by biological technologies, biorememdiation and phytoremediation, being the last partially applied also for metals. Technologies selection is no longer exclusively based on

  17. Remedial action at the Acid/Pueblo Canyon site, Los Alamos, New Mexico. Final report

    International Nuclear Information System (INIS)

    1984-10-01

    The Acid/Pueblo Canyon site (TA-45) was designated in 1976 for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP). During the period 1943 to 1964 untreated and treated liquid wastes generated by nuclear weapons research activities at the Los Alamos Scientific Laboratory (LASL) were discharged into the two canyons. A survey of the site conducted by LASL in 1976 to 1977 identified two areas where radiological contamination exceeded criteria levels. The selected remedial action was based on extensive radiological characterization and comprehensive engineering assessments and comprised the excavation and disposal of 390 yd 3 of contaminated soil and rock. This document describes the background to the remedial action, the parties involved in administering and executing it, the chronology of the work, verification of the adequacy of the remedial action, and the cost incurred. 14 references, 5 figures, 5 tables

  18. Biodegradation of Moringa oleifera's polymer blends.

    Science.gov (United States)

    Finzi-Quintão, Cristiane Medina; Novack, Kátia Monteiro; Bernardes-Silva, Ana Cláudia; Silva, Thais D; Moreira, Lucas E S; Braga, Luiza E M

    2017-11-10

    Vegetable oils are used as a base for the synthesis of polymers and monomers with structures similar to that of petroleum, as plasticizers for conventional polymers and biodegrading additives. The Moringa oleifera oil was extracted from seeds and polymerized after being submitted to 16 h of microwave irradiation without catalysers. This polymer was characterized and the efficiency of the oil polymerization was verified by the reduction of double bonds and the increase of molecular weight up to 50,000 g mol -1 . Films produced by a mixture of low-density polyethylene (LDPE) with poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA) present low tensile resistance and low biodegradation behaviour. In order to improve those properties, the Moringa polymer (PMO) was mixed with LDPE and PBAT/PLA in specific mass concentrations. The films produced with this mixture were characterized and submitted to biodegradation analysis. The PMO behaves as a compatibilizer by improving thermal properties, reducing the crystalline phase and improving the biodegradation behaviour. The biodegradation improved up to five times in comparison to conventional polymers and it restores the mechanical properties.

  19. New fungal biomasses for cyanide biodegradation.

    Science.gov (United States)

    Ozel, Yasemin Kevser; Gedikli, Serap; Aytar, Pınar; Unal, Arzu; Yamaç, Mustafa; Cabuk, Ahmet; Kolankaya, Nazif

    2010-10-01

    Cyanide, a hazardous substance, is released into the environment as a result of natural processes of various industrial activities which is a toxic pollutant according to Environmental Protection Agency. In nature, some microorganisms are responsible for the degradation of cyanide, but there is only limited information about the degradation characteristics of Basidiomycetes for cyanide. The aim of the present study is to determine cyanide degradation characteristics in some Basidiomycetes strains including Polyporus arcularius (T 438), Schizophyllum commune (T 701), Clavariadelphus truncatus (T 192), Pleurotus eryngii (M 102), Ganoderma applanatum (M 105), Trametes versicolor (D 22), Cerrena unicolor (D 30), Schizophyllum commune (D 35) and Ganoderma lucidum (D 33). The cyanide degradation activities of P. arcularius S. commune and G. lucidum were found to be more than that of the other fungi examined. The parameters including incubation time, amount of biomass, initial cyanide concentration, temperature, pH and agitation rate were optimized for the selected three potential fungal strains. The maximum cyanide degradation was obtained after 48 h of incubation at 30°C by P. arcularius (T 438). The optimum pH and agitation rate were measured as 10.5 and 150 rev/min, respectively. The amount of biomass was found as 3.0 g for the maximum cyanide biodegradation with an initial cyanide concentration of 100mg/L. In this study, agar was chosen entrapment agent for the immobilization of effective biomass. We suggested that P. arcularius (T 438) could be effective in the treatment of contaminated sites with cyanide due to capability of degrading cyanide. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. Biodegradability of degradable plastic waste.

    Science.gov (United States)

    Agamuthu, P; Faizura, Putri Nadzrul

    2005-04-01

    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.

  1. Remediation using trace element humate surfactant

    Science.gov (United States)

    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.

  2. Biodegradability of fuel-ethers in environment; Biodegradabilite des ethers-carburants dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Fayolle-Guichard, F.

    2005-04-01

    Fuel ethers (methyl tert-butyl ether or MTBE, ethyl tert-butyl ether or ETBE and tert-amyl methyl ether or TAME have been used as gasoline additives since about twenty years in order to meet the requirements for the octane index and to limit the polluting emission in exhaust pipe gas (unburnt hydrocarbons and carbon monoxide). The high water solubility and the poor biodegradability of these compounds make them pollutants frequently encountered in aquifers. The present manuscript summarizes the knowledge concerning the biodegradability of fuel ethers obtained both at IFP and during collaborations with the Pasteur Institute (Paris), the Biotechnology Research Institute (Montreal, Canada) and the Center for Environmental Biotechnology (University of Tennessee, USA). Rhodococcus ruber IFP 2001 and Mycobacterium austroafricanum IFP 2012, two microorganisms isolated at IFP for their ability to grow, respectively, on ETBE and MTBE, were studied in order to determine the intermediates produced during MTBE and ETBE biodegradation and the enzymes required for each biodegradation step, thus allowing us to propose MTBE and ETBE catabolic pathways. A proteomic approach, from the protein induced during the degradation of ETBE or MTBE to the genes encoding these different enzymes, was carried out. The isolation of such genes is required:1) to use them for help in determining the bio-remediation capacities in polluted aquifers (DNA micro-arrays), 2) to monitor the microorganisms isolated for their degradative capacities during bio-remediation processes (fluorescent in situ hybridization or FISH) and 3) to create new tools for the detection and the quantification of ETBE or MTBE in contaminated aquifers (bio-sensor). The manuscript also describes the different ways for the adaptation of microorganisms to the presence of a xenobiotic compound. (author)

  3. Introduction of environmentally degradable parameters to evaluate the biodegradability of biodegradable polymers.

    Science.gov (United States)

    Guo, Wenbin; Tao, Jian; Yang, Chao; Song, Cunjiang; Geng, Weitao; Li, Qiang; Wang, Yuanyuan; Kong, Meimei; Wang, Shufang

    2012-01-01

    Environmentally Degradable Parameter ((Ed)K) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept (Ed)K was introduced. A test procedure of using the ISO 14852 method and detecting the evolved carbon dioxide as an analytical parameter was developed, and the calculated (Ed)K was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the (Ed)K values of 100 and 0, respectively. Natural soil samples were inoculated into bioreactors, followed by determining the rates of biodegradation of the reference materials and 15 commercial BDPs over a 2-week test period. Finally, a formula was deduced to calculate the value of (Ed)K for each material. The (Ed)K values of the tested materials have a positive correlation to their biodegradation rates in the simulated soil environment, and they indicated the relative biodegradation rate of each material among all the tested materials. Therefore, the (Ed)K was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment.

  4. Introduction of Environmentally Degradable Parameters to Evaluate the Biodegradability of Biodegradable Polymers

    Science.gov (United States)

    Yang, Chao; Song, Cunjiang; Geng, Weitao; Li, Qiang; Wang, Yuanyuan; Kong, Meimei; Wang, Shufang

    2012-01-01

    Environmentally Degradable Parameter (Ed K) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept Ed K was introduced. A test procedure of using the ISO 14852 method and detecting the evolved carbon dioxide as an analytical parameter was developed, and the calculated Ed K was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the Ed K values of 100 and 0, respectively. Natural soil samples were inoculated into bioreactors, followed by determining the rates of biodegradation of the reference materials and 15 commercial BDPs over a 2-week test period. Finally, a formula was deduced to calculate the value of Ed K for each material. The Ed K values of the tested materials have a positive correlation to their biodegradation rates in the simulated soil environment, and they indicated the relative biodegradation rate of each material among all the tested materials. Therefore, the Ed K was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment. PMID:22675455

  5. 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.

  6. 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)

  7. A survey of folk remedies for gastrointestinal tract diseases from Thailand's three southern border provinces.

    Science.gov (United States)

    Neamsuvan, Oratai; Tuwaemaengae, Tuwaeyah; Bensulong, Fatin; Asae, Asma; Mosamae, Kholeel

    2012-10-31

    Gastrointestinal tract diseases commonly occur in Thailand. However, surveying for finding out traditional drugs has never been done. To quantify and categorize the folk medicinal remedies that are used for healing the gastrointestinal tract by the traditional healers living in Thailand's three southern border provinces. The Pattani, Yala and Narathiwat provinces were selected. Semi-structured interviews of nine healers were conducted to collect information that included the remedy names, herbal ingredients, plant parts used, preparation, properties and treatment methods. The data were then further analyzed. The results revealed that 39 multi-species remedies and 36 single-species remedies were used to treat gastrointestinal disorders. A total of 103 plant species and 5 other materia medica were used as therapeutics. Most of the plants used were of the Zingiberaceae, Fabaceae and Euphorbiaceae families. Furthermore, it was found that although most of the healers used different remedies for a particular disease, some of the ingredients might have been similar. For example, Caesalpinia bonduc (L.) Roxb. was an ingredient used for parasitic disease remedies, and Senna alata (L.) Roxb. was used for constipation remedies. A review of the literature revealed 57 plant species and 2 other materia medica that have already been tested for their biological activities, whereas 46 plant species and 3 materia medica have never been tested. Consequently, research should be performed to confirm the pharmacological properties of folk remedies. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. Biodegradable Polymers and Stem Cells for Bioprinting

    Directory of Open Access Journals (Sweden)

    Meijuan Lei

    2016-04-01

    Full Text Available It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

  9. Biodegradable Polymers and Stem Cells for Bioprinting.

    Science.gov (United States)

    Lei, Meijuan; Wang, Xiaohong

    2016-04-29

    It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

  10. Biodegradable nanoparticles for gene therapy technology

    International Nuclear Information System (INIS)

    Hosseinkhani, Hossein; He, Wen-Jie; Chiang, Chiao-Hsi; Hong, Po-Da; Yu, Dah-Shyong; Domb, Abraham J.; Ou, Keng-Liang

    2013-01-01

    Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes

  11. Biodegradable polyesters based on succinic acid

    Directory of Open Access Journals (Sweden)

    Nikolić Marija S.

    2003-01-01

    Full Text Available Two series of aliphatic polyesters based on succinic acid were synthesized by copolymerization with adipic acid for the first series of saturated polyesters, and with fumaric acid for the second series. Polyesters were prepared starting from the corresponding dimethyl esters and 1,4-butanediol by melt transesterification in the presence of a highly effective catalyst tetra-n-butyl-titanate, Ti(0Bu4. The molecular structure and composition of the copolyesters was determined by 1H NMR spectroscopy. The effect of copolymer composition on the physical and thermal properties of these random polyesters were investigated using differential scanning calorimetry. The degree of crystallinity was determined by DSC and wide angle X-ray. The degrees of crystallinity of the saturated and unsaturated copolyesters were generally reduced with respect to poly(butylene succinate, PBS. The melting temperatures of the saturated polyesters were lower, while the melting temperatures of the unsaturated copolyesters were higher than the melting temperature of PBS. The biodegradability of the polyesters was investigated by enzymatic degradation tests. The enzymatic degradation tests were performed in a buffer solution with Candida cylindracea lipase and for the unsaturated polyesters with Rhizopus arrhizus lipase. The extent of biodegradation was quantified as the weight loss of polyester films. Also the surface of the polyester films after degradation was observed using optical microscopy. It could be concluded that the biodegradability depended strongly on the degree of crystallinity, but also on the flexibility of the chain backbone. The highest biodegradation was observed for copolyesters containing 50 mol.% of adipic acid units, and in the series of unsaturated polyesters for copolyesters containing 5 and 10 mol.% of fumarate units. Although the degree of crystallinity of the unsaturated polyesters decreased slightly with increasing unsaturation, the biodegradation

  12. Histological evaluation of different biodegradable and non-biodegradable membranes implanted subcutaneously in rats

    DEFF Research Database (Denmark)

    Zhao, S; Pinholt, E M; Madsen, J E

    2000-01-01

    Different types of biodegradable membranes have become available for guided tissue regeneration. The purpose of this study was to evaluate histologically three different biodegradable membranes (Bio-Gide, Resolut and Vicryl) and one non-biodegradable membrane (expanded polytetrafluoroethylene/e-PTFE...... that e-PTFE was well tolerated and encapsulated by a fibrous connective tissue capsule. There was capsule formation around Resolut and Vicryl and around Bio-Gide in the early phase there was a wide inflammatory zone already. e-PTFE and Vicryl were stable materials while Resolut and Bio-Gide fragmented...

  13. Biodegradable containers from green waste materials

    Science.gov (United States)

    Sartore, Luciana; Schettini, Evelia; Pandini, Stefano; Bignotti, Fabio; Vox, Giuliano; D'Amore, Alberto

    2016-05-01

    Novel biodegradable polymeric materials based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene glycol) diglycidyl ether (PEG) or epoxidized soybean oil (ESO) were obtained and their physico-chemical properties and mechanical behaviour were evaluated. Different processing conditions and the introduction of fillers of natural origin, as saw dust and wood flour, were used to tailor the mechanical properties and the environmental durability of the product. The biodegradable products, which are almost completely manufactured from renewable-based raw materials, look promising for several applications, particularly in agriculture for the additional fertilizing action of PH or in packaging.

  14. Biodegradation of Crystal Violet by Agrobacterium radiobacter

    DEFF Research Database (Denmark)

    Parshetti, G.K.; Parshetti, S.G.; Telke, A.A.

    2011-01-01

    Violet (100 mg/L) was studied, maximum decolorization was observed with 15% inoculum concentration. A significant increase in the activities of laccase (184%) and aminopyrine Af-demethylase (300%) in cells obtained after decolorization indicated the involvement of these enzymes in decolorization process...... and phenol. We proposed the hypothetical metabolic pathway of Crystal Violet biodegradation by A. radiobacter. Phytotoxicity and microbial toxicity study showed that Crystal Violet biodegradation metabolites were less toxic to bacteria (A. radiobacter, P. aurugenosa and A. vinelandii) contributing to soil...

  15. Biodegradable multifunctional oil production chemicals: Thermal polyaspartates

    International Nuclear Information System (INIS)

    Ross, R.J.; Ravenscroft, P.D.

    1996-01-01

    The paper deals with biodegradable oil production chemicals. Control of both mineral scale and corrosion with a single, environmentally acceptable material is an ambitious goal. Polyaspartate polymers represent a significant milestone in the attainment of this goal. Thermal polyaspartates (TPA) are polycarboxylate polymers derived via thermal condensation of the naturally occurring amino acid aspartic acid. These protein-like polymers are highly biodegradable and non-toxic, and are produced by an environmentally benign manufacturing process. TPAs exhibit excellent mineral scale inhibition activity and CO 2 corrosion control. Laboratory data on scale inhibition and corrosion control in the North Sea oil field production applications is presented. 8 refs., 2 figs., 6 tabs

  16. Anaerobic biodegradability and treatment of Egyption domestic sewage

    NARCIS (Netherlands)

    Elmitwally, T.A.; Al-Sarawey, A.; El-Sherbiny, M.F.; Zeeman, G.; Lettinga, G.

    2003-01-01

    The anaerobic biodegradability of domestic sewage for four Egyptian villages and four Egyptian cities was determined in batch experiments. The results showed that the biodegradability of the Egyptian-villages sewage (73%) was higher than that of the cities (66%). The higher biodegradability of the

  17. Preparation and characterization of biodegradable poly(vinyl alcohol)

    African Journals Online (AJOL)

    Preparation and characterization of biodegradable poly(vinyl alcohol)/starch blends. ... Their mechanical properties, biodegradability and surface morphology were estimated and studied. The poly(vinyl alcohol)/starch blends show good ... Keywords: Starch, Acetylation, Biodegradation, Poly(vinyl alcohol), Polymer blend.

  18. Mass transfer analysis for terephthalic acid biodegradation by ...

    African Journals Online (AJOL)

    Biodegradation of terephthalic acid (TA) by polyvinyl alcohol (PVA)-alginate immobilized Pseudomonas sp. was carried out in a packed-bed reactor. The effect of inlet TA concentration on biodegradation was investigated at 30°C, pH 7 and flow rate of 20 ml/min. The effects of flow rate on mass transfer and biodegradation ...

  19. Synthetic biodegradable functional polymers for tissue engineering: a brief review

    OpenAIRE

    BaoLin, GUO; MA, Peter X.

    2014-01-01

    Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly (glyce...

  20. Status report: Fernald site remediation

    International Nuclear Information System (INIS)

    Craig, J.R. Jr.; Saric, J.A.; Schneider, T.; Yates, M.K.

    1995-01-01

    The Fernald site is rapidly transitioning from a Remedial Investigation/ Feasibility Study (RI/FS) site to one where design and construction of the remedies dominates. Fernald is one of the first sites in the Department of Energy (DOE) complex to accomplish this task and real physical progress is being made in moving the five operable units through the CERCLA process. Two of the required Records of Decision (ROD) are in hand and all five operable units will have received their RODs (IROD for OU3) by the end of 1995. Pre-design investigations, design work or construction are now in progress on the operable units. The lessons learned from the work done to date include implementing innovations in the RI and FS process as well as effective use of Removal Actions to begin the actual site remediation. Also, forging close working relationships with the Federal and State Regulators, citizens action groups and the Fernald Citizens Task Force has helped move the program forward. The Fernald successes have been achieved by close coordination and cooperation among all groups working on the projects and by application of innovative technologies within the decision making process

  1. Strategic planning for remediation projects

    International Nuclear Information System (INIS)

    Tapp, J.W.

    1995-01-01

    Remediation projects may range from a single leaking storage tank to an entire plant complex or producing oil and gas field. Strategic planning comes into play when the contamination of soil and groundwater is extensive. If adjacent landowners have been impacted or the community at large is concerned about the quality of drinking water, then strategic planning is even more important. (1) To manage highly complex interrelated issues--for example, the efforts expended on community relations can alter public opinion, which can impact regulatory agency decisions that affect cleanup standards, which can...and so on. (2) To ensure that all potential liabilities are managed--for example, preparation for the defense of future lawsuits is essential during site investigation and remediation. (3) To communicate with senior management--when the remediation team provides a strategic plan that includes both technical and business issues, senior management has the opportunity to become more involved and make sound policy decisions. The following discusses the elements of a strategic plan, who should participate in it, and the issues that should be considered

  2. Application of biosurfactants in environmental biotechnology; remediation of oil and heavy metal

    Directory of Open Access Journals (Sweden)

    Ahmad Fahim Mahmud

    2016-07-01

    Full Text Available Many toxic substances have been introduced into environment through human activities. These compounds are danger to human health when they are ultimately or immediately in contact with soil particles. A conventional method to reduce, degrade and remove these substances is associated with some risk. In recent years, microorganisms have proved a unique role in the degradation and detoxification of polluted soil and water environments and, this process has been termed bio reclamation. The diversity of bioemulsifiers/biosurfactants makes them an attractive group and important key roles in various fields of industrial as well as biotechnological applications such as enhanced oil recovery, biodegradation of pollutants, and pharmaceutics. Environmental application of microbial surfactant has been shown as a promising due to solubilization of low solubility compounds, low toxicity observed and efficacy in improving biodegradation. However, it is important to note that full scale tests and more information is require to predict the behavior and model of surfactant function on the remediation process with biosurfactants. The purpose of this review is to describe the state of art in the potential applications of biosurfactants in remediation of environmental pollution caused by oil and heavy metal.

  3. Low Temperature Thermal Desorption Processes for the Remediation of Soils Contaminated with Solvents, Hydrocarbons, and Petroleum Products

    National Research Council Canada - National Science Library

    Eskelund, G; Garragan, G

    1993-01-01

    ... of this technology for the remediation of soils elsewhere. Included in this report is scale-up efficiencies, costs, physical parameters and comparisons of low temperature thermal stripping technologies used in soil remediation. This report is designed to disseminate practical, implementation-related information to minimize, selection, design, costing, and construction problems associated with Low Temperature Volatile Systems (LTVS).

  4. Application of biotests for the determination of soil ecotoxicity after exposure to biodegradable plastics

    Directory of Open Access Journals (Sweden)

    Susanna Sforzini

    2016-10-01

    Full Text Available Biodegradable plastics are mostly applied in packaging materials (e.g. shopping bags, waste collection bags, catering products, and agricultural applications. In this last case, degradation takes place directly in soil where biodegradable plastic products are intentionally left after use (e.g. mulch films for weeds control. Due to the growing volumes of biodegradable polymers and plastics, interest in their environmental safety is increasing and more research is carried out. Some attempt has been made to apply biotests, used in other sectors of environmental sciences, in the assessment of biodegradable plastics safety. In this work, the quality of soils after biodegradation of the bioplastics Mater-Bi has been assessed with a large array of biotests based on model organisms representative of the different trophic levels in the food chains of the edaphic and aquatic ecosystems. Mater-Bi was degraded under controlled conditions for 6 months at a 1% concentration. The selected organisms included bacteria and protozoa (V. fischeri and D. discoideum, respectively, the green alga P. subcapitata, plants (the monocotyledon S. saccharatum and the dicotyledon L. sativum, and invertebrates animals (D. magna, a freshwater crustacean, and the Oligochaeta earthworm E. andrei, using both acute and chronic endpoints. The results of the applied ecotoxicological tests showed that the Mater-Bi materials tested at very high doses did not affect the soil quality. Soil exposed to Mater-Bi has no noxious effects on edaphic organisms; in particular, mono and dicotyledon plants results, indicate that Mater-Bi plastic products are innocuous for agricultural uses. The use of more sensitive chronic endpoints allows to exclude possible effects at population level. This is the first time that such a comprehensive approach is applied to the assessment of possible ecotoxicity effects induced by biodegradable plastics in soil and represents a possible starting point for

  5. 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

  6. Salmon Site Remedial Investigation Report

    International Nuclear Information System (INIS)

    1999-01-01

    This Salmon Site Remedial Investigation Report provides the results of activities initiated by the U.S. Department of Energy (DOE) to determine if contamination at the Salmon Site poses a current or future risk to human health and the environment. These results were used to develop and evaluate a range of risk-based remedial alternatives. Located in Lamar County, Mississippi, the Salmon Site was used by the U.S. Atomic Energy Commission (predecessor to the DOE) between 1964 and 1970 for two nuclear and two gas explosions conducted deep underground in a salt dome. The testing resulted in the release of radionuclides into the salt dome. During reentry drilling and other site activities, liquid and solid wastes containing radioactivity were generated resulting in surface soil and groundwater contamination. Most of the waste and contaminated soil and water were disposed of in 1993 during site restoration either in the cavities left by the tests or in an injection well. Other radioactive wastes were transported to the Nevada Test Site for disposal. Nonradioactive wastes were disposed of in pits at the site and capped with clean soil and graded. The preliminary investigation showed residual contamination in the Surface Ground Zero mud pits below the water table. Remedial investigations results concluded the contaminant concentrations detected present no significant risk to existing and/or future land users, if surface institutional controls and subsurface restrictions are maintained. Recent sampling results determined no significant contamination in the surface or shallow subsurface. The test cavity resulting from the experiments is contaminated and cannot be economically remediated with existing technologies. The ecological sampling did not detect biological uptake of contaminants in the plants or animals sampled. Based on the current use of the Salmon Site, the following remedial actions were identified to protect both human health and the environment: (1) the

  7. Challenges for Deep Vadose Zone Remediation at the Hanford Site

    International Nuclear Information System (INIS)

    Morse, J.G.; Charboneau, B.L.; Lober, R.W.; Triplett, M.B.

    2008-01-01

    The 'deep vadose zone' is defined as the region below the practical depth of surface remedy influence (e.g., excavation or barrier). At the Hanford Site, this region of the Central Plateau poses unique challenges for characterization and remediation. Currently, deep vadose zone characterization efforts and remedy selection are spread over multiple waste site Operable Units and tank farm Waste Management Areas. A particular challenge for this effort is the situation in which past leaks from single-shell tanks have become commingled with discharges from nearby liquid disposal sites. In addition, tests of potentially viable remediation technologies will be initiated in the next few years. The Hanford Site is working with all affected parties, including the Washington State Department of Ecology, the Environmental Protection Agency, DOE-RL, DOE-ORP, and multiple contractor organizations to develop remediation approaches. This effort addresses the complex and challenging technical and is evaluating the best strategy or combination of strategies for focusing technical investigations, including treatability studies to facilitate deep vadose zone remediation at the Hanford Site. In summary: Hanford's two DOE offices, Richland Operations and the Office of River Protection, are engaging the Site's regulators, EPA and the Washington State Department of Ecology, in a collaborative process to resolve one of Hanford's most challenging technical issues - investigation and remedy selection for the deep vadose zone. While this process has not reached its conclusion, several important findings are apparent. All parties agree that the current approach of addressing this problem is not likely to be successful and an alternative is needed. An essential initial step is to develop and then implement a deep vadose zone treatability test plan that logically organizes the testing of candidate technologies for application to the variety of Hanford's deep vadose zone problems. This plan is

  8. Overview of technology modeling in the Remedial Action Assessment System (RAAS)

    International Nuclear Information System (INIS)

    Johnson, C.D.; Bagaasen, L.M.; Chan, T.C.; Lamar, D.A.; Buelt, J.L.; Freeman, C.J.; Skeen, R.S.

    1994-08-01

    There are numerous hazardous waste sites under the jurisdiction of the US Department of Energy (DOE). To assist the cleanup of these sites in a more consistent, timely, and cost-effective manner, the Remedial Action Assessment System (RAAS) is being developed by the Pacific Northwest Laboratory (PNL). RAAS is a software tool designed to automate the initial technology selection within the remedial investigation/feasibility study (RI/FS) process. The software does several things for the user: (1) provides information about available remedial technologies, (2) sorts possible technologies to recommend a list of technologies applicable to a given site, (3) points out technical issues that may prevent the implementation of a technology, and (4) provides an estimate of the effectiveness of a given technology at a particular site. Information from RAAS can be used to compare remediation options and guide selection of technologies for further study

  9. Biodegradation of malathion by Bacillus licheniformis strain ML-1

    Directory of Open Access Journals (Sweden)

    Khan Sara

    2016-01-01

    Full Text Available Malathion, a well-known organophosphate pesticide, has been used in agriculture over the last two decades for controlling pests of economically important crops. In the present study, a single bacterium, ML-1, was isolated by soil-enrichment technique and identified as Bacillus licheniformis on the basis of the 16S rRNA technique. The bacterium was grown in carbon-free minimal salt medium (MSM and was found to be very efficient in utilizing malathion as the sole source of carbon. Biodegradation experiments were performed in MSM without carbon source to determine the malathion degradation by the selected strain, and the residues of malathion were determined quantitatively using HPLC techniques. Bacillus licheniformis showed very promising results and efficiently consumed malathion as the sole carbon source via malathion carboxylesterase (MCE, and about 78% malathion was degraded within 5 days. The carboxylesterase activity was determined by using crude extract while using malathion as substrate, and the residues were determined by HPLC. It has been found that the MCE hydrolyzed 87% malathion within 96 h of incubation. Characterization of crude MCE revealed that the enzyme is robust in nature in terms of organic solvents, as it was found to be stable in various concentrations of ethanol and acetonitrile. Similarly, and it can work in a wide pH and temperature range. The results of this study highlighted the potential of Bacillus licheniformis strain ML-1 as a biodegrader that can be used for the bioremediation of malathion-contaminated soil.

  10. Biodegradation of phytosanitary products in biological wastewater treatment.

    Science.gov (United States)

    Massot, A; Estève, K; Noilet, P; Méoule, C; Poupot, C; Mietton-Peuchot, M

    2012-04-15

    Agricultural activity generates two types of waste: firstly, biodegradable organic effluents generally treated by biological processes and, secondly, phytosanitary effluents which contain residues of plant protection products. The latter are collected and treated. Current technological solutions are essentially based on concentration or physical-chemical processes. However, recent improvements in the biodegradability of pesticides open the way to the consideration of alternative, biological, treatment using mixed liquor from wastewater plant activated sludge. The feasibility of the biological treatment of viticultural effluents has been evaluated by the application of pesticides to activated sludge. The necessity for selection of a pesticide-resistant biomass has been highlighted. The elimination of the phytosanitary products shows the potential of a resistant biomass in the treatment of pesticides. The aerated biological storage ponds at three wineries, followed by a sand or reed-bed filter, were used for the treatment of the total annual volume of the viticulture effluents and validate the laboratory experiments. The results show that the biological purification of pesticides by activated sludge is possible by allowing approximately 8 days for biomass adaptation. Stability of purification occurs between 20 and 30 days. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Biodegradation of norfloxacin by Penicillium frequentans isolated ...

    African Journals Online (AJOL)

    One norfloxacin-degrading fungi was isolated from soil contaminated by norfloxacin and preliminary identified as Penicillium frequentans. Indoor simulative degradation experiments were carried out to investigate the biodegradation kinetics of norfloxacin with or without NFX3 in soil. The results indicate that the ...

  12. Formulation and characterization of caffeine biodegradable chewing ...

    African Journals Online (AJOL)

    ) is a test for analysing the textural properties of food, in which the samples are ..... Food Technol 1978;. 32: 62-66. 16. Mehta FM, Trivedi P. Formulation and characterization of biodegradable medicated chewing gum delivery system for motion ...

  13. Cobalt-chitosan: Magnetic and biodegradable heterogeneous ...

    Indian Academy of Sciences (India)

    A novel and biodegradable cobalt-chitosan as a magnetic heterogeneous catalyst was synthesized and characterized by XPS, FT-IR, EDX and TEM. Catalytic performance of cobalt- chitosan was tested by aerobic oxidation of alkyl arenes and alcohols. The results show that the catalyst exhibits excellent conversion for ...

  14. Production of Polyhydroxyalkanoates, a bacterial biodegradable ...

    African Journals Online (AJOL)

    Administrator

    There has been considerable interest in the development and production of biodegradable polymer to solve the current problem of pollution caused ... horticultural agricultural waste, corn, cassava etc would be of economic interest considering the .... for efficient production of PHAs. (Yu, 2001, Du et al.,. 2001b; Du and Yu, ...

  15. Preparation of Natural and Synthetic Porous Biodegradable ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Preparation of Natural and Synthetic Porous Biodegradable Scaffolds for Infected Wounds. Characterised for their physical properties, pore size and release kinetics. Release kinetics of bioactive molecules (antibiotics) in a controlled fashion. Release pattern of the ...

  16. Production of Polyhydroxyalkanoates, a bacterial biodegradable ...

    African Journals Online (AJOL)

    ... production has restricted its applications. The possibility of producing this polymer commercially and at comparable cost has been the main focus in this area. Key Words: Polyhydroxyalkanoates, biodegradable polymer, bioplastic, poly(3-hydroxybutyrate), biosynthesis. African Journal of Biotechnology Vol.3(1) 2004: 18- ...

  17. Biodegradable polymers derived from amino acids.

    Science.gov (United States)

    Khan, Wahid; Muthupandian, Saravanan; Farah, Shady; Kumar, Neeraj; Domb, Abraham J

    2011-12-08

    In the past three decades, the use of polymeric materials has increased dramatically for biomedical applications. Many α-amino acids derived biodegradable polymers have also been intensely developed with the main goal to obtain bio-mimicking functional biomaterials. Polymers derived from α-amino acids may offer many advantages, as these polymers: (a) can be modified further to introduce new functions such as imaging, molecular targeting and drugs can be conjugated chemically to these polymers, (b) can improve on better biological properties like cell migration, adhesion and biodegradability, (c) can improve on mechanical and thermal properties and (d) their degradation products are expected to be non-toxic and readily metabolized/excreted from the body. This manuscript focuses on biodegradable polymers derived from natural amino acids, their synthesis, biocompatibility and biomedical applications. It is observed that polymers derived from α-amino acids constitute a promising family of biodegradable materials. These provide innovative multifunctional polymers possessing amino acid side groups with biological activity and with innumerous potential applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Biodegradable Shape Memory Polymers in Medicine.

    Science.gov (United States)

    Peterson, Gregory I; Dobrynin, Andrey V; Becker, Matthew L

    2017-11-01

    Shape memory materials have emerged as an important class of materials in medicine due to their ability to change shape in response to a specific stimulus, enabling the simplification of medical procedures, use of minimally invasive techniques, and access to new treatment modalities. Shape memory polymers, in particular, are well suited for such applications given their excellent shape memory performance, tunable materials properties, minimal toxicity, and potential for biodegradation and resorption. This review provides an overview of biodegradable shape memory polymers that have been used in medical applications. The majority of biodegradable shape memory polymers are based on thermally responsive polyesters or polymers that contain hydrolyzable ester linkages. These materials have been targeted for use in applications pertaining to embolization, drug delivery, stents, tissue engineering, and wound closure. The development of biodegradable shape memory polymers with unique properties or responsiveness to novel stimuli has the potential to facilitate the optimization and development of new medical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Evaluation of biodegradation and biocompatibility of collagen ...

    Indian Academy of Sciences (India)

    The aim of this study was to develop a new variant of membranes based on collagen (COL), chitosan (CHI) and alkaline phosphatase (ALP) immobilized and cross-linking with glutaraldehyde (GA) at different concentrations. The biodegradation in the presence of collagenase was investigated. Biocompatibility was ...

  20. Cobalt-chitosan: Magnetic and biodegradable heterogeneous ...

    Indian Academy of Sciences (India)

    Abstract. A novel and biodegradable cobalt-chitosan as a magnetic heterogeneous catalyst was synthesized and characterized by XPS, FT-IR, EDX and TEM. Catalytic performance of cobalt- chitosan was tested by aerobic oxidation of alkyl arenes and alcohols. The results show that the catalyst exhibits excellent ...

  1. hydrocarbons biodegradation and evidence of mixed petroleum ...

    African Journals Online (AJOL)

    DJFLEX

    mode (EI) at 70Ev ionisation energy and scanned from 50 to 650 dalton. 3.0 Result and discussion. 3.1 n-alkanes and Isoprenoid Hydrocarbons. The concentrations (mgkg-1) ..... community in the Yellowish geothermal environment. Nature 434, 1000-1014. Cross River System. HYDROCARBONS BIODEGRADATION AND ...

  2. Fate and biodegradability of sulfonated aromatic amines

    NARCIS (Netherlands)

    Tan, N.C.G.; Leeuwen, van A.; Voorthuizen, van E.M.; Slenders, P.; Prenafeta, F.X.; Temmink, H.; Lettinga, G.; Field, J.A.

    2005-01-01

    Ten sulfonated aromatic amines were tested for their aerobic and anaerobic biodegradability and toxicity potential in a variety of environmental inocula. Of all the compounds tested, only two aminobenzenesulfonic acid (ABS) isomers, 2- and 4-ABS, were degraded. The observed degradation occurred only

  3. Evaluation of biodegradation and biocompatibility of collagen ...

    Indian Academy of Sciences (India)

    The biodegradation in the presence of collagenase was investigated. Biocompatibility was evaluated by MTT assay using a mouse fibroblast cell culture type NCTC (clone 929). Non-cross-linked samples were biocompatible and membranes cross-linked with low concentrations of GA (0.04, 0.08%) were also iocompatible.

  4. Biodegradability of diesel and biodiesel blends

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-02

    May 2, 2008 ... The biodegradability of pure diesel and biodiesel and blends with different proportions of biodiesel (2%. (commercial); 5% and 20%) was evaluated employing the respirometric method and the redox indicator. 2,6-dichlorophenol indophenol (DCPIP) test. In the former, experiments simulating the ...

  5. Modeling aerobic biodegradation in the capillary fringe.

    Science.gov (United States)

    Luo, Jian; Kurt, Zohre; Hou, Deyi; Spain, Jim C

    2015-02-03

    Vapor intrusion from volatile subsurface contaminants can be mitigated by aerobic biodegradation. Laboratory column studies with contaminant sources of chlorobenzene and a mixture of chlorobenzene, 1,2-dichlorobenzene, and 1,4-dichlorobenzene showed that contaminants were rapidly degraded in thin reactive zones with high biomass and low substrate concentrations in the vicinity of the capillary fringe. Such behavior was well characterized by a model that includes oxygen-, substrate-, and biomass-dependent biodegradation kinetics along with diffusive transport processes. An analytical solution was derived to provide theoretical support for the simplification of reaction kinetics and the approximation of reactive zone location and mass flux relationships at steady state. Results demonstrate the potential of aerobic natural attenuation in the capillary fringe for preventing contaminant migration in the unsaturated zone. The solution indicates that increasing contaminant mass flux into the column creates a thinner reactive zone and pushes it toward the oxygen boundary, resulting in a shorter distance to the oxygen source and a larger oxygen mass flux that balances the contaminant mass flux. As a consequence, the aerobic biodegradation can reduce high contaminant concentrations to low levels within the capillary fringe and unsaturated zone. The results are consistent with the observations of thin reactive layers at the interface in unsaturated zones. The model considers biomass while including biodegradation in the capillary fringe and unsaturated zone and clearly demonstrates that microbial communities capable of using the contaminants as electron donors may lead to instantaneous degradation kinetics in the capillary fringe and unsaturated zone.

  6. Diisopropanolamine biodegradation potential at sour gas plants

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, L.M.; Greene, E.A.; Coy, D.L.; Fedorak, P.M.

    1998-12-31

    The potential for aerobic and anaerobic biodegradation of a sour gas treatment chemical, diisopropanolamine (DIPA), was studied using contaminated aquifer materials from three sour gas treatment sites in western Canada. DIPA was found to be readily consumed under aerobic conditions at 8 C and 28 C in shake flask cultures incubated with aquifer material from each of the sites, and this removal was characterized by first-order kinetics. In addition, DIPA biodegradation was found to occur under nitrate-, Mn(IV)-, and Fe(III)-reducing conditions at 28 C, and in some cases at 8 C, in laboratory microcosms. DIPA loss corresponded to consumption of nitrate, and production of Mn(II) and Fe(II) in viable microcosms compared to corresponding sterile controls. A threshold DIPA concentration near 40 mg/L was observed in the anaerobic microcosms. This report provides the first evidence that DIPA is biodegraded under anaerobic conditions, and the data suggest that biodegradation may contribute to DIPA attenuation under aerobic and anaerobic conditions in aquifers contaminated with this sour gas treatment chemical.

  7. Current trends in trichloroethylene biodegradation: a review.

    Science.gov (United States)

    Shukla, Awadhesh Kumar; Upadhyay, Siddh Nath; Dubey, Suresh Kumar

    2014-06-01

    Over the past few years biodegradation of trichloroethylene (TCE) using different microorganisms has been investigated by several researchers. In this review article, an attempt has been made to present a critical summary of the recent results related to two major processes--reductive dechlorination and aerobic co-metabolism used for TCE biodegradation. It has been shown that mainly Clostridium sp. DC-1, KYT-1, Dehalobacter, Dehalococcoides, Desulfuromonas, Desulfitobacterium, Propionibacterium sp. HK-1, and Sulfurospirillum bacterial communities are responsible for the reductive dechlorination of TCE. Efficacy of bacterial communities like Nitrosomonas, Pseudomonas, Rhodococcus, and Xanthobacter sp. etc. for TCE biodegradation under aerobic conditions has also been examined. Mixed cultures of diazotrophs and methanotrophs have been used for TCE degradation in batch and continuous cultures (biofilter) under aerobic conditions. In addition, some fungi (Trametes versicolor, Phanerochaete chrysosporium ME-446) and Actinomycetes have also been used for aerobic biodegradation of TCE. The available information on kinetics of biofiltration of TCE and its degradation end-products such as CO2 are discussed along with the available results on the diversity of bacterial community obtained using molecular biological approaches. It has emerged that there is a need to use metabolic engineering and molecular biological tools more intensively to improve the robustness of TCE degrading microbial species and assess their diversity.

  8. Biodegradable poly (lactic acid) microspheres containing total ...

    Indian Academy of Sciences (India)

    The fabrication of biodegradable poly(lactic acid) (PLA) microspheres containing total alkaloids of Caulis sinomenii was investigated. The formation, diameter, morphology and properties of the microspheres were characterized using Fourier transform infrared spectroscopy (FT–IR), laser particle size analyser and scanning ...

  9. Biodegradation of chlorobenzoic acids by ligninolytic fungi

    Czech Academy of Sciences Publication Activity Database

    Muzikář, Milan; Křesinová, Zdena; Svobodová, Kateřina; Filipová, Alena; Čvančarová, Monika; Cajthamlová, Kamila; Cajthaml, Tomáš

    2011-01-01

    Roč. 196, - (2011), s. 386-394 ISSN 0304-3894 R&D Projects: GA MŠk 2B06156; GA ČR GA525/09/1058 Institutional research plan: CEZ:AV0Z50200510 Keywords : Chlorobenzoic acid * Polychlorinated biphenyls * Biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 4.173, year: 2011

  10. Cobalt-chitosan: Magnetic and biodegradable heterogeneous ...

    Indian Academy of Sciences (India)

    Cobalt-chitosan: Magnetic and biodegradable catalyst. 1931. Table 3. Effects of the solvent, temperature and base on oxidation of phenylethyl alcohol using cobalt-chitosan.a. Entry. Solvent. Temperature. Base. Yield (%) b. 1. DMF. 100. K2CO3. 60. 2. DMF. 100. KOH. 60. 3. CH3CN. 80. K2CO3. 65. 4. H2O reflux. KOH. 10. 5.

  11. Biodegradation of synthetic detergents in wastewater

    African Journals Online (AJOL)

    STORAGESEVER

    2009-03-20

    Mar 20, 2009 ... Surfactants constitute a major ingredient of detergent components. Usually surfactants are disposed after use to sewage treatment plants (STPs). Here, biodegradation processes and adsorption on sludge particles remove these chemicals from wastewaters to a greater or lesser extent, depending on the ...

  12. Polyvinyl alcohol biodegradation under denitrifying conditions

    Czech Academy of Sciences Publication Activity Database

    Marušincová, H.; Husárová, L.; Růžička, J.; Ingr, M.; Navrátil, Václav; Buňková, L.; Koutný, M.

    2013-01-01

    Roč. 84, October (2013), s. 21-28 ISSN 0964-8305 Grant - others:GA ČR(CZ) GAP108/10/0200 Institutional support: RVO:61388963 Keywords : polyvinyl alcohol * biodegradation * denitrification * waste-water treatment * anaerobic * Steroidobacter Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.235, year: 2013

  13. Biodegradable polymersomes for targeted ultrasound imaging

    NARCIS (Netherlands)

    Zhou, W.; Hennink, W.E.; Feijen, J.; Meng, Fenghua; Sam, T; Engbers, G.H.M.; Feijen, Jan

    2006-01-01

    Biodegradable polymersomes with a sub-micron size were prepared by using poly(ethylene glycol)–polylactide (PEG–PDLLA) block-copolymers in aqueous media. Air-encapsulated polymersomes could be obtained by a lyophilization/rehydration procedure. Preliminary results showed that these polymersomes were

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

    Science.gov (United States)

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

    2018-03-21

    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. Published by Elsevier B.V.

  15. Remediation of Steel Slag on Acidic Soil Contaminated by Heavy Metal

    OpenAIRE

    Gu, Haihong; Li, Fuping; Guan, Xiang; Li, Zhongwei; Yu, Qiang

    2013-01-01

    The technology of in situ immobilization with amendments is an important measure that remediates the soil contaminated by heavy metal, and selecting economical and effective modifier is the key. The effects and mechanism of steel slag, the silicon-rich alkaline by-product which can remediate acidic soil contaminated by heavy metal, are mainly introduced in this paper to provide theory inferences for future research. Firstly, the paper analyzes current research situation of in situ immobilizat...

  16. Biodegradation of uranium-contaminated waste oil

    International Nuclear Information System (INIS)

    Hary, L.F.

    1983-01-01

    The Portsmouth Gaseous Diffusion Plant routinely generates quantities of uranium-contaminated waste oil. The current generation rate of waste oil is approximately 2000 gallons per year. The waste is presently biodegraded by landfarming on open field soil plots. However, due to the environmental concerns associated with this treatment process, studies were conducted to determine the optimum biodegradation conditions required for the destruction of this waste. Tests using respirometric flasks were conducted to determine the biodegradation rate for various types of Portsmouth waste oil. These tests were performed at three different loading rates, and on unfertilized and fertilized soil. Additional studies were conducted to evaluate the effectiveness of open field landfarming versus treatment at a greenhouse-like enclosure for the purpose of maintaining soil temperatures above ambient conditions. The respirometric tests concluded that the optimum waste oil loading rate is 10% weight of oil-carbon/weight of soil (30,600 gallons of uranium-contaminated waste oil/acre) on soils with adjusted carbon:nitrogen and carbon:phosphorus ratios of 60:1 and 800:1, respectively. Also, calculational results indicated that greenhouse technology does not provide a significant increase in biodegradation efficiency. Based on these study results, a 6300 ft. 2 abandoned anaerobic digester sludge drying bed is being modified into a permanent waste oil biodegradation facility. The advantage of using this area is that uranium contamination will be contained by the bed's existing leachate collection system. This modified facility will be capable of handling approximately 4500 gallons of waste oil per year; accordingly current waste generation quantities will be satisfactorily treated. 15 refs., 14 figs., 4 tabs

  17. Hydrocarbons biodegradation in unsaturated porous medium

    International Nuclear Information System (INIS)

    Gautier, C.

    2007-12-01

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  18. Mechanical characterization of commercial biodegradable plastic films

    Science.gov (United States)

    Vanstrom, Joseph R.

    Polylactic acid (PLA) is a biodegradable plastic that is relatively new compared to other plastics in use throughout industry. The material is produced by the polymerization of lactic acid which is produced by the fermentation of starches derived from renewable feedstocks such as corn. Polylactic acid can be manufactured to fit a wide variety of applications. This study details the mechanical and morphological properties of selected commercially available PLA film products. Testing was conducted at Iowa State University and in conjunction with the United States Department of Agriculture (USDA) BioPreferred ProgramRTM. Results acquired by Iowa State were compared to a similar study performed by the Cortec Corporation in 2006. The PLA films tested at Iowa State were acquired in 2009 and 2010. In addition to these two studies at ISU, the films that were acquired in 2009 were aged for a year in a controlled environment and then re-tested to determine effects of time (ageing) on the mechanical properties. All films displayed anisotropic properties which were confirmed by inspection of the films with polarized light. The mechanical testing of the films followed American Society for Testing and Materials (ASTM) standards. Mechanical characteristics included: tensile strength (ASTM D882), elongation of material at failure (ASTM D882), impact resistance (ASTM D1922), and tear resistance (ASTM D4272). The observed values amongst all the films ranged as followed: tensile strength 33.65--8.54 MPa; elongation at failure 1,665.1%--47.2%; tear resistance 3.61--0.46 N; and puncture resistance 2.22--0.28 J. There were significant differences between the observed data for a number of films and the reported data published by the Cortec Corp. In addition, there were significant differences between the newly acquired material from 2009 and 2010, as well as the newly acquired materials in 2009 and the aged 2009 materials, suggesting that ageing and manufacturing date had an effect on

  19. Methanogenic Paraffin Biodegradation: Alkylsuccinate Synthase Gene Quantification and Dicarboxylic Acid Production.

    Science.gov (United States)

    Oberding, Lisa K; Gieg, Lisa M

    2018-01-01

    applications for effective fuel-contaminated site remediation and for improved recovery from oil reservoirs. Previous studies have clearly demonstrated that short-chain alkanes (C 17 ) that comprise many fuel mixtures. Using an enrichment culture derived from a freshwater fuel-contaminated site, we demonstrate that the model waxy alkane n -octacosane can be biodegraded under methanogenic conditions by a presumed Smithella phylotype. Compared with that of controls, we show an increased abundance and expression of the assA gene, which is known to be important for anaerobic n -alkane metabolism. Metabolite analyses revealed the presence of a range of α,ω-dicarboxylic acids found only in n -octacosane-degrading cultures, a novel finding that lends insight as to how anaerobic communities may access waxes as growth substrates in anoxic environments. Copyright © 2017 American Society for Microbiology.

  20. Biodegradation of the veterinary antibiotics enrofloxacin and ceftiofur and associated microbial community dynamics.

    Science.gov (United States)

    Alexandrino, Diogo A M; Mucha, Ana P; Almeida, C Marisa R; Gao, Wei; Jia, Zhongjun; Carvalho, Maria F

    2017-03-01

    Fluoroquinolones and cephalosporins are two classes of veterinary antibiotics arising as pollutants of emerging concern. In this work, the microbial degradation of two representative antibiotics of both these classes, enrofloxacin (ENR) and ceftiofur (CEF), is reported. Biodegradation of the target antibiotics was investigated by supplementing the culture medium with ENR and CEF, individually and in mixture. Microbial inocula were obtained from rhizosphere sediments of plants derived from experimental constructed wetlands designed for the treatment of livestock wastewaters contaminated with trace amounts of these antibiotics. Selected microbial inocula were acclimated during a period of 5months, where the antibiotics were supplemented every three weeks at the concentration of 1mgL -1 , using acetate as a co-substrate. After this period, the acclimated consortia were investigated for their capacity to biodegrade 2 and 3mgL -1 of ENR and CEF. Complete removal of CEF from the inoculated culture medium was always observed within 21days, independently of its concentration or the concomitant presence of ENR. Biodegradation of ENR decreased with the increase in its concentration in the culture medium, with defluorination percentages decreasing from ca. 65 to 4%. Ciprofloxacin and norfloxacin were detected as biodegradation intermediates of ENR in the microbial cultures supplemented with this antibiotic, indicating that defluorination of at least part of ENR in these cultures is not an immediate catabolic step. Abiotic mechanisms showed high influence in the removal of CEF, affecting less ENR degradation. The acclimation process with the target antibiotics led to significant shifts in the structure and diversity of the microbial communities, predominantly selecting microorganisms belonging to the phyla Proteobacteria (e.g. Achromobacter, Variovorax and Stenotrophomonas genera) and Bacteroidetes (e.g. Dysgonomonas, Flavobacterium and Chryseobacterium genera). The results

  1. Tank Waste Remediation System Guide

    International Nuclear Information System (INIS)

    Robershotte, M.A.; Dirks, L.L.; Seaver, D.A.; Bothers, A.J.; Madden, M.S.

    1995-06-01

    The scope, number and complexity of Tank Waste Remediation System (TWRS) decisions require an integrated, consistent, and logical approach to decision making. TWRS has adopted a seven-step decision process applicable to all decisions. Not all decisions, however, require the same degree of rigor/detail. The decision impact will dictate the appropriate required detail. In the entire process, values, both from the public as well as from the decision makers, play a key role. This document concludes with a general discussion of the implementation process that includes the roles of concerned parties

  2. Horizontal wells in subsurface remediation

    International Nuclear Information System (INIS)

    Losonsky, G.; Beljin, M.S.

    1992-01-01

    This paper reports on horizontal wells which offer an effective alternative to vertical wells in various environmental remediation technologies. Hydrogeological advantages of horizontal wells over vertical wells include a larger zone of influence, greater screen length, higher specific capacity and lower groundwater screen entrance velocity. Because of these advantages, horizontal wells can reduce treatment time and costs of groundwater recovery (pump-and-treat), in situ groundwater aeration (sparging) and soil gas extraction (vacuum extraction). Horizontal wells are also more effective than vertical wells in landfill leachate collection (under-drains), bioremediation, and horizontal grout injection

  3. Coastal hypoxia responses to remediation

    Science.gov (United States)

    Kemp, W. M.; Testa, J. M.; Conley, D. J.; Gilbert, D.; Hagy, J. D.

    2009-07-01

    The incidence and intensity of hypoxic waters in coastal aquatic ecosystems has been expanding in recent decades coincident with eutrophication of the coastal zone. Because of the negative effects hypoxia has on many organisms, extensive efforts have been made to reduce the size and duration of hypoxia in many coastal waters. Although it has been broadly assumed that reductions in nutrient loading rates would reverse eutrophication and consequently, hypoxia, recent analyses of historical data from European and North American coastal systems suggest little evidence for simple linear response trajectories. We review existing data, analyses, and models that relate variations in the extent and intensity of hypoxia to changes in loading rates for inorganic nutrients and labile organic matter. We also assess existing knowledge of physical and ecological factors regulating oxygen in coastal marine waters and examine a broad range of examples where hypoxia responses to reductions in nutrient (or organic matter) inputs have been documented. Of the 22 systems identified where concurrent time series of loading and O2 were available, half displayed relatively clear and direct recoveries following remediation. We explored in detail 5 well-studied systems that have exhibited complex, non-linear responses to loading, including apparent "regime shifts." A summary of these analyses suggests that O2 conditions improved rapidly and linearly in systems where remediation focused on organic inputs from sewage plants, which were the primary drivers of hypoxia. In larger more open systems where diffuse nutrient loads are more important in fueling O2 depletion and where climatic influences are pronounced, responses to remediation tend to follow non-linear trends that may include hysteresis and time-lags. Improved understanding of hypoxia remediation requires that future studies use comparative approaches and consider multiple regulating factors including: (1) the dominant temporal scales

  4. Green PCB Remediation from Sediment Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — An ongoing problem facing the global environmental community including NASA centers is the removal and remediation of polychlorinated biphenyls (PCBs). PCBs were...

  5. 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.

  6. Biodegradation of low-density polyethylene (LDPE) by mixed culture of Lysinibacillus xylanilyticus and Aspergillus niger in soil.

    Science.gov (United States)

    Esmaeili, Atefeh; Pourbabaee, Ahmad Ali; Alikhani, Hossein Ali; Shabani, Farzin; Esmaeili, Ensieh

    2013-01-01

    In this study, two strains of Aspergillus sp. and Lysinibacillus sp. with remarkable abilities to degrade low-density polyethylene (LDPE) were isolated from landfill soils in Tehran using enrichment culture and screening procedures. The biodegradation process was performed for 126 days in soil using UV- and non-UV-irradiated pure LDPE films without pro-oxidant additives in the presence and absence of mixed cultures of selected microorganisms. The process was monitored by measuring the microbial population, the biomass carbon, pH and respiration in the soil, and the mechanical properties of the films. The carbon dioxide measurements in the soil showed that the biodegradation in the un-inoculated treatments were slow and were about 7.6% and 8.6% of the mineralisation measured for the non-UV-irradiated and UV-irradiated LDPE, respectively, after 126 days. In contrast, in the presence of the selected microorganisms, biodegradation was much more efficient and the percentages of biodegradation were 29.5% and 15.8% for the UV-irradiated and non-UV-irradiated films, respectively. The percentage decrease in the carbonyl index was higher for the UV-irradiated LDPE when the biodegradation was performed in soil inoculated with the selected microorganisms. The percentage elongation of the films decreased during the biodegradation process. The Fourier transform infra-red (FT-IR), x-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to determine structural, morphological and surface changes on polyethylene. These analyses showed that the selected microorganisms could modify and colonise both types of polyethylene. This study also confirmed the ability of these isolates to utilise virgin polyethylene without pro-oxidant additives and oxidation pretreatment, as the carbon source.

  7. Biodegradation of low-density polyethylene (LDPE by mixed culture of Lysinibacillus xylanilyticus and Aspergillus niger in soil.

    Directory of Open Access Journals (Sweden)

    Atefeh Esmaeili

    Full Text Available In this study, two strains of Aspergillus sp. and Lysinibacillus sp. with remarkable abilities to degrade low-density polyethylene (LDPE were isolated from landfill soils in Tehran using enrichment culture and screening procedures. The biodegradation process was performed for 126 days in soil using UV- and non-UV-irradiated pure LDPE films without pro-oxidant additives in the presence and absence of mixed cultures of selected microorganisms. The process was monitored by measuring the microbial population, the biomass carbon, pH and respiration in the soil, and the mechanical properties of the films. The carbon dioxide measurements in the soil showed that the biodegradation in the un-inoculated treatments were slow and were about 7.6% and 8.6% of the mineralisation measured for the non-UV-irradiated and UV-irradiated LDPE, respectively, after 126 days. In contrast, in the presence of the selected microorganisms, biodegradation was much more efficient and the percentages of biodegradation were 29.5% and 15.8% for the UV-irradiated and non-UV-irradiated films, respectively. The percentage decrease in the carbonyl index was higher for the UV-irradiated LDPE when the biodegradation was performed in soil inoculated with the selected microorganisms. The percentage elongation of the films decreased during the biodegradation process. The Fourier transform infra-red (FT-IR, x-ray diffraction (XRD and scanning electron microscopy (SEM were used to determine structural, morphological and surface changes on polyethylene. These analyses showed that the selected microorganisms could modify and colonise both types of polyethylene. This study also confirmed the ability of these isolates to utilise virgin polyethylene without pro-oxidant additives and oxidation pretreatment, as the carbon source.

  8. Remediation of at-risk medical students: theory in action.

    Science.gov (United States)

    Winston, Kalman A; Van Der Vleuten, Cees P M; Scherpbier, Albert J J A

    2013-09-27

    Previous work has shown that a programme that draws on a blend of theories makes a positive difference to outcomes for students who fail and repeat their first semester at medical school. Exploration of student and teacher perspectives revealed that remediation of struggling medical students can be achieved through a cognitive apprenticeship within a small community of inquiry. This community needs expert teachers capable of performing a unique combination of roles (facilitator, nurturing mentor, disciplinarian, diagnostician and role model), with high levels of teaching presence and practical wisdom. Yet, despite participants' convergent opinions on the elements of effective remediation, significant differences were found between outcomes of students working with experienced and inexperienced teachers. The current study explores the actual practice of teachers on this remediation course, aiming to exemplify elements of our theory of remediation and explore differences between teachers. Since it is in the classroom context that the interactions that constitute the complex process of remediation emerge, this practice-based research has focused on direct observation of classroom teaching. Nineteen hours of small group sessions were recorded and transcribed. Drawing on ethnography and sociocultural discourse analysis, selected samples of talk-in-context demonstrate how the various elements of remediation play out in practice, highlighting aspects that are most effective, and identifying differences between experienced and novice teachers. Long-term student outcomes are strongly correlated to teacher experience (r, 0.81). Compared to inexperienced teachers, experienced teachers provide more challenging, disruptive facilitation, and take a dialogic stance that encourages more collaborative group dynamics. They are more expert at diagnosing cognitive errors, provide frequent metacognitive time-outs and make explicit links across the curriculum. Remediation is effective

  9. Remediation of at-risk medical students: theory in action

    Science.gov (United States)

    2013-01-01

    Background Previous work has shown that a programme that draws on a blend of theories makes a positive difference to outcomes for students who fail and repeat their first semester at medical school. Exploration of student and teacher perspectives revealed that remediation of struggling medical students can be achieved through a cognitive apprenticeship within a small community of inquiry. This community needs expert teachers capable of performing a unique combination of roles (facilitator, nurturing mentor, disciplinarian, diagnostician and role model), with high levels of teaching presence and practical wisdom. Yet, despite participants’ convergent opinions on the elements of effective remediation, significant differences were found between outcomes of students working with experienced and inexperienced teachers. The current study explores the actual practice of teachers on this remediation course, aiming to exemplify elements of our theory of remediation and explore differences between teachers. Methods Since it is in the classroom context that the interactions that constitute the complex process of remediation emerge, this practice-based research has focused on direct observation of classroom teaching. Nineteen hours of small group sessions were recorded and transcribed. Drawing on ethnography and sociocultural discourse analysis, selected samples of talk-in-context demonstrate how the various elements of remediation play out in practice, highlighting aspects that are most effective, and identifying differences between experienced and novice teachers. Results Long-term student outcomes are strongly correlated to teacher experience (r, 0.81). Compared to inexperienced teachers, experienced teachers provide more challenging, disruptive facilitation, and take a dialogic stance that encourages more collaborative group dynamics. They are more expert at diagnosing cognitive errors, provide frequent metacognitive time-outs and make explicit links across the

  10. An economic decision framework using modeling for improving aquifer remediation design

    International Nuclear Information System (INIS)

    James, B.R.; Gwo, J.P.; Toran, L.E.

    1995-11-01

    Reducing cost is a critical challenge facing environmental remediation today. One of the most effective ways of reducing costs is to improve decision-making. This can range from choosing more cost- effective remediation alternatives (for example, determining whether a groundwater contamination plume should be remediated or not) to improving data collection (for example, determining when data collection should stoop). Uncertainty in site conditions presents a major challenge for effective decision-making. We present a framework for increasing the effectiveness of remedial design decision-making at groundwater contamination sites where there is uncertainty in many parameters that affect remediation design. The objective is to provide an easy-to-use economic framework for making remediation decisions. The presented framework is used to 1) select the best remedial design from a suite of possible ones, 2) estimate if additional data collection is cost-effective, and 3) determine the most important parameters to be sampled. The framework is developed by combining elements from Latin-Hypercube simulation of contaminant transport, economic risk-cost-benefit analysis, and Regional Sensitivity Analysis (RSA)

  11. An economic decision framework using modeling for improving aquifer remediation design

    Energy Technology Data Exchange (ETDEWEB)

    James, B.R.; Gwo, J.P.; Toran, L.E.

    1995-11-01

    Reducing cost is a critical challenge facing environmental remediation today. One of the most effective ways of reducing costs is to improve decision-making. This can range from choosing more cost- effective remediation alternatives (for example, determining whether a groundwater contamination plume should be remediated or not) to improving data collection (for example, determining when data collection should stoop). Uncertainty in site conditions presents a major challenge for effective decision-making. We present a framework for increasing the effectiveness of remedial design decision-making at groundwater contamination sites where there is uncertainty in many parameters that affect remediation design. The objective is to provide an easy-to-use economic framework for making remediation decisions. The presented framework is used to 1) select the best remedial design from a suite of possible ones, 2) estimate if additional data collection is cost-effective, and 3) determine the most important parameters to be sampled. The framework is developed by combining elements from Latin-Hypercube simulation of contaminant transport, economic risk-cost-benefit analysis, and Regional Sensitivity Analysis (RSA).

  12. Remedial Action Assessment System: A computer-based methodology for conducting feasibility studies

    International Nuclear Information System (INIS)

    White, M.K.; Buelt, J.L.; Stottlemyre, J.A.

    1991-02-01

    Because of the complexity and number of potential waste sites facing the US Department of Energy (DOE) for potential cleanup, DOE is supporting the development of a computer-based methodology to streamline the remedial investigation/feasibility study process. The Remedial Action Assessment System (RAAS), can be used for screening, linking, and evaluating established technology processes in support of conducting feasibility studies. It is also intended to do the same in support of corrective measures studies. The user interface employs menus, windows, help features, and graphical information while RAAS is in operation. Object-oriented programming is used to link unit processes into sets of compatible processes that form appropriate remedial alternatives. Once the remedial alternatives are formed, the RAAS methodology can evaluate them in terms of effectiveness, implementability, and cost. RAAS will access a user-selected risk assessment code to determine the reduction of risk after remedial action by each recommended alternative. The methodology will also help determine the implementability of the remedial alternatives at a site and access cost estimating tools to provide estimates of capital, operating, and maintenance costs. This paper presents the characteristics of two RAAS prototypes currently being developed. These include the RAAS Technology Information System, which accesses graphical, tabular and textual information about technologies, and the main RAAS methodology, which screens, links, and evaluates remedial technologies. 4 refs., 3 figs., 1 tab

  13. Biodegradability and process characterization of nonwovens formed from cotton and cellulose acetate fibers

    Science.gov (United States)

    Suh, Hageun

    A possible candidate as an environmentally friendly nonwoven fabric is one which can be formed from the thermal calendering of a cotton/cellulose acetate blend. The results presented have focused on biodegradable properties of the fibers, physical properties of the fabric, and process optimization of the thermal calendering. Biodegradation of cellulose has been intensively studied, and cellulose is believed to be readily biodegraded by many microorganisms due to the activity of cellulase enzymes. However, the biodegradability of cellulose acetate (CA) is less than certain. To determine a semi-quantitative measure of the biodegradation of CA fibers, the AATCC test method 30-1988 was selected. After a 12-week soil burial test, evidence of microbial attack on CA fabric was obtained on the basis of 27% strength loss. As a more reliable method, the ASTM test method D5209-91, an aerobic sludge test, was adopted, in which the amount of COsb2 evolved from the decomposition of CA, cotton and fiber blends was measured. The biodegradability of CA fibers was confirmed by showing COsb2 evolution, and the synergistic effects of multi-enzyme systems between cellulase and esterase were suggested based on the increased biodegradation rates in fiber blends. Opening, blending, carding, and thermal calendering processes were used in the fabrication of the nonwovens. Pretreatment with solvent vapors was introduced for modifying the softening temperatures of the cellulose acetate and for lowering the calendering temperatures required otherwise. The success of the solvent-assisted thermal calendering is demonstrated in enhanced tensile strengths of the nonwoven obtained with lower calendering temperatures. For process optimization, the experiment was designed for a 3-way factorial design with the following factors: bonding temperature, blend ratio and solvent treatment time. The effects of the factors on 18 physical properties were determined by analysis of variance, least

  14. 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…

  15. Simulation of DEHP biodegradation and sorption during the anaerobic digestion of secondary sludge

    DEFF Research Database (Denmark)

    Fountoulakis, M.S.; Stamatelatou, K.; Batstone, Damien J.

    2006-01-01

    Di-ethylhexyl phthalate (DEHP) has commonly been found in the sludge of municipal wastewater treatment plants especially during anaerobic processing. It is slowly biodegradable under anaerobic conditions. Due to its high hydrophobicity, sorption-desorption processes can be rate-limiting for the c......Di-ethylhexyl phthalate (DEHP) has commonly been found in the sludge of municipal wastewater treatment plants especially during anaerobic processing. It is slowly biodegradable under anaerobic conditions. Due to its high hydrophobicity, sorption-desorption processes can be rate......-limiting for the compound biodegradation. In this study, the anaerobic biodegradation of DEHP was investigated through batch kinetic experiments and dynamic transitions of a continuous stirred tank reactor (CSTR) fed with secondary sludge contaminated with DEHP. A widely accepted model (ADM1) was used to fit the anaerobic...... digestion of secondary sludge and was properly extended to. account for DEHP removal, in which mass transfer processes are also involved. It was shown that DEHP removal was limited by the transfer of DEHP within the solid fraction. The criterion selected for the distinction of the two sites was whether...

  16. Customizable Biopolymers for Heavy Metal Remediation

    Science.gov (United States)

    Kostal, Jan; Prabhukumar, Giridhar; Lao, U. Loi; Chen, Alin; Matsumoto, Mark; Mulchandani, Ashok; Chen*, Wilfred

    2005-10-01

    Nanoscale materials have been gaining increasing interest in the area of environmental remediation because of their unique physical, chemical and biological properties. One emerging area of research has been the development of novel materials with increased affinity, capacity, and selectivity for heavy metals because conventional technologies are often inadequate to reduce concentrations in wastewater to acceptable regulatory standards. Genetic and protein engineering have emerged as the latest tools for the construction of nanoscale materials that can be controlled precisely at the molecular level. With the advent of recombinant DNA techniques, it is now possible to create `artificial' protein polymers with fundamentally new molecular organization. The most significant feature of these nanoscale biopolymers is that they are specifically pre-programmed within a synthetic gene template and can be controlled precisely in terms of sizes, compositions and functions at the molecular level. In this review, the use of specifically designed protein-based nano-biomaterials with both metal-binding and tunable properties for heavy metal removal is summarized. Several different strategies for the selective removal of heavy metals such as cadmium and mercury are highlighted.

  17. Biodegradation of alpha and beta endosulfan by Aspergillus sydoni.

    Science.gov (United States)

    Goswami, Supriya; Vig, Komal; Singh, Dileep K

    2009-05-01

    The biodegradation of endosulfan and the metabolites formed were studied using fungi both in broth culture as well as in soil microcosm. Fungal strains were isolated from soil and grown in broth Czapek-dox medium. The strain which utilized endosulfan and showed maximum growth was selected for detailed studies. Maximum degrading capability in shake flask culture was shown by Aspergillus sydoni which degraded 95% of endosulfan alpha and 97% of endosulfan beta in 18 d of incubation. Soil microcosm study was also carried out using this strain in six different treatments. Endosulfan sulfate was the main metabolite formed along with small quantity of endosulfan ether and endosulfan lactone both in broth culture and soil microcosm. This isolated fungal strain will be a potential source for endosulfan degrading enzymes and can be used for bioremediation at the contaminated sites.

  18. [Biodegradable catheters and urinary stents. When?

    Science.gov (United States)

    Soria, F; Morcillo, E; López de Alda, A; Pastor, T; Sánchez-Margallo, F M

    2016-10-01

    One of the main wishes in the field of urinary catheters and stents is to arm them with biodegradable characteristics because we consider a failure of these devices the need for retrieval, the forgotten catheter syndrome as well as the adverse effects permanent devices cause after fulfilling their aim. The efforts focused in new designs, coatings and biomaterials aim to increase the biocompatibility of theses internal devices. Lately, there have been correct advances to answer the main challenges regarding biodegradable ureteral devices. Thus, modulation of the rate of degradation has been achieved thanks to new biomaterials and the use of copolymers that enable to choose the time of permanence as it is programmed with conventional double J catheters. Biocompatibility has improved with the use of new polymers that adapt better to the urine. Finally, one of the main problems is elimination of degraded fragments and experimentally it has be demonstrated that new designs elicit controlled degradation, from distal to proximal; using stranding and combination of copolymers degradation may be caused by dilution, reducing fragmentation to the last stages of life of the prosthesis. Moreover, it has been demonstrated that biodegradable catheters potentially may cause less urinary tract infection, less encrustation and predictably they will diminish catheter morbidity, since their degradation process reduces adverse effects. Regarding the development of biodegradable urethral stents, it is necessary to find biomaterials that enable maintaining their biomechanical properties in the long term, keeping open the urethral lumen both in patients with BPH and urethral stenosis. Modulation of the time of degradation of the prosthesis has been achieved, but the appearance of urothelial hyperplasia is still a constant in the initial phases after implantation. The development of drug eluting stents, anti-proliferative or anti-inflammatory, as well as biodegradable stents biocoated is a

  19. 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

  20. Electrokinetic remediation of contaminated soils

    International Nuclear Information System (INIS)

    Lindgren, E.R.; Kozak, M.W.; Mattson, E.D.

    1991-01-01

    Electrokinetic remediation of contaminated soil has been demonstrated for saturated and unsaturated sand in preliminary experiments using a novel transport visualization technique. Large anionic organic dyes were mixed with a portion of soil and the rate of electromigration of the dye in an imposed electric field was monitored photographically. One of the fastest current-normalized electromigration rates was measured in the driest sand, which contained 7% water by weight. This moisture content is typical of the moisture content in the unsaturated zone of subsurface native soils found in New Mexico. The characteristics of the electromigration were similar in both the saturated and unsaturated sand. The leading edge of the dye migration front was diffuse while the trailing edge was sharp and concentrated. This and other observed behavior may indicate a concentration effect, where the electromigration rate of dilute dye is greater than that of concentrated dye. The soil left after the trailing edge passed seemed to contain no residual dye in both the saturated and unsaturated cases. The success of demonstrating electromigration of large molecules in unsaturated soil is encouraging and indicates that it may be feasible to remediate in situ anionic heavy metals such as chromate from unsaturated soil with electrokinetic techniques. 23 refs., 7 figs

  1. Characterization technologies for environmental remediation

    Energy Technology Data Exchange (ETDEWEB)

    Pruett, J.G.

    1991-01-01

    Improved site characterization technologies are being developed at Martin Marietta Energy Systems for the US Department of Energy (DOE) Office of Technology Development (OTD) in support of environmental restoration activities throughout the DOE complex. Since site characterization is an expensive and time consuming process that must be performed prior to, during, and following remediation efforts, an obvious way to reduce the overall cost of remediation is to develop improved characterization methods. For example, the Derivative Ultraviolet Absorption Spectrometer (DUVAS), which is being field tested as part of the OTD program, is a fiberoptic device for in situ, real time measurement of aromatic organic compounds in groundwater. A transportable, direct sampling Ion Trap Mass Spectrometer (ITMS) is being developed for continuous monitoring of hazardous organic compounds in air. In areas where the environment is hazardous to human health, it is desirous to perform site characterization remotely; if robotics are to be employed, the Ultrasonic Ranging and Data System (USRADS) can be used to provide telemetry information on robot location as well as sensor measurements. Once fully developed, these technologies can be transferred to the private sector. 19 refs., 2 tabs.

  2. Remediation of oil-contaminated soil in Arctic Climate

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Fritt-Rasmussen, Janne; Rodrigo, Ana

    Oil spill is a problem in towns in Greenland, where oil is used for heating and transport. The problem may increase in the future with expected oil exploitation in Greenlandic marine areas and related terrestrial activities. Oil undergoes natural microbial degradation in which nutrients, temperat......Oil spill is a problem in towns in Greenland, where oil is used for heating and transport. The problem may increase in the future with expected oil exploitation in Greenlandic marine areas and related terrestrial activities. Oil undergoes natural microbial degradation in which nutrients......, temperature, water content, pE and pH are important factors for the degradation rate. In particular temperature and nutrient availability are challenges in the Arctic, and alternative solutions must be sought if biodegradation is to be implemented as a low-cost and low-tech solution in this region....... Experiments have been made with excavated oil-contaminated soil from the Greenlandic town Sisimiut to study different low-tech and low-cost solutions for remediation of oil-contamination...

  3. Remediation of oil-contaminated soil in Arctic Climate

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Fritt-Rasmussen, Janne; Rodrigo, Ana P.

    Oil spill is a problem in towns in Greenland, where oil is used for heating and transport. The problem may increase in the future with expected oil exploitation in Greenlandic marine areas and related terrestrial activities. Oil undergoes natural microbial degradation in which nutrients, temperat......Oil spill is a problem in towns in Greenland, where oil is used for heating and transport. The problem may increase in the future with expected oil exploitation in Greenlandic marine areas and related terrestrial activities. Oil undergoes natural microbial degradation in which nutrients......, temperature, water content, pE and pH are important factors for the degradation rate. In particular temperature and nutrient availability are challenges in the Arctic, and alternative solutions must be sought if biodegradation is to be implemented as a low-cost and lowtech solution in this region. Experiments...... have been made with excavated oil-contaminated soil from the Greenlandic town Sisimiut to study different low-tech and low-cost solutions for remediation of oil-contamination....

  4. Biodegradation of Paraoxan as an Organophosphate Pesticide with Pseudomonas plecoglocissida Transfected by opd Gene

    Directory of Open Access Journals (Sweden)

    Taghi Naserpour Farivar

    2017-02-01

    Full Text Available Background Organophosphate pesticides (OP are applied to agricultural farms and can be carried away into closely sewerage and gullies, which consequently carry water to rivers and lakes and when distributed in the environment they become polluted and require remediation. Objectives The current study aimed at producing a genetically engineered Pseudomonas plecoglossicida capable of biodegradation of the organophosphate pesticides, paraoxon. Methods Genetically engineered P. plecoglossicida was initially made by transferring polymerase chain reaction (PCR product of opd gene from Flavobacterium sp. ATCC 27551 into the chromosome of P. plecoglossicida. Results The constructed strain could hydrolyze paraoxon to p-nitrophenol and di-ethylphosphate in paraoxon supplemented in complete supplement mixture (CSM medium. The isolate could use paraoxon as the only source of carbon. Thus, the bacteria degraded the organophosphate pesticides, and utilized nutrient products of their degradation. Conclusions The observed versatility of genetically engineered P. plecoglossicida in biodegradation of xenobiotics suggested that this strain may be useful for the multipurpose bioremediation of contaminated agricultural and industrial sites.

  5. Effects of permeability heterogeneity on the performance of surfactant-enhanced remediation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.S. [Kyonggi Univ., Seoul (Korea, Republic of)

    2010-07-01

    The subsurface contamination by nonaqueous phase liquids (NAPLs) is a complicated process and difficult to treat because these organic contaminants tend to adsorb onto the soil matrix. They have low water solubility and a limited rate of mass transfer for biodegradation. NAPLs may leach from the soil for a longer period of time and may eventually become a long-term continuous contamination source of the soil and groundwater. One method to enhance pump-and-treat aquifer remediation performance involves surfactant-enhanced aquifer remediation (SEAR). Because their success depends on the delivery of injected chemical and water into the subsurface to contact the organic liquids, geologic heterogeneities are likely the main factors which reduce the effectiveness of SEAR processes. This paper presented a study that involved numerical simulations to assess the effect of spatial variability of aquifer permeability on NAPL recovery and injection pressure as well as spatial and temporal distributions of NAPLs during the remediation process. The paper outlined the mathematical backgrounds, numerical model, and results and discussion. It was concluded the effectiveness of SEAR is sensitive to injection time due to dispersion of surfactant slug with the presence of a higher degree of heterogeneity. 6 refs., 3 figs.

  6. Monitoring of In-Situ Remediation By Time Lapse 3D Geo-Electric Measurements

    Science.gov (United States)

    Kanli, A. I.; Tildy, P.; Neducza, B.; Nagy, P.; Hegymegi, C.

    2017-12-01

    Injection of chemical oxidant solution to degrade the subsurface contaminants can be used for hydrocarbon contamination remediation. In this study, we developed a non-destructive measurement strategy to monitor oxidative in-situ remediation processes. The difficulties of the presented study originate from the small volume of conductive solution that can be used due to environmental considerations. Due to the effect of conductive groundwater and the high clay content of the targeted layer and the small volume of conductive solution that can be used due to environmental considerations, a site specific synthetic modelling is necessary for measurement design involving the results of preliminary 2D ERT measurements, electrical conductivity measurements of different active agents and expected resistivity changes calculated by soil resistivity modelling. Because of chemical biodegradation, the results of soil resistivity modelling have suggested that the reagent have complex effects on contaminated soils. As a result the plume of resistivity changes caused by the injected agent was determined showing strong fracturing effect because of the high pressure of injection. 3D time-lapse geo-electric measurements were proven to provide a usable monitoring tool for in-situ remediation as a result of our sophisticated tests and synthetic modelling.

  7. Biodegradation of different petroleum hydrocarbons by free and immobilized microbial consortia.

    Science.gov (United States)

    Shen, Tiantian; Pi, Yongrui; Bao, Mutai; Xu, Nana; Li, Yiming; Lu, Jinren

    2015-12-01

    The efficiencies of free and immobilized microbial consortia in the degradation of different types of petroleum hydrocarbons were investigated. In this study, the biodegradation rates of naphthalene, phenanthrene, pyrene and crude oil reached about 80%, 30%, 56% and 48% under the optimum environmental conditions of free microbial consortia after 7 d. We evaluated five unique co-metabolic substances with petroleum hydrocarbons, α-lactose was the best co-metabolic substance among glucose, α-lactose, soluble starch, yeast powder and urea. The orthogonal biodegradation analysis results showed that semi-coke was the best immobilized carrier followed by walnut shell and activated carbon. Meanwhile, the significance of various factors that contribute to the biodegradation of semi-coke immobilized microbial consortia followed the order of: α-lactose > semi-coke > sodium alginate > CaCl2. Moreover, the degradation rate of the immobilized microbial consortium (47%) was higher than that of a free microbial consortium (26%) under environmental conditions such as the crude oil concentration of 3 g L(-1), NaCl concentration of 20 g L(-1), pH at 7.2-7.4 and temperature of 25 °C after 5 d. SEM and FTIR analyses revealed that the structure of semi-coke became more porous and easily adhered to the microbial consortium; the functional groups (e.g., hydroxy and phosphate) were identified in the microbial consortium and were changed by immobilization. This study demonstrated that the ability of microbial adaptation to the environment can be improved by immobilization which expands the application fields of microbial remediation.

  8. Biodegradation of sulfonamides by Shewanella oneidensis MR-1 and Shewanella sp. strain MR-4.

    Science.gov (United States)

    Mao, Fei; Liu, Xiaohong; Wu, Kang; Zhou, Chen; Si, Youbin

    2018-04-01

    Because of extensive sulfonamides application in aquaculture and animal husbandry and the consequent increase in sulfonamides discharged into the environment, strategies to remediate sulfonamide-contaminated environments are essential. In this study, the resistance of Shewanella oneidensis MR-1 and Shewanella sp. strain MR-4 to the sulfonamides sulfapyridine (SPY) and sulfamethoxazole (SMX) were determined, and sulfonamides degradation by these strains was assessed. Shewanella oneidensis MR-1 and Shewanella sp. strain MR-4 were resistant to SPY and SMX concentrations as high as 60 mg/L. After incubation for 5 days, 23.91 ± 1.80 and 23.43 ± 2.98% of SPY and 59.88 ± 1.23 and 63.89 ± 3.09% of SMX contained in the medium were degraded by S. oneidensis MR-1 and Shewanella sp. strain MR-4, respectively. The effects of the initial concentration of the sulfonamides and initial pH of the medium on biodegradation, and the degradation of different sulfonamides were assessed. The products were measured by LC-MS; with SPY as a substrate, 2-AP (2-aminopyridine) was the main stable metabolite, and with SMX as a substrate, 3A5MI (3-amino-5-methyl-isoxazole) was the main stable metabolite. The co-occurrence of 2-AP or 3A5MI and 4-aminobenzenesulfonic acid suggests that the initial step in the biodegradation of the two sulfonamides is S-N bond cleavage. These results suggest that S. oneidensis MR-1 and Shewanella sp. strain MR-4 are potential bacterial resources for biodegrading sulfonamides and therefore bioremediation of sulfonamide-polluted environments.

  9. Remediation of copper in vineyards--a mini review.

    Science.gov (United States)

    Mackie, K A; Müller, T; Kandeler, E

    2012-08-01

    Viticulturists use copper fungicide to combat Downy Mildew. Copper, a non-degradable heavy metal, can accumulate in soil or leach into water sources. Its accumulation in topsoil has impacted micro and macro organisms, spurring scientists to research in situ copper removal methods. Recent publications suggest that microorganism assisted phytoextraction, using plants and bacteria to actively extract copper, is most promising. As vineyards represent moderately polluted sites this technique has great potential. Active plant extraction and chelate assisted remediation extract too little copper or risk leaching, respectively. However, despite interesting pot experiment results using microorganism assisted phytoextraction, it remains a challenge to find plants that primarily accumulate copper in their shoots, a necessity in vineyards where whole plant removal would be time consuming and financially cumbersome. Vineyard remediation requires a holistic approach including sustainable soil management, proper plant selection, increasing biodiversity and microorganisms. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Inverse modeling of the biodegradation of emerging organic contaminants in the soil-plant system

    OpenAIRE

    Hurtado, Carlos; Trapp, Stefan; Bayona, Josep M.

    2016-01-01

    Understanding the processes involved in the uptake and accumulation of organic contaminants into plants is very important to assess the possible human risk associated with. Biodegradation of emerging contaminants in plants has been observed, but kinetical studies are rare. In this study, we analyse experimental data on the uptake of emerging organic contaminants into lettuce derived in a greenhouse experiment. Measured soil, root and leaf concentrations from four contaminants were selected wi...

  11. Biodegradation of Volatile Organic Compounds and Their Effects on Biodegradability under Co-Existing Conditions

    Science.gov (United States)

    Yoshikawa, Miho; Zhang, Ming; Toyota, Koki

    2017-01-01

    Volatile organic compounds (VOCs) are major pollutants that are found in contaminated sites, particularly in developed countries such as Japan. Various microorganisms that degrade individual VOCs have been reported, and genomic information related to their phylogenetic classification and VOC-degrading enzymes is available. However, the biodegradation of multiple VOCs remains a challenging issue. Practical sites, such as chemical factories, research facilities, and illegal dumping sites, are often contaminated with multiple VOCs. In order to investigate the potential of biodegrading multiple VOCs, we initially reviewed the biodegradation of individual VOCs. VOCs include chlorinated ethenes (tetrachloroethene, trichloroethene, dichloroethene, and vinyl chloride), BTEX (benzene, toluene, ethylbenzene, and xylene), and chlorinated methanes (carbon tetrachloride, chloroform, and dichloromethane). We also summarized essential information on the biodegradation of each kind of VOC under aerobic and anaerobic conditions, together with the microorganisms that are involved in VOC-degrading pathways. Interactions among multiple VOCs were then discussed based on concrete examples. Under conditions in which multiple VOCs co-exist, the biodegradation of a VOC may be constrained, enhanced, and/or unaffected by other compounds. Co-metabolism may enhance the degradation of other VOCs. In contrast, constraints are imposed by the toxicity of co-existing VOCs and their by-products, catabolite repression, or competition between VOC-degrading enzymes. This review provides fundamental, but systematic information for designing strategies for the bioremediation of multiple VOCs, as well as information on the role of key microorganisms that degrade VOCs. PMID:28904262

  12. Biodegradation of Volatile Organic Compounds and Their Effects on Biodegradability under Co-Existing Conditions.

    Science.gov (United States)

    Yoshikawa, Miho; Zhang, Ming; Toyota, Koki

    2017-09-27

    Volatile organic compounds (VOCs) are major pollutants that are found in contaminated sites, particularly in developed countries such as Japan. Various microorganisms that degrade individual VOCs have been reported, and genomic information related to their phylogenetic classification and VOC-degrading enzymes is available. However, the biodegradation of multiple VOCs remains a challenging issue. Practical sites, such as chemical factories, research facilities, and illegal dumping sites, are often contaminated with multiple VOCs. In order to investigate the potential of biodegrading multiple VOCs, we initially reviewed the biodegradation of individual VOCs. VOCs include chlorinated ethenes (tetrachloroethene, trichloroethene, dichloroethene, and vinyl chloride), BTEX (benzene, toluene, ethylbenzene, and xylene), and chlorinated methanes (carbon tetrachloride, chloroform, and dichloromethane). We also summarized essential information on the biodegradation of each kind of VOC under aerobic and anaerobic conditions, together with the microorganisms that are involved in VOC-degrading pathways. Interactions among multiple VOCs were then discussed based on concrete examples. Under conditions in which multiple VOCs co-exist, the biodegradation of a VOC may be constrained, enhanced, and/or unaffected by other compounds. Co-metabolism may enhance the degradation of other VOCs. In contrast, constraints are imposed by the toxicity of co-existing VOCs and their by-products, catabolite repression, or competition between VOC-degrading enzymes. This review provides fundamental, but systematic information for designing strategies for the bioremediation of multiple VOCs, as well as information on the role of key microorganisms that degrade VOCs.

  13. Research of the biodegradability of degradable/biodegradable plastic material in various types of environments

    Directory of Open Access Journals (Sweden)

    Dana Adamcová

    2017-04-01

    Full Text Available Research was carried out in order to assess biodegradability of degradable/biodegradable materials made of HDPE and mixed with totally degradable plastic additive (TDPA additive or made of polyethylene (PE with the addition of pro-oxidant additive (d2w additive, advertised as 100% degradable or certifi ed as compostable within various types of environments. Research conditions were: (i controlled composting environment – laboratory-scale, (ii real composting conditions – domestic compost bin, (iii real composting conditions – industrial composting plant and (iv landfill conditions. The results demonstrate that the materials made of HDPE and mixed with totally degradable plastic additive (TDPA additive or made of polyethylene (PE with the addition of pro-oxidant additive (d2w additive or advertised as 100% degradable did not biodegrade in any of the above-described conditions and remained completely intact at the end of the tests. Biodegradation of the certified compostable plastic bags proceeded very well in laboratory-scale conditions and in real composting conditions – industrial composting plant, however, these materials did not biodegrade in real composting conditions – domestic compost bin and landfill conditions.

  14. Nanoparticles from Degradation of Biodegradable Plastic Mulch

    Science.gov (United States)

    Flury, Markus; Sintim, Henry; Bary, Andy; English, Marie; Schaefer, Sean

    2017-04-01

    Plastic mulch films are commonly used in crop production. They provide multiple benefits, including control of weeds and insects, increase of soil and air temperature, reduction of evaporation, and prevention of soil erosion. The use of plastic mulch film in agriculture has great potential to increase food production and security. Plastic mulch films must be retrieved and disposed after usage. Biodegradable plastic mulch films, who can be tilled into the soil after usage offer great benefits as alternative to conventional polyethylene plastic. However, it has to be shown that the degradation of these mulches is complete and no micro- and nanoparticles are released during degradation. We conducted a field experiment with biodegradable mulches and tested mulch degradation. Mulch was removed from the field after the growing season and composted to facilitate degradation. We found that micro- and nanoparticles were released during degradation of the mulch films in compost. This raises concerns about degradation in soils as well.

  15. Modeling ready biodegradability of fragrance materials.

    Science.gov (United States)

    Ceriani, Lidia; Papa, Ester; Kovarich, Simona; Boethling, Robert; Gramatica, Paola

    2015-06-01

    In the present study, quantitative structure activity relationships were developed for predicting ready biodegradability of approximately 200 heterogeneous fragrance materials. Two classification methods, classification and regression tree (CART) and k-nearest neighbors (kNN), were applied to perform the modeling. The models were validated with multiple external prediction sets, and the structural applicability domain was verified by the leverage approach. The best models had good sensitivity (internal ≥80%; external ≥68%), specificity (internal ≥80%; external 73%), and overall accuracy (≥75%). Results from the comparison with BIOWIN global models, based on group contribution method, show that specific models developed in the present study perform better in prediction than BIOWIN6, in particular for the correct classification of not readily biodegradable fragrance materials. © 2015 SETAC.

  16. Drama, dissensus, remediation and a fluttering butterfly

    DEFF Research Database (Denmark)

    Kusk, Hanne

    2017-01-01

    Why is it important to pay attention to democracy and polyphony when working with remediation in a multimodal drama project in introductory schooling? This question is elucidated and investigated in this article on the basis of a drama project case study conducted at Hundborg Friskole. The study......-based process of remediation, and how this impacts children’s democratic education....

  17. Remedial principles and meaningful engagement in education ...

    African Journals Online (AJOL)

    This article evaluates the meaningful engagement doctrine in the education rights jurisprudence of the Constitutional Court in the light of a set of normative principles developed by Susan Sturm for evaluating participatory public law remedies. It commences by identifying four principles for evaluating participatory remedies ...

  18. Remediation of the Maxey Flats Site

    International Nuclear Information System (INIS)

    1990-01-01

    This report describes issues associated with remedial action of Maxey Flats, a low-level radioactive waste disposal site from 1963-1977, located in Fleming County, Kentucky. Present remedial action alternatives being considered are discussed along with emergency plans, ground water monitoring plans, and budgets

  19. Laboratory Experiment on Electrokinetic Remediation of Soil

    Science.gov (United States)

    Elsayed-Ali, Alya H.; Abdel-Fattah, Tarek; Elsayed-Ali, Hani E.

    2011-01-01

    Electrokinetic remediation is a method of decontaminating soil containing heavy metals and polar organic contaminants by passing a direct current through the soil. An undergraduate chemistry laboratory is described to demonstrate electrokinetic remediation of soil contaminated with copper. A 30 cm electrokinetic cell with an applied voltage of 30…

  20. Remedial investigation/feasibility study for the David Witherspoon, Inc., 901 Site, Knoxville, Tennessee: Volume 1

    International Nuclear Information System (INIS)

    1996-10-01

    This remedial investigation (RI)/feasibility study (FS) supports the selection of remedial actions for the David Witherspoon, Inc. 901 Maryville Pike Site in Knoxville, Tennessee. Operations at the site, used as a recycling center, have resulted in past, present, and potential future releases of hazardous substances in to the environment. This Site is a Tennessee Superfund site. A phased approach was planned to (1) gather existing data from previous investigations managed by the Tenn. Dept. of Environment and Conservation; (2) perform a preliminary RI, including risk assessments, and an FS with existing data to identify areas where remedial action may be necessary; (3) gather additional field data to adequately define the nature and extent of risk-based contaminants that present identifiable threats to human and/or ecological receptors; and (4) develop remedial action alternatives to reduce risks to acceptable levels

  1. Remedial investigation/feasibility study for the David Witherspoon, Inc., 901 Site, Knoxville, Tennessee: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This remedial investigation (RI)/feasibility study (FS) supports the selection of remedial actions for the David Witherspoon, Inc. 901 Maryville Pike Site in Knoxville, Tennessee. Operations at the site, used as a recycling center, have resulted in past, present, and potential future releases of hazardous substances in to the environment. This Site is a Tennessee Superfund site. A phased approach was planned to (1) gather existing data from previous investigations managed by the Tenn. Dept. of Environment and Conservation; (2) perform a preliminary RI, including risk assessments, and an FS with existing data to identify areas where remedial action may be necessary; (3) gather additional field data to adequately define the nature and extent of risk-based contaminants that present identifiable threats to human and/or ecological receptors; and (4) develop remedial action alternatives to reduce risks to acceptable levels.

  2. Biodegradation and Transformation of Nitroaromatic Compounds (POSTPRINT)

    Science.gov (United States)

    2012-07-01

    From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT... MAR -1997 Biodegradation and Transformation of Nitroaromatic Compounds (POSTPRINT) 1900B56A Nishino, Shirley F.; Spain, Jim C. Armstrong Laboratory...space to accommodate bulk matter, and con· cainment of leachates. Generally, not more than 10% of the composting pile can be contaminate d soil (66

  3. Biodegradation of PCDDs/PCDFs and PCBs

    OpenAIRE

    Urbaniak, Magdalena

    2013-01-01

    Rozdział 4 książki Biodegradation - Engineering and Technology Edited by Rolando Chamy and Francisca Rosenkranz • “Innovative resources and effective methods of safety improvement and durability of buildings and transport infrastructure in the sustainable development” financed by the European Union, from the European Fund of Regional Development based on the Operational Programme of the Innovative Economy, POIG.01.01.02-10-106/09

  4. Methotrexate-loaded biodegradable nanoparticles: preparation ...

    Indian Academy of Sciences (India)

    Administrator

    effects as well as to achieve anticipated sustained release properties. In recent years, biodegradable polymeric ... 8 h and lyophilized with vacuum pressure of < 50 mTorr and at a temperature of –40 °C for 48 h. ... out in dialysis tubing using phosphate buffer pH 6∙8 at. 37 ± 0∙5 °C and at 50 rpm. In vitro drug release was.

  5. 40 CFR Appendix C to Part 63 - Determination of the Fraction Biodegraded (Fbio) in a Biological Treatment Unit

    Science.gov (United States)

    2010-07-01

    .... Biodegradability of Organic Substances in the Aquatic Environment. CRC Press, Boca Raton, FL. 1990. 4. Grady, C.P.L... preparation of solutions, dilution procedures, sampling procedures, monitoring of conditions, etc. 6. A... correlation method of estimating selected zone concentrations if monitoring of each zone is required, or if...

  6. 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.

  7. Biodegradation of ion-exchange media

    International Nuclear Information System (INIS)

    Bowerman, B.S.; Clinton, J.H.; Cowdery, S.R.

    1988-08-01

    Ion-exchange media, both bead resins and powdered filter media, are used in nuclear power plants to remove radioactivity from process water prior to reuse or environmental discharge. Since the ion- exchange media are made from synthetic hydrocarbon-based polymers, they may be susceptible to damage from biological activity. The purpose of this study was to investigate some of the more basic aspects of biodegradation of ion-exchange media, specifically to evaluate the ability of microorganisms to utilize the ion-exchange media or materials sorbed on them as a food source. The ASTM-G22 test, alone and combined with the Bartha Pramer respirometric method, failed to indicate the biodegradability of the ion-exchange media. The limitation of these methods was that they used a single test organism. In later phases of this study, a mixed microbial culture was grown from resin waste samples obtained from the BNL High Flux Beam Reactor. These microorganisms were used to evaluate the susceptibility of different types of ion-exchange media to biological attack. Qualitative assessments of biodegradability were based on visual observations of culture growths. Greater susceptibility was associated with increased turbidity in solution indicative of bacterial growth, and more luxuriant fungal mycelial growth in solution or directly on the ion-exchange resin beads. 21 refs., 9 figs., 18 tabs

  8. Corexit 9500 Enhances Oil Biodegradation and Changes ...

    Science.gov (United States)

    While COREXIT 9500 is widely applied after oil spills for its reported dispersing activity, there is still a debate on the effectiveness on enhancing oil biodegradation and its potential toxic effect on microbial communities. To better understand the impact of COREXIT 9500 on the structure and activity levels of hydrocarbon degrading microbial communities, we analyzed next-generation 16S rRNA gene sequencing libraries of hydrocarbon enrichments grown at cryophilic and mesophilic conditions and using both DNA and RNA extracts as sequencing templates. Oil biodegradation patterns in both cryophilic and mesophilic enrichments were consistent with those reported in the literature (i.e., aliphatics were degraded faster than aromatics). A slight increase in biodegradation was observed in the presence of COREXIT at both 25°C and 5°C experiments. Differences in community structure were observed between treatment conditions in the DNA-based libraries. The 25°C consortia was dominated by unclassified members of the Vibrio, Pseudoidiomarina, Marinobacter, Alcanivorax, and Thallassospira species, while the 5°C consortia were dominated by several genera of Flavobacteria, Alcanivorax and Oleispira. With the exception of Vibrio-like species, members of these genera have been linked to hydrocarbon degradation and have been observed after oil spills. Colwellia and Cycloclasticus, known aromatic degraders, was also found in these enrichments. RNA-based sequencing of 25°C

  9. Development of a biodegradable bone cement

    International Nuclear Information System (INIS)

    Yusof Abdullah; Nurhaslinda Ee Abdullah; Wee Pee Chai; Norita Mohd Zain

    2002-01-01

    Biodegradable bone cement is a newly developed bone repair material, which is able to give immediate support to the implant area, and does not obstruct the bone repairing and regeneration process through appropriate biodegradation rate, which is synchronized with the mechanical load it should bear. The purpose of this study is to locally produce biodegradable bone cement using HA as absorbable filler. The cement is composed of an absorbable filler and unsaturated polyester for 100% degradation. Cross-linking effect is achieved through the action of poly (vinyl pyrrol lidone) (PVP) and an initiator. On the other hand, PPF was synthesized using direct esterification method. Characteristics of the bone cement were studied; these included the curing time, cross-linking effect and curing temperature. The products were characterized using X-Ray diffraction (XRD) to perform phase analysis and Scanning Electrons Microscopes to determine the morphology. The physical and mechanical properties of the bone cement were also investigated. The biocompatibility of the bone cement was tested using simulated body physiological solution. (Author)

  10. Research Plan: Foam Delivery of Remedial Amendments to Deep Vadose Zone for Metals and Radionuclides Remediation

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Lirong; Hart, Andrea T.; Szecsody, James E.; Zhang, Z. F.; Freedman, Vicky L.; Ankeny, Mark; Hull, Laurence; Oostrom, Martinus; Freshley, Mark D.; Wellman, Dawn M.

    2009-01-16

    Research proposals were submitted to the Scientific and Technical Basis for In Situ Treatment of Metals and Radionuclides Technical Working Group under the US Department of Energy (DOE) Environmental Management Office (specifically, EM-22). After a peer review and selection process, the proposal, “Foam Delivery of Remedial Amendments to Deep Vadose Zone for Metals and Radionuclides Remediation,” submitted by Pacific Northwest National Laboratory (PNNL) was selected for support by the program. A research plan was requested for this EM funded project. The overall objective of this project is to develop foam delivery technology for the distribution of remedial amendments to deep vadose zone sediments for in situ immobilization of metal and radionuclide contaminants. The focus of this research in FY 2009 is on the physical aspects of the foam delivery approach. Specific objectives are to 1) study the foam quality (i.e. the gas volume fraction in foam) influence on injection pressure, 2) study the sediment air permeability influence on injection pressure, 3) investigate liquid uptake in sediment and determine whether a water front will be formed during foam delivery, 4) test amendment distance (and mass) delivery by foam from the injection point, 5) study the enhanced sweeping over heterogeneous systems (i.e., low K zones) by foam delivery relative to water-based delivery under vadose zone conditions, and 6) numerically simulate foam delivery processes in the vadose zone. Laboratory scale experiments will be conducted at PNNL to study a range of basic physical aspects of the foam propagation in sediments, including foam quality and sediment permeability influence on injection pressure, liquid uptake, and foam sweeping across heterogeneous systems. This study will be augmented with separate studies to be conducted at MSE Technology Applications, Inc. (MSE) to evaluate foam transport and amendment delivery at the intermediate-scale. The results of intermediate

  11. Research Plan: Foam Delivery of Remedial Amendments to Deep Vadose Zone for Metals and Radionuclides Remediation

    International Nuclear Information System (INIS)

    Zhong, Lirong; Hart, Andrea T.; Szecsody, James E.; Zhang, Z.F.; Freedman, Vicky L.; Ankeny, Mark; Hull, Laurence; Oostrom, Martinus; Freshley, Mark D.; Wellman, Dawn M.

    2009-01-01

    Research proposals were submitted to the Scientific and Technical Basis for In Situ Treatment of Metals and Radionuclides Technical Working Group under the US Department of Energy (DOE) Environmental Management Office (specifically, EM-22). After a peer review and selection process, the proposal, 'Foam Delivery of Remedial Amendments to Deep Vadose Zone for Metals and Radionuclides Remediation,' submitted by Pacific Northwest National Laboratory (PNNL) was selected for support by the program. A research plan was requested for this EM funded project. The overall objective of this project is to develop foam delivery technology for the distribution of remedial amendments to deep vadose zone sediments for in situ immobilization of metal and radionuclide contaminants. The focus of this research in FY 2009 is on the physical aspects of the foam delivery approach. Specific objectives are to (1) study the foam quality (i.e. the gas volume fraction in foam) influence on injection pressure, (2) study the sediment air permeability influence on injection pressure, (3) investigate liquid uptake in sediment and determine whether a water front will be formed during foam delivery, (4) test amendment distance (and mass) delivery by foam from the injection point, (5) study the enhanced sweeping over heterogeneous systems (i.e., low K zones) by foam delivery relative to water-based delivery under vadose zone conditions, and (6) numerically simulate foam delivery processes in the vadose zone. Laboratory scale experiments will be conducted at PNNL to study a range of basic physical aspects of the foam propagation in sediments, including foam quality and sediment permeability influence on injection pressure, liquid uptake, and foam sweeping across heterogeneous systems. This study will be augmented with separate studies to be conducted at MSE Technology Applications, Inc. (MSE) to evaluate foam transport and amendment delivery at the intermediate-scale. The results of intermediate

  12. Influence of bioselector processes on 17α-ethinylestradiol biodegradation in activated sludge wastewater treatment systems.

    Science.gov (United States)

    Ziels, Ryan M; Lust, Mariko J; Gough, Heidi L; Strand, Stuart E; Stensel, H David

    2014-06-03

    The removal of the potent endocrine-disrupting estrogen hormone, 17α-ethinylestradiol (EE2), in municipal wastewater treatment plant (WWTP) activated sludge (AS) processes can occur through biodegradation by heterotrophic bacteria growing on other organic wastewater substrates. Different kinetic and metabolic substrate utilization conditions created with AS bioselector processes can affect the heterotrophic population composition in AS. The primary goal of this research was to determine if these changes also affect specific EE2 biodegradation kinetics. A series of experiments were conducted with parallel bench-scale AS reactors treating municipal wastewater with estrogens at 100-300 ng/L concentrations to evaluate the effect of bioselector designs on pseudo first-order EE2 biodegradation kinetics normalized to mixed liquor volatile suspended solids (VSS). Kinetic rate coefficient (kb) values for EE2 biodegradation ranged from 5.0 to 18.9 L/g VSS/d at temperatures of 18 °C to 24 °C. EE2 kb values for aerobic biomass growth at low initial food to mass ratio feeding conditions (F/Mf) were 1.4 to 2.2 times greater than that from growth at high initial F/Mf. Anoxic/aerobic and anaerobic/aerobic metabolic bioselector reactors achieving biological nutrient removal had similar EE2 kb values, which were lower than that in aerobic AS reactors with biomass growth at low initial F/Mf. These results provide evidence that population selection with growth at low organic substrate concentrations can lead to improved EE2 biodegradation kinetics in AS treatment.

  13. Light Pollution Responses and Remedies

    CERN Document Server

    Mizon, Bob

    2012-01-01

    Light pollution is a major threat to astronomy across the entire developed world. The night sky that most of us can see bears little relationship to the spectacular vistas that our ancestors have gazed at for tens of thousands of years. It is ironic that as our understanding of the universe has improved, our ability to see it has been dramatically reduced by the skyglow of our civilization. In the second edition of Light Pollution - Responses and Remedies, Bob Mizon delves into the history and practice of lighting and how its misue has not only stolen the stars, but blighted our lives and those of our fellow-creatures on this planet. This book suggests how we can win back the night sky and at the same time save energy and money, improve our health, and even lower crime rate! It also includes a list of targets for urban stargazers, and recommendations for ensuring sane lighting worldwide.

  14. An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Aravind, Priyadharshini, E-mail: priya.bdu07@gmail.com [Corrosion and Materials Protection Division (CMPD), CSIR—Central electrochemical research institute (CECRI), Karaikudi 630 003 (India); Selvaraj, Hosimin [Corrosion and Materials Protection Division (CMPD), CSIR—Central electrochemical research institute (CECRI), Karaikudi 630 003 (India); Ferro, Sergio [Ecas4 Australia, Unit 8, 1 London Road, Mile End, South Australia 5031 (Australia); Sundaram, Maruthamuthu [Corrosion and Materials Protection Division (CMPD), CSIR—Central electrochemical research institute (CECRI), Karaikudi 630 003 (India)

    2016-11-15

    Highlights: • Firstly, the mediated electro-oxidation allows rapid discoloration of the effluent. • Cost effective sunlight-mediated removal of bio-toxic active chlorine species. • Electrochemical pretreatment enhances the biodegradability of textile wastewater. • About 90% COD removal was achieved by a subsequent biodegradation. • By-products from degradation of dyes have shown to be ecofriendly and non-toxic. - Abstract: A hybrid approach for the remediation of recalcitrant dye wastewater is proposed. The chlorine-mediated electrochemical oxidation of real textile effluents and synthetic samples (using Ti/IrO{sub 2}-RuO{sub 2}-TiO{sub 2} anodes), lead to discoloration by 92% and 89%, respectively, in 100 min, without significant mineralization. The remediation was obtained through biodegradation, after removing the residual bio-toxic active chlorine species via sunlight exposition. Results show that the electrochemical discoloration enhances the effluent biodegradability with about 90% COD removal employing acclimatized naphthalene-degrading bacterial consortia, within 144 h. Based on results obtained through FT-IR and GC–MS, it is likely that azo group stripping and oxidative cleavage of dyes occur due to the nucleophilic attack of active chlorine species during electro-oxidation. This leads to generation of aromatic intermediates which are further desulfonated, deaminated or oxidized only at their functional groups. These aromatic intermediates were mineralized into simpler organic acids and aldehydes by bacterial consortia. Phyto-toxicity trials on Vigna radiata confirmed the toxic nature of the untreated dye solutions. An increase in root and shoot development was observed with the electrochemically treated solutions, the same was higher in case of bio-treated solutions. Overall, obtained results confirm the capability of the proposed hybrid oxidation scheme for the remediation of textile wastewater.

  15. An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment

    International Nuclear Information System (INIS)

    Aravind, Priyadharshini; Selvaraj, Hosimin; Ferro, Sergio; Sundaram, Maruthamuthu

    2016-01-01

    Highlights: • Firstly, the mediated electro-oxidation allows rapid discoloration of the effluent. • Cost effective sunlight-mediated removal of bio-toxic active chlorine species. • Electrochemical pretreatment enhances the biodegradability of textile wastewater. • About 90% COD removal was achieved by a subsequent biodegradation. • By-products from degradation of dyes have shown to be ecofriendly and non-toxic. - Abstract: A hybrid approach for the remediation of recalcitrant dye wastewater is proposed. The chlorine-mediated electrochemical oxidation of real textile effluents and synthetic samples (using Ti/IrO 2 -RuO 2 -TiO 2 anodes), lead to discoloration by 92% and 89%, respectively, in 100 min, without significant mineralization. The remediation was obtained through biodegradation, after removing the residual bio-toxic active chlorine species via sunlight exposition. Results show that the electrochemical discoloration enhances the effluent biodegradability with about 90% COD removal employing acclimatized naphthalene-degrading bacterial consortia, within 144 h. Based on results obtained through FT-IR and GC–MS, it is likely that azo group stripping and oxidative cleavage of dyes occur due to the nucleophilic attack of active chlorine species during electro-oxidation. This leads to generation of aromatic intermediates which are further desulfonated, deaminated or oxidized only at their functional groups. These aromatic intermediates were mineralized into simpler organic acids and aldehydes by bacterial consortia. Phyto-toxicity trials on Vigna radiata confirmed the toxic nature of the untreated dye solutions. An increase in root and shoot development was observed with the electrochemically treated solutions, the same was higher in case of bio-treated solutions. Overall, obtained results confirm the capability of the proposed hybrid oxidation scheme for the remediation of textile wastewater.

  16. Remedial transactions curtailment via optimization

    Directory of Open Access Journals (Sweden)

    Maksimović Viktor

    2009-01-01

    Full Text Available The new method developed in this paper is aiming at transmission congestion management (CM. The new, Optimal Transactions Management method (OTM, is based on linear programming (LP, DC load flow (DCLF and linear security constraints. The OTM method is embedded in Available Transfer Capabilities (ATCs and Power Transfer Distribution Factors (PTDFs definitions' environment. Well-suited for both preventive and corrective modes of operation, the OTM method aids transmission system operator in running a congested power system network, where congestions are due to transactions. Potential congestion threat is solved by finding the 'culprit' transaction and its optimal reduction. Besides the proposed downsizing of scheduled and/or committed transactions, controls of the OTM method also include redispatching of generation and load levels. The task is to establish a system state without constraint violations. To ensure the feasible network solution, both DC and AC power flows are used. The common 5 nodes/7 lines Ward&Hale sample power system is used to clarify the OTM method. Besides, six other power system networks including the real-life power system network of Serbia, Macedonia and Montenegro (part of the South East Europe - SEE grid are used to test remedial potentials and CPU-time performances of the method. The 24-hour daily demand diagram is used with all test networks to study the effects of transactions as they are being superimposed to the regional grid. The remedial, transactions-curtailing OTM method is found well suited for market-related analyses precluding the hour-ahead, the day-ahead dispatch, as well as the real-time generation dispatch. It could also suit for the novel, Day Ahead Congestion Forecast (DACF procedure used in power markets. .

  17. Flow assurance intervention, hydrates remediation

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, Christopher S. [Oceaneering International Inc., Houston, TX (United States)

    2012-07-01

    This paper addresses the issues of removing hydrates in sub sea flow lines and associated equipment with an Remotely Operated Vehicle (ROV) of opportunity and a multi-service-vessel (MSV). The paper is split into three topics: the equipment used with the ROV, assessing the interface points and handling fluids produced from drawing down the pressure. Each section is explained thoroughly and backed up with real world experience. The equipment section details information from actual jobs performed and why the particular components were utilized. The system is generally contained in an ROV mounted skid. Pumps are utilized to draw down the pressure inside the hydrated section of equipment, removing one of the three necessary components for hydrates formation. Once the section is pumped down, several options exist for handling the fluids pumped out of the system: pumping to surface, re-injection into the well, or injection into an operating flow line. This method of hydrates remediation is both economical and timely. Hydrate blockages form in low temperatures and high pressures. Reducing the pressure or increasing the temperature so the conditions lie to the right of the hydrate dissociation curve will slowly decompose the blockage. Depressurization and the use of MEG or methanol will give favorable conditions to remove the hydrate plug. Oceaneering has the capabilities to remove hydrates using the FRS in conjunction with an installation vessel to dispose of the gas and fluid removed from the flow line. Hydrate remediation techniques should be implemented into the initial design to reduce costs later. The cost of stopped production combined with the day rate for equipment needed for hydrate removal outweighs the costs if no technique is utilized. (author)

  18. Biodegradation of flax fiber reinforced poly lactic acid

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available Woven and nonwoven flax fiber reinforced poly lactic acid (PLA biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM. Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive, biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even after 80–90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add different amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site.

  19. Critical evaluation of biodegradable polymers used in nanodrugs

    Science.gov (United States)

    Marin, Edgar; Briceño, Maria Isabel; Caballero-George, Catherina

    2013-01-01

    Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed. PMID:23990720

  20. Critical evaluation of biodegradable polymers used in nanodrugs.

    Science.gov (United States)

    Marin, Edgar; Briceño, Maria Isabel; Caballero-George, Catherina

    2013-01-01

    Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed.

  1. Accelerating Quinoline Biodegradation and Oxidation with Endogenous Electron Donors.

    Science.gov (United States)

    Bai, Qi; Yang, Lihui; Li, Rongjie; Chen, Bin; Zhang, Lili; Zhang, Yongming; Rittmann, Bruce E

    2015-10-06

    Quinoline, a recalcitrant heterocyclic compound, is biodegraded by a series of reactions that begin with mono-oxygenations, which require an intracellular electron donor. Photolysis of quinoline can generate readily biodegradable products, such as oxalate, whose bio-oxidation can generate endogenous electron donors that ought to accelerate quinoline biodegradation and, ultimately, mineralization. To test this hypothesis, we compared three protocols for the biodegradation of quinoline: direct biodegradation (B), biodegradation after photolysis of 1 h (P1h+B) or 2 h (P2h+B), and biodegradation by adding oxalate commensurate to the amount generated from photolysis of 1 h (O1+B) or 2 h (O2+B). The experimental results show that P1h+B and P2h+B accelerated quinoline biodegradation by 19% and 50%, respectively, compared to B. Protocols O1+B and O2+B also gave 19% and 50% increases, respectively. During quinoline biodegradation, its first intermediate, 2-hydroxyquinoline, accumulated gradually in parallel to quinoline loss but declined once quinoline was depleted. Mono-oxygenation of 2-hydroxyquinoline competed with mono-oxygenation of quinoline, but the inhibition was relieved when extra electrons donors were added from oxalate, whether formed by UV photolysis or added exogenously. Rapid oxalate oxidation stimulated both mono-oxygenations, which accelerated the overall quinoline oxidation that provided the bulk of the electron donor.

  2. Biodegradation of endosulfan by mixed bacteria culture strains of ...

    African Journals Online (AJOL)

    Biodegradation of endosulfan by mixed bacteria culture strains of Pseudomonas aeruginosa and Staphylococcus aureus. Nsidibeabasi Calvin Nwokem, Calvin Onyedika Nwokem, Casmir Emmanuel Gimba, Beatrice Nkiruka Iwuala ...

  3. Hydrodynamic analysis application of contaminated groundwater remediation to oil hydrocarbons

    Directory of Open Access Journals (Sweden)

    Pajić Predrag R.

    2017-01-01

    Full Text Available In this paper, the application of the hydrodynamic analysis in the selected ‘pumping and treatment’ remediation method of groundwater hydrocarbon pollution in the case of the Pancevo oil refinery is examined. The applied hydrodynamic analysis represents a regular and necessary approach in modern hydrogeology. Previous chemical analysis of soil and groundwater samples at observation objects revealed their pollution by oil products. New researches included the constraction of 12 piezometric boreholes of varying depths, geoelectric soil sounding, ‘in situ’ measurement of the present contaminant, detected as a hydrophobic phase of LNAPL, chemical analysis of soil and groundwater samples with emphasis on total petroleum hydrocarbons (TPH content, total fats and mineral oils, mercury cations and other characteristic compounds, etc. These researches define the volume of contamination issued by the ‘light’ (LNAPL contamination phase. The selected remediation method for this type of pollution is the ‘Pump and Treat’ method, which implies the pumping of contaminated groundwater from aquifer and their subsequent treatment. A hydrodynamic method was used to select the optimal hydrotechnical solution for LNAPL extraction. On the mathematical model, the prediction calculations for two variant solutions were carried out (‘hydraulic isolation’ and complex for the application of groundwater contamination remediation characterized as front pollution substance (by extraction and injection wells or infiltration pool. By extraction wells performing, it would be possible to remove the LNAPL from the surface of the water with special pumps-skimmers. The importance of the hydrodynamic method application is, in addition to the hydrotechnical solution selection for the LNAPL drainage, the provision of quality basis for the dimensioning of these objects based on the results of the groundwater balance.

  4. Biodegradation of radioactive organic liquid waste from spent fuel reprocessing

    International Nuclear Information System (INIS)

    Ferreira, Rafael Vicente de Padua

    2008-01-01

    The research and development program in reprocessing of low burn-up spent fuel elements began in Brazil in 70's, originating the lab-scale hot cell, known as Celeste located at Nuclear and Energy Research Institute, IPEN - CNEN/SP. The program was ended at the beginning of 90's, and the laboratory was closed down. Part of the radioactive waste generated mainly from the analytical laboratories is stored waiting for treatment at the Waste Management Laboratory, and it is constituted by mixture of aqueous and organic phases. The most widely used technique for the treatment of radioactive liquid wastes is the solidification in cement matrix, due to the low processing costs and compatibility with a wide variety of wastes. However, organics are generally incompatible with cement, interfering with the hydration and setting processes, and requiring pre -treatment with special additives to stabilize or destroy them. The objective of this work can be divided in three parts: organic compounds characterization in the radioactive liquid waste; the occurrence of bacterial consortia from Pocos de Caldas uranium mine soil and Sao Sebastiao estuary sediments that are able to degrade organic compounds; and the development of a methodology to biodegrade organic compounds from the radioactive liquid waste aiming the cementation. From the characterization analysis, TBP and ethyl acetate were chosen to be degraded. The results showed that selected bacterial consortia were efficient for the organic liquid wastes degradation. At the end of the experiments the biodegradation level were 66% for ethyl acetate and 70% for the TBP. (author)

  5. Evaluation of French Guiana traditional antimalarial remedies.

    Science.gov (United States)

    Bertani, S; Bourdy, G; Landau, I; Robinson, J C; Esterre, Ph; Deharo, E

    2005-04-08

    In order to evaluate the antimalarial potential of traditional remedies used in French Guiana, 35 remedies were prepared in their traditional form and screened for blood schizonticidal activity in vitro on Plasmodium falciparum chloroquine re4sistant strain (W2). Some of these extracts were screened in vivo against Plasmodium yoelii rodent malaria. Ferriprotoporphyrin inhibition test was also performed. Four remedies, widely used among the population as preventives, were able to inhibit more than 50% of the parasite growth in vivo at around 100 mg/kg: Irlbachia alata (Gentiananceae), Picrolemma pseudocoffea (Simaroubaceae), Quassia amara (Simaroubaceae), Tinospora crispa (Menispermaceae) and Zanthoxylum rhoifolium (Rutaceae). Five remedies displayed an IC50 in vitro < 10 microg/ml: Picrolemma pseudocoffea, Pseudoxandra cuspidata (Annonaceae) and Quassia amara leaves and stem, together with a multi-ingredient recipe. Two remedies were more active than a Cinchona preparation on the ferriprotoporphyrin inhibition test: Picrolemma pseudocoffea and Quassia amara. We also showed that a traditional preventive remedy, made from Geissospermum argenteum bark macerated in rum, was able to impair the intrahepatic cycle of the parasite. For the first time, traditional remedies from French Guiana have been directly tested on malarial pharmacological assays and some have been shown to be active.

  6. 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

  7. Environmental restoration and remediation technical data management plan

    International Nuclear Information System (INIS)

    Key, K.T.; Fox, R.D.

    1994-02-01

    The tasks performed in the Remedial Investigation/Feasibility Study (RI/FS) work plan for each Hanford Site operable unit must meet the requirements of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) and the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement, Ecology et. al 1992). An extensive amount of data will be generated in the evaluation and remediation of hazardous waste sites at the Site. The data must be of sufficient quality, as they will be used to evaluate the need, select the method(s), and support the full remediation of the waste sites as stipulated in the Tri-Party Agreement. In particular, a data management plan (DMP) is to be included in an RI/FS work plan for managing the technical data obtained during the characterization of an operable unit, as well as other data related to the study of the operable unit. Resource Conservation and Recovery Act of 1976 (RCRA) sites are involved in the operable unit. Thus, the data management activities for the operable unit should be applied consistently to RCRA sites in the operable unit as well. This DMP provides common direction for managing-the environmental technical data of all defined operable units at the Hanford Site during the RI/FS activities. Details specific to an operable unit will be included in the actual work plan of that operable unit

  8. 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.

  9. An Overview of Biodegradation of LNAPLs in Coastal (Semi)-arid Environment.

    KAUST Repository

    Yadav, Brijesh Kumar

    2011-02-22

    Contamination of soil and water due to the release of light non-aqueous phase liquids (LNAPLs) is a ubiquitous problem. The problem is more severe in arid and semi-arid coastal regions where most of the petroleum production and related refinery industries are located. Biological treatment of these organic contaminated resources is receiving increasing interests and where applicable, can serve as a cost-effective remediation alternative. The success of bioremediation greatly depends on the prevailing environmental variables, and their remediation favoring customization requires a sound understanding of their integrated behavior on fate and transport of LNAPLs under site-specific conditions. The arid and semi-arid coastal sites are characterized by specific environmental extremes; primarily, varying low and high temperatures, high salinity, water table dynamics, and fluctuating soil moisture content. An understanding of the behavior of these environmental variables on biological interactions with LNAPLs would be helpful in customizing the bioremediation for restoring problematic sites in these regions. Therefore, this paper reviews the microbial degradation of LNAPLs in soil-water, considering the influences of prevailing environmental parameters of arid and semi-arid coastal regions. First, the mechanism of biodegradation of LNAPLs is discussed briefly, followed by a summary of popular kinetic models used by researchers for describing the degradation rate of these hydrocarbons. Next, the impact of soil moisture content, water table dynamics, and soil-water temperature on the fate and transport of LNAPLs are discussed, including an overview of the studies conducted so far. Finally, based on the reviewed information, a general conclusion is presented with recommendations for future research subjects on optimizing the bioremediation technique in the field under the aforesaid environmental conditions. The present review will be useful to better understand the

  10. Remedial investigations for quarry bulk wastes

    International Nuclear Information System (INIS)

    1989-12-01

    The US Department of Energy proposes, as a separate operable unit of the Weldon Spring Site Remedial Action Project, to remove contaminated bulk wastes from the Weldon Spring quarry and transport them approximately four miles to the chemical plant portion of the raffinate pits and chemical plant area. The wastes will be held in temporary storage prior to the record of decision for the overall remedial action. The decision on the ultimate disposal of these bulk wastes will be included as part of the decision for management of the waste materials resulting from remedial action activities at the raffinate pits and chemical plant area. 86 refs., 71 figs., 83 tabs

  11. 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

  12. 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

  13. Biodegradation of Textile Dyes by Fungi Isolated from North Indian Field Soil

    Directory of Open Access Journals (Sweden)

    Arshi Shahid

    2013-07-01

    Full Text Available In this study one azo dye "Congo red", two triphenymethane dyes "Crystal violet" and "Methylene blue" have been selected for biodegradation using three soil fungal isolates A. niger, F. oxysporum and T. lignorum. These fungal strains were isolated from field soil. Three methods were selected for biodegradation, viz. agar overlay and liquid media methods; stationary and shaking conditions at 25°C. The experiment was conducted for 10 days and the results were periodically observed. Aspergillus niger decolorized maximum Congo red (74.07% followed by Crystal violet (33.82% and Methylene blue (22.44% under liquid medium (stationary condition. Whereas, under same conditions, T. lignorum decolorized maximum crystal violet (92.7%, Methylene blue (48.3% and Congo red (35.25%. Use of T. lignorum as dye bio degrader or decolorizer has been done first time in this study. Fusarium oxysporum performed better under shaking conditions compared to stationary and overlay method. It can be concluded that among soil fungus T. lignorum could be used as efficient dye decolorizer especially for crystal violet and A. niger for Congo red. The excellent performance of T. lignorum and F. oxysporum in the biodegradation of textile dyes of different chemical structures reinforces the potential of these fungi for environmental decontamination similar to white rot fungi.

  14. Cost of presumptive source term Remedial Actions Laboratory for energy-related health research, University of California, Davis

    International Nuclear Information System (INIS)

    Last, G.V.; Bagaasen, L.M.; Josephson, G.B.; Lanigan, D.C.; Liikala, T.L.; Newcomer, D.R.; Pearson, A.W.; Teel, S.S.

    1995-12-01

    A Remedial Investigation/Feasibility Study (RI/FS) is in progress at the Laboratory for Energy Related Health Research (LEHR) at the University of California, Davis. The purpose of the RI/FS is to gather sufficient information to support an informed risk management decision regarding the most appropriate remedial actions for impacted areas of the facility. In an effort to expedite remediation of the LEHR facility, the remedial project managers requested a more detailed evaluation of a selected set of remedial actions. In particular, they requested information on both characterization and remedial action costs. The US Department of Energy -- Oakland Office requested the assistance of the Pacific Northwest National Laboratory to prepare order-of-magnitude cost estimates for presumptive remedial actions being considered for the five source term operable units. The cost estimates presented in this report include characterization costs, capital costs, and annual operation and maintenance (O ampersand M) costs. These cost estimates are intended to aid planning and direction of future environmental remediation efforts

  15. An entropy spring model for the Young's modulus change of biodegradable polymers during biodegradation.

    Science.gov (United States)

    Wang, Ying; Han, Xiaoxiao; Pan, Jingzhe; Sinka, Csaba

    2010-01-01

    This paper presents a model for the change in Young's modulus of biodegradable polymers due to hydrolysis cleavage of the polymer chains. The model is based on the entropy spring theory for amorphous polymers. It is assumed that isolated polymer chain cleavage and very short polymer chains do not affect the entropy change in a linear biodegradable polymer during its deformation. It is then possible to relate the Young's modulus to the average molecular weight in a computer simulated hydrolysis process of polymer chain sessions. The experimental data obtained by Tsuji [Tsuji, H., 2002. Autocatalytic hydrolysis of amorphous-made polylactides: Effects of L-lactide content, tacticity, and enantiomeric polymer blending. Polymers 43, 1789-1796] for poly(L-lactic acid) and poly(D-lactic acid) are examined using the model. It is shown that the model can provide a common thread through Tsuji's experimental data. A further numerical case study demonstrates that the Young's modulus obtained using very thin samples, such as those obtained by Tsuji, cannot be directly used to calculate the load carried by a device made of the same polymer but of various thicknesses. This is because the Young's modulus varies significantly in a biodegradable device due to the heterogeneous nature of the hydrolysis reaction. The governing equations for biodegradation and the relation between the Young's modulus and average molecular weight can be combined to calculate the load transfer from a degrading device to a healing bone.

  16. Preparation of new biodegradable materials by grafting of polycarprolactone onto starch and their biodegradability studies

    International Nuclear Information System (INIS)

    Najemi, L.; Zerroukhi, A.; Jeanmaire, T.; Raihane, M.; Chamkh, F.; Qatibi, A.; Bennisse, R.

    2009-01-01

    The starch is a natural polymer which has the advantage of being biodegradable, renewable in quantity unlimited at very accessible prices. However its poor mechanical properties, depending on its hydrophobic character, and also its absorption of water restrict is applicability considerable especially for packing. (Author)

  17. Inverse modeling of the biodegradation of emerging organic contaminants in the soil-plant system

    DEFF Research Database (Denmark)

    Hurtado, Carlos; Trapp, Stefan; Bayona, Josep M.

    2016-01-01

    Understanding the processes involved in the uptake and accumulation of organic contaminants into plants is very important to assess the possible human risk associated with. Biodegradation of emerging contaminants in plants has been observed, but kinetical studies are rare. In this study, we analyse...... experimental data on the uptake of emerging organic contaminants into lettuce derived in a greenhouse experiment. Measured soil, root and leaf concentrations from four contaminants were selected within the applicability domain of a steady-state two-compartment standard plant uptake model: bisphenol A (BPA......), carbamazepine (CBZ), triclosan (TCS) and caffeine (CAF). The model overestimated concentrations in most cases, when no degradation rates in plants were entered. Subsequently, biodegradation rates were fitted so that the measured concentrations were met.Obtained degradation kinetics are in the order, BPA

  18. FINASOL OSR 52 active components biodegradation by using the biologic activator Biolen IG 30

    International Nuclear Information System (INIS)

    Bergueiro, J. R.; Luengo, M. C.; Socias, S.; Perez, F.; Laseca, D.; Perez-Navarro, A.; Morales, N.

    1997-01-01

    Degradation of the active ingredients in the FINASOL OSR 52, a commonly used dispersant in the treatment of marine oil spills, was studied. BIOLEN IG 30, comprising a mixture of bacteria, specially selected for their ability to degrade a wide range of chemical compounds, was used as the biodegrading agent. The kinetic coefficients of the degradation process were determined at different conditions, at ambient temperature, and at controlled 20 degrees C. BIOLEN IC 10 biologic activator was found to be adequate for total ionic and anionic dispersant degradation of the FINASOL OSR 52 at room temperature and at controlled 20 degrees C. Weekly addition of one gram of BIOLEN IG 30 was observed to improve biodegradation percentages for both ionic and anionic dispersants at controlled 20 degrees C. 12 refs., 5 tabs., 4 figs

  19. Combination of biochar amendment and mycoremediation for polycyclic aromatic hydrocarbons immobilization and biodegradation in creosote-contaminated soil.

    Science.gov (United States)

    García-Delgado, Carlos; Alfaro-Barta, Irene; Eymar, Enrique

    2015-03-21

    Soils impregnated with creosote contain high concentrations of polycyclic aromatic hydrocarbons (PAH). To bioremediate these soils and avoid PAH spread, different bioremediation strategies were tested, based on natural attenuation, biochar application, wheat straw biostimulation, Pleurotus ostreatus mycoremediation, and the novel sequential application of biochar for 21 days and P. ostreatus 21 days more. Soil was sampled after 21 and 42 days after the remediation application. The efficiency and effectiveness of each remediation treatment were assessed according to PAH degradation and immobilization, fungal and bacterial development, soil eco-toxicity and legal considerations. Natural attenuation and biochar treatments did not achieve adequate PAH removal and soil eco-toxicity reduction. Biostimulation showed the highest bacterial development but low PAH degradation rate. Mycoremediation achieved the best PAH degradation rate and the lowest bioavailable fraction and soil eco-toxicity. This bioremediation strategy achieved PAH concentrations below Spanish legislation for contaminated soils (RD 9/2005). Sequential application of biochar and P. ostreatus was the second treatment most effective for PAH biodegradation and immobilization. However, the activity of P. ostreatus was increased by previous biochar application and PAH degradation efficiency was increased. Therefore, the combined strategy for PAH degradation have high potential to increase remediation efficiency. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Development of aliphatic biodegradable photoluminescent polymers.

    Science.gov (United States)

    Yang, Jian; Zhang, Yi; Gautam, Santosh; Liu, Li; Dey, Jagannath; Chen, Wei; Mason, Ralph P; Serrano, Carlos A; Schug, Kevin A; Tang, Liping

    2009-06-23

    None of the current biodegradable polymers can function as both implant materials and fluorescent imaging probes. The objective of this study was to develop aliphatic biodegradable photoluminescent polymers (BPLPs) and their associated cross-linked variants (CBPLPs) for biomedical applications. BPLPs are degradable oligomers synthesized from biocompatible monomers including citric acid, aliphatic diols, and various amino acids via a convenient and cost-effective polycondensation reaction. BPLPs can be further cross-linked into elastomeric cross-linked polymers, CBPLPs. We have shown representatively that BPLP-cysteine (BPLP-Cys) and BPLP-serine (BPLP-Ser) offer advantages over the traditional fluorescent organic dyes and quantum dots because of their preliminarily demonstrated cytocompatibility in vitro, minimal chronic inflammatory responses in vivo, controlled degradability and high quantum yields (up to 62.33%), tunable fluorescence emission (up to 725 nm), and photostability. The tensile strength of CBPLP-Cys film ranged from 3.25 +/- 0.13 MPa to 6.5 +/- 0.8 MPa and the initial Modulus was in a range of 3.34 +/- 0.15 MPa to 7.02 +/- 1.40 MPa. Elastic CBPLP-Cys could be elongated up to 240 +/- 36%. The compressive modulus of BPLP-Cys (0.6) (1:1:0.6 OD:CA:Cys) porous scaffold was 39.60 +/- 5.90 KPa confirming the soft nature of the scaffolds. BPLPs also possess great processability for micro/nano-fabrication. We demonstrate the feasibility of using BPLP-Ser nanoparticles ("biodegradable quantum dots") for in vitro cellular labeling and noninvasive in vivo imaging of tissue engineering scaffolds. The development of BPLPs and CBPLPs represents a new direction in developing fluorescent biomaterials and could impact tissue engineering, drug delivery, bioimaging.