Testing of multistep soil washing for radiocesium-contaminated soil containing plant matter

International Nuclear Information System (INIS)

Funakawa, Masafumi; Tagawa, Akihiro; Okuda, Nobuyasu

2012-01-01

Decontamination work following radiocesium exposure requires a vast reduction in the amount of contaminated soil generated. The current study subjected 4 types of contaminated soil with different properties to multistep soil washing under the same conditions. This study also determined the effectiveness of radiocesium decontamination and the extent to which the amount of contaminated soil was reduced. In addition, the effectiveness of plant matter separation, adsorbent addition, and grinding as part of multistep soil washing was determined using the same contaminated soil. Results of testing indicated that the rate of radiocesium decontamination ranged from 73.6 to 89.2% and the recovery rate ranged from 51.5 to 84.2% for twice-treated soil, regardless of the soil properties or cesium level. Plant matter in soil had a high radiocesium level. However, there was little plant matter in our soil sample. Therefore, plant matter separation had little effect on the improvement in the percentage of radiocesium decontamination of twice-treated soil. Soil surface grinding improved the rate of radiocesium decontamination of twice-treated soil. However, radiocesium in soil tightly bound with minerals in the soil; thus, the addition of an adsorbent also failed to improve the rate of radiocesium decontamination. (author)

Bio-mechanical removing of contaminated soils: a field experiment

International Nuclear Information System (INIS)

Jouve, A.; Maubert, H.; Schulte, E.

1992-01-01

If, in spite of safety precautions, a major nuclear accident would occur, countermeasures should be taken to attenuate the impact of radioactive deposits. The European RESSAC program (REhabilitation of Soils and Surfaces after an ACcident) aims at studying actions for normal life return in contaminated zones. One of them, called the Decontaminating Vegetal Network (D.V.N.) associates the biological action of turfing plants, producing a dense root-network capable to trap the top contaminated soil particles, and the mechanical efficiency of a turf harvester which can remove only 1 cm of soil. This performance, not associated with other techniques of soil removal such as scrapers or bulldozers, leads to minimize the waste production. The D.V.N is a vegetal cover spread over the contaminated soil, using the hydro-seeding technique. The growing plants are forming a pleasant lawn which may have a positive impact on the public opinion compared to techniques using bitumen mixtures to cover the soil. Field experiments involving labelling solutions of stable molybdenum salts simulating the contamination of the soil have shown that this technique can be applied as well on homogeneous cultivated soil surfaces as on roughly ploughed soils. 4 refs., 3 figs., 2 tabs

Remediation of a radioactively contaminated soil using a mobile soil-washing system

International Nuclear Information System (INIS)

Grant, D.C.; Lahoda, E.J.; Dietrich, A.J.; Weigle, D.H.; Keegan, C.P.; Sachse, J.D.

1993-01-01

In order to obtain free-release of a former uranium mining site in Texas, it was required that the surface soil meet specific radiological guidelines. The soil has been contaminated with uranium and radium as a result of the spillage of well-drilling material, process solutions, and ion exchange resins during mining. To meet the required guidelines, the contaminated soil had to be either removed and disposed of off-site or remediated. For economic and long-term liability reasons, remediation of the soil by soil washing was performed. The remediation of this site utilizing the Scientific Ecology Group's soil washing system is discussed in this paper

Pollution of soil and groundwater from infiltration of highly contaminated stormwater - a case study

DEFF Research Database (Denmark)

Mikkelsen, P.S.; Häfliger, M.; Ochs, M.

1997-01-01

and subsurface sediments and some even exceeded guidelines fixed to preserve the fertility of soil. However, the contamination decreased rapidly with depth. None of the measured metal concentrations in simulated soil solutions exceeded defined drinking water quality standards. Surprisingly, the surface......A surface and a sub-surface infiltration system that received runoff water from trafficked roads for several decades was dug up and the contamination with heavy metals, PAH and AOX was investigated. Most measured solid phase concentrations exceeded background concentrations in nearby surface soils...... contamination due to stormwater infiltration, but highlights that well absorbable contaminants readily available in urban stormwater runoff eventually build up in surface soils and sub-surface sediments to environmentally critical concentration levels. Thus, on the one hand stormwater infiltration systems may...

Hydrocarbon degradation potential in reference soils and soils contaminated with jet fuel

International Nuclear Information System (INIS)

Lee, R.F.; Hoeppel, R.

1991-01-01

Petroleum degradation in surface and subsurface soils is affected by such factors as moisture content, pH, soil type, soil organics, temperature, and oxygen concentrations. In this paper, the authors determine the degradation rates of 14 C-labeled hydrocarbons added to soils collected from a contaminated surface site, contaminated subsurface sites, and a clean reference site. The radiolabeled hydrocarbons used include benzene, toluene, naphthalene, 1-methynaphthalene, phenanthrene, fluorene, anthracene, chrysene, and hexadecane. Microbial degradation rates were based on determination of mineralization rates (production of 14 CO 2 ) of hydrocarbons that were added to soil samples. Since water was added and oxygen was not limiting, the hydrocarbon rates determined are likely to be higher than those occurring in situ. Using radiolabeled hydrocarbons, information can be provided on differences in the degradation rates of various petroleum compounds in different types of soils at a site, on possible production of petroleum metabolites in the soil, and on the importance of anaerobic petroleum degradation and the effects of nutrient, water, and surfactant addition on biodegradation rates

Remediation of diesel-oil-contaminated soil using peat

International Nuclear Information System (INIS)

Ghaly, R.A.; Pyke, J.B.; Ghaly, A.E.; Ugursal, V.I.

1999-01-01

We investigated a remediation process for diesel-contaminated soil, in which water was used to remove the diesel from the soil and peat was used to absorb the diesel layer formed on the surface of the water. The percolation of water through the soil was uniform. The time required for water to percolate the soil and for the layers (soil, water, and diesel) to separate depended on the soil depth. Both the depth of soil and mixing affected the thickness of the diesel layer and thus diesel recovery from the contaminated soil. Higher diesel recovery was achieved with smaller soil depth and mixing. The initial moisture content and the lower heating value of the peat were 7.1% and 17.65 MJ/kg, respectively. The final moisture content and lower heating value of the diesel-contaminated peat obtained from the experiment with mixing were 8.65 - 10.80% and 32.57 - 35.81 MJ/kg, respectively. The energy content of the diesel-contaminated peat is much higher than that of coal, and the moisture content is within the range recommended for biomass gasification. (author)

Soil science basis and the effect of oil contamination on chemical properties of soils

International Nuclear Information System (INIS)

Wagner, A.; Miehlich, G.

1993-01-01

The changes in soil chemistry properties due to oil contamination and decontamination are examined. One main point of the work is the determination of the effect of oil on the availability of nutrients in the soil. Nutrients are not only present dissolved in the soil solution, but are for the most part reversibly adsorbed by exchangers on loaded surfaces. The clay minerals, the organic substance and iron and manganese oxide act as exchangers. Knowledge on surface structure and reactions in soils contaminated by oil is to be obtained via examination of the exchange behaviour of different bio-elements. The results supply the basis for the cleaning up technique, the judgement of cleaned materials and their reusability. (orig.) [de

NCRP soil contamination task group

International Nuclear Information System (INIS)

Jacobs, D.G.

1987-01-01

The National Council of Radiation Protection and Measurements (NCRP) has recently established a Task Group on Soil Contamination to describe and evaluate the migration pathways and modes of radiation exposure that can potentially arise due to radioactive contamination of soil. The purpose of this paper is to describe the scientific principles for evaluation of soil contamination which can be used as a basis for derivation of soil contamination limits for specific situations. This paper describes scenarios that can lead to soil contamination, important characteristics of soil contamination, the subsequent migration pathways and exposure modes, and the application of principles in the report in deriving soil contamination limits. The migration pathways and exposure modes discussed in this paper include: direct radiation exposure; and exhalation of gases

Selective flotation for the removal of radionuclides from contaminated soil

International Nuclear Information System (INIS)

Miller, J.D.; Yu, Q.; Lu, Y.Q.

1995-01-01

Low-level radioactive contaminated soils (10--500 pci/gm) created by defense-related activities at certain Superfund sites, such as Nevada Test Site (NTS), is a current environmental concern. Many of these contaminated sites may require appropriate cleanup and restoration, which could cost billions of dollars and put tremendous pressure on limited financial resources. Therefore, the development of a selective flotation process to separate such radionuclides from contaminated soils should be considered. In this study, both a pure depleted UO 2 sample and three synthetic UO 2 /soil mixtures were used to evaluate surface chemistry features and to examine the possibility for the flotation of fine UO 2 particles from selected soils. It was intended that this model system would be a reasonable representation of contaminated soils such as those found the Nevada Test Site which are reported to be contaminated by PuO 2 fallout. The effect of reagent schedule, particle size distribution, and surface charge are discussed with respect to the flotation separation of the UO 2 /soil mixtures. It was found that both commercial fatty acids and reagent grade sodium oleate are effective collectors for UO 2 flotation provided the pH is adjusted to the range of pH 8--9. The bench-scale flotation results successfully demonstrated that froth flotation technology can be used to remove UO 2 from such model contaminated soils with appropriate flotation chemistry conditions which depend on the soil characteristics and other pretreatment procedures

Soil sampling for environmental contaminants

International Nuclear Information System (INIS)

2004-10-01

The Consultants Meeting on Sampling Strategies, Sampling and Storage of Soil for Environmental Monitoring of Contaminants was organized by the International Atomic Energy Agency to evaluate methods for soil sampling in radionuclide monitoring and heavy metal surveys for identification of punctual contamination (hot particles) in large area surveys and screening experiments. A group of experts was invited by the IAEA to discuss and recommend methods for representative soil sampling for different kinds of environmental issues. The ultimate sinks for all kinds of contaminants dispersed within the natural environment through human activities are sediment and soil. Soil is a particularly difficult matrix for environmental pollution studies as it is generally composed of a multitude of geological and biological materials resulting from weathering and degradation, including particles of different sizes with varying surface and chemical properties. There are so many different soil types categorized according to their content of biological matter, from sandy soils to loam and peat soils, which make analytical characterization even more complicated. Soil sampling for environmental monitoring of pollutants, therefore, is still a matter of debate in the community of soil, environmental and analytical sciences. The scope of the consultants meeting included evaluating existing techniques with regard to their practicability, reliability and applicability to different purposes, developing strategies of representative soil sampling for cases not yet considered by current techniques and recommending validated techniques applicable to laboratories in developing Member States. This TECDOC includes a critical survey of existing approaches and their feasibility to be applied in developing countries. The report is valuable for radioanalytical laboratories in Member States. It would assist them in quality control and accreditation process

Risk assessment of soil contamination criteria

International Nuclear Information System (INIS)

King, C.M.; Marter, W.L.; Montaque, D.F.; Holton, G.A.

1987-06-01

Criteria have been developed to select radioactive and nonradioactive contaminants at waste sites detailed analysis and risk assessment. These criteria were based on soil and water quality guidelines developed by various government agencies to determine if the criteria were appropriate. We performed a risk assessment of a hypothetical site which contained radioactive and nonradioactive contaminants at levels equal to the criteria values. Risks to the public from atmospheric, surface water, and groundwater exposure pathways were examined. Health risks to the public from atmospheric releases of radioactive and nonradioactive materials from a waste at soil criteria contamination levels are low. Health risks to the maximally exposed individual to chemical carcinogens are considerably below traditional EPA action levels. And health risks to the maximally exposed individual to atmospherically released radioactive contaminants is 1.88 x 10 -7 , more than a factor of 5 less than 10 -6 . Based on our atmospheric exposure pathways analysis and risk assessment, the applied soil criteria are appropriate for screening out unimportant risk contributors to human health from atmospheric exposure pathways. 13 refs., 3 figs., 7 tabs

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

Science.gov (United States)

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

2018-08-15

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

Restoration of contaminated soils

International Nuclear Information System (INIS)

Miranda J, Jose Eduardo

2009-01-01

A great variety of techniques are used for the restoration of contaminated soils. The contamination is present by both organic and inorganic pollutants. Environmental conditions and soil characteristics should take into account in order to implement a remedial technique. The bioremediation technologies are showed as help to remove a variety of soil contaminants. (author) [es

An investigation of inorganic antimony species and antimony associated with soil humic acid molar mass fractions in contaminated soils

International Nuclear Information System (INIS)

Steely, Sarah; Amarasiriwardena, Dulasiri; Xing Baoshan

2007-01-01

The presence of antimony compounds is often suspected in the soil of apple orchards contaminated with lead arsenate pesticide and in the soil of shooting ranges. Nitric acid (1 M) extractable Sb from the shooting range (8300 μg kg -1 ) and the apple orchard (69 μg kg -1 ) had considerably higher surface Sb levels than the control site ( -1 ), and Sb was confined to the top ∼30 cm soil layer. Sb(V) was the principal species in the shooting range and the apple orchard surface soils. Size exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS) analysis of humic acids isolated from the two contaminated soils demonstrated that Sb has complexed to humic acid molar mass fractions. The results also indicate that humic acids have the ability to arrest the mobility of Sb through soils and would be beneficial in converting Sb(III) to a less toxic species, Sb(V), in contaminated areas. - The soil surface and depth distribution Sb(V) and Sb(III) species in a contaminated apple orchard and a shooting range, and the effect soil humic acids on inorganic antimony species is reported

Phytoremediation of soils contaminated by cadmium

Science.gov (United States)

Watai, H.; Miyazaki, T.; Fujikawa, T.; Mizoguchi, M.

2004-12-01

Phytoremediation is a technique to clean up soils contaminated with heavy metals. Advantages of this method are that (1) This technique is suitable to cleanup soils slightly contaminated with heavy metals in relatively wide area. (2) The expense for clean up is lower than civil engineering techniques. (3) This method can remove heavy metals fundamentally from contaminated. (4) The heavy metals are able to recycle by ashing of plants. Many researches have been done on the phytoremediation up to now, but almost all these researches were devoted to clarify the phytoremediation from the view point of plants themselves. However, few efforts have been devoted to analyze the migrations of heavy metals in soils during the phytoremediation process. The objective of this study is to clarify the features of Cd migration when plant roots are absorbing Cd from the ambient soils. Especially, we focused on finding the Cd migration pattern by changing the soil condition such as plant growing periods, planting densities, and the initial Cd concentration in soils. We planted sunflowers in columns filled with Cd contaminated soils because sunflower is a well-known hyperaccumulator of Cd from soils. By cutting the shoots of plants at the soil surface, and by keeping the plant roots in the soils without disturbance, the Cd concentrations, moisture contents, pH distributions, EC distributions, and dry weight of residual roots in the soils were carefully analyzed. The experimental results showed that (1)The growth of the planted sunflowers were suffered by applying of Cd. (2)The decrease of suction was affected by water uptake by roots at the depth from 0 to 5 cm. Water contents with plants in soils decrease more than without plants. (3)Cd adsorption by roots was predominant within 5cm from soil surface. In addition, it was also shown that there was an optimal Cd concentration where Cd is most effectively adsorbed by the plant. In this experiment we found that 40 to 60 mg kg-1 was the

Surface soil contamination standards for Rockwell Hanford Operations

International Nuclear Information System (INIS)

Boothe, G.F.

1981-01-01

The 200 Areas of the Hanford site contain soils contaminated with levels of radioactivity ranging from fallout concentrations to levels requiring radiological controls. Some contamination is more or less uniformly distributed, and some occurs as discrete specks or spots of activity. Because of the acute need for standards, the Rockwell Environmental Protection (EP) Group proceeded to develop standards; these were approved by Rockwell in October 1979. It must be emphasized that these standards are only applicable to the 200 Areas of the Hanford site or other areas under Rockwell's jurisdiction. It is assumed that access to these areas will always be restricted and that land-use restrictions will be maintained. Contamination limits for areas used by the general public would normally be lower than the limits derived in this case. It appears that the Rockwell standards divided by a factor of 5 to 10 may be reasonable contamination guidelines for the general environment

PHYTOREMEDIATION OF SOILS CONTAMINATED WITH WOOD PRESERVATIVES: GREENHOUSE AND FIELD EVALUATIONS

Science.gov (United States)

Phytoremediation was evaluated as a potential treatment for the creosote-contaminated surface soil at the McCormick and Baxter (M&B) Superfund Site in Portland, OR. Soil a the M&B site is contaminated with pentachlorophenol (PCP) and polyaromatic hydrocarbons (PAHs). Eight indivi...

The effect of soil type on the electrodialytic remediation of lead-contaminated soil

DEFF Research Database (Denmark)

Jensen, Pernille Erland; Ottosen, Lisbeth M.; Harmon, Thomas C.

2007-01-01

experiments with ten representative industrially Pb-contaminated surface soils. Results indicate that Pb-speciation is of primary importance. Specifically, organic matter and stable compounds like PbCrO4 can impede and possibly even preclude soil remediation. In soils rich in carbonate, where the acidic front...... to the catholyte. Thus, the presence of carbonate negatively influences the remediation time. Pb bound to soluble organic matter is also transported towards the anolyte during EDR. The primary effect of the mainly insoluble organic matter commonly present in surface soil is however to immobilize Pb and impede...

Fixation of soil surface contamination using natural polysaccharides

International Nuclear Information System (INIS)

Sackschewsky, M.R.

1993-09-01

Natural polysaccharides were evaluated as alternatives to commercially available dust-control agents for application in buried-waste and contaminated-soil remediation situations. Materials were identified and evaluated with specific criteria in mind: the materials must be environmentally benign and must not introduce any additional hazardous materials; they must be effective for at least 2 or 3 days, but they do not necessarily have to be effective for more than 2 to 3 weeks; they should be relatively resistant to light traffic; they must not interfere with subsequent soil treatment techniques, especially soil washing; and they must be relatively inexpensive. Two products, a pregelled potato starch and a mixture of carbohydrates derived from sugar beets, were selected for evaluation. Testing included small- and large-scale field demonstrations, laboratory physical property analyses, and wind-tunnel evaluations

Heavy metal contamination of surface soil in electronic waste dismantling area: site investigation and source-apportionment analysis.

Science.gov (United States)

Jinhui Li; Huabo Duan; Pixing Shi

2011-07-01

The dismantling and disposal of electronic waste (e-waste) in developing countries is causing increasing concern because of its impacts on the environment and risks to human health. Heavy-metal concentrations in the surface soils of Guiyu (Guangdong Province, China) were monitored to determine the status of heavy-metal contamination on e-waste dismantling area with a more than 20 years history. Two metalloids and nine metals were selected for investigation. This paper also attempts to compare the data among a variety of e-waste dismantling areas, after reviewing a number of heavy-metal contamination-related studies in such areas in China over the past decade. In addition, source apportionment of heavy metal in the surface soil of these areas has been analysed. Both the MSW open-burning sites probably contained invaluable e-waste and abandoned sites formerly involved in informal recycling activities are the new sources of soil-based environmental pollution in Guiyu. Although printed circuit board waste is thought to be the main source of heavy-metal emissions during e-waste processing, requirement is necessary to soundly manage the plastic separated from e-waste, which mostly contains heavy metals and other toxic substances.

Accelerated remediation of pesticide-contaminated soil with zerovalent iron

Energy Technology Data Exchange (ETDEWEB)

Shea, P.J. [University of Nebraska-Lincoln, Lincoln, NE 68583-0915 (United States)]. E-mail: pshea@unl.edu; Machacek, T.A. [University of Nebraska-Lincoln, Lincoln, NE 68583-0915 (United States); Comfort, S.D. [University of Nebraska-Lincoln, Lincoln, NE 68583-0915 (United States)

2004-11-01

High pesticide concentrations in soil from spills or discharges can result in point-source contamination of ground and surface waters. Cost-effective technologies are needed for on-site treatment that meet clean-up goals and restore soil function. Remediation is particularly challenging when a mixture of pesticides is present. Zerovalent iron (Fe{sup 0}) has been shown to promote reductive dechlorination and nitro group reduction of a wide range of contaminants in soil and water. We employed Fe{sup 0} for on-site treatment of soil containing >1000 mg metolachlor, >55 mg alachlor, >64 mg atrazine, >35 mg pendimethalin, and >10 mg chlorpyrifos kg{sup -1}. While concentrations were highly variable within the windrowed soil, treatment with 5% (w/w) Fe{sup 0} resulted in >60% destruction of the five pesticides within 90 d and increased to >90% when 2% (w/w) Al{sub 2}(SO{sub 4}){sub 3} was added to the Fe{sup 0}. GC/MS analysis confirmed dechlorination of metolachlor and alachlor during treatment. Our observations support the use of Fe{sup 0} for ex situ treatment of pesticide-contaminated soil. - Capsule: Zerovalent iron promotes pesticide degradation in highly contaminated soil.

Bioremediation of contaminated soil

International Nuclear Information System (INIS)

Balba, M.T.; Ying, A.C.; McNeice, T.G.

1992-01-01

Microorganisms, especially bacteria, yeast and fungi are capable of degrading many kinds of xenobiotic compounds and toxic chemicals such as petroleum hydrocarbon compounds. These microorganisms are ubiquitous in nature and, despite their enormous versatility, there are numerous cases in which long-term contamination of soil and groundwater has been observed. The persistence of the contamination is usually caused by the inability of microorganisms to metabolize these compounds under the prevailing environmental condition. This paper reports on biological remediation of contaminated sites which can be accomplished by using naturally-occurring microorganisms to treat the contaminants. The development of a bioremediation program for a specific contaminated soil system usually includes: A thorough site/soil/waste characterization; Treatability studies

Airborne soil particulates as vehicles for Salmonella contamination of tomatoes.

Science.gov (United States)

Kumar, Govindaraj Dev; Williams, Robert C; Al Qublan, Hamzeh M; Sriranganathan, Nammalwar; Boyer, Renee R; Eifert, Joseph D

2017-02-21

The presence of dust is ubiquitous in the produce growing environment and its deposition on edible crops could occur. The potential of wind-distributed soil particulate to serve as a vehicle for S. Newport transfer to tomato blossoms and consequently, to fruits, was explored. Blossoms were challenged with previously autoclaved soil containing S. Newport (9.39log CFU/g) by brushing and airborne transfer. One hundred percent of blossoms brushed with S. Newport-contaminated soil tested positive for presence of the pathogen one week after contact (PCompressed air was used to simulate wind currents and direct soil particulates towards blossoms. Airborne soil particulates resulted in contamination of 29% of the blossoms with S. Newport one week after contact. Biophotonic imaging of blossoms post-contact with bioluminescent S. Newport-contaminated airborne soil particulates revealed transfer of the pathogen on petal, stamen and pedicel structures. Both fruits and calyxes that developed from blossoms contaminated with airborne soil particulates were positive for presence of S. Newport in both fruit (66.6%) and calyx (77.7%). Presence of S. Newport in surface-sterilized fruit and calyx tissue tested indicated internalization of the pathogen. These results show that airborne soil particulates could serve as a vehicle for Salmonella. Hence, Salmonella contaminated dust and soil particulate dispersion could contribute to pathogen contamination of fruit, indicating an omnipresent yet relatively unexplored contamination route. Copyright © 2016 Elsevier B.V. All rights reserved.

Contamination of ground water, surface water, and soil, and evaluation of selected ground-water pumping alternatives in the Canal Creek area of Aberdeen Proving Ground, Maryland

Science.gov (United States)

Lorah, Michelle M.; Clark, Jeffrey S.

1996-01-01

Chemical manufacturing, munitions filling, and other military-support activities have resulted in the contamination of ground water, surface water, and soil in the Canal Creek area of Aberdeen Proving Ground, Maryland. Chlorinated volatile organic compounds, including 1,1,2,2-tetrachloroethane and trichloroethylene, are widespread ground-water contaminants in two aquifers that are composed of unconsolidated sand and gravel. Distribution and fate of chlorinated organic compounds in the ground water has been affected by the movement and dissolution of solvents in their dense immiscible phase and by microbial degradation under anaerobic conditions. Detection of volatile organic contaminants in adjacent surface water indicates that shallow contaminated ground water discharges to surface water. Semivolatile organic compounds, especially polycyclic aromatic hydrocarbons, are the most prevalent organic contaminants in soils. Various trace elements, such as arsenic, cadmium, lead, and zinc, were found in elevated concentrations in ground water, surface water, and soil. Simulations with a ground-water-flow model and particle tracker postprocessor show that, without remedial pumpage, the contaminants will eventually migrate to Canal Creek and Gunpowder River. Simulations indicate that remedial pumpage of 2.0 million gallons per day from existing wells is needed to capture all particles originating in the contaminant plumes. Simulated pumpage from offsite wells screened in a lower confined aquifer does not affect the flow of contaminated ground water in the Canal Creek area.

Actinide migration from contaminated soil to surface water at the rocky flats environmental technology site

International Nuclear Information System (INIS)

Santschi, Peter H.; Roberts, Kimberly

2002-01-01

Surficial soils of the Rocky Flats Environmental Technology Site (RFETS) contain elevated levels of 239,240 Pu and 241 Am due to wind dispersal of soil particles, contaminated in the 1960's by leaking drums stored on the 903 Pad. Over the past 4 years, actinide mobility in the surface environment at RFETS, Golden, Colorado, USA, was examined through field and laboratory experiments. From measurements of total 239,240 Pu and 241 Am concentrations in storm runoff and pond discharge samples, collected during spring and summer times, it was established that most of the actinide transport from contaminated soils to streams occurred in the particulate (0.45μm) and colloidal (3kDa - 0.45μm) phases. Controlled laboratory investigations of soil resuspension, indicated that remobilization of colloid-bound Pu during soil erosion events can be enhanced by humic acids. 2-D Polyacrylamide Gel electrophoresis (PAGE) experiments of radiolabeled colloidal organic and inorganic matter, extracted from RFETS soils, suggested that colloidal Pu, which was focused at pH IEP of 4.5, is mainly associated with organic (humic acids) colloids of 10-15 kDa molecular weight. Pu(IV) oxide and inorganic colloids such as iron and aluminum oxides have pH IEP of 8-10. While some clay minerals also have pH IEP of 3-5, no Al was found coincident with Pu. This finding has important ramifications for possible remediation, erosion controls, and land-management strategies. (author)

Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves

Directory of Open Access Journals (Sweden)

Wulandari P.S.

2010-01-01

Full Text Available Ultrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application.

Using biochar for remediation of soils contaminated with heavy metals and organic pollutants.

Science.gov (United States)

Zhang, Xiaokai; Wang, Hailong; He, Lizhi; Lu, Kouping; Sarmah, Ajit; Li, Jianwu; Bolan, Nanthi S; Pei, Jianchuan; Huang, Huagang

2013-12-01

Soil contamination with heavy metals and organic pollutants has increasingly become a serious global environmental issue in recent years. Considerable efforts have been made to remediate contaminated soils. Biochar has a large surface area, and high capacity to adsorb heavy metals and organic pollutants. Biochar can potentially be used to reduce the bioavailability and leachability of heavy metals and organic pollutants in soils through adsorption and other physicochemical reactions. Biochar is typically an alkaline material which can increase soil pH and contribute to stabilization of heavy metals. Application of biochar for remediation of contaminated soils may provide a new solution to the soil pollution problem. This paper provides an overview on the impact of biochar on the environmental fate and mobility of heavy metals and organic pollutants in contaminated soils and its implication for remediation of contaminated soils. Further research directions are identified to ensure a safe and sustainable use of biochar as a soil amendment for remediation of contaminated soils.

Allowable residual contamination levels of radionuclides in soil from pathway analysis

International Nuclear Information System (INIS)

Nyquist, J.E.; Baes, C.F. III

1987-01-01

The Remedial Action Program (RAP) at Oak Ridge National Laboratory will include well drilling, facility upgrades, and other waste management operations likely to involve soils contaminated with radionuclides. A preliminary protocol and generalized criteria for handling contaminated soils is needed to coordinate and plan RAP activities, but there exists only limited information on contaminate nature and distribution at ORNL RAP sites. Furthermore, projections of long-term decommissioning and closure options for these sites are preliminary. They have adapted a pathway analysis model, DECOM, to quantify risks to human health from radionuclides in soil and used it to outline preliminary criteria for determining the fate of contaminated soil produced during RAP activities. They assumed that the site could be available for unrestricted use immediately upon decontamination. The pathways considered are consumption of food grown on the contaminated soil, including direct ingestion of soil from poorly washed vegetables, direct radiation from the ground surface, inhalation of resuspended radioactive soil, and drinking water from a well drilled through or near the contaminated soil. We will discuss the assumptions and simplifications implicit in DECOM, the site-specific data required, and the results of initial calculations for the Oak Ridge Reservation

Immobilization of Lead Migrating from Contaminated Soil in Rhizosphere Soil of Barley (Hordeum vulgare L.) and Hairy Vetch (Vicia villosa) Using Hydroxyapatite.

Science.gov (United States)

Katoh, Masahiko; Risky, Elsya; Sato, Takeshi

2017-10-23

This study conducted plant growth tests using a rhizobox system to quantitatively determine the distance of immobilization lead migrating from contaminated soil into uncontaminated rhizosphere soil, and to assess the lead phases accumulated in rhizosphere soil by sequential extraction. Without the hydroxyapatite, exchangeable lead fractions increased as the rhizosphere soil got closer to the contaminated soil. Exchangeable lead fractions were higher even in the rhizosphere soil that shares a boundary with the root surface than in the soil before being planted. Thus, plant growth of hairy vetch was lower in the soil without the hydroxyapatite than in the soil with the hydroxyapatite. The presence of hydroxyapatite may immobilize the majority of lead migrating from contaminated soil into the rhizosphere soil within 1 mm from the contaminated soil. The dominant lead fraction in the rhizosphere soil with the hydroxyapatite was residual. Thus, plant growth was not suppressed and the lead concentration of the plant shoot remained at the background level. These results indicate that the presence of hydroxyapatite in the rhizosphere soil at 5% wt may immobilize most of the lead migrating into the rhizosphere soil within 1 mm from the contaminated soil, resulting in the prevention of lead migration toward the root surface.

Groundwater-soil-crop relationship with respect to arsenic contamination in farming villages of Bangladesh - A preliminary study

International Nuclear Information System (INIS)

Kurosawa, Kiyoshi; Egashira, Kazuhiko; Tani, Masakazu; Jahiruddin, M.; Moslehuddin, Abu Zofar Md.; Rahman, Zulfikar Md.

2008-01-01

To clarify the groundwater-soil-crop relationship with respect to arsenic (As) contamination, As concentration was measured in tubewell (TW) water, surface soil from farmyards and paddy fields, and fresh taro (Colocasia esculenta) leaves from farmyards in the farming villages of Bangladesh. The As concentration in TW water from farmyards was at least four times higher than the Bangladesh drinking water standard, and the concentration in fresh taro leaves was equal to or higher than those reported previously for leafy vegetables in Bangladesh. As concentration of surface soils in both farmyards and paddy fields was positively correlated with that of the TW water. Further, the concentration in surface soil was positively correlated with levels in fresh taro leaves in the farmyard. This study, therefore, clarified the groundwater-soil-crop relationship in farmyards and the relationship between groundwater-soil in paddy fields to assess the extent of As contamination in Bangladeshi villages. - By extracting arsenic contaminated groundwater from a well, surface soil surrounding the well and crops planted in the surface soil became contaminated with arsenic

Bench Scale Treatability Studies of Contaminated Soil Using Soil Washing Technique

Directory of Open Access Journals (Sweden)

M. K. Gupta

2010-01-01

Full Text Available Soil contamination is one of the most widespread and serious environmental problems confronting both the industrialized as well as developing nations like India. Different contaminants have different physicochemical properties, which influence the geochemical reactions induced in the soils and may bring about changes in their engineering and environmental behaviour. Several technologies exist for the remediation of contaminated soil and water. In the present study soil washing technique using plain water with surfactants as an enhancer was used to study the remediation of soil contaminated with (i an organic contaminant (engine lubricant oil and (ii an inorganic contaminant (heavy metal. The lubricant engine oil was used at different percentages (by dry weight of the soil to artificially contaminate the soil. It was found that geotechnical properties of the soil underwent large modifications on account of mixing with the lubricant oil. The sorption experiments were conducted with cadmium metal in aqueous medium at different initial concentration of the metal and at varying pH values of the sorbing medium. For the remediation of contaminated soil matrices, a nonionic surfactant was used for the restoration of geotechnical properties of lubricant oil contaminated soil samples, whereas an anionic surfactant was employed to desorb cadmium from the contaminated soil matrix. The surfactant in case of soil contaminated with the lubricant oil was able to restore properties to an extent of 98% vis-à-vis the virgin soil, while up to 54% cadmium was desorbed from the contaminated soil matrix in surfactant aided desorption experiments.

Assessment of Hyporheic Zone, Flood-Plain, Soil-Gas, Soil, and Surface-Water Contamination at the McCoys Creek Chemical Training Area, Fort Gordon, Georgia, 2009-2010

Science.gov (United States)

Guimaraes, Wladmir B.; Falls, W. Fred; Caldwell, Andral W.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

2011-01-01

The U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Georgia, assessed the hyporheic zone, flood plain, soil gas, soil, and surface water for contaminants at the McCoys Creek Chemical Training Area (MCTA) at Fort Gordon, from October 2009 to September 2010. The assessment included the detection of organic contaminants in the hyporheic zone, flood plain, soil gas, and surface water. In addition, the organic contaminant assessment included the analysis of organic compounds classified as explosives and chemical agents in selected areas. Inorganic contaminants were assessed in soil and surface-water samples. The assessment was conducted to provide environmental contamination data to the U.S. Army at Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Ten passive samplers were deployed in the hyporheic zone and flood plain, and total petroleum hydrocarbons (TPH) and octane were detected above the method detection level in every sampler. Other organic compounds detected above the method detection level in the hyporheic zone and flood-plain samplers were trichloroethylene, and cis- and trans- 1, 2-dichloroethylene. One trip blank detected TPH below the method detection level but above the nondetection level. The concentrations of TPH in the samplers were many times greater than the concentrations detected in the blank; therefore, all other TPH concentrations detected are considered to represent environmental conditions. Seventy-one soil-gas samplers were deployed in a grid pattern across the MCTA. Three trip blanks and three method blanks were used and not deployed, and TPH was detected above the method detection level in two trip blanks and one method blank. Detection of TPH was observed at all 71 samplers, but because TPH was detected in the trip and method blanks, TPH was

Quantifying Diffuse Contamination: Method and Application to Pb in Soil.

Science.gov (United States)

Fabian, Karl; Reimann, Clemens; de Caritat, Patrice

2017-06-20

A new method for detecting and quantifying diffuse contamination at the continental to regional scale is based on the analysis of cumulative distribution functions (CDFs). It uses cumulative probability (CP) plots for spatially representative data sets, preferably containing >1000 determinations. Simulations demonstrate how different types of contamination influence elemental CDFs of different sample media. It is found that diffuse contamination is characterized by a distinctive shift of the low-concentration end of the distribution of the studied element in its CP plot. Diffuse contamination can be detected and quantified via either (1) comparing the distribution of the contaminating element to that of an element with a geochemically comparable behavior but no contamination source (e.g., Pb vs Rb), or (2) comparing the top soil distribution of an element to the distribution of the same element in subsoil samples from the same area, taking soil forming processes into consideration. Both procedures are demonstrated for geochemical soil data sets from Europe, Australia, and the U.S.A. Several different data sets from Europe deliver comparable results at different scales. Diffuse Pb contamination in surface soil is estimated to be contamination sources and can be used to efficiently monitor diffuse contamination at the continental to regional scale.

A petroleum contaminated soil bioremediation facility

Energy Technology Data Exchange (ETDEWEB)

Lombard, K.; Hazen, T.

1994-06-01

The amount of petroleum contaminated soil (PCS) at the Savannah River site (SRS) that has been identified, excavated and is currently in storage has increased several fold during the last few years. Several factors have contributed to this problem: (1) South Carolina Department of Health ad Environmental control (SCDHEC) lowered the sanitary landfill maximum concentration for total petroleum hydrocarbons (TPH) in the soil from 500 to 100 parts per million (ppm), (2) removal and replacement of underground storage tanks at several sites, (3) most recently SCDHEC disallowed aeration for treatment of contaminated soil, and (4) discovery of several very large contaminated areas of soil associated with leaking underground storage tanks (LUST), leaking pipes, disposal areas, and spills. Thus, SRS has an urgent need to remediate large quantities of contaminated soil that are currently stockpiled and the anticipated contaminated soils to be generated from accidental spills. As long as we utilize petroleum based compounds at the site, we will continue to generate contaminated soil that will require remediation.

A petroleum contaminated soil bioremediation facility

International Nuclear Information System (INIS)

Lombard, K.; Hazen, T.

1994-01-01

The amount of petroleum contaminated soil (PCS) at the Savannah River site (SRS) that has been identified, excavated and is currently in storage has increased several fold during the last few years. Several factors have contributed to this problem: (1) South Carolina Department of Health ad Environmental control (SCDHEC) lowered the sanitary landfill maximum concentration for total petroleum hydrocarbons (TPH) in the soil from 500 to 100 parts per million (ppm), (2) removal and replacement of underground storage tanks at several sites, (3) most recently SCDHEC disallowed aeration for treatment of contaminated soil, and (4) discovery of several very large contaminated areas of soil associated with leaking underground storage tanks (LUST), leaking pipes, disposal areas, and spills. Thus, SRS has an urgent need to remediate large quantities of contaminated soil that are currently stockpiled and the anticipated contaminated soils to be generated from accidental spills. As long as we utilize petroleum based compounds at the site, we will continue to generate contaminated soil that will require remediation

Contaminated soil concrete blocks

NARCIS (Netherlands)

de Korte, A.C.J.; Brouwers, Jos; Limbachiya, Mukesh C.; Kew, Hsein Y.

2009-01-01

According to Dutch law the contaminated soil needs to be remediated or immobilised. The main focus in this article is the design of concrete blocks, containing contaminated soil, that are suitable for large production, financial feasible and meets all technical and environmental requirements. In

Plant uptake of radiocesium from contaminated soils

International Nuclear Information System (INIS)

Pipiska, M.; Lesny, J.; Hornik, M.; Augustin, J.

2004-01-01

Phytoextraction field experiments were conducted on soil contaminated with radiocesium to determine the capacity of autochthonous grasses and weeds to accumulate 137 Cs. The aim of the study was to evaluate the potential of spontaneously growing vegetation as a tool for decontamination of non-agricultural contaminated land. As a test field, the closed monitored area of the radioactive wastewater treatment plant of the Nuclear Power Plant in Jaslovskie Bohunice, Slovakia was used. contamination was irregularly distributed from the level of background to spots with maximal activity up to 900 Bq/g soil. Sequential extraction analysis of soil samples showed the following extractability of radiocesium (as percent of total): water 2 = 0.3-1.1%; 1M CH 3 COONa = 0.3-0.9%; 0.04 M NH 4 Cl (in 25% CH 3 COOH) = 0.9-1.4% and 30% H 2 O 2 - 0.02 M HNO 3 = 4.5-9.0%.Specific radioactivity of the most efficiently bioaccumulating plant species did not exceed 4.0 BqKg -1 (dry weight biomass). These correspond to the soil-to-plant transfer factor (TF) values up to 44.4x10 -4 BqKg -1 crop, d.w.)/(BqKg -1 soil d.w). Aggregated transfer factor (T ag ) of the average sample of the whole crop harvested from defined area was 0.5x10 -5 (Bqkg -1 d.w. crop)/(Bqm -2 soil). It can be concluded that low mobility of radiocesium in analysed soil type, confirmed by sequential extraction analyses, is the main hindrance for practical application for autochthonous plants as a phytoremediation tool for aged contaminated area of non-cultivated sites. Plant cover can efficiently serve only as a soil surface-stabilising layer, mitigating the migration of radiocesium into the surrounding environment. (author)

Treatment of NORM contaminated soil from the oilfields.

Science.gov (United States)

Abdellah, W M; Al-Masri, M S

2014-03-01

Uncontrolled disposal of oilfield produced water in the surrounding environment could lead to soil contamination by naturally occurring radioactive materials (NORM). Large volumes of soil become highly contaminated with radium isotopes ((226)Ra and (228)Ra). In the present work, laboratory experiments have been conducted to reduce the activity concentration of (226)Ra in soil. Two techniques were used, namely mechanical separation and chemical treatment. Screening of contaminated soil using vibratory sieve shaker was performed to evaluate the feasibility of particle size separation. The fractions obtained were ranged from less than 38 μm to higher than 300 μm. The results show that (226)Ra activity concentrations vary widely from fraction to fraction. On the other hand, leaching of (226)Ra from soil by aqueous solutions (distilled water, mineral acids, alkaline medias and selective solvents) has been performed. In most cases, relatively low concentrations of radium were transferred to solutions, which indicates that only small portions of radium are present on the surface of soil particles (around 4.6%), while most radium located within soil particles; only concentrated nitric acid was most effective where 50% of (226)Ra was removed to aqueous phase. However, mechanical method was found to be easy and effective, taking into account safety procedures to be followed during the implementation of the blending and homogenization. Chemical extraction methods were found to be less effective. The results obtained in this study can be utilized to approach the final option for disposal of NORM contaminated soil in the oilfields. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessment of lead, cadmium, and zinc contamination of roadside soils, surface films, and vegetables in Kampala City, Uganda

International Nuclear Information System (INIS)

Nabulo, Grace; Oryem-Origa, Hannington; Diamond, Miriam

2006-01-01

The relationship between traffic density and trace metal concentrations in roadside soils, surface films, and a selected vegetable weed, Amaranthus dubius Mart. Ex Thell., was determined in 11 farming sites along major highways around Kampala City in Uganda. Surface soil, atmospherically deposited surface films on windows, and leaves of Amaranthus dubius were sampled at known distances from the roads and analyzed for lead (Pb), zinc (Zn), and cadmium (Cd) using flame atomic absorption spectrophotometry. Atmospherically deposited trace metal particulates were sampled using window glass as an inert, passive collector. Total trace metal concentrations in soils ranged from 30.0±2.3 to 64.6±11.7 mg/kg Pb, 78.4±18.4 to 265.6±63.2 mg/kg Zn, and 0.8±0.13 to 1.40±0.16 mg/kg Cd. Total trace metal levels in soil decreased rapidly with distance from the road. Total Pb decreased with distance up to 30 m from the road, where it reached a background soil concentration of 28 mg/kg dry weight. The study found background values of 50 and 1.4 mg/kg for Zn and Cd in roadside soils, respectively. Similarly, Pb concentration in Amaranthus dubius leaves decreased with increasing distance from the road edge. The dominant pathway for Pb contamination was from atmospheric deposition, which was consistent with Pb concentrations in surface films. The mean Pb concentrations in leaves of roadside crops were higher than those in their respective roots, with the highest leaf-to-root ratio observed in the Brassica oleraceae acephala group. The lowest Pb and Zn concentrations were found in the fruit compared to the leaves of the same crops. Leaves of roadside vegetables were therefore considered a potential source of heavy metal contamination to farmers and consumers in urban areas. It is recommended that leafy vegetables should be grown 30 m from roads in high-traffic, urban areas

An experimental study on mass loading of soil particles on plant surfaces

International Nuclear Information System (INIS)

Li, J. G.; Gerzabek, M. H.; Mueck, K.

1994-01-01

Radionuclide contaminated soil adhered to plant surfaces can contribute to human ingestion dose. To determine this contribution, a method of 46 Sc neutron activation analysis was established and tested, by which a detection limit of 0.05 mg soil per g dry plant biomass can be obtained. In the field and greenhouse experiment the mass loading of soil on ryegrass (Lolium perenne L.) and broadbean (Vicia faba L.) was investigated and the contribution from rainsplash and wind erosion were evaluated separately. Soil retained on plant surfaces in field conditions in Seibersdorf/Austria was 5.77 ± 1.44 mg soil per g dry plant for ryegrass and 9.51 ± 0.73 mg soil per g dry plant for broadbean. Estimates of contribution from rainsplash and wind erosion to soil contamination of plants during the experimental period are 68 % and 32 % for broadbean 47 % and 53 % for ryegrass respectively. Mass loading results from field studies indicate that soil adhesion on plant surfaces can contribute up to 23 % of plant 137 Cs contamination, the transfer factors modified by mass loading decline differently, depending on 137 Cs concentration of the soil and the soil mass adhered to plant surfaces. (author)

Decontamination of hydrocarbon contaminated soil

International Nuclear Information System (INIS)

Smith, A.J.

1991-01-01

This patent describes the method of treating hydrocarbon contaminated soil. It comprises forming the soil into a flowing particulate stream, forming an aqueous liquid mixture of water and treating substance that reacts with hydrocarbon to form CO 2 and water, dispersing the liquid mixture into the particulate soil stream to wet the particulate, allowing the substance to react with the wetted soil particulate to thereby form CO 2 and water, thereby the resultant soil is beneficially treated, the stream being freely projected to dwell at a level and then fall, and the dispersing includes spraying the liquid mixture into the projected stream at the dwell, the substance consisting of natural bacteria, and at a concentration level in the mixture of between 100 to 3,000 PPM of bacteria to water, the soil forming step including impacting the soil to reduce it to particles less than about 1 inches in cross dimension, and including forming the wetting particulate into a first layer on a surface to allow the substance to react

Organochlorine pesticides in surface soils from obsolete pesticide dumping ground in Hyderabad City, Pakistan: contamination levels and their potential for air-soil exchange.

Science.gov (United States)

Alamdar, Ambreen; Syed, Jabir Hussain; Malik, Riffat Naseem; Katsoyiannis, Athanasios; Liu, Junwen; Li, Jun; Zhang, Gan; Jones, Kevin C

2014-02-01

This study was conducted to examine organochlorine pesticides (OCPs) contamination levels in the surface soil and air samples together with air-soil exchange fluxes at an obsolete pesticide dumping ground and the associated areas from Hyderabad City, Pakistan. Among all the sampling sites, concentrations of OCPs in the soil and air samples were found highest in obsolete pesticide dumping ground, whereas dominant contaminants were dichlorodiphenyltrichloroethane (DDTs) (soil: 77-212,200 ng g(-1); air: 90,700 pg m(-3)) and hexachlorocyclohexane (HCHs) (soil: 43-4,090 ng g(-1); air: 97,400 pg m(-3)) followed by chlordane, heptachlor and hexachlorobenzene (HCB). OCPs diagnostic indicative ratios reflect historical use as well as fresh input in the study area. Moreover, the air and soil fugacity ratios (0.9-1.0) at the dumping ground reflecting a tendency towards net volatilization of OCPs, while at the other sampling sites, the fugacity ratios indicate in some cases deposition and in other cases volatilization. Elevated concentrations of DDTs and HCHs at pesticide dumping ground and its surroundings pose potential exposure risk to biological organisms, to the safety of agricultural products and to the human health. Our study thus emphasizes the need of spatio-temporal monitoring of OCPs at local and regional scale to assess and remediate the future adverse implications. © 2013.

Soil management planning for military installations: Strategy for identifying contaminated soils

International Nuclear Information System (INIS)

Makdisi, R.S.; Baskin, D.A.; Downey, D.; Taffinder, S.A.

1992-01-01

Numerous federal and state regulations mandate the proper handling and disposal and/or treatment of contaminated soils. The Land Disposal Ban and the increasing lack of new or proximal land disposal facilities, coupled with the increasing liability of off-site disposal, have created a need for altering the traditional methods of managing contaminated sods. To delineate soil management decisions, a Soil Management Plan (SMP) was developed which incorporates the substantive requirements of CERCLA/SARA and RCRA into the ongoing base activities (i.e., construction projects, utility repairs and maintenance) and other environmental projects (i.e., underground storage tank removals) that may involve contaminated soils. The decision-making process is developed to guide base personnel in recognizing contamination, following proper sampling and temporary storage procedures, preventing unnecessary human exposure and isolating soils for removal off-site or treatment on-site. The SMP also contains a comprehensive review of soil remediation technologies, such as biological treatment, soil vapor extraction, soil washing, biofiltering, thermal desorption, soil stabilization/solidification, chemical/physical treatment and incineration. Contaminant types expected at the federal military facility are cross-referenced to the appropriate remediation technologies to determine the specific base needs for a soil treatment unit. An example of a conceptual design for a hydrocarbon-contaminated soil treatment unit is presented for a base where underground fuel tanks are the principal source of soil contamination

Phytoremediation of soils contaminated with toxic elements and radionuclides

International Nuclear Information System (INIS)

Cornish, J.E.; Goldberg, W.C.; Levine, R.S.; Benemann, J.R.

1995-01-01

At many US Department of Energy (US DOE) facilities and other sites, surface soils over relatively large areas are contaminated with heavy metals, radionuclides, and other toxic elements, often at only a relatively small factor above regulatory action levels. Cleanup of such sites presents major challenges, because currently available soil remediation technologies can be very expensive. In response, the US DOE's Office of Technology Development, through the Western Environmental Technology Office, is sponsoring research in the area of phytoremediation. Phytoremediation is an emerging technology that uses higher plants to transfer toxic elements and radionuclides from surface soils into aboveground biomass. Some plants, termed hyperaccumulators, take up toxic elements in substantial amounts, resulting in concentrations in aboveground biomass over 100 times those observed with conventional plants. After growth, the plant biomass is harvested, and the toxic elements are concentrated and reclaimed or disposed of. As growing, harvesting, and processing plant biomass is relatively inexpensive, phytoremediation can be a low-cost technology for remediation of extensive areas having lightly to moderately contaminated soils. This paper reviews the potential of hyper- and moderate accumulator plants in soil remediation, provides some comparative cost estimates, and outlines ongoing work initiated by the US DOE

Phytoremediation of Soils Contaminated by Chlorinnated Hydrocarbons

Science.gov (United States)

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

2001-12-01

In recent years, the possible use of deep rooted plants for phytoremediation of soil contaminants has been offered as a potential alternative for waste management, particularly for in situ remediation of large volumes of contaminated soils. Major objectives of this study are to evaluate the effectiveness of a warm season grass (Eastern Gamagrass) and a cool season prairie grass (Annual Ryegrass) in the phytoremediation of the soil contaminated with volatile organic compounds e.g., trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,1,1-trichloroethane (TCA) and to determine the main mechanisms of target contaminant dissipation. The preliminary tests and laboratory scale tests were conducted to identify the main mechanisms for phytoremediation of the target contaminants, and to apply the technique in green house application under field conditions. The results of microcosm and bioreactor experiments showed that volatilization can be the dominant pathway of the target contaminant mass losses in soils. Toxicity tests, conducted in nutrient solution in the growth room, and in the greenhouse, showed that both Eastern gamagrass and Annual ryegrass could grow without harmful effects at up to 400 ppm each of all three contaminants together. Preliminary greenhouse experimentw were conducted with the 1.5 m long and 0.3 m diameter PVC columns. Soil gas concentrations monitored and microbial biomass in bulk and rhizosphere soil, root properties, and contaminant concentration in soil after 100 days were analyzed. The results showed that the soil gas concentration of contaminants has rapidly decreased especially in the upper soil and the contaminant concentraitons in soil were also significantly decreased to 0.024, 0.228, and 0.002 of C/Co for TCE, PCE and TCA, respectively. Significant plant effects were not found however showed contaminant loss through volatilization and plant contamination by air.

Remediation of lead-contaminated soils

International Nuclear Information System (INIS)

Peters, R.W.; Shem, L.

1992-01-01

Excavation and transport of soil contaminated with heavy metals has generally been the standard remediation technique for treatment of heavy-metal-contaminated soils. This approach is not a permanent solution; moreover, off-site shipment and disposal of contaminated soil involves high expense, liability, and appropriate regulatory approval. Recently, a number of other techniques have been investigated for treating such contaminated sites, including flotation, solidification/stabilization, vitrification, and chemical extraction. This paper reports the results of a laboratory investigation determining the efficiency of using chelating agents to extract lead from contaminated soils. Lead concentrations in the soils ranged from 500 to 10,000 mg/kg. Ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) were examined for their potential extractive capabilities. Concentrations of the chelating agents ranged from 0.01 to 0.10 M. The pH of the suspensions in which the extractions were performed ranged from 4 to 12. Results showed that the removal of lead using NTA and water was ph-dependent, whereas the removal of lead using EDTA was ph-insensitive. Maximum removals of lead were 68.7%,19.1%, and 7.3% using EDTA, NTA, and water, respectively (as compared with initial lead concentrations)

Bioremediation of PAH contaminated soil samples

International Nuclear Information System (INIS)

Joshi, M.M.; Lee, S.

1994-01-01

Soils contaminated with polynuclear aromatic hydrocarbons (PAHs) pose a hazard to life. The remediation of such sites can be done using physical, chemical, and biological treatment methods or a combination of them. It is of interest to study the decontamination of soil using bioremediation. The experiments were conducted using Acinetobacter (ATCC 31012) at room temperature without pH or temperature control. In the first series of experiments, contaminated soil samples obtained from Alberta Research Council were analyzed to determine the toxic contaminant and their composition in the soil. These samples were then treated using aerobic fermentation and removal efficiency for each contaminant was determined. In the second series of experiments, a single contaminant was used to prepare a synthetic soil sample. This sample of known composition was then treated using aerobic fermentation in continuously stirred flasks. In one set of flasks, contaminant was the only carbon source and in the other set, starch was an additional carbon source. In the third series of experiments, the synthetic contaminated soil sample was treated in continuously stirred flasks in the first set and in fixed bed in the second set and the removal efficiencies were compared. The removal efficiencies obtained indicated the extent of biodegradation for various contaminants, the effect of additional carbon source, and performance in fixed bed without external aeration

An experimental study on mass loading of soil particles on plant surfaces

International Nuclear Information System (INIS)

Li, J.; Gerzabek, M.H.; Mueck, K.

1994-03-01

Radionuclide contaminated soil adhered to plant surfaces can contribute to human ingestion dose. To determine this contribution, a method of 46 Sc neutron activation analysis was established and tested, by which a detection limit of 0.05 mg soil per g dry plant biomass can be obtained. In the field and greenhouse experiment the mass loading of soil on ryegrass (Lolium perenne L.) and broad bean (Vicia faba L.) was investigated and the contribution from rainsplash and wind erosion were evaluated separately. Soil retained on plant surfaces in field conditions in Seibersdorf/Austria was 5.77 ± 1.44 mg soil per g dry plant for ryegrass and 9.51 ± 0.73 mg soil per g dry plant for broad bean. Estimates of contribution from rainsplash and wind erosion to soil contamination of plant during the experimental period are 68 % and 32 % for broadbean, 47 % and 53 % for ryegrass, respectively. Mass loading results from field studies indicate that soil adhesion on plant surfaces can contribute up to 23 % of plant 137 Cs contamination, the transfer factors modified by mass loading decline differently, depending on 137 Cs concentration of the soil and the soil mass adhered to plant surfaces. (authors)

Is soil dressing a way once and for all in remediation of arsenic contaminated soils? A case study of arsenic re-accumulation in soils remediated by soil dressing in Hunan Province, China.

Science.gov (United States)

Su, Shiming; Bai, Lingyu; Wei, Caibing; Gao, Xiang; Zhang, Tuo; Wang, Yanan; Li, Lianfang; Wang, Jinjin; Wu, Cuixia; Zeng, Xibai

2015-07-01

The investigation of arsenic (As) re-accumulation in an area previously remediated by soil dressing will help in sustainable controlling the risks of As to local ecosystems and should influence management decisions about remediation strategies. In this study, As content in an area remediated by soil dressing and the possible As accumulation risk in agricultural products were investigated. The results indicated that after 7 years of agricultural activities, the average As content (24.6 mg kg(-1)) in surface soil of the investigated area increased by 83.6% compared with that (13.4 mg kg(-1)) in clean soil. Of the surface soil samples (n = 88), 21.6% had As levels that exceeded the limits of the Environmental Quality Standard for Soils of China (GB 15618-1995) and 98.9% of the surface soil samples with As contents exceeding that in clean soil was observed. Soil dressing might be not a remediation method once and for all in some contaminated areas, even though no significant difference in available As content was found between clean (0.18 mg kg(-1)) and surface (0.22 mg kg(-1)) soils. The foreign As in surface soil of the investigated area mainly specifically sorbed with soil colloid or associated with hydrous oxides of Fe and Al, or existed in residual fraction. The upward movement of contaminated soil from the deeper layers and the atmospheric deposition of slag particles might be responsible for the re-accumulation of As in the investigated area. Decreases in soil pH in the investigated soils and the fact that no plant samples had As levels exceeding the limits of the National Food Safety Standards for Contaminants of China (GB 2762-2012) were also observed.

Uranium-contaminated soil pilot treatment study

International Nuclear Information System (INIS)

Turney, W.R.J.R.; Mason, C.F.V.; Michelotti, R.A.

1996-01-01

A pilot treatment study is proving to be effective for the remediation of uranium-contaminated soil from a site at the Los Alamos National Laboratory by use of a two-step, zero-discharge, 100% recycle system. Candidate uranium-contaminated soils were characterized for uranium content, uranium speciation, organic content, size fractionization, and pH. Geochemical computer codes were used to forecast possible uranium leach scenarios. Uranium contamination was not homogenous throughout the soil. In the first step, following excavation, the soil was sorted by use of the ThemoNuclean Services segmented gate system. Following the sorting, uranium-contaminated soil was remediated in a containerized vat leach process by use of sodium-bicarbonate leach solution. Leach solution containing uranium-carbonate complexes is to be treated by use of ion-exchange media and then recycled. Following the treatment process the ion exchange media will be disposed of in an approved low-level radioactive landfill. It is anticipated that treated soils will meet Department of Energy site closure guidelines, and will be given open-quotes no further actionclose quotes status. Treated soils are to be returned to the excavation site. A volume reduction of contaminated soils will successfully be achieved by the treatment process. Cost of the treatment (per cubic meter) is comparable or less than other current popular methods of uranium-contamination remediation

Wind effected redistribution of surface contamination. Progress report, September 1974--August 1975

International Nuclear Information System (INIS)

Amato, A.J.

1975-01-01

Theoretical resuspension ratios were computed through the extension of a one-dimensional model used to simulate the wind effected movement of surface contaminants. The surface movement of contamination associated with inhalable size particles was considered in relation to time, space, wind velocity, distance from the source, soil resuspension ratios, and other variables. A computer program was developed to calculate the wind effected distribution of surface contaminants. (U.S.)

Sorption ability of the soil and its impact on environmental contamination

OpenAIRE

H?ibov?, ??rka; Gargo?ov?, Helena Zl?malov?; V?vrov?, Milada

2015-01-01

From the physical point of view, soil is a heterogenic polydisperse system. It often becomes a place of a secondary contamination during extinguishing uncontrolled areal fires in nature. Foam extinguishing agents (FEAs), used at these events, basically contain surface active substances and perfluorinated compounds. These tend to be captured in the soil matrix due to their specific properties. Contaminants could be partly flushed out with rainwater, which causes several times dilution of conta...

Phytoextraction of low level U-contaminated soil

International Nuclear Information System (INIS)

Vandenhove, H.A.; Hees, M. van

2002-01-01

The nuclear fuel cycle may be a source of environmental contamination. Uranium exploitation produces large quantities of wastes but also accidental spills at nuclear fuel production, reprocessing or waste treatment plants have led to soil contamination with uranium. U-contaminated soil is generally excavated, packaged and removed which is a costly enterprise. Soil washing has also shown promising in removing U from contaminated soil, but results in the generation of liquid wastes and the deterioration of soil properties. In contrast, phytoextraction, the use of plants to remove contaminants from polluted soil, allows for in situ treatment and does not generate liquid wastes. Furthermore, the contaminated site is covered by plants during phytoextraction and wind and water erosion will be reduced. The phytoextraction potential depends on the amount of radionuclides extracted and the biomass produced. Hyper-accumulating plants often have a low biomass production. Moreover, uranium soil-to-plant transfer factors (TF: ratio of U concentration in dry plant tissue to concentration in soil) rarely exceed a value of 0.1 gg -1 . With a TF of 0.1 gg -1 and a biomass yield of 15t dry weigh ha -1 only 0.1% of the soil uranium will be annually immobilised in the plant biomass. These figures clearly show that the phytoextraction option is not a feasible remediation option, unless the uranium bioavailability could be drastically increased. It was shown that citric acid addition to highly contaminated U contaminated soil increased the U-accumulation of Brassica juncea 1000-fold. The objective of the present paper is to find out if low level U contaminated soil can be phytoextracted in order to achieve proposed release limits

Desorption and bioremediation of hydrocarbon contaminated soils

International Nuclear Information System (INIS)

Gray, M.R.

1998-01-01

A study was conducted in which the extent and pattern of contaminant biodegradation during bioremediation of four industrially-contaminated soils were examined to determine which factors control the ultimate extent of biodegradation and which limit the success of biological treatment. It was noted that although bioremediation is inexpensive and has low environmental impact, it often fails to completely remove the hydrocarbons in soils because of the complex interactions between contaminants, the soil environment, and the active microorganisms. In this study, the competency of the microorganisms in the soil to degrade the contaminants was examined. The equilibrium partitioning of the contaminants between the soil and the aqueous phase was also examined along with the transport of contaminants out of soil particles. The role of diffusion of compounds in the soil and the importance of direct contact between microorganisms and the hydrocarbons was determined. Methods for selecting suitable sites for biological treatment were also described

Soil washing and post-wash biological treatment of petroleum hydrocarbon contaminated soils

OpenAIRE

Bhandari, Alok

1992-01-01

A laboratory scale study was conducted to investigate the treatability of petroleum contaminated soils by soil washing and subsequent biological treatment of the different soil fractions. In addition to soils obtained from contaminated sites, studies were also performed on soils contaminated in the laboratory. Soil washing was performed using a bench-scale soil washing system. Washing was carried out with simultaneous fractionation of the bulk soil into sand, silt and clay fractions. Cl...

Measurement of residual radioactive surface contamination by 2-D laser heated TLD

International Nuclear Information System (INIS)

Jones, S.C.

1997-06-01

The feasibility of applying and adapting a two-dimensional laser heated thermoluminescence dosimetry system to the problem of surveying for radioactive surface contamination was studied. The system consists of a CO 2 laser-based reader and monolithic arrays of thin dosimeter elements. The arrays consist of 10,201 thermoluminescent phosphor elements of 40 micron thickness, covering a 900 cm 2 area. Array substrates are 125 micron thick polyimide sheets, enabling them to easily conform to regular surface shapes, especially for survey of surfaces that are inaccessible for standard survey instruments. The passive, integrating radiation detectors are sensitive to alpha and beta radiation at contamination levels below release guideline limits. Required contact times with potentially contaminated surfaces are under one hour to achieve detection of transuranic alpha emission at 100 dpm/100 cm 2 . Positional information obtained from array evaluation is useful for locating contamination zones. Unique capabilities of this system for survey of sites, facilities and material include measurement inside pipes and other geometrical configurations that prevent standard surveys, and below-surface measurement of alpha and beta emitters in contaminated soils. These applications imply a reduction of material that must be classified as radioactive waste by virtue of its possibility of contamination, and cost savings in soil sampling at contaminated sites

Lead immobilization and phosphorus availability in phosphate-amended, mine-contaminated soils.

Science.gov (United States)

Osborne, Lydia R; Baker, Leslie L; Strawn, Daniel G

2015-01-01

Over a century of mining activities in the Coeur d'Alene mining district in Idaho have contaminated soils of the downstream basin with lead, arsenic, zinc, and cadmium. Elevated soil-Pb levels are a significant hazard to the health of humans and wildlife in the region. One in situ treatment approach for remediating Pb-contaminated soils is application of phosphorus to promote the formation of lead phosphate minerals that have low solubility. However, this remediation strategy may result in excess P runoff to surface waters, which can lead to eutrophication, particularly when used in riparian areas. Research presented in this paper describes experiments in which monopotassium phosphate (KHPO) solution was applied to two Pb-contaminated soils from the Coeur d'Alene River valley to determine how P loading rates affect both Pb immobilization and P mobility and to determine if an optimal P amendment rate can be predicted. Toxicity characteristic leaching procedure extractions were used to assess changes in Pb availability for uptake by an organism or mobilization through the soil, and Bray extractions were used to assess P availability for leaching out of the soil system. For the two soils tested, increasing phosphate amendment caused decreasing Pb extractability. Phosphorus amendment rates above approximately 70 mg kg, however, did not provide any additional Pb immobilization. Phosphorus availability increased with increasing phosphate application rate. An empirical relationship is presented that predicts extractable Pb as a function of extractable P. This relationship allows for prediction of the amount of Pb that can be immobilized at specified P leaching amounts, such as regulatory levels that have been established to minimize risks for surface water degradation. Results suggest that phosphate can be used to immobilize Pb in contaminated wetland or riparian areas without posing risks of P loading to surface waters. Copyright © by the American Society of Agronomy

Dechlorination of Hexachlorobenzene in Contaminated Soils Using a Nanometallic Al/CaO Dispersion Mixture: Optimization through Response Surface Methodology

Science.gov (United States)

Jiang, Yuhui; Shang, Yixuan; Yu, Shuyao; Liu, Jianguo

2018-01-01

Hexachlorobenzene (HCB) contamination of soils remains a significant environmental challenge all over the world. Reductive stabilization is a developing technology that can decompose the HCB with a dechlorination process. A nanometallic Al/CaO (n-Al/CaO) dispersion mixture was developed utilizing ball-milling technology in this study. The dechlorination efficiency of HCB in contaminated soils by the n-Al/CaO grinding treatment was evaluated. Response surface methodology (RSM) was employed to investigate the effects of three variables (soil moisture content, n-Al/CaO dosage and grinding time) and the interactions between these variables under the Box-Behnken Design (BBD). A high regression coefficient value (R2 = 0.9807) and low p value (soil moisture content, n-Al/CaO dosage, and grinding time were found to be 7% (m/m), 17.7% (m/m), and 24 h, respectively, in the experimental ranges and levels. Under optimal conditions, the dechlorination efficiency was 80%. The intermediate product analysis indicated that dechlorination was the process by stepwise loss of chloride atoms. The main pathway observed within 24 h was HCB → pentachlorobenzene (PeCB) → 1,2,3,4-tetrachlorobenzene (TeCB) and 1,2,4,5-TeCB. The results indicated that the moderate soil moisture content was crucial for the hydrodechlorination of HCB. A probable mechanism was proposed wherein water acted like a hydrogen donor and promoted the hydrodechlorination process. The potential application of n-Al/CaO is an environmentally-friendly and cost-effective option for decontamination of HCB-contaminated soils. PMID:29702570

Chemical fingerprinting of hydrocarbon-contamination in soil

DEFF Research Database (Denmark)

Boll, Esther Sørensen; Nejrup, Jens; Jensen, Julie K.

2015-01-01

Chemical fingerprinting analyses of 29 hydrocarbon-contaminated soils were performed to assess the soil quality and determine the main contaminant sources. The results were compared to an assessment based on concentrations of the 16 priority polycyclic aromatic hydrocarbons pointed out by the U...... and in assessing weathering trends of hydrocarbon contamination in the soils. Multivariate data analysis of sum-normalized concentrations could as a stand-alone tool distinguish between hydrocarbon sources of petrogenic and pyrogenic origin, differentiate within petrogenic sources, and detect weathering trends....... Diagnostic ratios of PACs were not successful for source identification of the heavily weathered hydrocarbon sources in the soils. The fingerprinting of contaminated soils revealed an underestimation of PACs in petrogenic contaminated soils when the assessment was based solely on EPAPAH16. As alkyl...

Bioremediation of petroleum contaminated soil

International Nuclear Information System (INIS)

Autry, A.R.; Ellis, G.M.

1992-01-01

This paper reports on bioremediation, which offers a cost-competitive, effective remediation alternative for soil contaminated with petroleum products. These technologies involve using microorganisms to biologically degrade organic constituents in contaminated soil. All bioremediation applications must mitigate various environmental rate limiting factors so that the biodegradation rates for petroleum hydrocarbons are optimized in field-relevant situations. Traditional bioremediation applications include landfarming, bioreactors, and composting. A more recent bioremediation application that has proven successful involves excavation of contaminated soil. The process involves the placement of the soils into a powerscreen, where it is screened to remove rocks and larger debris. The screened soil is then conveyed to a ribbon blender, where it is mixed in batch with nutrient solution containing nitrogen, phosphorus, water, and surfactants. Each mixed soil batch is then placed in a curing pile, where it remains undisturbed for the remainder of the treatment process, during which time biodegradation by naturally occurring microorganisms, utilizing biochemical pathways mediated by enzymes, will occur

CONTAMINATED SOIL VOLUME ESTIMATE TRACKING METHODOLOGY

International Nuclear Information System (INIS)

Durham, L.A.; Johnson, R.L.; Rieman, C.; Kenna, T.; Pilon, R.

2003-01-01

The U.S. Army Corps of Engineers (USACE) is conducting a cleanup of radiologically contaminated properties under the Formerly Utilized Sites Remedial Action Program (FUSRAP). The largest cost element for most of the FUSRAP sites is the transportation and disposal of contaminated soil. Project managers and engineers need an estimate of the volume of contaminated soil to determine project costs and schedule. Once excavation activities begin and additional remedial action data are collected, the actual quantity of contaminated soil often deviates from the original estimate, resulting in cost and schedule impacts to the project. The project costs and schedule need to be frequently updated by tracking the actual quantities of excavated soil and contaminated soil remaining during the life of a remedial action project. A soil volume estimate tracking methodology was developed to provide a mechanism for project managers and engineers to create better project controls of costs and schedule. For the FUSRAP Linde site, an estimate of the initial volume of in situ soil above the specified cleanup guidelines was calculated on the basis of discrete soil sample data and other relevant data using indicator geostatistical techniques combined with Bayesian analysis. During the remedial action, updated volume estimates of remaining in situ soils requiring excavation were calculated on a periodic basis. In addition to taking into account the volume of soil that had been excavated, the updated volume estimates incorporated both new gamma walkover surveys and discrete sample data collected as part of the remedial action. A civil survey company provided periodic estimates of actual in situ excavated soil volumes. By using the results from the civil survey of actual in situ volumes excavated and the updated estimate of the remaining volume of contaminated soil requiring excavation, the USACE Buffalo District was able to forecast and update project costs and schedule. The soil volume

Bench Scale Treatability Studies of Contaminated Soil Using Soil Washing Technique

OpenAIRE

Gupta, M. K.; Srivastava, R. K.; Singh, A. K.

2010-01-01

Soil contamination is one of the most widespread and serious environmental problems confronting both the industrialized as well as developing nations like India. Different contaminants have different physicochemical properties, which influence the geochemical reactions induced in the soils and may bring about changes in their engineering and environmental behaviour. Several technologies exist for the remediation of contaminated soil and water. In the present study soil washing technique using...

Natural attenuation of diesel aliphatic hydrocarbons in contaminated agricultural soil

International Nuclear Information System (INIS)

Serrano, Antonio; Gallego, Mercedes; Gonzalez, Jose Luis; Tejada, Manuel

2008-01-01

A diesel fuel spill at a concentration of 1 L m -2 soil was simulated on a 12 m 2 plot of agricultural land, and natural attenuation of aliphatic hydrocarbons was monitored over a period of 400 days following the spill after which the aliphatic hydrocarbon concentrations were found to be below the legal contamination threshold for soil. The main fraction of these compounds (95%) remained at the surface layer (0-10 cm). Shortly after the spill (viz. between days 0 and 18), evaporation was the main origin of the dramatic decrease in pollutant concentrations in the soil. Thereafter, soil microorganisms used aliphatic hydrocarbons as sources of carbon and energy, as confirmed by the degradation ratios found. Soil quality indicators, soil microbial biomass and dehydrogenase activity, regained their original levels about 200 days after the spill. - The effect of aliphatic hydrocarbons contamination on soil quality was monitored over a period of 400 days after a Diesel fuel spill

Geophysical Monitoring of Hydrocarbon-Contaminated Soils Remediated with a Bioelectrochemical System.

Science.gov (United States)

Mao, Deqiang; Lu, Lu; Revil, André; Zuo, Yi; Hinton, John; Ren, Zhiyong Jason

2016-08-02

Efficient noninvasive techniques are desired for monitoring the remediation process of contaminated soils. We applied the direct current resistivity technique to image conductivity changes in sandbox experiments where two sandy and clayey soils were initially contaminated with diesel hydrocarbon. The experiments were conducted over a 230 day period. The removal of hydrocarbon was enhanced by a bioelectrochemical system (BES) and the electrical potentials of the BES reactors were also monitored during the course of the experiment. We found that the variation in electrical conductivity shown in the tomograms correlate well with diesel removal from the sandy soil, but this is not the case with the clayey soil. The clayey soil is characterized by a larger specific surface area and therefore a larger surface conductivity. In sandy soil, the removal of the diesel and products from degradation leads to an increase in electrical conductivity during the first 69 days. This is expected since diesel is electrically insulating. For both soils, the activity of BES reactors is moderately imaged by the inverted conductivity tomogram of the reactor. An increase in current production by electrochemically active bacteria activity corresponds to an increase in conductivity of the reactor.

The organic contamination level based on the total soil mass is not a proper index of the soil contamination intensity

Science.gov (United States)

Hung, H.-W.; Daniel, Sheng G.; Lin, T.-F.; Su, Y.; Chiou, C.T.

2009-01-01

Concentrations of organic contaminants in common productive soils based on the total soil mass give a misleading account of actual contamination effects. This is attributed to the fact that productive soils are essentially water-saturated, with the result that the soil uptake of organic compounds occurs principally by partition into the soil organic matter (SOM). This report illustrates that the soil contamination intensity of a compound is governed by the concentration in the SOM (Com) rather than by the concentration in whole soil (Cs). Supporting data consist of the measured levels and toxicities of many pesticides in soils of widely differing SOM contents and the related levels in in-situ crops that defy explanation by the Cs values. This SOM-based index is timely needed for evaluating the contamination effects of food crops grown in different soils and for establishing a dependable priority ranking for intended remediation of numerous contamination sites.

Measurement of radioactive soil contamination from the air

International Nuclear Information System (INIS)

Loman, A.C.; Kuile, C.R. ter; Slaper, H.

1990-09-01

In-situ gamma spectrometry can be used to determine the qualitative and quantitative deposition of radioactive materials on the ground surface. By applying the in-situ spectrometry method using either a helicopter or an airplane, large areas can be scanned in a short period of time. In this report the results of in-situ gamma spectroscopic measurements taken from a helicopter are described. Measurements were carried out using a single point source, a field of 36 point sources, and using the present ground contamination due to fall-out from the Chernobyl accident and atom bombs. The results of these measurements were used to determine calibration factors, which were in agreement with a calibration obtained using more simple (and less expensive) laboratory measurements in combination with flux calculations. Detection limits for the measurement of surface contamination were determined. At a height of 50 meters above the surface and using a measurement time of 2 minutes, the minimally detectable surface contamination was 1.1 kBqm -2 for a Cs-137 contamination and 2.1 kBqm -2 for I-131 contamination. Fall-out determinations based on measurements taken at a height of 50 meters were in agreement with determinations taken at a height of 1 meter, and with the results obtained measuring soil samples. The in-situ gamma spectroscopy, using helicopter or airplane, is a fast and powerful method for mapping surface contamination. (author). 13 refs.; 18 figs.; 13 tabs

Pilot-scale feasibility of petroleum hydrocarbon-contaminated soil in situ bioremediation

International Nuclear Information System (INIS)

Walker, J.F. Jr.; Walker, A.B.

1995-01-01

An environmental project was conducted to evaluate in situ bioremediation of petroleum hydrocarbon-contaminated soils on Kwajalein Island, a US Army Kwajalein Atoll base in the Republic of the Marshall Islands. Results of laboratory column studies determined that nutrient loadings stimulated biodegradation rates and that bioremediation of hydrocarbon-contaminated soils at Kwajalein was possible using indigenous microbes. The column studies were followed by an ∼10-month on-site demonstration at Kwajalein to further evaluate in situ bioremediation and to determine design and operating conditions necessary to optimize the process. The demonstration site contained low levels of total petroleum hydrocarbons (diesel fuel) in the soil near the ground surface, with concentrations increasing to ∼10,000 mg/kg in the soil near the groundwater. The demonstration utilized 12 in situ plots to evaluate the effects of various combinations of water, air, and nutrient additions on both the microbial population and the hydrocarbon concentration within the treatment plots as a function of depth from the ground surface

Surfactant flooding of diesel-contaminated soils

International Nuclear Information System (INIS)

Peters, R.W.; Montemagno, C.D.; Shem, L.; Lewis, B.A.

1991-01-01

At one installation, approximately 60,000 gallons of No. 2 diesel fuel leaked into the subsurface environment, with contamination at depths of 6 to 34 m below the surface. Argonne National Laboratory was contracted to perform treatability studies for site remediation. The treatability studies focused on four separate phases: (1) leachability studies on the various contaminated soil borings, (2) air stripping studies, (3) bioremediation studies, and (4) surfactant screening/surfactant flooding studies. This paper summarizes the fourth phase of this research program after initial surfactant screening of 21 surfactants. Three of the surfactants were used for the surfactant flooding studies; the results from that phase of the research program are described

Application of carbon nanotubes to immobilize heavy metals in contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Matos, Martim P. S. R.; Correia, António Alberto S., E-mail: aalberto@dec.uc.pt [University of Coimbra, Department of Civil Engineering, CIEPQPF—Chemical Process Engineering and Forest Products Research Centre (Portugal); Rasteiro, Maria G. [University of Coimbra, Department of Chemical Engineering, CIEPQPF (Portugal)

2017-04-15

The contamination of soils with heavy metals is a growing concern in modern societies. To avoid the spread of contamination, soil stabilization techniques can be applied mixing materials with the soil in order to partially immobilize heavy metals. Carbon nanotubes (CNTs) are nanomaterials known for its exceptional properties, like high surface area and adsorption capacity. Due to these unique properties, the potential use of CNTs in heavy metal contaminated water has been studied, with very satisfactory results; however, their application in contaminated soils is practically unexplored. This experimental work is focused on studying the potential of using CNTs in soil remediation, especially to immobilize the heavy metals ions: lead (Pb{sup 2+}), copper (Cu{sup 2+}), nickel (Ni{sup 2+}), and zinc (Zn{sup 2+}), commonly present in contaminated soils. In order to avoid CNT agglomeration, which originates the loss of their beneficial properties, an aqueous suspension of CNTs was prepared using a non-ionic surfactant combined with ultrasonic energy to promote CNTs dispersion. Then, the soil, with and without the addition of CNTs, was subjected to adsorption tests to evaluate the CNT capacity to improve heavy metal immobilization. To validate the adsorption test results, permeability tests were executed, simulating the conditions of a real-case scenario. The results obtained led to the conclusion that the addition of a small amount of dispersed CNTs can successfully increase the adsorption capacity of the soil and consequently improve the immobilization of heavy metals in the soil matrix. The immobilization percentage varies with the different heavy metals under study.

Application of carbon nanotubes to immobilize heavy metals in contaminated soils

International Nuclear Information System (INIS)

Matos, Martim P. S. R.; Correia, António Alberto S.; Rasteiro, Maria G.

2017-01-01

The contamination of soils with heavy metals is a growing concern in modern societies. To avoid the spread of contamination, soil stabilization techniques can be applied mixing materials with the soil in order to partially immobilize heavy metals. Carbon nanotubes (CNTs) are nanomaterials known for its exceptional properties, like high surface area and adsorption capacity. Due to these unique properties, the potential use of CNTs in heavy metal contaminated water has been studied, with very satisfactory results; however, their application in contaminated soils is practically unexplored. This experimental work is focused on studying the potential of using CNTs in soil remediation, especially to immobilize the heavy metals ions: lead (Pb"2"+), copper (Cu"2"+), nickel (Ni"2"+), and zinc (Zn"2"+), commonly present in contaminated soils. In order to avoid CNT agglomeration, which originates the loss of their beneficial properties, an aqueous suspension of CNTs was prepared using a non-ionic surfactant combined with ultrasonic energy to promote CNTs dispersion. Then, the soil, with and without the addition of CNTs, was subjected to adsorption tests to evaluate the CNT capacity to improve heavy metal immobilization. To validate the adsorption test results, permeability tests were executed, simulating the conditions of a real-case scenario. The results obtained led to the conclusion that the addition of a small amount of dispersed CNTs can successfully increase the adsorption capacity of the soil and consequently improve the immobilization of heavy metals in the soil matrix. The immobilization percentage varies with the different heavy metals under study.

Application of carbon nanotubes to immobilize heavy metals in contaminated soils

Science.gov (United States)

Matos, Martim P. S. R.; Correia, António Alberto S.; Rasteiro, Maria G.

2017-04-01

The contamination of soils with heavy metals is a growing concern in modern societies. To avoid the spread of contamination, soil stabilization techniques can be applied mixing materials with the soil in order to partially immobilize heavy metals. Carbon nanotubes (CNTs) are nanomaterials known for its exceptional properties, like high surface area and adsorption capacity. Due to these unique properties, the potential use of CNTs in heavy metal contaminated water has been studied, with very satisfactory results; however, their application in contaminated soils is practically unexplored. This experimental work is focused on studying the potential of using CNTs in soil remediation, especially to immobilize the heavy metals ions: lead (Pb2+), copper (Cu2+), nickel (Ni2+), and zinc (Zn2+), commonly present in contaminated soils. In order to avoid CNT agglomeration, which originates the loss of their beneficial properties, an aqueous suspension of CNTs was prepared using a non-ionic surfactant combined with ultrasonic energy to promote CNTs dispersion. Then, the soil, with and without the addition of CNTs, was subjected to adsorption tests to evaluate the CNT capacity to improve heavy metal immobilization. To validate the adsorption test results, permeability tests were executed, simulating the conditions of a real-case scenario. The results obtained led to the conclusion that the addition of a small amount of dispersed CNTs can successfully increase the adsorption capacity of the soil and consequently improve the immobilization of heavy metals in the soil matrix. The immobilization percentage varies with the different heavy metals under study.

Volatilisation of aromatic hydrocarbons from soil: part II, fluxes from coal tar contaminated soils residing below the soil surface

International Nuclear Information System (INIS)

Lindhardt, B.; Christensen, T.H.

1996-01-01

The non-steady-state fluxes of aromatic hydrocarbons from coal tar contaminated soil, placed below a 5 cm deep layer of uncontaminated soil, were measured in the laboratory over a period of 53 days. The contaminated soil originated from a former gasworks site and contained concentrations of 11 selected aromatic hydrocarbons between 50 to 840 μg/cm 3 . Where the microbial activity was inhibited, the fluxes stabilized on a semi-steady-state level for the monocyclic aromatic hydrocarbons, naphthalene and 1-methylnaphthalene after a period of 10-20 days. Fluxes of acenaphthene and fluorene were only measurable in an experiment that utilized a cover soil with a low organic content. The fluxes were predicted by a numerical model assuming that the compounds acted independently of each other and that local equilibrium between the air, water, and sorbed phases existed. The model overestimated the fluxes for all the detected aromatic hydrocarbons by a factor of 1.3 to 12. When the cover soil was adapted to degrade naphthalene, the fluxes of naphthalene and 1-methylnaphthalene approached the detection limit after 5 to 8 days. Thereafter the fluxes of these two compounds were less than predicted by the model employing half-life values of 0.5 and 1 day for naphthalene and 1-methylnaphthalene respectively. 10 refs., 6 figs., 7 tabs

Frozen Soil Barrier. Subsurface Contaminants Focus Area. OST Reference No. 51

International Nuclear Information System (INIS)

1999-01-01

Problem: Hazardous and radioactive materials have historically been disposed of at the surface during operations at Department of Energy facilities. These contaminants have entered the subsurface, contaminating soils and groundwater resources. Remediation of these groundwater plumes using the baseline technology of pump and treat is expensive and takes a long time to complete. Containment of these groundwater plumes can be alternative or an addition to the remediation activities. Standard containment technologies include slurry walls, sheet piling, and grouting. These are permanent structures that once installed are difficult to remove. How It Works: Frozen Soil Barrier technology provides a containment alternative, with the key difference being that the barrier can be easily removed after a period of time, such as after the remediation or removal of the source is completed. Frozen Soil Barrier technology can be used to isolate and control the migration of underground radioactive or other hazardous contaminants subject to transport by groundwater flow. Frozen Soil Barrier technology consists of a series of subsurface heat transfer devices, known as thermoprobes, which are installed around a contaminant source and function to freeze the soil pore water. The barrier can easily be maintained in place until remediation or removal of the contaminants is complete, at which time the barrier is allowed to thaw.

A fully continuous supercritical fluid extraction system for contaminated soil

International Nuclear Information System (INIS)

Ryan, M.; Stiver, W.H.

2007-01-01

Brownfield sites are contaminated sites in an urban setting. There are hundreds of thousands of such sites, where contaminants migrate to the atmosphere, seep into groundwater, runoff into surface water and enter the food chain through plant uptake and soil ingestion. The Sydney Tar Ponds alone contain more than a million tonnes of contaminated soils and sediments. Soil vapour extraction, incineration, bioremediation, solvent extraction and land filling are among the remediation techniques that have been developed for brownfield sites over the years. However, no single technology is ideally suited to all cases because of the diversity of contaminants and diversity of site characterization. This paper focused on supercritical fluid extraction (SFE) which is well suited to sites contaminated with polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metal. A fully continuous laboratory-scale SFE process for a slurry-based system was designed and constructed to handle the supercritical carbon dioxide (SC-CO 2 ) and the soil slurry. The system continuously pumps carbon dioxide under supercritical conditions and soil slurry into a counter-current contacting column. The testing soil was Delhi loamy sand, spiked with 10 mg/g of naphthalene. The soil slurry ranged from 0.0028 g dry soil per g slurry to 0.072 g/g. The operating temperature was 43 degrees C and the operating pressure was 7.7 MPa. Near steady state, fully continuous flow was achieved with runs lasting up to 2 hours. The quantifiable recoveries of naphthalene from the soil slurry was demonstrated and the mass transfer coefficients for the system were quantified in order to provide the foundation to advance to a full-scale system and costing analysis. 14 refs., 1 tab., 3 figs

A fully continuous supercritical fluid extraction system for contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Ryan, M.; Stiver, W.H. [Guelph Univ., ON (Canada). School of Engineering

2007-04-15

Brownfield sites are contaminated sites in an urban setting. There are hundreds of thousands of such sites, where contaminants migrate to the atmosphere, seep into groundwater, runoff into surface water and enter the food chain through plant uptake and soil ingestion. The Sydney Tar Ponds alone contain more than a million tonnes of contaminated soils and sediments. Soil vapour extraction, incineration, bioremediation, solvent extraction and land filling are among the remediation techniques that have been developed for brownfield sites over the years. However, no single technology is ideally suited to all cases because of the diversity of contaminants and diversity of site characterization. This paper focused on supercritical fluid extraction (SFE) which is well suited to sites contaminated with polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metal. A fully continuous laboratory-scale SFE process for a slurry-based system was designed and constructed to handle the supercritical carbon dioxide (SC-CO{sub 2}) and the soil slurry. The system continuously pumps carbon dioxide under supercritical conditions and soil slurry into a counter-current contacting column. The testing soil was Delhi loamy sand, spiked with 10 mg/g of naphthalene. The soil slurry ranged from 0.0028 g dry soil per g slurry to 0.072 g/g. The operating temperature was 43 degrees C and the operating pressure was 7.7 MPa. Near steady state, fully continuous flow was achieved with runs lasting up to 2 hours. The quantifiable recoveries of naphthalene from the soil slurry was demonstrated and the mass transfer coefficients for the system were quantified in order to provide the foundation to advance to a full-scale system and costing analysis. 14 refs., 1 tab., 3 figs.

Dechlorination of Hexachlorobenzene in Contaminated Soils Using a Nanometallic Al/CaO Dispersion Mixture: Optimization through Response Surface Methodology

Directory of Open Access Journals (Sweden)

Yuhui Jiang

2018-04-01

Full Text Available Hexachlorobenzene (HCB contamination of soils remains a significant environmental challenge all over the world. Reductive stabilization is a developing technology that can decompose the HCB with a dechlorination process. A nanometallic Al/CaO (n-Al/CaO dispersion mixture was developed utilizing ball-milling technology in this study. The dechlorination efficiency of HCB in contaminated soils by the n-Al/CaO grinding treatment was evaluated. Response surface methodology (RSM was employed to investigate the effects of three variables (soil moisture content, n-Al/CaO dosage and grinding time and the interactions between these variables under the Box-Behnken Design (BBD. A high regression coefficient value (R2 = 0.9807 and low p value (<0.0001 of the quadratic model indicated that the model was accurate in predicting the experimental results. The optimal soil moisture content, n-Al/CaO dosage, and grinding time were found to be 7% (m/m, 17.7% (m/m, and 24 h, respectively, in the experimental ranges and levels. Under optimal conditions, the dechlorination efficiency was 80%. The intermediate product analysis indicated that dechlorination was the process by stepwise loss of chloride atoms. The main pathway observed within 24 h was HCB → pentachlorobenzene (PeCB → 1,2,3,4-tetrachlorobenzene (TeCB and 1,2,4,5-TeCB. The results indicated that the moderate soil moisture content was crucial for the hydrodechlorination of HCB. A probable mechanism was proposed wherein water acted like a hydrogen donor and promoted the hydrodechlorination process. The potential application of n-Al/CaO is an environmentally-friendly and cost-effective option for decontamination of HCB-contaminated soils.

Process for in-situ biodegradation of hydrocarbon contaminated soil

International Nuclear Information System (INIS)

Ely, D.L.; Heffner, D.A.

1991-01-01

This patent describes an in situ process for biodegrading hydrocarbons by drawing oxygen into an undisturbed hydrocarbon contaminated zone in a fluid permeable soil. It comprises: establishing a borehole extending from the earth's surface through a hydrocarbon contaminated zone having hydrocarbon degrading microbes therein; lining the borehole with a fluid impermeable liner coaxially spaced and sealingly connected to the inside surface of the borehole and extending from the earth's surface to the hydrocarbon-contaminated zone; the liner including a fluid permeable portion extending from the lower end thereof and through at least a portion of the hydrocarbon contaminated zone, fluidly connecting a source of negative pressure to the fluid impermeable line; evacuating gas from the borehole through the fluid permeable portion of the liner at a rate sufficient to draw air from the earth's surface into the hydrocarbon containing zone; and adjusting the flow rate of the evacuated gas so that the amount of hydrocarbon biodegradation therein is within 50% of the maximum hydrocarbon biodegradation rate as detected by the volume of carbon dioxide in the evacuated gas

Contamination of roadside soil and vegetation with lead, zinc and cadmium

Energy Technology Data Exchange (ETDEWEB)

Shimada, N; Sumiyoshi, M; Toyoda, S; Sato, Y; Kojima, M

1973-01-01

In order to survey the contamination of roadside soil and vegetation with heavy metals, distributions of Pb, Zn and Cd were examined in roadside soil and grass samples from some locations adjacent to heavily traveled route No. 6. Sampling sites were selected at comparatively level areas at both Matsudo and Kashiwa, Chiba prefecture. Concentrations of Pb and Zn in roadside soil decreased with distance from traffic. The same tendency was also observed in the case of Cd. Pb, Zn and Cd contents in grass samples increased remarkably at the adjacent site of traffic. These findings suggest that the contamination of roadside soil and vegetation with Pb, Zn and Cd must be caused by traffic. Pb, Zn and Cd contents in surface soil varied with climatological and seasonal conditions. Contents of Pb, Zn and Cd in grasses grown at the identical site of roadside varied with plant species and with sampling seasons. Concentrations of heavy metals in Solidago altissima L. increased with the lapse of time. Contents of Pb, Zn and Cd in roadside subsoil were less than those in surface soil. In both soils, a significant correlation was observed between concentrations of heavy metals in soils and the distance from traffic.

Treatment of chromium contaminated soil using bioremediation

Science.gov (United States)

Purwanti, Ipung Fitri; Putri, Tesya Paramita; Kurniawan, Setyo Budi

2017-11-01

Chromium contamination in soil occurs due to the disposal of chromium industrial wastewater or sludge that excess the quality standard. Chromium concentration in soil is ranged between 1 to 300 mg/kg while the maximum health standard is 2.5 mg/kg. Bioremediation is one of technology that could be used for remediating heavy metal contamination in soil. Bacteria have an ability to remove heavy metal from soil. One bacteria species that capable to remove chromium from soil is Bacillus subtilis. The aim of this research was to know the chromium removal percentage in contaminated soil by Bacillus subtilis. Artificial chromium contaminated soil was used by mixing 425gram sand and chromium trichloride solution. Concentration of chromium added into the spiked soil were 50, 75, and 100 mg/L. During 14 days, pH, soil temperature and soil moisture were tested. Initial and final number of bacterial colony and chromium concentration analysed. The result showed that the highest percentage of chromium removal was 11% at a chromium concentration of 75 mg/L

The tolerance efficiency of Panicum maximum and Helianthus annuus in TNT-contaminated soil and nZVI-contaminated soil.

Science.gov (United States)

Jiamjitrpanich, Waraporn; Parkpian, Preeda; Polprasert, Chongrak; Laurent, François; Kosanlavit, Rachain

2012-01-01

This study was designed to compare the initial method for phytoremediation involving germination and transplantation. The study was also to determine the tolerance efficiency of Panicum maximum (Purple guinea grass) and Helianthus annuus (Sunflower) in TNT-contaminated soil and nZVI-contaminated soil. It was found that the transplantation of Panicum maximum and Helianthus annuus was more suitable than germination as the initiate method of nano-phytoremediation potting test. The study also showed that Panicum maximum was more tolerance than Helianthus annuus in TNT and nZVI-contaminated soil. Therefore, Panicum maximum in the transplantation method should be selected as a hyperaccumulated plant for nano-phytoremediation potting tests. Maximum tolerance dosage of Panicum maximum to TNT-concentration soil was 320 mg/kg and nZVI-contaminated soil was 1000 mg/kg in the transplantation method.

The time-dependent effect of the biological component of 137Cs soil contamination

International Nuclear Information System (INIS)

Dederichs, H.; Pillath, J.; Lennartz, R.; Hill, P.; Hille, R.

2004-01-01

In investigations of the long-term development of the population dose in the highly contaminated regions of the Commonwealth of Independence States it was found that the external dose has not decreased as strongly as expected since 1992. Further investigations have shown that, contrary to expectations, no linear correlation can be observed between soil contamination and measured area dose rate. As a contribution towards clarifying these issues, the area dose rate and the soil contamination including the plant fraction were investigated in the Korma district, Belarus. It was found that it is necessary to cover and average over larger areas in order to determine from ground contamination the long-term development of the external dose commitment. This means that for this purpose the introduction of an ''effective'' surface contamination (sum of mineral and organic contamination components) is necessary. The phenomena observed are described in a model, which permits an analytical calculation of the contamination profile in soil taking migration and transfer effects into account. The differences observed between the measured soil contamination and the resulting external doses or the directly measured dose rate can be explained by the proposed model. Moreover, their long-term development can be calculated. The results show that a time decade after the accident the biological part of the ''effective'' soil contamination becomes dominant and cannot be neglected. (orig.)

Experiment on Physical Desalinisation of Uranium-contaminated Gravel Surface

International Nuclear Information System (INIS)

Park, Uk-Ryang; Kim, Gye-Nam; Kim, Seung-Soo; Han, Gyu-Seong; Moon, Jai-Kwon

2014-01-01

As a result, the method to wash uranium-contaminated gravels could not get satisfactory desalinization rate. During the long oxidization process it was judged that uranium penetrated inside the gravels, so we tried to increase the desalinization rate by fragmentizing them into pieces and then washing them. The desalinization rate after fragmentizing the gravels into pieces and washing them brought a satisfactory result.. However, we could obtain desired concentration for gravels with high uranium concentration by fragmentizing them and breaking them further into even smaller pieces. Likewise, desalinization using soil washing process is complicated and has to go through multiple washing steps, resulting in too much of waste fluid generated accordingly. The increase of waste fluid generated leads to the increase in by-products of the final disposal process later on, bringing a not good economic result. Furthermore, taking into account that the desalinization rate is 65% during soil washing process, it is expected that gravel washing will show a similar desalinization result; it is considered uneasy to have a perfect desalinization only by soil washing. The grinding method is actually used in the primary desalinization process in order to desalinize radioactivity-contaminated concrete. This method does desalinization by grinding the radioactivity-contaminated area of the concrete surface with desalinization equipment, which enables a near-to-perfect desalinization for relatively thinly contaminated surface. Likewise, this research verified the degree of desalinization by applying the grinding method and comparing it to the fragmentizing-washing method, and attempted to find a method to desalinize uranium-contaminated gravels more effectively. In order to desalinize uranium-contaminated gravels more effectively and compare to the existing washing-desalinization method, we conducted a desalinization experiment with grinding method that grinds gravel surface. As a

Hydrogen peroxide treatment of TCE contaminated soil

International Nuclear Information System (INIS)

Hurst, D.H.; Robinson, K.G.; Siegrist, R.L.

1993-01-01

Solvent contaminated soils are ubiquitous in the industrial world and represent a significant environmental hazard due to their persistence and potentially negative impacts on human health and the environment. Environmental regulations favor treatment of soils with options which reduce the volume and toxicity of contaminants in place. One such treatment option is the in-situ application of hydrogen peroxide to soils contaminated with chlorinated solvents such as trichloroethylene (TCE). This study investigated hydrogen peroxide mass loading rates on removal of TCE from soils of varying organic matter content. Batch experiments conducted on contaminated loam samples using GC headspace analysis showed up to 80% TCE removal upon peroxide treatment. Column experiments conducted on sandy loam soils with high organic matter content showed only 25% TCE removal, even at hydrogen peroxide additions of 25 g peroxide per kg soil

Surface contamination effects on leaf chemical composition in the Atlantic Forest

International Nuclear Information System (INIS)

Ferrari, A.A.; Franca, E.J.; Fernandes, E.A.N.; Bacchi, M.A.

2006-01-01

The exogenous material that adheres to the leaf surface affects the elemental composition of the plant itself, thereby constituting one of the major error sources in plant analysis. The present work investigated the surface contamination of leaves from the Atlantic Forest. Instrumental neutron activation analysis (INAA) was applied to assess the efficiency of leaf EDTA-washing. Chemical element concentrations were corrected using Sc (soil tracer) since resuspended soil is the main source of contamination in leaves. As a result, EDTA-washing should be used mainly for the evaluation of terrigenous elements, while the Sc-corrected concentrations are considered satisfactory for the other elements. (author)

In-situ bioremediation: Or how to get nutrients to all the contaminated soil

International Nuclear Information System (INIS)

Jackson, D.S.; Scovazzo, P.

1994-01-01

Petroleum contamination is a pervasive environmental problem. Bioremediation is winning favor primarily because the soil may be treated on site and systems can be installed to operate without interfering with facility activities. Although bioremediation has been utilized for many years, its acceptance as a cost-effective approach is only now being realized. KEMRON applied in-situ bioremediation at a retired rail yard which had maintained a diesel locomotive refueling station supplied by two 20,000 gallon above ground storage tanks. Contamination originated from both spillage at the pumps and leaking fuel distribution lines. The contamination spread over a 3 acre area from the surface to a depth of up to 20 feet. Levels of diesel contamination found in the soil ranged from less than a 100 ppm to more than 25,000 ppm. The volume of soil which ultimately required treatment was more than 60,000 cubic yards. Several remedial options were examined including excavation and disposal. Excavation was rejected because it would have been cost prohibitive due to the random distribution of the contaminated soil. In-situ Bioremediation was selected as the only alternative which could successfully treat all the contaminated soils. This paper focuses on how KEMRON solved four major problems which would have prevented a successful remediation project. These problems were: soil compaction, random distribution of contaminated soils, potential free product, and extremely high levels of dissolved iron in the groundwater

Developing an integration tool for soil contamination assessment

Science.gov (United States)

Anaya-Romero, Maria; Zingg, Felix; Pérez-Álvarez, José Miguel; Madejón, Paula; Kotb Abd-Elmabod, Sameh

2015-04-01

In the last decades, huge soil areas have been negatively influenced or altered in multiples forms. Soils and, consequently, underground water, have been contaminated by accumulation of contaminants from agricultural activities (fertilizers and pesticides) industrial activities (harmful material dumping, sludge, flying ashes) and urban activities (hydrocarbon, metals from vehicle traffic, urban waste dumping). In the framework of the RECARE project, local partners across Europe are focusing on a wide range of soil threats, as soil contamination, and aiming to develop effective prevention, remediation and restoration measures by designing and applying targeted land management strategies (van Lynden et al., 2013). In this context, the Guadiamar Green Corridor (Southern Spain) was used as a case study, aiming to obtain soil data and new information in order to assess soil contamination. The main threat in the Guadiamar valley is soil contamination after a mine spill occurred on April 1998. About four hm3 of acid waters and two hm3 of mud, rich in heavy metals, were released into the Agrio and Guadiamar rivers affecting more than 4,600 ha of agricultural and pasture land. Main trace elements contaminating soil and water were As, Cd, Cu, Pb, Tl and Zn. The objective of the present research is to develop informatics tools that integrate soil database, models and interactive platforms for soil contamination assessment. Preliminary results were obtained related to the compilation of harmonized databases including geographical, hydro-meteorological, soil and socio-economic variables based on spatial analysis and stakeholder's consultation. Further research will be modellization and upscaling at the European level, in order to obtain a scientifically-technical predictive tool for the assessment of soil contamination.

Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

Energy Technology Data Exchange (ETDEWEB)

Al-Rajab, Abdul Jabbar; Sabourin, Lyne [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Lapen, David R. [Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6 (Canada); Topp, Edward, E-mail: ed.topp@agr.gc.ca [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Department of Biology, Western University, London, ON N6A 5B7 (Canada)

2015-04-15

In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with {sup 14}C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules. - Highlights: • We characterized the soil fate of four organic contaminants carried in biosolids. • Biosolids were placed on the soil surface or incorporated within the soil profile. • Naproxen, triclosan and triclocarban were dissipated more rapidly when incorporated. • Depth of placement did not influence the rate of carbamazepine dissipation. • Soil incorporation of biosolids will result in more rapid dissipation of contaminants.

Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

International Nuclear Information System (INIS)

Al-Rajab, Abdul Jabbar; Sabourin, Lyne; Lapen, David R.; Topp, Edward

2015-01-01

In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with 14 C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules. - Highlights: • We characterized the soil fate of four organic contaminants carried in biosolids. • Biosolids were placed on the soil surface or incorporated within the soil profile. • Naproxen, triclosan and triclocarban were dissipated more rapidly when incorporated. • Depth of placement did not influence the rate of carbamazepine dissipation. • Soil incorporation of biosolids will result in more rapid dissipation of contaminants

Speciation of zinc in contaminated soils

International Nuclear Information System (INIS)

Stephan, Chadi H.; Courchesne, Francois; Hendershot, William H.; McGrath, Steve P.; Chaudri, Amar M.; Sappin-Didier, Valerie; Sauve, Sebastien

2008-01-01

The chemical speciation of zinc in soil solutions is critical to the understanding of its bioavailability and potential toxic effects. We studied the speciation of Zn in soil solution extracts from 66 contaminated soils representative of a wide range of field conditions in both North America and Europe. Within this dataset, we evaluated the links among the dissolved concentrations of zinc and the speciation of Zn 2+ , soil solution pH, total soil Zn, dissolved organic matter (DOM), soil organic matter (SOM) and the concentrations of different inorganic anions. The solid-liquid partitioning coefficient (K d ) for Zn ranged from 17 to 13,100 L kg -1 soil. The fraction of dissolved Zn bound to DOM varied from 60% to 98% and the soil solution free Zn 2+ varied from 40% to 60% of the labile Zn. Multiple regression equations to predict free Zn 2+ , dissolved Zn and the solid-liquid partitioning of Zn are given for potential use in environmental fate modeling and risk assessment. The multiple regressions also highlight some of the most important soil properties controlling the solubility and chemical speciation of zinc in contaminated soils. - We studied the relationships among the chemical speciation of Zn in soil solution extracts from 66 contaminated soils and various physicochemical properties of the soils

A consideration on internal dose evaluation and intervention based on a surface contamination concept

International Nuclear Information System (INIS)

Yasuda, H.

1997-01-01

Long-term radiation doses received by the inhabitants after the Chernobyl accident have been evaluated according to the surface contamination levels on the ground surface. The health effects have also been discussed by comparison between the surface-contaminated area and the uncontaminated control area. Selected protective measures were carried out in accordance with the contamination level of surface soil. These have been based on the 'surface contamination concept' which assumes that the radiation risk to inhabitants is proportional to the level of ground-surface contamination. The observations collected in regions around Chernobyl, however, show that the internal radiation doses to the inhabitants poorly correlate with the surface contamination level. This fact poses a question on the suitability of dose evaluations and interventions based on this concept

Biological detoxification of a hydrocarbon contaminated soil

International Nuclear Information System (INIS)

Fabbri, F.; Lucchese, G.; Nardella, A.

2005-01-01

The soil quality of an industrial site chronically contaminated by 39000 mg/kg of oil was detrimentally affected. Soil treatments by bio-pile and land-farming resulted in a reduction of the level of contamination exceeding 90% of the original values, but without reaching regulatory limits. However, the bio-remediation treatments dramatically reduced the mobility of the contaminants and, accordingly, microbial tests clearly indicate that the soil quality improved to acceptable levels, similar to those typically observed in unaltered soils. Hydrocarbon mobility was estimated by the use of water and mild extractants (methanol and sodium dodecyl sulphate) to leach the contaminants from the soil; soil quality was evaluated by comparing the values of selected microbial and enzymatic parameters of the treated soil samples to reference values determined for natural soils. Microbial assessments included: measurement of the nitrification potential, dehydrogenase activity, measures of respiration and lipase activity, microbial counts (MPN on rich media) and Microtox TM assays of the water elutriate. Dermal absorption potential was evaluated using absorption on C 18 disks

Radioactive surface contamination monitors

International Nuclear Information System (INIS)

Aoyama, Kei; Minagoshi, Atsushi; Hasegawa, Toru

1994-01-01

To reduce radiation exposure and prevent contamination from spreading, each nuclear power plant has established a radiation controlled area. People and articles out of the controlled area are checked for the surface contamination of radioactive materials with surface contamination monitors. Fuji Electric has repeatedly improved these monitors on the basis of user's needs. This paper outlines typical of a surface contamination monitor, a personal surface contamination monitor, an article surface contamination monitor and a laundry monitor, and the whole-body counter of an internal contamination monitor. (author)

Complex conductivity of oil-contaminated clayey soils

Science.gov (United States)

Deng, Y.; Revil, A.; Shi, X.

2017-12-01

Non-intrusive hydrogeophysical techniques have been wildly applied to detect organic contaminants because of the difference of electrical properties for contaminated soil. Among them, spectral induced polarization (SIP) has emerged as a promising tool for the identification of contamination due to its sensitivity to the chemistry of pore water, solid-fluid interfaces and fluid content. Previous works have investigated the influences of oil on the electrical signatures of porous media, which demonstrated the potentials of SIP in the detection of hydrocarbon contamination. However, few works have done on the SIP response of oil in clayey soils. In this study, we perform a set of SIP measurements on the clayey samples under different water saturations. These clayey soils are characterized by relatively high cation exchange capacity. The objective in this work is to test the empirical relationships between the three exponents, including the cementation exponent (m), the saturation exponent (n) and the quadrature conductivity exponent (p), which is expected to reduce the model parameters needed in geophysical and hydraulic properties predictions. Our results show that the complex conductivity are saturation dependent. The magnitude of both in-phase and quadrature conductivities generally decrease with decreasing water saturation. The shape of quadrature conductivity spectra slightly changes when water saturation decreases in some cases. The saturation exponent slightly increases with cation exchange capacity, specific surface area and clay content, with an average value around 2.05. Compared to saturation exponent, the quadrature conductivity exponent apparently increases with cation exchange capacity and specific surface area while has little to do with the clay content. Further, the results indicate that the quadrature conductivity exponent p does not strictly obey to p=n-1 as proposed by Vinegar and Waxman (1984). Instead, it mostly ranges between p=n-1.5 and p=n-0

The role of soil quality maps in the reuse of lightly contaminated soil

OpenAIRE

Lamé, F.P.J.; Leenaers, H.; Zegwaard, J.

2000-01-01

In 1999 the Dutch government agreed on a new policy regarding the reuse of lightly contaminated soil. From now on, lightly contaminated soil may be reused under conditions of soil-quality management. The municipal authorities supervise the reuse under this new regime. Two basic criteria need to be met before reuse of lightly contaminated soil is allowed. Firstly, the quality of the soil has to be characterised on a soil quality map. Secondly, the soil that will be reused has to be of the same...

Trench 'bathtubbing' and surface plutonium contamination at a legacy radioactive waste site.

Science.gov (United States)

Payne, Timothy E; Harrison, Jennifer J; Hughes, Catherine E; Johansen, Mathew P; Thiruvoth, Sangeeth; Wilsher, Kerry L; Cendón, Dioni I; Hankin, Stuart I; Rowling, Brett; Zawadzki, Atun

2013-01-01

Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (~12 Bq/L of (239+240)Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest (239+240)Pu soil activity was 829 Bq/kg in a shallow sample (0-1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the 'bathtub' effect.

Ex situ treatment of hydrocarbon-contaminated soil using biosurfactants from Lactobacillus pentosus.

Science.gov (United States)

Moldes, Ana Belén; Paradelo, Remigio; Rubinos, David; Devesa-Rey, Rosa; Cruz, José Manuel; Barral, María Teresa

2011-09-14

The utilization of biosurfactants for the bioremediation of contaminated soil is not yet well established, because of the high production cost of biosurfactants. Consequently, it is interesting to look for new biosurfactants that can be produced at a large scale, and it can be employed for the bioremediation of contaminated sites. In this work, biosurfactants from Lactobacillus pentosus growing in hemicellulosic sugars solutions, with a similar composition of sugars found in trimming vine shoot hydrolysates, were employed in the bioremediation of soil contaminated with octane. It was observed that the presence of biosurfactant from L. pentosus accelerated the biodegradation of octane in soil. After 15 days of treatment, biosurfactants from L. pentosus reduced the concentration of octane in the soil to 58.6 and 62.8%, for soil charged with 700 and 70,000 mg/kg of hydrocarbon, respectively, whereas after 30 days of treatment, 76% of octane in soil was biodegraded in both cases. In the absence of biosurfactant and after 15 days of incubation, only 1.2 and 24% of octane was biodegraded in soil charged with 700 and 70,000 mg/kg of octane, respectively. Thus, the use of biosurfactants from L. pentosus, as part of a well-designed bioremediation process, can provide mechanisms to mobilize the target contaminants from the soil surface to make them more available to the microbial population.

Heavy metal movement in metal-contaminated soil profiles

Energy Technology Data Exchange (ETDEWEB)

Li, Zhenbin; Shuman, L.M. [Univ. of Georgia, Griffin, GA (United States)

1996-10-01

Heavy metal movement in soil profiles is a major environmental concern because even slow transport through the soil may eventually lead to deterioration of groundwater quality. In this study, three metal-contaminated soil (Fuquay, Dothan, and Clarendon) were selected from cropland were a high-metal flue dust had been applied annually for 6 years to raise soil pH, with application ending 4 years before sampling. One uncontaminated soil (Tifton) from the same physiographic area was also sampled as a control. Soil samples were collected in 15-cm increments from the surface to 105 cm in depth. Total contents of Zn, Cd, and Pb in the soils samples were determined. To better understand metal movement in relation to metal fractions in the soil profile, soil samples were also extracted sequentially for exchangeable (EXC), organic matter (OM), Mn oxide (MNO), amorphous Fe oxide (AFEO), crystalline Fe oxide (CFEO), and residual (RES) fractions. 35 refs., 6 figs., 2 tabs.

Contaminant Gradients in Trees: Directional Tree Coring Reveals Boundaries of Soil and Soil-Gas Contamination with Potential Applications in Vapor Intrusion Assessment.

Science.gov (United States)

Wilson, Jordan L; Samaranayake, V A; Limmer, Matthew A; Schumacher, John G; Burken, Joel G

2017-12-19

Contaminated sites pose ecological and human-health risks through exposure to contaminated soil and groundwater. Whereas we can readily locate, monitor, and track contaminants in groundwater, it is harder to perform these tasks in the vadose zone. In this study, tree-core samples were collected at a Superfund site to determine if the sample-collection location around a particular tree could reveal the subsurface location, or direction, of soil and soil-gas contaminant plumes. Contaminant-centroid vectors were calculated from tree-core data to reveal contaminant distributions in directional tree samples at a higher resolution, and vectors were correlated with soil-gas characterization collected using conventional methods. Results clearly demonstrated that directional tree coring around tree trunks can indicate gradients in soil and soil-gas contaminant plumes, and the strength of the correlations were directly proportionate to the magnitude of tree-core concentration gradients (spearman's coefficient of -0.61 and -0.55 in soil and tree-core gradients, respectively). Linear regression indicates agreement between the concentration-centroid vectors is significantly affected by in planta and soil concentration gradients and when concentration centroids in soil are closer to trees. Given the existing link between soil-gas and vapor intrusion, this study also indicates that directional tree coring might be applicable in vapor intrusion assessment.

A review of biochars' potential role in the remediation, revegetation and restoration of contaminated soils

International Nuclear Information System (INIS)

Beesley, Luke; Moreno-Jimenez, Eduardo; Gomez-Eyles, Jose L.; Harris, Eva; Robinson, Brett; Sizmur, Tom

2011-01-01

Biochars are biological residues combusted under low oxygen conditions, resulting in a porous, low density carbon rich material. Their large surface areas and cation exchange capacities, determined to a large extent by source materials and pyrolysis temperatures, enables enhanced sorption of both organic and inorganic contaminants to their surfaces, reducing pollutant mobility when amending contaminated soils. Liming effects or release of carbon into soil solution may increase arsenic mobility, whilst low capital but enhanced retention of plant nutrients can restrict revegetation on degraded soils amended only with biochars; the combination of composts, manures and other amendments with biochars could be their most effective deployment to soils requiring stabilisation by revegetation. Specific mechanisms of contaminant-biochar retention and release over time and the environmental impact of biochar amendments on soil organisms remain somewhat unclear but must be investigated to ensure that the management of environmental pollution coincides with ecological sustainability. - Highlights: → Biochars can reduce mobilities of some organic and inorganic pollutants in soil. → Source material and production conditions influence pollutant retention. → Highly alkaline pH and water soluble carbon can undesirably mobilise some elements. → Large surface area may be toxic to soil fauna but create microbial niches. → Efficacy of biochar may depend on other organic materials applied in combination. - Biochars can reduce the mobility and impact of some soil pollutants but, if applied alone, may fail to support soil restoration, revegetation and hence ecologically circumspect remediation.

Phytoremediation of soils contaminated with radionuclides

International Nuclear Information System (INIS)

Yamaguchi, Isamu

2004-01-01

Aiming at efficient phytoremediation of soils contaminated with radionuclides, we examined the effect of soil microbes on the uptake ability of plants using the multitracer technique to find that tomato rhizofungi in Fusarium spp. can stimulate the uptake of 85 Sr and 137 Cs by the plants. The synergic effect of a nonpathogenic strain of F. oxysporum on the uptake of radionuclides by plants proved to be enhanced by introducing a phytochelatin synthase gene into the fungus. Since soil contamination by radionuclides is still an unsolved problem in many parts of the world. Studies on phytoremediation of polluted soil environment will be important for developing effective strategies and devising adequate techniques to reduce human risks caused by food contamination of radionuclides. (author)

Thermal remediation of tar-contaminated soil and oil-contaminated gravel

International Nuclear Information System (INIS)

Anthony, E.J.; Wang, J.

2005-01-01

High temperature treatments are commonly considered for the decontamination of soil as they have the advantages of reliability, high capacity, and effective destruction of hazardous materials with reduced long-term liability. This paper examined the remediation of soil contaminated by coal tar as well as gravel contaminated by oil. Pilot plant studies were conducted using 2 representative incineration technologies: rotary kiln and fluidized bed. The coal tar contaminated soil had accumulated over a few decades at a calcination plant in western Canada. The soil was sticky and could not be handled by conventional feeding and combustion systems. Crushed lignite was mixed with the soil as an auxiliary fuel and to reduce stickiness. A pilot plant furnace was used to evaluate the potential of decontamination in a rotary calciner. An analysis of both a modelling study and the test results showed that complete decontamination could be achieved in the targeted calciner. The results suggested that energy recovery was also possible, which could in turn make the remediation process more cost-effective. Decontamination of oil-contaminated gravel was conducted with a pilot plant fluidized bed combustor to study the feasibility of using incineration technology in the remediation of gravel and debris contaminated by oil spills. Results indicated that the gravel was decontaminated with acceptable emission performance. It was concluded that the study will be valuable to the application of commercial incineration processes for the remediation of polluted soils. It was observed that the weathering of the oiled gravel lowered the rate of decontamination. A small amount of salt water resulted in lowered decontamination rates, which may be an important factor for situations involving the remediation of shoreline gravel contaminated by oil. 24 refs., 6 tabs., 7 figs

Soil moisture effects during bioventing in fuel-contaminated arid soils

International Nuclear Information System (INIS)

Zwick, T.C.; Leeson, A.; Hinchee, R.E.; Hoeppel, R.E.; Bowling, L.

1995-01-01

This study evaluated the effects of soil moisture addition on microbial activity during bioventing of dry, sandy soils at the Marine Corps Air Ground Combat Center (MCAGCC), Twentynine Palms, California. Soils at the site have been contaminated to a depth of approximately 80 ft (24 m) with gasoline, JP-5 jet fuel, and diesel fuel. Based on the low soil moisture measured at the site (2 to 3% by weight), it was determined that soil moisture may be limiting biodegradation. To evaluate the effect that moisture addition had on microbial activity under field conditions, a subsurface drip irrigation system was installed above the fuel hydrocarbon plume. Irrigation water was obtained from two monitoring wells on the site, where groundwater was approximately 192 ft (59 m) below ground surface. Advancement of the wetting front was monitored. In situ respiration rates increased significantly after moisture addition. The results of this study provide evidence for the potential applicability of moisture addition in conjunction with bioventing for site remediation in arid environments. Further work is planned to investigate optimization of moisture addition

Biological Treatment of Petroleum in Radiologically Contaminated Soil

Energy Technology Data Exchange (ETDEWEB)

BERRY, CHRISTOPHER

2005-11-14

This chapter describes ex situ bioremediation of the petroleum portion of radiologically co-contaminated soils using microorganisms isolated from a waste site and innovative bioreactor technology. Microorganisms first isolated and screened in the laboratory for bioremediation of petroleum were eventually used to treat soils in a bioreactor. The bioreactor treated soils contaminated with over 20,000 mg/kg total petroleum hydrocarbon and reduced the levels to less than 100 mg/kg in 22 months. After treatment, the soils were permanently disposed as low-level radiological waste. The petroleum and radiologically contaminated soil (PRCS) bioreactor operated using bioventing to control the supply of oxygen (air) to the soil being treated. The system treated 3.67 tons of PCRS amended with weathered compost, ammonium nitrate, fertilizer, and water. In addition, a consortium of microbes (patent pending) isolated at the Savannah River National Laboratory from a petroleum-contaminated site was added to the PRCS system. During operation, degradation of petroleum waste was accounted for through monitoring of carbon dioxide levels in the system effluent. The project demonstrated that co-contaminated soils could be successfully treated through bioventing and bioaugmentation to remove petroleum contamination to levels below 100 mg/kg while protecting workers and the environment from radiological contamination.

Effects of Two Kinds of Biochars on Soil Cu Availability in Contaminated Soil

Directory of Open Access Journals (Sweden)

WANG Xiao-qi

2016-07-01

Full Text Available This paper is aimed to research the impacts of different biochars(0,1%,2%,4%, including maize biochar and phytolacca root biochar, on rape growth and the soil Cu availability in the Cu-contaminated red soil via a series of pot experiments. The results showed that, compared with the control, the addition of two kinds of biochars could increase the biomass of the rape. In low Cu-contaminated red soil, added 4% maize biochar and phytolacca root biochar increased the biomass by 21.2 times and 67.9 times; however, the biomass were increased by 8.6 times and 109.6 times under high Cu-contaminated soil. The addition of phytolacca root biochar could increase the soil pH significantly, which has been increased by 0.4~1.6 units with the addition of phytolacca root biochar in low Cu-contaminated red soil, and it had 0.25~1.35 units more than that with maize biochar; In high Cu-contaminated red soil, with the addition of phytolacca root biochar, soil pH was increased by 0.33~1.52 units, which was 0.3~1.25 units higher than maize biochar. There was a significant effect on reducing the soil Cu availability with the addition of the two biochars. Among them, 4% addition of maize biochar and phytolacca root biochar could reduce soil available Cu content by 21.9% and 45.2% in low Cu-contaminated soil, however, it was decreased by 41.9% and 53.8% in high Cu-contaminated soil. Both of the two biochars were able to reduce the Cu accumulation in rape, where there was a decrease by 21.2% and 67.8% with he addition of 4% maize biochar and phytolacca root biochar under low Cu-contaminated soil, and it was decreased by 19.9% and 66.8% in high Cu-contaminated soil respectively. Both of the biochars could ameliorate the acidity and Cu availability in the red soil, enhance the biomass of the rape and reduce the Cu accumulation in rape, but phytolacca root biochar had more effective influence than maize biochar.

Organic contaminants in soil : desorption kinetics and microbial degradation

NARCIS (Netherlands)

Schlebaum, W.

1999-01-01

The availability of organic contaminants in soils or sediments for microbial degradation or removal by physical means (e.g.) soil washing or soil venting) depends on the desorption kinetics of these contaminants from the soil matrix. When the organic contaminants desorb very slow from the

In-situ vitrification of radioactively contaminated soils: summary paper

International Nuclear Information System (INIS)

Buelt, J.L.; Fitzpatrick, V.F.

1987-01-01

The in-situ vitrification (ISV) process is a new technology that has been developed from its conceptual phase through selected field-scale application tests during the last six years. In situ vitrification converts contaminated soils and waste inclusions into a durable glass and crystalline waste form by in-place melting. Electrodes are inserted into the soil to be treated and an electrical current is passed through the soil to be treated and an electrical current is passed through the soil to melt it. After cooling, the process fixes (TRU) and fission product radionuclides making them relatively nonleachable, resistant to intrusion, and nondispersible when intentionally disturbed. Another application considered for isolation of radioactively contaminated soils, but not yet developed, is the generation of impermeable barrier walls to prevent ground water seepage into a site. The barrier technique could also be used over the surface of an existing disposal site to deter plant and animal intrusion. The development units have been extensively tested with many types of soils and waste inclusions such as concrete, buried metals, sealed containers, organic chemicals with high boiling points such as polychlorinated biphenyls, and inorganic chemicals, including toxic heavy metals, nitrates, and sulfates. Nitrates and organics are destroyed, while heavy metals and fluorides are retained to a high percentage within the molten soil during processing. At $200 to $300/m 3 for radioactive waste, the process is economically competitive with many alternative remediation processes. The ISV process has been developed to the point where it is ready for large-scale field testing at an actual TRU-contaminated soil site. 5 references, 2 figures, 2 tables

Bioremediation of soils contaminated with fuel oils

International Nuclear Information System (INIS)

Baker, K.H.; Herson, D.S.; Vercellon-Smith, P.; Cronce, R.C.

1991-01-01

A utility company discovered soils in their plant contaminated with diesel fuel and related fuel oils (300-450 ppm). The soils were excavated and removed to a concrete pad for treatment. The authors conducted laboratory studies to determine if biostimulation or bioaugmentation would be appropriate for treating the soils. Microbial numbers and soil respiration were monitored in microcosms supplemented with: (1) organic nutrients, (2) inorganic nutrients, and (3) inorganic nutrients plus additional adapted microorganisms. Their studies indicated that biostimulation via the addition of inorganic nutrients would be appropriate at this site. Treatment cells for the contaminated soils were constructed. Initial data indicates that a 35% reduction in the concentration of contaminants has occurred within the first month of operation

Contaminants migration in the soil: the influence of transfer between the mobile and stationary phases

International Nuclear Information System (INIS)

Moreira, R.M.; Sabino, C.S.V.; Macedo, W.A.

1996-01-01

Three transport mechanisms control the contaminant migration in saturated soils: advection, diffusion and interchanges between liquid and solid phases. These interchanges define the retention by the soil and the contaminant delay related to the liquid phase flow. Therefore, the knowledge of the adsorption/desorption characteristics of the solute in solid surfaces is fundamental for the evaluation of toxic agent releases to the compartment soil. This communication reports the study which is being performed by the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) in this area, particularly with cesium and mercury by using X-ray absorption spectroscopy for contaminants migration

Long-range alpha detection applied to soil contamination and waste monitoring

International Nuclear Information System (INIS)

MacArthur, D.W.; Allander, K.S.; Bounds, J.A.; Close, D.A.; McAtee, J.L.

1992-01-01

Alpha contamination monitoring has been traditionally limited by the short range of alpha particles in air and through detector windows. The long-range alpha detector (LRAD) described in this paper circumvents that limitation by detecting alpha-produced ions, rather than alpha particles directly. Since the LRAD is sensitive to all ions, it can monitor all contamination present on a large surface at one time. Because air is the ''detector gas,'' the LRAD can detect contamination on any surface to which air can penetrate. We present data showing the sensitivity of LRAD detectors, as well as documenting their ability to detect alpha sources in previously unmonitorable locations, and verifying the ion lifetime. Specific designs and results for soil contamination and waste monitors are also included

Long-range alpha detection applied to soil surface monitoring

International Nuclear Information System (INIS)

Caress, R.W.; Allander, K.S.; Bounds, J.A.; Catlett, M.M.; MacArthur, D.W.; Rutherford, D.A.

1992-01-01

The long-range alpha detection (LRAD) technique depends on the detection of ion pairs generated by alpha particles losing energy in air rather than on detection of the alpha particles themselves. Typical alpha particles generated by uranium will travel less than 3 cm in air. In contrast, the ions have been successfully detected many inches or feet away from the contamination. Since LRAD detection systems are sensitive to all ions simultaneously, large LRAD soil surface monitors (SSMS) can be used to collect all of the ions from a large sample. The LRAD SSMs are designed around the fan-less LRAD detector. In this case a five-sided box with an open bottom is placed on the soil surface. Ions generated by alpha decays on the soil surface are collected on a charged copper plate within the box. These ions create a small current from the plate to ground which is monitored with a sensitive electrometer. The current measured is proportional to the number of ions in the box, which is, in turn, proportional to the amount of alpha contamination on the surface of the soil. This report includes the design and construction of a 1-m by 1-m SSM as well as the results of a study at Fernald, OH, as part of the Uranium in Soils Integrated Demonstration

Modified natural diatomite and its enhanced immobilization of lead, copper and cadmium in simulated contaminated soils

International Nuclear Information System (INIS)

Ye, Xinxin; Kang, Shenghong; Wang, Huimin; Li, Hongying; Zhang, Yunxia; Wang, Guozhong; Zhao, Huijun

2015-01-01

Highlights: • We modify natural diatomite using the facile acid treatment and ultrasonication. • Modification add pore volume, surface area and electronegativity of natural diatomite. • Modified diatomite is superior to natural diatomite in soil heavy metal remediation. • Modified diatomite can be promising for in-situ immobilization of heavy metal in soil. - Abstract: Natural diatomite was modified through facile acid treatment and ultrasonication, which increased its electronegativity, and the pore volume and surface area achieved to 0.211 cm 3 g −1 and 76.9 m 2 g −1 , respectively. Modified diatomite was investigated to immobilize the potential toxic elements (PTEs) of Pb, Cu and Cd in simulated contaminated soil comparing to natural diatomite. When incubated with contaminated soils at rates of 2.5% and 5.0% by weight for 90 days, modified diatomite was more effective in immobilizing Pb, Cu and Cd than natural diatomite. After treated with 5.0% modified diatomite for 90 days, the contaminated soils showed 69.7%, 49.7% and 23.7% reductions in Pb, Cu and Cd concentrations after 0.01 M CaCl 2 extraction, respectively. The concentrations of Pb, Cu and Cd were reduced by 66.7%, 47.2% and 33.1% in the leaching procedure, respectively. The surface complexation played an important role in the immobilization of PTEs in soils. The decreased extractable metal content of soil was accompanied by improved microbial activity which significantly increased (P < 0.05) in 5.0% modified diatomite-amended soils. These results suggested that modified diatomite with micro/nanostructured characteristics increased the immobilization of PTEs in contaminated soil and had great potential as green and low-cost amendments

Bioremediation of petroleum-contaminated soil

International Nuclear Information System (INIS)

Pearce, K.; Snyman, H.G.; Oellermann, R.A.; Gerber, A.

1995-01-01

A pilot-scale study was conducted to evaluate the application of land-farming techniques in bioremediating a soil highly contaminated with petroleum products. A commercial biosupplement, and one prepared with indigenous microorganisms from the contaminated soil, were tested. Application of either of the biosupplements, in addition to the control of pH, moisture, and oxygen levels, resulted in a 94% reduction of the initial total petroleum hydrocarbon concentration (TPHC) (32% mass/mass) over a 70-day period. Implementation of these findings at full scale to bioremediate highly weathered petroleum products showed an average reduction of 89% over 5.5 months. Target levels of 1,400 mg/kg soil were reached from an initial average TPHC concentration of 12,200 mg/kg soil

Plant Mounds as Concentration and Stabilization Agents for Actinide Soil Contaminants in Nevada

Energy Technology Data Exchange (ETDEWEB)

D.S. Shafer; J. Gommes

2009-02-03

Plant mounds or blow-sand mounds are accumulations of soil particles and plant debris around the base of shrubs and are common features in deserts in the southwestern United States. An important factor in their formation is that shrubs create surface roughness that causes wind-suspended particles to be deposited and resist further suspension. Shrub mounds occur in some plant communities on the Nevada Test Site, the Nevada Test and Training Range (NTTR), and Tonopah Test Range (TTR), including areas of surface soil contamination from past nuclear testing. In the 1970s as part of early studies to understand properties of actinides in the environment, the Nevada Applied Ecology Group (NAEG) examined the accumulation of isotopes of Pu, 241Am, and U in plant mounds at safety experiment and storage-transportation test sites of nuclear devices. Although aerial concentrations of these contaminants were highest in the intershrub or desert pavement areas, the concentration in mounds were higher than in equal volumes of intershrub or desert pavement soil. The NAEG studies found the ratio of contaminant concentration of actinides in soil to be greater (1.6 to 2.0) in shrub mounds than in the surrounding areas of desert pavement. At Project 57 on the NTTR, 17 percent of the area was covered in mounds while at Clean Slate III on the TTR, 32 percent of the area was covered in mounds. If equivalent volumes of contaminated soil were compared between mounds and desert pavement areas at these sites, then the former might contain as much as 34 and 62 percent of the contaminant inventory, respectively. Not accounting for radionuclides associated with shrub mounds would cause the inventory of contaminants and potential exposure to be underestimated. In addition, preservation of shrub mounds could be important part of long-term stewardship if these sites are closed by fencing and posting with administrative controls.

Treatability of volatile chlorinated hydrocarbon-contaminated soils of different textures along a vertical profile by mechanical soil aeration: A laboratory test.

Science.gov (United States)

Ma, Yan; Shi, Yi; Hou, Deyi; Zhang, Xi; Chen, Jiaqi; Wang, Zhifen; Xu, Zhu; Li, Fasheng; Du, Xiaoming

2017-04-01

Mechanical soil aeration is a simple, effective, and low-cost soil remediation technology that is suitable for sites contaminated with volatile chlorinated hydrocarbons (VCHs). Conventionally, this technique is used to treat the mixed soil of a site without considering the diversity and treatability of different soils within the site. A laboratory test was conducted to evaluate the effectiveness of mechanical soil aeration for remediating soils of different textures (silty, clayey, and sandy soils) along a vertical profile at an abandoned chloro-alkali chemical site in China. The collected soils were artificially contaminated with chloroform (TCM) and trichloroethylene (TCE). Mechanical soil aeration was effective for remediating VCHs (removal efficiency >98%). The volatilization process was described by an exponential kinetic function. In the early stage of treatment (0-7hr), rapid contaminant volatilization followed a pseudo-first order kinetic model. VCH concentrations decreased to low levels and showed a tailing phenomenon with very slow contaminant release after 8hr. Compared with silty and sandy soils, clayey soil has high organic-matter content, a large specific surface area, a high clay fraction, and a complex pore structure. These characteristics substantially influenced the removal process, making it less efficient, more time consuming, and consequently more expensive. Our findings provide a potential basis for optimizing soil remediation strategy in a cost-effective manner. Copyright © 2016. Published by Elsevier B.V.

Bioremediation of Pyrene-Contaminated Soils Using Biosurfactant

Directory of Open Access Journals (Sweden)

Jorfi

2014-10-01

Full Text Available Background Polycyclic aromatic hydrocarbons (PAHs are persistence organic chemicals with proved carcinogenic and mutagenic hazards. These compounds are usually adsorbed in soils in vicinity of oil and gas industries. Bioremediation of PAHs contaminated soils is difficult due to hydrophobic nature of PAHs. Objectives The main purpose of the current study was to determine the pyrene removal efficiency in synthetically contaminated soil, using biosurfactant. Materials and Methods Four pure bacterial strains capable of pyrene degradation were isolated from contaminated soils via enrichment techniques. The soil samples were spiked with an initial pyrene concentration of 500 mg/kg and subjected to bioremediation using a mixed culture comprised of previously isolated strains, in addition to application of biosurfactant during 63 days. Results The pyrene removal efficiency in samples containing biosurfactant, without biosurfactant and controls, were 86.4%, 59.8% and 14%, respectively, after 63 days. The difference of pyrene removal efficiency between the biosurfactant-containing samples and the ones without it was significant (P < 0.05. Conclusions Application of rhamnolipid biosurfactant produced by Pseudomonas aeruginosa significantly improved pyrene removal in contaminated soils.

Development of Decontamination Process for Soil Contaminated Uranium

International Nuclear Information System (INIS)

Kim, Gye-Nam; Kim, Seung-Soo; Park, Uk-Rang; Han, Gyu-Seong; Moon, Jei-Kwon

2014-01-01

Various experiments with full-scaled electrokinetic equipment, soil washing equipment, and gravel washing equipment were performed to remove 238 U from contaminated soils of below 0.4 Bq/g. The repetition number and the removal efficiencies of the soil and gravel washing equipment were evaluated. The decontamination periods by the soil and gravel electrokinetic equipment were evaluated. Finally, a work process of full-scaled decontamination equipment was developed. Contaminated soils were classified into soils and gravels using a 8.0 cm sieve. Soils were sent to the soil washing equipment, while gravels were sent to the gravel washing equipment. Soils sent to the soil washing equipment were sent to the soil electrokinetic equipment after soil washing. A repetition number of soil washing was two times. The washed gravels were sent to the gravel electrokinetic equipment. Gravel contaminated with a high concentration requires crushing after gravel washing

Development of Decontamination Process for Soil Contaminated Uranium

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye-Nam; Kim, Seung-Soo; Park, Uk-Rang; Han, Gyu-Seong; Moon, Jei-Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-10-15

Various experiments with full-scaled electrokinetic equipment, soil washing equipment, and gravel washing equipment were performed to remove {sup 238}U from contaminated soils of below 0.4 Bq/g. The repetition number and the removal efficiencies of the soil and gravel washing equipment were evaluated. The decontamination periods by the soil and gravel electrokinetic equipment were evaluated. Finally, a work process of full-scaled decontamination equipment was developed. Contaminated soils were classified into soils and gravels using a 8.0 cm sieve. Soils were sent to the soil washing equipment, while gravels were sent to the gravel washing equipment. Soils sent to the soil washing equipment were sent to the soil electrokinetic equipment after soil washing. A repetition number of soil washing was two times. The washed gravels were sent to the gravel electrokinetic equipment. Gravel contaminated with a high concentration requires crushing after gravel washing.

Soil contamination issues at U.S. ports

International Nuclear Information System (INIS)

Rice, D.W.; Hagner, D.

1991-01-01

This paper reports that seven large and medium size west coast ports were surveyed during August 1990 to determine their involvement with hydrocarbon contaminated soils and activities associated with the characterization and remediation of these soils. All ports surveyed indicated that hey have hydrocarbon contaminated soil problems. Although other west coast ports do not have the scale of petroleum transfer and storage facilities that the Prot of Los Angeles has, all ports had tenants with bulk oil or fuel storage in aboveground tanks and were undertaking characterization and remediation work. Hydrocarbon contaminated soil problems were associated with these facilities or with decommissioned facilities of this type

Analysis of soils contaminated with petroleum constituents

International Nuclear Information System (INIS)

O'Shay, T.A.; Hoddinott, K.

1994-01-01

This symposium was held in Atlanta, Georgia on June 24, 1993. The purpose of the symposium was to provide a forum for exchange of information on petroleum contaminated soils. When spilled on the ground, petroleum products can cause massive problems in the environment. In this Special Technical Publication (STP), papers were selected in two categories; the analytical procedures for soil contaminated with petroleum hydrocarbons and the behavior of hydrocarbon contaminated soils. Individual papers have been processed separately for inclusion in the appropriate data bases

Agricultural contamination in soil-groundwater-surface water systems in the North China Plain

DEFF Research Database (Denmark)

Brauns, Bentje

of fertilizers and pesticides. Unfortunately, the lack of regulation or oversight has led to the overuse of these agrochemicals: current application rates (in kg/ha) are two- to threefold higher than in most developed countries, and this is taking its toll on the environment. Problems include severe surface...... water and groundwater pollution by nitrogen and pesticides, soil degradation, bioaccumulation of toxic compounds, and more. It is crucial for China to do improve the safeguarding of its water resources in order to sustain the livelihoods of its people and ensure safe supply of drinking water. Recently......-groundwater interaction was chosen, and field work was performed between October 2012 and March 2014. Results from the field study showed that fertilizer inputs were excessive, and could be reduced substantially. Contaminated river water was infiltrating – and carrying ammonium pollution – into the shallow groundwater...

Bioremediation potential of diesel-contaminated Libyan soil.

Science.gov (United States)

Koshlaf, Eman; Shahsavari, Esmaeil; Aburto-Medina, Arturo; Taha, Mohamed; Haleyur, Nagalakshmi; Makadia, Tanvi H; Morrison, Paul D; Ball, Andrew S

2016-11-01

Bioremediation is a broadly applied environmentally friendly and economical treatment for the clean-up of sites contaminated by petroleum hydrocarbons. However, the application of this technology to contaminated soil in Libya has not been fully exploited. In this study, the efficacy of different bioremediation processes (necrophytoremediation using pea straw, bioaugmentation and a combination of both treatments) together with natural attenuation were assessed in diesel contaminated Libyan soils. The addition of pea straw was found to be the best bioremediation treatment for cleaning up diesel contaminated Libyan soil after 12 weeks. The greatest TPH degradation, 96.1% (18,239.6mgkg(-1)) and 95% (17,991.14mgkg(-1)) were obtained when the soil was amended with pea straw alone and in combination with a hydrocarbonoclastic consortium respectively. In contrast, natural attenuation resulted in a significantly lower TPH reduction of 76% (14,444.5mgkg(-1)). The presence of pea straw also led to a significant increased recovery of hydrocarbon degraders; 5.7log CFU g(-1) dry soil, compared to 4.4log CFUg(-1) dry soil for the untreated (natural attenuation) soil. DGGE and Illumina 16S metagenomic analyses confirm shifts in bacterial communities compared with original soil after 12 weeks incubation. In addition, metagenomic analysis showed that original soil contained hydrocarbon degraders (e.g. Pseudoxanthomonas spp. and Alcanivorax spp.). However, they require a biostimulant (in this case pea straw) to become active. This study is the first to report successful oil bioremediation with pea straw in Libya. It demonstrates the effectiveness of pea straw in enhancing bioremediation of the diesel-contaminated Libyan soil. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessment of heavy metals contamination in surface layers of Roztocze National Park forest soils (SE Poland) by indices of pollution.

Science.gov (United States)

Mazurek, Ryszard; Kowalska, Joanna; Gąsiorek, Michał; Zadrożny, Paweł; Józefowska, Agnieszka; Zaleski, Tomasz; Kępka, Wojciech; Tymczuk, Maryla; Orłowska, Kalina

2017-02-01

In most cases, in soils exposed to heavy metals accumulation, the highest content of heavy metals was noted in the surface layers of the soil profile. Accumulation of heavy metals may occur both as a result of natural processes as well as anthropogenic activities. The quality of the soil exposed to heavy metal contamination can be evaluated by indices of pollution. On the basis of determined heavy metals (Pb, Zn, Cu, Mn, Ni and Cr) in the soils of Roztocze National Park the following indices of pollution were calculated: Enrichment Factor (EF), Geoaccumulation Index (I geo ), Nemerow Pollution Index (PI Nemerow ) and Potential Ecological Risk (RI). Additionally, we introduced and calculated the Biogeochemical Index (BGI), which supports determination of the ability of the organic horizon to accumulate heavy metals. A tens of times higher content of Pb, Zn, Cu and Mn was found in the surface layers compared to their content in the parent material. This distribution of heavy metals in the studied soils was related to the influence of anthropogenic pollution (both local and distant sources of emission), as well as soil properties such as pH, organic carbon and total nitrogen content. Copyright © 2016 Elsevier Ltd. All rights reserved.

A review of biochars' potential role in the remediation, revegetation and restoration of contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Beesley, Luke, E-mail: luke.beesley@hutton.ac.uk [James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom); Moreno-Jimenez, Eduardo [Departamento de Quimica Agricola, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Gomez-Eyles, Jose L. [Department of Civil and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250 (United States); Harris, Eva; Robinson, Brett [Department of Soil and Physical Sciences, Lincoln University, Lincoln 7647 (New Zealand); Sizmur, Tom [Soil Research Centre, Department of Geography and Environmental Science, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom)

2011-12-15

Biochars are biological residues combusted under low oxygen conditions, resulting in a porous, low density carbon rich material. Their large surface areas and cation exchange capacities, determined to a large extent by source materials and pyrolysis temperatures, enables enhanced sorption of both organic and inorganic contaminants to their surfaces, reducing pollutant mobility when amending contaminated soils. Liming effects or release of carbon into soil solution may increase arsenic mobility, whilst low capital but enhanced retention of plant nutrients can restrict revegetation on degraded soils amended only with biochars; the combination of composts, manures and other amendments with biochars could be their most effective deployment to soils requiring stabilisation by revegetation. Specific mechanisms of contaminant-biochar retention and release over time and the environmental impact of biochar amendments on soil organisms remain somewhat unclear but must be investigated to ensure that the management of environmental pollution coincides with ecological sustainability. - Highlights: > Biochars can reduce mobilities of some organic and inorganic pollutants in soil. > Source material and production conditions influence pollutant retention. > Highly alkaline pH and water soluble carbon can undesirably mobilise some elements. > Large surface area may be toxic to soil fauna but create microbial niches. > Efficacy of biochar may depend on other organic materials applied in combination. - Biochars can reduce the mobility and impact of some soil pollutants but, if applied alone, may fail to support soil restoration, revegetation and hence ecologically circumspect remediation.

SOIL WASHING TREATABILITY TESTS FOR PESTICIDE- CONTAMINATED SOIL

Science.gov (United States)

The 1987 Sand Creek Operable Unit 5 record of decision (ROD) identified soil washing as the selected technology to remediate soils contaminated with high levels of organochlorine pesticides, herbicides, and metals. Initial treatability tests conducted to assess the applicability...

Biochar as possible long-term soil amendment for phytostabilisation of TE-contaminated soils.

Science.gov (United States)

Bopp, Charlotte; Christl, Iso; Schulin, Rainer; Evangelou, Michael W H

2016-09-01

Soils contaminated by trace elements (TEs) pose a high risk to their surrounding areas as TEs can spread by wind and water erosion or leaching. A possible option to reduce TE transfer from these sites is phytostabilisation. It is a long-term and cost-effective rehabilitation strategy which aims at immobilising TEs within the soil by vegetation cover and amendment application. One possible amendment is biochar. It is charred organic matter which has been shown to immobilise metals due to its high surface area and alkaline pH. Doubts have been expressed about the longevity of this immobilising effect as it could dissipate once the carbonates in the biochar have dissolved. Therefore, in a pot experiment, we determined plant metal uptake by ryegrass (Lolium perenne) from three TE-contaminated soils treated with two biochars, which differed only in their pH (acidic, 2.80; alkaline, 9.33) and carbonate (0.17 and 7.3 %) content. Root biomass was increased by the application of the alkaline biochar due to the decrease in TE toxicity. Zinc and Cu bioavailability and plant uptake were equally reduced by both biochars, showing that surface area plays an important role in metal immobilisation. Biochar could serve as a long-term amendment for TE immobilisation even after its alkalinity effect has dissipated.

Evaluation of Carbonation Effects on Cement-Solidified Contaminated Soil Used in Road Subgrade

Directory of Open Access Journals (Sweden)

Yundong Zhou

2018-01-01

Full Text Available Cement solidification/stabilization is widely used towards contaminated soil since it has a low price and significant improvement for the structural capacity of soil. To increase the usage of the solidified matrix, cement-solidified contaminated soil was used as road subgrade material. In this study, carbonation effect that reflected the durability on strength characteristics of cement-solidified contaminated soil and the settlement of pavement were evaluated through experimental and numerical analysis, respectively. According to results, compressive strengths of specimens with 1% Pb(II under carbonation and standard curing range from 0.44 MPa to 1.17 MPa and 0.14 MPa to 2.67 MPa, respectively. The relatively low strengths were attributed to immobilization of heavy metal, which consumed part of SiO2, Al2O3, and CaO components in the cement or kaolin and reduced the hydration and pozzolanic reaction materials. This phenomenon further decreased the strength of solidified soils. The carbonation depth of 1% Cu(II or Zn(II contaminated soils was 18 mm, which significantly increased with the increase of curing time and contamination concentration. Furthermore, the finite element calculation results showed that surface settlements decreased with the increase of modulus of subgrade and the distance away from the center. At the center, the pavement settlement was proportional to the level of traffic load.

Assessment of produced water contaminated soils to determine remediation requirements

International Nuclear Information System (INIS)

Clodfelter, C.

1995-01-01

Produced water and drilling fluids can impact the agricultural properties of soil and result in potential regulatory and legal liabilities. Produced water typically is classified as saline or a brine and affects surface soils by increasing the sodium and chloride content. Sources of produced water which can lead to problems include spills from flowlines and tank batteries, permitted surface water discharges and pit areas, particularly the larger pits including reserve pits, emergency pits and saltwater disposal pits. Methods to assess produced water spills include soil sampling with various chemical analyses and surface geophysical methods. A variety of laboratory analytical methods are available for soil assessment which include electrical conductivity, sodium adsorption ratio, cation exchange capacity, exchangeable sodium percent and others. Limiting the list of analytical parameters to reduce cost and still obtain the data necessary to assess the extent of contamination and determine remediation requirements can be difficult. The advantage to using analytical techniques is that often regulatory remediation standards are tied to soil properties determined from laboratory analysis. Surface geophysical techniques can be an inexpensive method to rapidly determine the extent and relative magnitude of saline soils. Data interpretations can also provide an indication of the horizontal as well as the vertical extent of impacted soils. The following discussion focuses on produced water spills on soil and assessment of the impacted soil. Produced water typically contains dissolved hydrocarbons which are not addressed in this discussion

Algal tests with soil suspensions and elutriates: A comparative evaluation for PAH contaminated soils

DEFF Research Database (Denmark)

Baun, Anders; Justesen, Kasper Bo; Nyholm, Niels

2002-01-01

An algal growth inhibition test procedure with soil suspensions is proposed and evaluated for PAH-contaminated soil. The growth rate reduction of the standard freshwater green alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum) was used as the toxicity endpoint......, and was quantified by measuring the fluorescence of solvent-extracted algal pigments. No growth rate reduction was detected for soil contents up to 20 g/l testing five non-contaminated Danish soils. Comparative testing with PAH-contaminated soil elutriates and soil suspensions showed that the suspensions had...

Flotation separation of uranium from contaminated soils

International Nuclear Information System (INIS)

Misra, M.; Mehta, R.; Garcia, H.; Chai, C.D.; Smith, R.W.

1995-01-01

The volume of low-level contaminated soil at the Department of Energy's Nuclear Weapon Sites are in the order of several million tons. Most of the contaminants are uranium, plutonium, other heavy metals and organic compounds. Selected physical separation processes have shown demonstrated potential in concentrating the radionuclides in a small fraction of the soil. Depending upon the size, nature of bonding and distributions of radionuclides, more than 90% of the radionuclide activity can be concentrated in a small volume of fraction of the soil. The physico-chemical separation processes such as flotation in a mechanical and microbubble tall column cell have shown promising applications in cleaning up the high volume contaminated soil

Bioremediation of petroleum-contaminated soil: A Review

Science.gov (United States)

Yuniati, M. D.

2018-02-01

Petroleum is the major source of energy for various industries and daily life. Releasing petroleum into the environment whether accidentally or due to human activities is a main cause of soil pollution. Soil contaminated with petroleum has a serious hazard to human health and causes environmental problems as well. Petroleum pollutants, mainly hydrocarbon, are classified as priority pollutants. The application of microorganisms or microbial processes to remove or degrade contaminants from soil is called bioremediation. This microbiological decontamination is claimed to be an efficient, economic and versatile alternative to physicochemical treatment. This article presents an overview about bioremediation of petroleum-contaminated soil. It also includes an explanation about the types of bioremediation technologies as well as the processes.

Modified natural diatomite and its enhanced immobilization of lead, copper and cadmium in simulated contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Ye, Xinxin, E-mail: xxye@issp.ac.cn [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Kang, Shenghong; Wang, Huimin [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Li, Hongying [Institute of Soil and Fertilizer, Anhui Academy of Agricultural Sciences, Hefei 230031 (China); Zhang, Yunxia [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wang, Guozhong, E-mail: gzhwang@issp.ac.cn [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhao, Huijun [Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Centre for Clean Environment and Energy, Gold Coast Campus, Griffith University, Queensland 4222 (Australia)

2015-05-30

Highlights: • We modify natural diatomite using the facile acid treatment and ultrasonication. • Modification add pore volume, surface area and electronegativity of natural diatomite. • Modified diatomite is superior to natural diatomite in soil heavy metal remediation. • Modified diatomite can be promising for in-situ immobilization of heavy metal in soil. - Abstract: Natural diatomite was modified through facile acid treatment and ultrasonication, which increased its electronegativity, and the pore volume and surface area achieved to 0.211 cm{sup 3} g{sup −1} and 76.9 m{sup 2} g{sup −1}, respectively. Modified diatomite was investigated to immobilize the potential toxic elements (PTEs) of Pb, Cu and Cd in simulated contaminated soil comparing to natural diatomite. When incubated with contaminated soils at rates of 2.5% and 5.0% by weight for 90 days, modified diatomite was more effective in immobilizing Pb, Cu and Cd than natural diatomite. After treated with 5.0% modified diatomite for 90 days, the contaminated soils showed 69.7%, 49.7% and 23.7% reductions in Pb, Cu and Cd concentrations after 0.01 M CaCl{sub 2} extraction, respectively. The concentrations of Pb, Cu and Cd were reduced by 66.7%, 47.2% and 33.1% in the leaching procedure, respectively. The surface complexation played an important role in the immobilization of PTEs in soils. The decreased extractable metal content of soil was accompanied by improved microbial activity which significantly increased (P < 0.05) in 5.0% modified diatomite-amended soils. These results suggested that modified diatomite with micro/nanostructured characteristics increased the immobilization of PTEs in contaminated soil and had great potential as green and low-cost amendments.

Bioremediation of uranium contaminated Fernald soils

International Nuclear Information System (INIS)

Delwiche, M.E.; Wey, J.E.; Torma, A.E.

1994-01-01

This study investigated the use of microbial bioleaching for removal of uranium from contaminated soils. The ability of bacteria to assist in oxidation and solubilization of uranium was compared to the ability of fungi to produce complexing compounds which have the same effect. Biosorption of uranium by fungi was also measured. Soil samples were examined for changes in mineralogical properties due to these processes. On the basis of these laboratory scale studies a generalized flow sheet is proposed for bioremediation of contaminated Fernald soils

Contaminant resorption during soil washing

International Nuclear Information System (INIS)

Gombert, D.

1993-01-01

To evaluate the applicability of soil washing to a specific site requires some basic research in how contaminants are bound. Much can be learned from sequential extraction methodology based on micronutrient bioavailability studies wherein the soil matrix is chemically dissected to selectively remove particular fixation mechanisms independently. This procedure uses a series of progressively more aggressive solvents to dissolve the principle phases that make up a soil, however, the published studies do not appear to consider the potential for a contaminant released from one type of site to resorb on another site during an extraction. This physical model assumes no ion exchange or adsorption at sites either previously occupied by other ions, or exposed by the dissolution. Therefore, to make engineering use of the sequential extraction data, the release of contamination must be evaluated relative to the effects of resorption. Time release studies were conducted to determine the optimum duration for extraction to maximize complete destruction of the target matrix fraction while minimizing contaminant resorption. Tests with and without a potassium brine present to inhibit cesium resorption indicated extraction efficiency could be enhanced by as much as a factor of ten using the brine

Assessing the fate of antibiotic contaminants in metal contaminated soils four years after cessation of long-term waste water irrigation

International Nuclear Information System (INIS)

Tamtam, Fatima; Oort, Folkert van; Le Bot, Barbara; Dinh, Tuc; Mompelat, Sophie; Chevreuil, Marc; Lamy, Isabelle; Thiry, Medard

2011-01-01

Spreading of urban wastewater on agricultural land may lead to concomitant input of organic and inorganic pollutants. Such multiple pollution sites offer unique opportunities to study the fate of both heavy metals and pharmaceuticals. We examined the occurrence and fate of selected antibiotics in sandy-textured soils, sampled four years after cessation of 100 years irrigation with urban wastewater from the Paris agglomeration. Previous studies on heavy metal contamination of these soils guided our sampling strategy. Six antibiotics were studied, including quinolones, with a strong affinity for organic and mineral soil components, and sulfonamides, a group of more mobile molecules. Bulk samples were collected from surface horizons in different irrigation fields, but also in subsurface horizons in two selected profiles. In surface horizons, three quinolones (oxolinic acid, nalidixic acid, and flumequine) were present in eight samples out of nine. Their contents varied spatially, but were well-correlated one to another. Their distributions showed great similarities regarding spatial distribution of total organic carbon and heavy metal contents, consistent with a common origin by wastewater irrigation. Highest concentrations were observed for sampling sites close to irrigation water outlets, reaching 22 μg kg -1 for nalidixic acid. Within soil profiles, the two antibiotic groups demonstrated an opposite behavior: quinolones, found only in surface horizons; sulfamethoxazole, detected in clay-rich subsurface horizons, concomitant with Zn accumulation. Such distribution patterns are consistent with chemical adsorption properties of the two antibiotic groups: immobilization of quinolones in the surface horizons ascribed to strong affinity for organic matter (OM), migration of sulfamethoxazole due to a lower affinity for OM and its interception and retention in electronegative charged clay-rich horizons. Our work suggests that antibiotics may represent a durable

Bioremediation of lead contaminated soil with Rhodobacter sphaeroides.

Science.gov (United States)

Li, Xiaomin; Peng, Weihua; Jia, Yingying; Lu, Lin; Fan, Wenhong

2016-08-01

Bioremediation with microorganisms is a promising technique for heavy metal contaminated soil. Rhodobacter sphaeroides was previously isolated from oil field injection water and used for bioremediation of lead (Pb) contaminated soil in the present study. Based on the investigation of the optimum culturing conditions and the tolerance to Pb, we employed the microorganism for the remediation of Pb contaminated soil simulated at different contamination levels. It was found that the optimum temperature, pH, and inoculum size for R. sphaeroides is 30-35 °C, 7, and 2 × 10(8) mL(-1), respectively. Rhodobacter sphaeroides did not remove the Pb from soil but did change its speciation. During the bioremediation process, more available fractions were transformed to less accessible and inert fractions; in particular, the exchangeable phase was dramatically decreased while the residual phase was substantially increased. A wheat seedling growing experiment showed that Pb phytoavailability was reduced in amended soils. Results inferred that the main mechanism by which R. sphaeroides treats Pb contaminated soil is the precipitation formation of inert compounds, including lead sulfate and lead sulfide. Although the Pb bioremediation efficiency on wheat was not very high (14.78% root and 24.01% in leaf), R. sphaeroides remains a promising alternative for Pb remediation in contaminated soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Using Plants for the Bioremediation (Phyto-remediation) of Chromium-Contaminated Soils

International Nuclear Information System (INIS)

Abdel-Sabour, M.F.; Al-Salama, Y.J.

2003-01-01

A trial was made to study the use of hyper accumulator plant species to extract Cr out of contaminated soils. Three soils (A,B, and C) were selected in this experiment, Soil A: Polluted soil from El-Gabal El-Asfer farm. (subjected to sewage effluent irrigation for more than 75 years). Soil B: Polluted soil from Bahtem area (subjected to sewage effluent irrigation for more than 30 years). Soil C: Polluted soil from Mostorud area (irrigated with contaminated water for more than 30 years due to direct discharge of industrial wastewater to irrigation water canals). Four Kg of each air-dried surface soil sample (0-20 cm) were packed in plastic containers in three replicates. Four plant species tested in this study namely, Sorghum (Sorghum Vulgar L.), Clover (Trifolium Pretense L.), Panikum (Panicum antidotal) and Canola (Brassica Napous.); were grown on each tested soil in a complete randomized block experimental design. Plant shoots were harvested every 60 days (three cuts) for sorghum, clover and panikum. In case of canola plants, the shoots were harvested after 60 days (vegetative stage) and 85 days(fruiting stage). The roots of all species were collected after the final cut. Initial and final soil samples were taken for Cr analyses using neutron activation analyses technique (NAA)

Assessment of the feasibility of anaerobic composting for treatment of perchlorate - contaminated soils in a war zone

Directory of Open Access Journals (Sweden)

Mohammad Mehdi Amin

2015-01-01

Full Text Available Aims: The objectives of this study were to determine the perchlorate concentrations in surface soils and assess feasibility of anaerobic bioremediation in full-scale for perchlorate-contaminated soils in a war zone. Materials and Methods: Fifteen samples of surface soil were collected using a composite sampling method in the study area. The soil samples, after extraction and preparation, were analyzed by ion chromatography. Anaerobic composting technique (soil excavation, mixing with manure, transfer into treatment cell and cover with a 6-mil high-density polyethylene liner considered to cleanup perchlorate-contaminated soil in a war zone. Results: The concentration of perchlorate in the soil surface samples ranged from 3 to 107.9 mg/kg, which is more than State advisory levels for residential and protection of domestic groundwater use pathway. This study indicates that technologies, skills, experience, raw materials (manure, lands, and machinery needed for implementation of full-scale composting, are available in the study area. Conclusions: Based on the results, anaerobic composting technique could be considered as a feasible, viable and cost-effective alternative for perchlorate bioremediation in the study area. According to the available of techniques and skills, successful experiences of anaerobic composting in other countries, and potential of study area, The application of anaerobic composting is technically feasible and can be use for perchlorate contaminated soil cleanup in a zone war.

Integrated electrokinetics-adsorption remediation of saline-sodic soils: effects of voltage gradient and contaminant concentration on soil electrical conductivity.

Science.gov (United States)

Essa, Mohammed Hussain; Mu'azu, Nuhu Dalhat; Lukman, Salihu; Bukhari, Alaadin

2013-01-01

In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil electrical conductivity. Box-Behnken Design (BBD) was used for the experimental design and response surface methodology (RSM) was employed to model, optimize, and interpret the results obtained using Design-Expert version 8 platform. The total number of experiments conducted was 15 with voltage gradient, polarity reversal rate, and initial contaminant concentration as variables. The main target response discussed in this paper is the soil electrical conductivity due to its importance in electrokinetic remediation process. Responses obtained were fitted to quadratic models whose R (2) ranges from 84.66% to 99.19% with insignificant lack of fit in each case. Among the investigated factors, voltage gradient and initial contaminant concentration were found to be the most significant influential factors.

Integrated Electrokinetics-Adsorption Remediation of Saline-Sodic Soils: Effects of Voltage Gradient and Contaminant Concentration on Soil Electrical Conductivity

Directory of Open Access Journals (Sweden)

Mohammed Hussain Essa

2013-01-01

Full Text Available In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg, was used in this study to investigate the effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil electrical conductivity. Box-Behnken Design (BBD was used for the experimental design and response surface methodology (RSM was employed to model, optimize, and interpret the results obtained using Design-Expert version 8 platform. The total number of experiments conducted was 15 with voltage gradient, polarity reversal rate, and initial contaminant concentration as variables. The main target response discussed in this paper is the soil electrical conductivity due to its importance in electrokinetic remediation process. Responses obtained were fitted to quadratic models whose R2 ranges from 84.66% to 99.19% with insignificant lack of fit in each case. Among the investigated factors, voltage gradient and initial contaminant concentration were found to be the most significant influential factors.

Assessment of soil contamination in area surrounding Tuwaitha nuclear facilities

International Nuclear Information System (INIS)

Al-Taii, A.A.F.; AI-Jobori, S.H.; Al-Maadhidi, J.F.

2012-01-01

The wide spread looting of the Tuwaitha Nuclear Facilities as well as damaging of some buildings in 2003, had offered possibilities of contamination of soil environment inside the Site. The objective of the present work was to investigate soil contamination to help in future decontamination programs. A total of 25 soil surface samples (including one reference sample) covered different locations in the Site were collected in March 2011. High purity Ge detector was used for gamma spectrometry of soil samples. Data of total and spectral gamma for U series, Th series, 40 K and 137 Cs are presented. Slight variations were observed in specific activity of the U series 214 Bi or 214 Pb and 226 Ra among measured soil samples where the range was 10.3-12.7 for 214 Bi as compared with 12.2-33.4 Bq/kg for 226 Ra. Values of both 214 Bi and 226 Ra are in the range of reference sample specific activity indicating that no evidence of contamination had occurred in the investigated area. Results of activity concentrations of thorium series 228 Ac or 208 Tl, 212 Pb, and 212 Bi are in the range of reference sample and close to those values given worldwide for natural uranium in soil. The levels of 40 K in soil are within the natural abundance of this isotope in the soil where the range was 207.6-266.1 with 220.3 Bq/kg for the reference sample. On the other hand, 137 Cs specific activities showed great variation among measured samples. The minimum value for 137 Cs was 0.6 and the maximum 7.6 compared with 0.8 Bq/kg for the control soil sample. The non-uniformity of radioactivity concentration of 137 Cs suggest the presence of contamination in some locations although this level is considered as an acceptable level and no hazardous effect will be generated.

Arsenic in contaminated soil and river sediment

International Nuclear Information System (INIS)

Bombach, G.; Pierra, A.; Klemm, W.

1994-01-01

Different areas in the Erzgebirge mountains are contaminated by high arsenic concentration which is caused by the occurrence of ore and industrial sources. The study showed clearly a high concentration of arsenic in the surface and under soil (A and B horizons) in the Freiberg district. The distribution of the arsenic concentration in the area, the content of water soluble arsenic, the several oxidation states (As 3+ , As 5+ ) and the bonding types have been analyzed. (orig.)

Improving the phytoremediation of heavy metals contaminated soil by use of sewage sludge.

Science.gov (United States)

Placek, Agnieszka; Grobelak, Anna; Kacprzak, Malgorzata

2016-01-01

Sewage sludge, in particular from the food industry, is characterized by fertilizing properties, due to the high content of organic matter and nutrients. The application of sewage sludge causes an improvement of soil parameters as well as increase in cation exchange capacity, and thus stronger binding of cations in the soil environment, which involves the immobilization of nutrients and greater resistance to contamination. In a field experiment sewage sludge has been used as an additive to the soil supporting the phytoremediation process of land contaminated with heavy metals (Cd, Zn, and Pb) using trees species: Scots pine (Pinus silvestris L.), Norway spruce (Picea abies L.), and oak (Quercus robur L.). The aim of the research was to determine how the application of sewage sludge into the soil surface improves the phytoremediation process. The conducted field experiment demonstrated that selected trees like Scots pine and Norway spruce, because of its excellent adaptability, can be used in the remediation of soil. Oak should not be used in the phytoremediation process of soils contaminated with high concentrations of trace elements in the soil, because a significant amount of heavy metals was accumulated in the leaves of oak causing a risk of recontamination.

Assessment Of Depleted Uranium Contamination In Selective IRAQI Soils

International Nuclear Information System (INIS)

Mohammed, A.A.; Hussien, A.Sh.M.; Tawfiq, N.F.

2008-01-01

The aim of this research was to measure the radiation exposure rates in three selected Locations in southren part of Iraq (two in Nassireya, and one in Amara) resulted from the existence of depleted uranium in soil and metal pieces have been taken from destroyed tank and study mathmatically the concentration of Depleted Uranium by its dispersion from soil surface by winds and rains from 2003 to 2007. The exposure rates were measured using inspector device, while depleted uranium concentration in soil samples and tank's matal pieces were detected with Solid State Nuclear Track Detectors(SSNTDs). The wind and rain effects were considered in the calculation of dispersion effect on depleted uranium concentration in soil, where the wind effect were calculated with respect to the sites nature and soil conditions, and rain effect with respect to dispersive-convective equation for radionuclide in soil. The results obtained for the exposure rates were high near the penetrated surfac, moderate and low in soil and metal pices. The Depleted Uranium concentration in soil and metal pieces have the highest value in Nassireya. The results from dispersion calculation (wind & rain) showed that the depleted uranium concentration in 2008 will be less than the danger level and in allowable contamination range

Ecological Role of Soils upon Radioactive Contamination

Science.gov (United States)

Tsvetnov, Evgeny; Shcheglov, Alexei; Tsvenova, Olga

2016-04-01

The ecological role of soils upon radioactive contamination is clearly manifested in the system of notions about ecosystems services, i.e., benefits gained by humans from ecosystems and their components, including soils (Millennium Ecosystem Assessment, 2005). For the soils, these services are considered on the basis of soil functions in the biosphere that belong to the protective ecosystem functions within the group of soil functions known under the names of "Buffer and protective biogeocenotic shield" (at the level of particular biogeocenoses) and "Protective shield of the biosphere" (at the global biospheric level) (according to Dobrovol'skii & Nikitin, 2005). With respect to radionuclides, this group includes (1) the depositing function, i.e., the accumulation and long-term sequestration of radioactive substances by the soil after atmospheric fallout; (2) the geochemical function, i.e., the regulation of horizontal and vertical fluxes of radionuclides in the system of geochemically conjugated landscapes and in the soil-groundwater and soil-plant systems; and (3) the dose-forming function that is manifested by the shielding capacity of the soil with respect to the external ionizing radiation (lowering of the dose from external radiation) and by the regulation of the migration of radionuclides in the trophic chain (lowering of the dose from internal radiation). The depositing and geochemical functions of the soils are interrelated, which is seen from quantitative estimates of the dynamics of the fluxes of radionuclides in the considered systems (soil-plant, soil-groundwater, etc.). The downward migration of radionuclides into the lower soil layers proceeds very slowly: for decades, more than 90% of the pool of radionuclides is stored in the topmost 10 cm of the soil profile. In the first 3-5 years after the fallout, the downward migration of radionuclides with infiltrating water flows decreases from several percent to decimals and hundredths of percent from the

Remediation of contaminated soil by cement treatment

International Nuclear Information System (INIS)

Dimovic, S.

2004-01-01

This manuscript presents the most applicable remedial technologies for contaminated soil with focus on cement stabilisation/solidification treatment. These technologies are examined in the light of soil contamination with depleted uranium in the large area of south Serbia,after Nato bombing 1999. (author) [sr

Possibilities of using Eisenia Andrei earthworms as bioindicators of radioactive soil contamination

International Nuclear Information System (INIS)

Galanda, D.; Strisovska, J.; Lacenova, A.

2017-01-01

Eisenia Andrei is known under various generic names such as Californian daisy, red daisy, tiger worm etc. It is a species of earthworm that is physiologically adapted to life in a medium containing organic matter. Staining (vermiremedia technology) of soils contaminated with heavy metals belongs among innovative and efficient techniques. According to published works, this technology is easy to apply. Dandelions are used for soil rehabilitation, rejuvenation and mineral enrichment in the soil. In the soil environment, the effect of the sunsets is known as the drilosphere of the system, that is, the soil is under their direct influence. The aim of the present paper was to verify the possibility of application and subsequent use of Eisenia Andrei sunflowers as bioindicators in soil contaminated by radionuclides "2"3"9Pu and "2"4"1Am, which are significant anthropogenic radionuclides emitting alpha particles. Another circle of radionuclides were anthropogenic radionuclides "6"0Co and "1"3"7Cs emitting gamma rays. Based on the radionuclides used, two groups of target-contaminated samples were subjected to experimentation and spectrometric analysis alone. The first group of experimental subjects was made up of earthworms living in alpha radionuclide-enriched soils, and in the second group of gamma-radionuclides. Radiochemical analysis of alpha radionuclides was performed by a separation method of extraction chromatography using commercial sorbents from Triskem-TEVA Resin and DGA Resin. The preparation of specimens for the spectroscopic analysis of the emitted alpha configuration was performed by co-precipitation with NdCl_3. The measurement itself was performed with the ORTEC 576A Alpha Spectrometer with the GammaVision software. The activity of gamma radionuclides in a sample of animals devoid of possible surface contamination from the nutrient medium of the contaminated soil was measured using the Ortec gamma spectrometer. (authors)

Screening of plants for phytoremediation of oil-contaminated soil.

Science.gov (United States)

Ikeura, Hiromi; Kawasaki, Yu; Kaimi, Etsuko; Nishiwaki, Junko; Noborio, Kosuke; Tamaki, Masahiko

2016-01-01

Several species of ornamental flowering plants were evaluated regarding their phytoremediation ability for the cleanup of oil-contaminated soil in Japanese environmental conditions. Thirty-three species of plants were grown in oil-contaminated soil, and Mimosa, Zinnia, Gazania, and cypress vine were selected for further assessment on the basis of their favorable initial growth. No significant difference was observed in the above-ground and under-ground dry matter weight of Gazania 180 days after sowing between contaminated and non-contaminated plots. However, the other 3 species of plants died by the 180th day, indicating that Gazania has an especially strong tolerance for oil-contaminated soil. The total petroleum hydrocarbon concentration of the soils in which the 4 species of plants were grown decreased by 45-49% by the 180th day. Compared to an irrigated plot, the dehydrogenase activity of the contaminated soil also increased significantly, indicating a phytoremediation effect by the 4 tested plants. Mimosa, Zinnia, and cypress vine all died by the 180th day after seeding, but the roots themselves became a source of nutrients for the soil microorganisms, which led to a phytoremediation effect by increase in the oil degradation activity. It has been indicated that Gazania is most appropriate for phytoremediation of oil-contaminated soil.

Sorption ability of the soil and its impact on environmental contamination

Science.gov (United States)

Gargošová, Helena Zlámalová; Vávrová, Milada

2014-01-01

From the physical point of view, soil is a heterogenic polydisperse system. It often becomes a place of a secondary contamination during extinguishing uncontrolled areal fires in nature. Foam extinguishing agents (FEAs), used at these events, basically contain surface active substances and perfluorinated compounds. These tend to be captured in the soil matrix due to their specific properties. Contaminants could be partly flushed out with rainwater, which causes several times dilution of contamination and lower ecotoxic activity. However in the dry season, foam solution infiltrates into the bed soil without any dilution. This study deals with the direct influence of soil the sorption complex on ecotoxicity of five selected FEAs, i.e. Expyrol F 15, Finiflam F 15, Moussol APS F 15, Pyrocool B and Sthamex F 15. The substances tested were prepared in concentration of work solution and then applied on standard soil matrix LUFA 2.3. For experimental purposes, a column infiltration apparatus was designed and compiled. Filtrates were collected and then tested using the plant organisms Sinapis alba and Allium cepa L. The study compared ecotoxicologic effects of filtrates with an original work solution. Moussol APS F 15 seems to be the least ecotoxic of the FEAs tested. A direct influence of soil sorption complex onto ecotoxicity reduction was also established. This finding demonstrates the sorption ability of soil particles and ion exchange activity of the soil matrix. It is a positive finding for biota of aquatic environment, yet at the expense of those in soil. PMID:26109897

Modified natural diatomite and its enhanced immobilization of lead, copper and cadmium in simulated contaminated soils.

Science.gov (United States)

Ye, Xinxin; Kang, Shenghong; Wang, Huimin; Li, Hongying; Zhang, Yunxia; Wang, Guozhong; Zhao, Huijun

2015-05-30

Natural diatomite was modified through facile acid treatment and ultrasonication, which increased its electronegativity, and the pore volume and surface area achieved to 0.211 cm(3) g(-1) and 76.9 m(2) g(-1), respectively. Modified diatomite was investigated to immobilize the potential toxic elements (PTEs) of Pb, Cu and Cd in simulated contaminated soil comparing to natural diatomite. When incubated with contaminated soils at rates of 2.5% and 5.0% by weight for 90 days, modified diatomite was more effective in immobilizing Pb, Cu and Cd than natural diatomite. After treated with 5.0% modified diatomite for 90 days, the contaminated soils showed 69.7%, 49.7% and 23.7% reductions in Pb, Cu and Cd concentrations after 0.01 M CaCl2 extraction, respectively. The concentrations of Pb, Cu and Cd were reduced by 66.7%, 47.2% and 33.1% in the leaching procedure, respectively. The surface complexation played an important role in the immobilization of PTEs in soils. The decreased extractable metal content of soil was accompanied by improved microbial activity which significantly increased (Psoils. These results suggested that modified diatomite with micro/nanostructured characteristics increased the immobilization of PTEs in contaminated soil and had great potential as green and low-cost amendments. Copyright © 2015 Elsevier B.V. All rights reserved.

Radionuclide contaminated soil: Laboratory study and economic analysis of soil washing. Final report

International Nuclear Information System (INIS)

Fuhrmann, M.; Zhou, H.; Patel, B.; Bowerman, B.; Brower, J.

1996-01-01

The objective of the work discussed in this report is to determine if soil washing is a feasible method to remediate contaminated soils from the Hazardous Waste Management Facility (HWMF) at Brookhaven National Laboratory (BNL). The contaminants are predominantly Cs-137 and Sr-90. The authors have assumed that the target activity for Cs-137 is 50 pCi/g and that remediation is required for soils having greater activities. Cs-137 is the limiting contaminant because it is present in much greater quantities than Sr-90. This work was done in three parts, in which they: estimated the volume of contaminated soil as a function of Cs-137 content, determined if simple removal of the fine grained fraction of the soil (the material that is less than 0.063 mm) would effectively reduce the activity of the remaining soil to levels below the 50 pCi/g target, assessed the effectiveness of chemical and mechanical (as well as combinations of the two) methods of soil decontamination. From this analysis the authors were then able to develop a cost estimate for soil washing and for a baseline against which soil washing was compared

Soil contamination studies

International Nuclear Information System (INIS)

1997-06-01

The objective of this project was to develop a quick screening method that accurately identifies and quantifies the amount of alpha-emitting radionuclides in infinitely-thick soil samples using a Frisch grid ionization chamber. An additional objective of the work was to provide the US Department of Energy, Nevada Operations Office and its contractors with information on the theoretical and actual measured results of atmospheric testing contamination of soil and water at the Nevada Test Site through a comprehensive search of existing literature

Radioactive contamination of the Dutch soil in consequence of the nuclear reactor accident at Chernobyl

International Nuclear Information System (INIS)

Koester, H.W.; Mattern, F.C.M.; Pennders, R.M.J.

1987-01-01

As a consequence of the reactor accident in Chernobyl air, contaminated with radioactive materials, spread over the Netherlands. From 2nd May to 6th May, with dry and to a greater extent with wet deposits, important quantities of radionuclides came upon the earth surface. In this period the weather circumstances within the Netherlands differed strongly resulting in distinct variations in deposit. In this document a preliminary picture is given of the contamination of the Dutch bottom on the basis of soil samplings made in the first few months after the accident. No attention is paid to geographic differences in bottom contamination. The contamination of the bottom is expressed in Bq/kg dry soil as well as in Bq/m 2 soil. 5 refs.; 6 tabs. (H.W.)

The Influence of Soil Chemical Factors on In Situ Bioremediation of Soil Contamination

Energy Technology Data Exchange (ETDEWEB)

Breedveld, Gijs D.

1997-12-31

Mineral oil is the major energy source in Western society. Production, transport and distribution of oil and oil products cause serious contamination problems of water, air and soil. The present thesis studies the natural biodegradation processes in the soil environment which can remove contamination by oil products and creosote. The main physical/chemical processes determining the distribution of organic contaminants between the soil solid, aqueous and vapour phase are discussed. Then a short introduction to soil microbiology and environmental factors important for biodegradation is given. There is a discussion of engineered and natural bioremediation methods and the problems related to scaling up laboratory experiments to field scale remediation. Bioremediation will seldom remove the contaminants completely; a residue remains. Factors affecting the level of residual contamination and the consequences for contaminant availability are discussed. Finally, the main findings of the work are summarized and recommendations for further research are given. 111 refs., 41 figs., 19 tabs.

Statistical sampling strategies for survey of soil contamination

NARCIS (Netherlands)

Brus, D.J.

2011-01-01

This chapter reviews methods for selecting sampling locations in contaminated soils for three situations. In the first situation a global estimate of the soil contamination in an area is required. The result of the surey is a number or a series of numbers per contaminant, e.g. the estimated mean

Effects of past copper contamination and soil structure on copper leaching from soil

DEFF Research Database (Denmark)

Paradelo, M; Møldrup, Per; Arthur, Emmanuel

2013-01-01

Copper contamination affects biological, chemical, and physical soil properties and associated ecological functions. Changes in soil pore organization as a result of Cu contamination can dramatically affect flow and contaminant transport in polluted soils. This study assessed the influence of soil...... structure on the movement of water and Cu in a long-term polluted soil. Undisturbed soil cores collected along a Cu gradient (from about 20 to about 3800 mg Cu kg−1 soil) were scanned using X-ray computed tomography (CT). Leaching experiments were performed to analyze tracer transport, colloid leaching......, and dissolved organic carbon (DOC) and Cu losses. The 5% arrival time (t0.05) and apparent dispersivity (λapp) for tracer breakthrough were calculated by fitting the experimental data to a nonparametric, double-lognormal probability density function. Soil bulk density, which did not follow the Cu gradient...

Phyto-remediation of contaminated soils

International Nuclear Information System (INIS)

Chagvardieff, P.

2014-01-01

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

Bioremediation of soil contaminated crude oil by Agaricomycetes.

Science.gov (United States)

Mohammadi-Sichani, M Maryam; Assadi, M Mazaheri; Farazmand, A; Kianirad, M; Ahadi, A M; Ghahderijani, H Hadian

2017-01-01

One of the most important environmental problems is the decontamination of petroleum hydrocarbons polluted soil, particularly in the oil-rich country. Bioremediation is the most effective way to remove these pollutants in the soil. Spent mushroom compost has great ability to decompose lignin-like pollution. The purpose of this study was the bioremediation of soil contaminated with crude oil by an Agaricomycetes . Soil sample amended with spent mushroom compost into 3%, 5% and 10% (w/w) with or without fertilizer. Ecotoxicity germination test was conducted with Lipidium sativa . The amplified fragment (18 s rDNA) sequence of this mushroom confirmed that the strain belonged to Pleurotus ostreatus species with complete homology (100% identity). All tests experiment sets were effective at supporting the degradation of petroleum hydrocarbons contaminated soil after three months. Petroleum contaminated soil amended with Spent mushroom compost 10% and fertilizer removed 64.7% of total petroleum hydrocarbons compared control. The germination index (%) in ecotoxicity tests ranged from 60.4 to 93.8%. This showed that the petroleum hydrocarbons contaminated soil amended with 10% Spent mushroom compost had higher bioremediation ability and reduced soil toxicity in less than three months.

Electrokinetic treatment of contaminated soils, sludges, and lagoons

International Nuclear Information System (INIS)

Wittle, J.K.; Pamukcu, S.

1993-04-01

The electrokinetic process is an emerging technology for in-situ soil decontamination, in which chemical species, both ionic and nonionic are transported to an electrode site in soil. These products are subsequently removed from the ground via collection systems engineered for each specific application. Electrokinetics refer to movement of water, ions and charged particles relative to one another under the action of an applied direct current electric field. In a porous compact matrix of surface charged particles such as soil, the ion containing pore fluid may be made to flow to collection sites under the applied field. This report describes the effort undertaken to investigate electrokinetically enhanced transport of soil contaminants in synthetic systems. These systems consisted of clay or clay-sand mixtures containing known concentration of a selected heavy metal salt solution or an organic compound. Metals, surrogate radio nuclides and organic compounds evaluated in the program were representatives of those found at a majority of DOE sites. Degree of removal of these metals from soil by the electrokinetic treatment process was assessed through the metal concentration profiles generated across the soil between the electrodes. The best removals, from about 85 to 95% were achieved at the anode side of the soil specimens. Transient pH change had an effect on the metal movement via transient creation of different metal species with different ionic mobilities, as well as changing of the surface characteristics of the soil medium

Remediation of soil contaminated with polycyclic aromatic ...

African Journals Online (AJOL)

user

2011-02-14

Feb 14, 2011 ... The aim of this study was to determine ways of remediating soils contaminated with polycyclic aromatic hydrocarbons (PAHs) associated with crude oil. The study involves the use of planted cowpeas, mushrooms, algae, dead vegetable and live earthworm, and fire-heating of the contaminated garden soil ...

Biochar- and phosphate-induced immobilization of heavy metals in contaminated soil and water: implication on simultaneous remediation of contaminated soil and groundwater.

Science.gov (United States)

Liang, Yuan; Cao, Xinde; Zhao, Ling; Arellano, Eduardo

2014-03-01

Long-term wastewater irrigation or solid waste disposal has resulted in the heavy metal contamination in both soil and groundwater. It is often separately implemented for remediation of contaminated soil or groundwater at a specific site. The main objective of this study was to demonstrate the hypothesis of simultaneous remediation of both heavy metal contaminated soil and groundwater by integrating the chemical immobilization and pump-and-treat methods. To accomplish the objective, three experiments were conducted, i.e., an incubation experiment was first conducted to determine how dairy-manure-derived biochar and phosphate rock tailing induced immobilization of Cd in the Cd-contaminated soils; second, a batch sorption experiment was carried out to determine whether the pre-amended contaminated soil still had the ability to retain Pb, Zn and Cd from aqueous solution. BCR sequential extraction as well as XRD and SEM analysis were conducted to explore the possible retention mechanism; and last, a laboratory-scale model test was undertaken by leaching the Pb, Zn, and Cd contaminated groundwater through the pre-amended contaminated soils to demonstrate how the heavy metals in both contaminated soil and groundwater were simultaneously retained and immobilized. The incubation experiment showed that the phosphate biochar were effective in immobilizing soil Cd with Cd concentration in TCLP (toxicity characteristics leaching procedure) extract reduced by 19.6 % and 13.7 %, respectively. The batch sorption experiment revealed that the pre-amended soil still had ability to retain Pb, Zn, and Cd from aqueous solution. The phosphate-induced metal retention was mainly due to the metal-phosphate precipitation, while both sorption and precipitation were responsible for the metal stabilization in the biochar amendment. The laboratory-scale test demonstrated that the soil amended with phosphate removed groundwater Pb, Zn, and Cd by 96.4 %, 44.6 %, and 49.2 %, respectively, and the

Evaluation of hydrophobicity in PAH-contaminated soils during phytoremediation

International Nuclear Information System (INIS)

Cofield, Naressa; Banks, M. Katherine; Schwab, A. Paul

2007-01-01

The impact of recalcitrant organic compounds on soil hydrophobicity was evaluated in contaminated soil from a manufactured gas plant site following 12 months of phytoremediation. Significant reduction in soil wetting and water retention was observed in contaminated soil compared to an uncontaminated control. Phytoremediation was effective at reducing total PAHs by 69% with corresponding changes in soil classification from extremely hydrophobic (initial sample) to moderately-strongly hydrophobic (planted) and hydrophilic-very hydrophilic (unplanted) after 12 months. The greatest reduction in soil hydrophobicity was observed in the unplanted, unfertilized treatments that had the lowest removal rate of PAHs. The presence of plants may contribute to hydrophobicity in contaminated soil. - The presence of recalcitrant hydrophobic organic pollutants may enhance soil hydrophobicity

Trench ‘Bathtubbing’ and Surface Plutonium Contamination at a Legacy Radioactive Waste Site

Science.gov (United States)

2013-01-01

Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (∼12 Bq/L of 239+240Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest 239+240Pu soil activity was 829 Bq/kg in a shallow sample (0–1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the ‘bathtub’ effect. PMID:24256473

The study of metal contamination in urban soils of Hong Kong using a GIS-based approach

International Nuclear Information System (INIS)

Li Xiangdong; Lee Siulan; Wong Szechung; Shi Wenzhong; Thornton, Iain

2004-01-01

The study of regional variations and the anthropogenic contamination by metals of soils is very important for environmental planning and monitoring in urban areas. An extensive survey was conducted in the highly urbanized Kowloon area (46.9 km 2 ) of Hong Kong, using a systematic sampling strategy with a sampling density of 3-5 composite soil samples (0-15 cm) per km 2 . Geochemical maps of 'total' metals (Cd, Cr, Cu, Ni, Pb and Zn) from strong acid extraction in the surface soils were produced based on geographical information system (GIS) technology. A significant spatial relationship was found for Ni, Cu, Pb and Zn in the soils using a GIS-based analysis, suggesting that these metal contaminants in the soils of the Kowloon area had common sources. Several hot-spot areas of metal contamination were identified from the composite metal geochemical map, mainly in the old industrial and residential areas. A further GIS analysis revealed that road junctions, major roads and industrial buildings were possible sources of heavy metals in the urban soils. The Pb isotope composition of the contaminated soils showed clear anthropogenic origins. - GIS can be used to identify soil contamination hot-spot areas and to assess potential pollutant sources in an urban community

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

Chemical fingerprinting of hydrocarbon-contamination in soil.

Science.gov (United States)

Boll, Esther S; Nejrup, Jens; Jensen, Julie K; Christensen, Jan H

2015-03-01

Chemical fingerprinting analyses of 29 hydrocarbon-contaminated soils were performed to assess the soil quality and determine the main contaminant sources. The results were compared to an assessment based on concentrations of the 16 priority polycyclic aromatic hydrocarbons pointed out by the U.S. Environmental Protection Agency (EPAPAH16) and total petroleum hydrocarbon (TPH). The chemical fingerprinting strategy proposed in this study included four tiers: (i) qualitative analysis of GC-FID chromatograms, (ii) comparison of the chemical composition of both un-substituted and alkyl-substituted polycyclic aromatic compounds (PACs), (iii) diagnostic ratios of selected PACs, and (iv) multivariate data analysis of sum-normalized PAC concentrations. The assessment criteria included quantitative analysis of 19 PACs and C1-C4 alkyl-substituted homologues of naphthalene, fluorene, dibenzothiophene, phenanthrene, pyrene, and chrysene; and 13 oxygenated polycyclic aromatic compounds (O-PACs). The chemical composition of un-substituted and alkyl-substituted PACs and visual interpretation of GC-FID chromatograms were in combination successful in differentiating pyrogenic and petrogenic hydrocarbon sources and in assessing weathering trends of hydrocarbon contamination in the soils. Multivariate data analysis of sum-normalized concentrations could as a stand-alone tool distinguish between hydrocarbon sources of petrogenic and pyrogenic origin, differentiate within petrogenic sources, and detect weathering trends. Diagnostic ratios of PACs were not successful for source identification of the heavily weathered hydrocarbon sources in the soils. The fingerprinting of contaminated soils revealed an underestimation of PACs in petrogenic contaminated soils when the assessment was based solely on EPAPAH16. As alkyl-substituted PACs are dominant in petrogenic sources, the evaluation of the total load of PACs based on EPAPAH16 was not representative. Likewise, the O-PACs are not

Application of autoradiographic methods for contaminant distribution studies in soils

International Nuclear Information System (INIS)

Povetko, O.G.; Higley, K.A.

2000-01-01

In order to determine physical location of contaminants in soil, solidified soil 'thin' sections, which preserve the undisturbed structural characteristics of the original soil, were prepared. This paper describes an application of different autoradiographic methods to identify the distribution of selected nuclides along key structural features of sample soils and sizes of 'hot particles' of contaminant. These autoradiographic methods included contact autoradiography using CR-39 (Homalite Plastics) plastic alpha track detectors and neutron-induced autoradiography that produced fission fragment tracks in Lexan (Thrust Industries, Inc.) plastic detectors. Intact soil samples containing weapons-grade plutonium from Rocky Flats Environmental Test Site and control samples from outside the site location were used in thin soil section preparation. Distribution of particles of actinides was observed and analyzed through the soil section depth profile from the surface to the 15-cm depth. The combination of two autoradiographic methods allowed to distinguish alpha- emitting particles of natural U, 239+240 Pu and non-fissile alpha-emitters. Locations of 990 alpha 'stars' caused by 239+240 Pu and 241 Am 'hot particles' were recorded, particles were sized, their size-frequency, depth and activity distributions were analyzed. Several large colloidal conglomerates of 239+240 Pu and 241 Am 'hot particles' were found in soil profile. Their alpha and fission fragment 'star' images were micro photographed. (author)

Organoclays reduce arsenic bioavailability and bioaccessibility in contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Sarkar, Binoy; Naidu, Ravi; Rahman, Mohammad Mahmudur; Megharaj, Mallavarapu; Xi, Yunfei [South Australia Univ., Mawson Lakes, SA (AU). Centre for Environmental Risk Assessment and Remediation (CERAR); South Australia Univ., Mawson Lakes, SA (AU). Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE)

2012-05-15

Purpose: Naturally occurring layer silicate clay minerals can be value added by modifying their surface properties to enhance their efficacy in the remediation of environmental contaminants. Silicate clay minerals modified by the introduction of organic molecules into the mineral structure are known as organoclays and show much promise for environmental remediation applications. The present study assesses the extent of decrease in bioavailable and bioaccessible arsenic (As) via enhanced adsorption by soil treated with organoclays. Materials and methods: Organoclays were prepared from hexadecyl trimethylammonium bromide (HDTMA) and Arquad {sup registered} 2HT-75 (Arquad) at surfactant loadings equivalent to twice the cation exchange capacity (CEC) of an Australian bentonite and characterised by X-ray diffraction (XRD). Batch experiments were conducted to evaluate the adsorption of arsenate onto the organoclays from aqueous solutions. Encouraged by these results, the organoclays were applied to As-spiked soils, at 10% and 20% (w/w) rates, to assess their capacity to stabilise soil As. After 1 month of incubation in the laboratory, bioavailable (1 mM Ca(NO{sub 3}){sub 2} extractable) and bioaccessible (1 M glycine extractable) As from the spiked soils were assessed. Results and discussion: Both the organobentonites effectively removed As from aqueous solutions. The adsorbent prepared with Arquad adsorbed 23% more As from aqueous phase than adsorbent prepared with HDTMA. Adsorption of As was controlled by anion exchange and electrostatic attraction. When applied to As-contaminated soils, the organoclays reduced the bioavailable As by as much as 81%. The extent of reduction of bioaccessible As was only up to 58%. The adsorbents were not as efficient in reducing bioaccessible As in contaminated soils as compared with bioavailable As. It could be attributed to the extreme pH condition (pH = 3) of the extractant used in the physiologically based extraction test method for

The role of soil quality maps in the reuse of lightly contaminated soil

NARCIS (Netherlands)

Lamé, F.P.J.; Leenaers, H.; Zegwaard, J.

2000-01-01

In 1999 the Dutch government agreed on a new policy regarding the reuse of lightly contaminated soil. From now on, lightly contaminated soil may be reused under conditions of soil-quality management. The municipal authorities supervise the reuse under this new regime. Two basic criteria need to be

Sorption of BTX mixtures to contaminated and uncontaminated site soils

International Nuclear Information System (INIS)

Uchrin, C.G.; Koshy, K.; Wojtenko, I.

1995-01-01

Both adsorption and desorption studies are being performed examining benzene, toluene, and meta-xylene (BTX) as single components, binary mixtures, and trinary mixture onto both existing contaminated soils as well as some uncontaminated reference soils. The contaminated soils were obtained from an oil refinery site and another industrial site in New Jersey. The oil refinery site soil did not exhibit significant amounts of either benzene, toluene or xylene but was contaminated with other compounds while the other industrial site soil was contaminated with toluene among other compounds. The organic carbon content of the soils ranged from 0.14 to 2.91 percent. Preliminary adsorption studies showed BTX to strongly sorb to these soils. The adsorption studies onto the reference soils also demonstrated the effect of organic matter on adsorption. Sequential batch desorption studies show the BTX to desorb quickly, reaching equilibrium within 48 hours. Long-term uptake and release were not noted with these soil/contaminant systems

Enhanced bioremediation of PAH contaminated soils from coal processing sites

International Nuclear Information System (INIS)

Joshi, M.M.; Lee, S.

1995-01-01

The polycyclic aromatic hydrocarbons (PAH) are a potential hazard to health due to their carcinogenic, mutagenic nature and acute toxicity and there is an imminent need for remediation of PAH contaminated soils abounding the several coke oven and town gas sites. Aerobic biological degradation of PAHs is an innovative technology and has shown high decontamination efficiencies, complete mineralization of contaminants, and is environmentally safe. The present study investigates the remediation of PAH contaminated soils achieved using Acinetobacter species and fungal strain Phanerochaete Chrysosporium. The soil used for the experiments was an industrially contaminated soil obtained from Alberta Research Council (ARC) primary cleanup facility, Alberta, Canada. Soil characterization was done using High Performance Liquid Chromatography (HPLC) to qualitatively and quantitatively determine the contaminants in the soil. Artificially contaminated soil was also used for some experiments. All the experiments were conducted under completely mixed conditions with suitable oxygen and nutrient amendments. The removal efficiency obtained for various PAHs using the two microorganisms was compared

Assessment of combined electro–nanoremediation of molinate contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Gomes, Helena I., E-mail: hrg@campus.fct.unl.pt [CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); CERNAS — Research Center for Natural Resources, Environment and Society, Escola Superior Agraria de Coimbra, Instituto Politecnico de Coimbra, Bencanta, 3045-601 Coimbra (Portugal); Fan, Guangping [CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences (ISSCAS), East Beijing Road, Nanjing 210008 (China); Mateus, Eduardo P. [CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Dias-Ferreira, Celia [CERNAS — Research Center for Natural Resources, Environment and Society, Escola Superior Agraria de Coimbra, Instituto Politecnico de Coimbra, Bencanta, 3045-601 Coimbra (Portugal); Ribeiro, Alexandra B. [CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

2014-09-15

Molinate is a pesticide widely used, both in space and time, for weed control in rice paddies. Due to its water solubility and affinity to organic matter, it is a contaminant of concern in ground and surface waters, soils and sediments. Previous works have showed that molinate can be removed from soils through electrokinetic (EK) remediation. In this work, molinate degradation by zero valent iron nanoparticles (nZVI) was tested in soils for the first time. Soil is a highly complex matrix, and pollutant partitioning between soil and water and its degradation rates in different matrices is quite challenging. A system combining nZVI and EK was also set up in order to study the nanoparticles and molinate transport, as well as molinate degradation. Results showed that molinate could be degraded by nZVI in soils, even though the process is more time demanding and degradation percentages are lower than in an aqueous solution. This shows the importance of testing contaminant degradation, not only in aqueous solutions, but also in the soil-sorbed fraction. It was also found that soil type was the most significant factor influencing iron and molinate transport. The main advantage of the simultaneous use of both methods is the molinate degradation instead of its accumulation in the catholyte. - Highlights: • Molinate is degraded in soil by zero valent iron nanoparticles (nZVI). • Higher contact time of nZVI with soil facilitates molinate degradation. • Soil type was the most significant factor influencing iron and molinate transport. • When using nZVI and EK molinate is not only transported to catholyte, but also degraded.

A soil washing pilot plant for removing petroleum hydrocarbons from contaminated soils

International Nuclear Information System (INIS)

Toor, I.A.; Roehrig, G.R.

1992-01-01

A soil washing pilot plant was built and tested for its ability to remove petroleum hydrocarbons from certain soils. The ITEX soil washing pilot plant is a trailer mountable mobile unit which has a washing capacity of two tons per hour of contaminated soils. A benchscale study was carried out prior to the fabrication of the pilot plant. The first sample was contaminated with diesel fuel while the second sample was contaminated with crude oil. Various nonionic, cationic and anionic cleaning agents were evaluated for their ability to remove petroleum hydrocarbons from these materials. The nonionic cleaning agents were more successful in cleaning the soils in general. The ultimate surfactant choice was based on several factors including cost, biodegradability, cleaning efficiency and other technical considerations. The soil samples were characterized in terms of their particle size distributions. Commercial diesel fuel was carefully mixed in this sand to prepare a representative sample for the pilot plant study. Two pilot runs were made using this material. A multistage washing study was also conducted in the laboratory which indicates that the contamination level can be reduced to 100 ppm using only four stages. Because the pilot plant washing efficiency is twice as high, it is believed that ultimate contamination levels can be reduced to lower levels using the same number of stages. However, this hypothesis has not been demonstrated to date

Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type

DEFF Research Database (Denmark)

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

2015-01-01

Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero...... nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used...... as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two...

Evaluation of soil flushing of complex contaminated soil: An experimental and modeling simulation study

Energy Technology Data Exchange (ETDEWEB)

Yun, Sung Mi; Kang, Christina S. [Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Kim, Jonghwa [Department of Industrial Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Kim, Han S., E-mail: hankim@konkuk.ac.kr [Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)

2015-04-28

Highlights: • Remediation of complex contaminated soil achieved by sequential soil flushing. • Removal of Zn, Pb, and heavy petroleum oils using 0.05 M citric acid and 2% SDS. • Unified desorption distribution coefficients modeled and experimentally determined. • Nonequilibrium models for the transport behavior of complex contaminants in soils. - Abstract: The removal of heavy metals (Zn and Pb) and heavy petroleum oils (HPOs) from a soil with complex contamination was examined by soil flushing. Desorption and transport behaviors of the complex contaminants were assessed by batch and continuous flow reactor experiments and through modeling simulations. Flushing a one-dimensional flow column packed with complex contaminated soil sequentially with citric acid then a surfactant resulted in the removal of 85.6% of Zn, 62% of Pb, and 31.6% of HPO. The desorption distribution coefficients, K{sub Ubatch} and K{sub Lbatch}, converged to constant values as C{sub e} increased. An equilibrium model (ADR) and nonequilibrium models (TSNE and TRNE) were used to predict the desorption and transport of complex contaminants. The nonequilibrium models demonstrated better fits with the experimental values obtained from the column test than the equilibrium model. The ranges of K{sub Ubatch} and K{sub Lbatch} were very close to those of K{sub Ufit} and K{sub Lfit} determined from model simulations. The parameters (R, β, ω, α, and f) determined from model simulations were useful for characterizing the transport of contaminants within the soil matrix. The results of this study provide useful information for the operational parameters of the flushing process for soils with complex contamination.

Enhanced ex-situ bioremediation of soil contaminated with ...

African Journals Online (AJOL)

contaminated soil. Thus, the objective of this study was to investigate the feasibility and effectiveness of using electrical biostimulation processes to enhance ex-situ bioremediation of soils contaminated with organic pollutants. The effect of ...

Soil remediation: humic acids as natural surfactants in the washings of highly contaminated soils

International Nuclear Information System (INIS)

Conte, Pellegrino; Agretto, Anna; Spaccini, Riccardo; Piccolo, Alessandro

2005-01-01

The remediation of the highly contaminated site around the former chemical plant of ACNA (near Savona) in Northern Italy is a top priority in Italy. The aim of the present work was to contribute in finding innovative and environmental-friendly technology to remediate soils from the ACNA contaminated site. Two soils sampled from the ACNA site (A and B), differing in texture and amount and type of organic contaminants, were subjected to soil washings by comparing the removal efficiency of water, two synthetic surfactants, sodium dodecylsulphate (SDS) and Triton X-100 (TX100), and a solution of a natural surfactant, a humic acid (HA) at its critical micelle concentration (CMC). The extraction of pollutants by sonication and soxhlet was conducted before and after the soil washings. Soil A was richer in polycyclic aromatic hydrocarbons, whereas soil B had a larger content of thiophenes. Sonication resulted more analytically efficient in the fine-textured soil B. The coarse-textured soil A was extracted with a general equal efficiency also by soxhlet. Clean-up by water was unable to exhaustively remove contaminants from the two soils, whereas all the organic surfactants revealed very similar efficiencies (up to 90%) in the removal of the contaminants from the soils. Hence, the use of solutions of natural HAs appears as a better choice for soil washings of highly polluted soils due to their additional capacity to promote microbial activity, in contrast to synthetic surfactants, for a further natural attenuation in washed soils. - Solutions of natural humic acids appear to be a better choice for washing highly polluted soils

Prospects for separating heavy metal from contaminated soil

International Nuclear Information System (INIS)

Langen, M.; Hoberg, H.; Hamacher, B.

1994-01-01

For decades, large quantities of organic and inorganic pollutants have been brought into the soil as a result of the industrial operations of smelting and coking plants. This paper reports on the prospects of separating heavy metals from soil contaminated by smelting and coking plants by means of a physical/chemical washing procedure. Besides the description of virgin soil characteristics, cleaning results and process parameters of calssification, density separation and flotation processes are presented. It is shown that heavy metal pollution of virgin soil can be reduced by the classical process stages of soil washing. The metal content of virgin soil are critically assessed whereby the limits of the physical-chimical washing process will also be entered into. Emphasis is placed on the significance of the determination of limiting values for inorganic contamination, especially for soil contaminated with both organic and inorganic pollution. (orig.) [de

In situ chemical fixation of arsenic-contaminated soils: Anexperimental study

Energy Technology Data Exchange (ETDEWEB)

Yang, Li; Donahoe, Rona J.; Redwine, James C.

2007-03-27

procedure (TCLP) and EPA Method 1312 [USEPA.Method 1312:synthetic precipitation leaching procedure. Test methods for evaluatingsolid waste, physical/chemical methods. 3rd ed. Washington, DC: U.S.Environmental Protection Agency, Office of Solid Waste. U.S. GovernmentPrinting Office; 1994]synthetic precipitation leaching procedure(SPLP).Both FW and BH soils showed significant decreases in arsenicleachability for all three treatment solutions, compared to untreatedsoil. While soils treated with solution (3) showed the best results withsubsequent TCLP sequential leaching, SPLP sequential leaching of treatedsoils indicated that lowest arsenic mobility was obtained using treatmentsolution (1). Treatment solution (1) with only FeSO4 is considered thebest choice for remediation of arsenic-contaminated soil because SPLPsequential leaching better simulates natural weathering. Analysis oftreated soils produced no evidence of newly-formed arsenic-bearing phasesin either soil after treatment. Sequential chemical extractions oftreated soils indicate that surface complexation of arsenic on ferrichydroxide is the major mechanism for the fixation process.

Improving the phytoremediation of heavy metals contaminated soil by use of sewage sludge

Science.gov (United States)

Placek, Agnieszka; Grobelak, Anna; Kacprzak, Malgorzata

2016-01-01

ABSTRACT Sewage sludge, in particular from the food industry, is characterized by fertilizing properties, due to the high content of organic matter and nutrients. The application of sewage sludge causes an improvement of soil parameters as well as increase in cation exchange capacity, and thus stronger binding of cations in the soil environment, which involves the immobilization of nutrients and greater resistance to contamination. In a field experiment sewage sludge has been used as an additive to the soil supporting the phytoremediation process of land contaminated with heavy metals (Cd, Zn, and Pb) using trees species: Scots pine (Pinus silvestris L.), Norway spruce (Picea abies L.), and oak (Quercus robur L.). The aim of the research was to determine how the application of sewage sludge into the soil surface improves the phytoremediation process. The conducted field experiment demonstrated that selected trees like Scots pine and Norway spruce, because of its excellent adaptability, can be used in the remediation of soil. Oak should not be used in the phytoremediation process of soils contaminated with high concentrations of trace elements in the soil, because a significant amount of heavy metals was accumulated in the leaves of oak causing a risk of recontamination. PMID:26368503

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

Science.gov (United States)

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

2012-08-15

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

Uptake of Organic Contaminants from Soil into Vegetables and Fruits

DEFF Research Database (Denmark)

Trapp, Stefan; Legind, Charlotte Nielsen

2011-01-01

Contaminants may enter vegetables and fruits by several pathways: by uptake with soil pore water, by diffusion from soil or air, by deposition of soil or airborne particles, or by direct application. The contaminant-specific and plantspecific properties that determine the importance...... of these pathways are described in this chapter. A variety of models have been developed, specific for crop types and with steady-state or dynamic solutions. Model simulations can identify sensitive properties and relevant processes. Persistent, polar (log KOW contaminants have...... the highest potential for accumulation from soil, and concentrations in leaves may be several hundred times higher than in soil. However, for most contaminants the accumulation in vegetables or fruits is much lower. Lipophilic (log KOW > 3) contaminants are mainly transported to leaves by attached soil...

Soil contamination with cadmium, consequences and remediation using organic amendments.

Science.gov (United States)

Khan, Muhammad Amjad; Khan, Sardar; Khan, Anwarzeb; Alam, Mehboob

2017-12-01

Cadmium (Cd) contamination of soil and food crops is a ubiquitous environmental problem that has resulted from uncontrolled industrialization, unsustainable urbanization and intensive agricultural practices. Being a toxic element, Cd poses high threats to soil quality, food safety, and human health. Land is the ultimate source of waste disposal and utilization therefore, Cd released from different sources (natural and anthropogenic), eventually reaches soil, and then subsequently bio-accumulates in food crops. The stabilization of Cd in contaminated soil using organic amendments is an environmentally friendly and cost effective technique used for remediation of moderate to high contaminated soil. Globally, substantial amounts of organic waste are generated every day that can be used as a source of nutrients, and also as conditioners to improve soil quality. This review paper focuses on the sources, generation, and use of different organic amendments to remediate Cd contaminated soil, discusses their effects on soil physical and chemical properties, Cd bioavailability, plant uptake, and human health risk. Moreover, it also provides an update of the most relevant findings about the application of organic amendments to remediate Cd contaminated soil and associated mechanisms. Finally, future research needs and directions for the remediation of Cd contaminated soil using organic amendments are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Spreading of 137 C in the Goiania urban area by resuspension and transport of surface soil

International Nuclear Information System (INIS)

Rio, Monica Pires do; Amaral, Eliana

2002-01-01

The resuspension of surface soil was considered the mechanism responsible by the spreading of 137 Cs after the Goiania accident, which affected an urban area of about 1 km 2 . Studies on the transport of 137 Cs associated to the surface soil were performed in a house located at 57 th Street, close to the main focus of contamination, from 05/89 to 07/00. Periodically, samples of surface soil and soil profile were collected at the house yards and street dust sampling at representative locations was performed in order to know the extension of the contamination in the city. The soil profile samples have shown the low mobility of 137 Cs in deep layers of the soil, although a slight long-term decrease of the 137 Cs activity concentration in the surface soil were observed. The 137 Cs activity concentration in the street dust samples also decrease with time, suggesting a natural dilution of the contamination in those samples; higher values were only found in few locations close to the foci of primary deposition and no additional spreading of the radionuclide is expected to occur from that area. Street dust sampling is a suitable method to assess the spreading of caesium in urban environment. (author)

Remediation of soils contaminated with heavy metals

Energy Technology Data Exchange (ETDEWEB)

Boni, M.R.; D' Aprile, L. [Univ. of Rome ' ' La Sapienza' ' , Dept. of Hydraulic Transportation and Roads (Italy)

2001-07-01

In December 1999 Italy issued the national regulation (DM 471/99) for the clean-up of contaminated sites. This regulation applies both to derelict and to still operating industrial plants and waste management facilities. Target concentration values for clean-up interventions are issued and the requirements for design and planning of technical operation are defined. The selection of the appropriate clean-up technology are based on the following main criteria: - reduce the concentration in environmental media and the migration of pollutants without removing soil off-site; - in order to reduce contaminated material removal and transportation, remedial actions of soil, subsoil and groundwater should preferably be based on in-situ treatments. In-situ technologies commonly applied in Italy to the remediation of soils contaminated by heavy metals (As, Cd, Cr, Hg, Pb) are: - containment (caps, vertical barriers); - soil flushing; - cement based solidification/stabilization. (orig.)

Petroleum Contaminated Soil Treatment Using Surfactant and Hydrogen Peroxide

Directory of Open Access Journals (Sweden)

Ilza Lobo

2010-12-01

Full Text Available The process of washing soil with surfactants, sodium lauryl ether sulphate (LESS and sodium lauryl sulphate (SDS was combined with chemical oxidation using hydrogen peroxide, with a view to in situ remediation of clay soil contaminated with hydrocarbons oil. The evaluation of the efficiency of the procedure was the removal of polyaromatic hydrocarbons and the comparison of physical and chemical characteristics of contaminated soil and uncontaminated from the same region. The combination of these two techniques, soil washing and application of an oxidizing agent, presented as a process of effective remediation for soils contaminated with petroleum products in subtropical regions.

Highly charged swelling mica reduces Cu bioavailability in Cu-contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Stuckey, Jason W. [Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802 (United States); Neaman, Alexander [Facultad de Agronomia, P. Universidad Catolica de Valparaiso, Centro Regional de Estudios en Alimentos Saludables (Chile); Ravella, Ramesh; Komarneni, Sridhar [Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802 (United States); Martinez, Carmen Enid [Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802 (United States)], E-mail: cem17@psu.edu

2009-01-15

This is the first test of a highly charged swelling mica's (Na-2-mica) ability to reduce the plant-absorbed Cu in Cu-contaminated soils from Chile. Perennial ryegrass (Lolium perenne L.) was grown in two acid soils (Sector 2: pH 4.2, total Cu = 172 mg Cu kg{sup -1} and Sector 3: pH 4.2, total Cu = 112 mg Cu kg{sup -1}) amended with 0.5% and 1% (w/w) mica, and 1% (w/w) montmorillonite. At 10 weeks of growth, both mica treatments decreased the shoot Cu of ryegrass grown in Sector 2 producing shoot Cu concentrations above 21-22 mg Cu kg{sup -1} (the phytotoxicity threshold for that species), yet the mica treatments did not reduce shoot Cu concentrations when grown in Sector 3, which were at a typical level. The mica treatments improved shoot growth in Sector 3 by reducing free and extractable Cu to low enough levels where other nutrients could compete for plant absorption and translocation. In addition, the mica treatments improved root growth in both soils, and the 1% mica treatment reduced root Cu in both soils. This swelling mica warrants further testing of its ability to assist re-vegetation and reduce Cu bioavailability in Cu-contaminated surface soils. - In situ remediation of Cu-contaminated soils with a synthetic mica (Na-2-mica) will aid in re-vegetative efforts.

Bioventing feasibility study of low permeability soils for remediation of petroleum contamination

International Nuclear Information System (INIS)

Brackney, K.M.

1994-01-01

A site characterization of leaking underground gasoline and diesel storage tanks at the University of Idaho, West Farm Operations Center, identified approximately 800 cubic yards of petroleum-contaminated soil exceedingly regulatory action limits of 100 ppm TPH. Bioventing, a combination of in situ soil vapor extraction and microbial degradation, was selected as a remedial alternative on the basis of the presumably unsaturated paleo-soil with a 45-foot depth to groundwater, and a microbial study which concluded that indigenous petroleum-degrading microorganisms existed throughout the contamination. Soil vapor extraction tests were conducted by applying a 60-inch water column vacuum to a soil vapor extraction well and monitoring pneumatic pressure drawdown in 12 adjacent pneumatic piezometers and vertically distributed piezometer clusters. Pressure drawdown vs time data plots indicated that air permeability is inadequate everywhere at the site except at 20 feet below ground surface. Low soil permeability creates conditions for a perched water table that was documented during the investigation, resulting in unsatisfactory conditions for in situ bioventing. 8 refs., 14 figs

Soil-to-Rice Transfer of {sup 99}Tc in Paddy Soils Contaminated in Two Different Ways

Energy Technology Data Exchange (ETDEWEB)

Choi, Yongho; Lim, Kwangmuk; Jun, In; Kim, Byungho; Keum, Dongkwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

Rice is one of the most important food crops in the world. All isotopes of technetium (Tc) are radioactive, and the environmentally most important one is {sup 99}Tc because of its very long half-life (2.1x10{sup 5} years) and relatively high {sup 235}U-fission yield. Accordingly, it is one of the critical radionuclides in an environmental impact assessment for radioactive waste disposal. A significant amount of {sup 99}Tc can be released into the atmosphere in a severe reactor accident as was shown in the Chernobyl accident. It is a pure better emitter and thus internal exposure via food consumption may be a primary contributor to the {sup 99}Tc radiation dose to humans. Paddy rice fields can be contaminated with {sup 99}Tc in various ways. In the present study, greenhouse experiments were conducted to investigate the transfer of {sup 99}Tc from four paddy soils contaminated in two different ways. One was to simulate plowing the topsoil after a pre-transplanting deposition of {sup 99}Tc, whereas the other was to simulate a {sup 99}Tc deposition onto the surface water shortly after transplanting. Soil-to-rice transfer of {sup 99}Tc in paddy soils was experimentally investigated for two different scenarios of the paddy-field contamination. It was demonstrated that a post-transplanting deposition of {sup 99}Tc onto the surface water can lead to a much higher transfer than a pre-transplanting deposition followed by plowing. The surface-water concentrations of {sup 99}Tc following the post-transplanting deposition was markedly higher than those following the pre-transplanting deposition, possibly indicating a much higher plant-base uptake of {sup 99}Tc following the post-transplanting deposition. The present results can be referred to in a radiological impact assessment for the contamination of paddy fields with {sup 99}Tc by chronic or acute releases from nuclear facilities.

Origins and transport of aquatic dioxins in the Japanese watershed: soil contamination, land use, and soil runoff events.

Science.gov (United States)

Kanematsu, Masakazu; Shimizu, Yoshihisa; Sato, Keisuke; Kim, Suejin; Suzuki, Tasuma; Park, Baeksoo; Saino, Reiko; Nakamura, Masafumi

2009-06-15

Significant dioxins accumulations in Japanese forests and paddy fields have been observed, and surface soil runoff caused by rainfall and irrigation (i.e., soil puddling in paddy fields) results in dioxins input into the aquatic environment. An extensive investigation into the origins and transport of aquatic dioxins in the Yasu watershed, Japan was conducted considering surface soil contamination level, land use, and type of soil runoff event (i.e., irrigation runoff [IR], rainfall runoff [RR], and base flow [BF]). Combined use of the chemically activated luciferase expression (CALUX) assay together with high-resolution gas chromatography and high-resolution mass spectrometry (HRGC/HRMS) efficiently enabled this study, so that origins, transport, and dynamic movement of aquatic dioxins in the watershed were revealed. The particulate organic carbon normalized particulate-dioxins WHO-toxic equivalent (TEQ) concentration predicted by the CALUX assay (Spar) was found to be a convenient molecular marker to indicate origins of aquatic dioxins and clearly reflect surface soil contamination level, land use, and soil runoff events. Using experimental results and theoretical modeling, the annual loading amount of dioxins at the middle reach of the river was estimated to be 0.458 mg WHO-TEQ in 2004. More than 96.6% of the annual loading amount was attributed to RR and derived almost evenly from forest and paddy fields at the study location. Because the annual loading amount at the middle reach is less than 0.5% of the total dioxins accumulated in the upper basin, dioxins runoff from the Japanese watershed will continue. This study shows that the combined use of the bioassay with HRGC/HRMS can provide new insights into dioxins transport and fate in the environment.

Germination and initial growth of Campomanesia xanthocarpa O. Berg. (Myrtaceae, in petroleum-contaminated soil and bioremediated soil

Directory of Open Access Journals (Sweden)

AM. Gogosz

Full Text Available In 2000 there was an oil spill at the Getúlio Vargas Refinery (REPAR in Paraná. Nearly five years after contamination and the use of bioremediation, a study was carried out to identify the effects of the contaminated soil and the bioremediated soil on the germination and initial growth of C. xanthocarpa. The experiment was established with soil from REPAR, with three treatment groups: contaminated soil (C, bioremediated soil (B and uncontaminated soil (U; with five repetitions of 50 seeds each. There was no significant difference in the percentage of germination and the speed of germination index. The production of total biomass (30 - 60 days and shoot biomass (60 days was greater in the bioremediated soil compared to the other treatments. The averages for the root biomass were lower in the contaminated soil than in the bioremediated soil. The shoot length and the total length of the seedling in the contaminated soil and uncontaminated soil were lower than in the bioremediated soil.

Hybrid electrokinetic method applied to mix contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Mansour, H.; Maria, E. [Dept. of Building Civil and Environmental Engineering, Concordia Univ., Montreal (Canada)

2001-07-01

Several industrials and municipal areas in North America are contaminated with heavy metals and petroleum products. This mix contamination presents a particularly difficult task for remediation when is exposed in clayey soil. The objective of this research was to find a method to cleanup mix contaminated clayey soils. Finally, a multifunctional hybrid electrokinetic method was investigated. Clayey soil was contaminated with lead and nickel (heavy metals) at the level of 1000 ppm and phenanthrene (PAH) of 600 ppm. Electrokinetic surfactant supply system was applied to mobilize, transport and removal of phenanthrene. A chelation agent (EDTA) was also electrokinetically supplied to mobilize heavy metals. The studies were performed on 8 lab scale electrokinetic cells. The mix contaminated clayey soil was subjected to DC total voltage gradient of 0.3 V/cm. Supplied liquids (surfactant and EDTA) were introduced in different periods of time (22 days, 42 days) in order to optimize the most excessive removal of contaminants. The ph, electrical parameters, volume supplied, and volume discharged was monitored continuously during each experiment. At the end of these tests soil and cathalyte were subjected to physico-chemical analysis. The paper discusses results of experiments including the optimal energy use, removal efficiency of phenanthrene, as well, transport and removal of heavy metals. The results of this study can be applied for in-situ hybrid electrokinetic technology to remediate clayey sites contaminated with petroleum product mixed with heavy metals (e.g. manufacture Gas Plant Sites). (orig.)

Bioremediation of contaminated soil: Strategy and case histories

International Nuclear Information System (INIS)

Balba, M.T.; Ying, A.C.; McNeice, T.G.

1991-01-01

Microorganisms are capable of degrading many kinds of xenobiotic compounds and toxic chemicals. These microorganisms are ubiquitous in nature and there are numerous cases in which long-term contamination of soil and groundwater has been observed. The persistence of the contamination is usually caused by the inability of micro-organisms to metabolize these compounds under the prevailing environmental conditions. Two general reasons account for the failure of microbes to degrade pollutants in any environment: (1) inherent molecular recalcitrance of the contaminants and (2) environmental factors. The inherent molecular recalcitrance is usually associated with xenobiotic compounds where the chemical structure of the molecule is such that microbes and enzymes required for its catabolism have not evolved yet in nature. The environmental factors include a range of physicochemical conditions which influence microbial growth and activity. Biological remediation of contaminated sites can be accomplished using naturally-occurring microorganisms to treat the contaminants. Only particular groups of microorganisms are capable of decomposing specific compounds. The development of a bioremediation program for a specific contaminated soil system usually includes: thorough site/soil/waste characterization; treatability studies; and design and implementation of the bioremediation plan. The results of in situ and ex situ treatment programs involving the cleanup of petroleum hydrocarbon-contaminated soil will be discussed in detail. The paper will address key issues affecting the success of the bioremediation process such as nutrient transport, metal precipitation and potential soil clogging, microbial inoculation, etc

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

Biological technologies for the remediation of co-contaminated soil.

Science.gov (United States)

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

2017-12-01

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

Waste reduction by separation of contaminated soils during environmental restoration

International Nuclear Information System (INIS)

Roybal, J.A.; Conway, R.; Galloway, B.; Vinsant, E.; Slavin, P.; Guerin, D.

1998-06-01

During cleanup of contaminated sites, Sandia National Laboratories, New Mexico (SNL/NM) frequently encounters soils with low-level radioactive contamination. The contamination is not uniformly distributed, but occurs within areas of clean soil. Because it is difficult to characterize heterogeneously contaminated soils in detail and to excavate such soils precisely using heavy equipment, it is common for large quantities of uncontaminated soil to be removed during excavation of contaminated sites. This practice results in the commingling and disposal of clean and contaminated material as low-level waste (LLW), or possibly low-level mixed waste (LLMW). Until recently, volume reduction of radioactively contaminated soil depended on manual screening and analysis of samples, which is a costly and impractical approach and does not uphold As Low As Reasonably Achievable (ALARA) principles. To reduce the amount of LLW and LLMW generated during the excavation process, SNL/NM is evaluating two alternative technologies. The first of these, the Segmented Gate System (SGS), is an automated system that located and removes gamma-ray emitting radionuclides from a host matrix (soil, sand, dry sludge). The matrix materials is transported by a conveyor to an analyzer/separation system, which segregates the clean and contaminated material based on radionuclide activity level. The SGS was used to process radioactively contaminated soil from the excavation of the Radioactive Waste Landfill. The second technology, Large Area Gamma Spectroscopy (LAGS), utilizes a gamma spec analyzer suspended over a slab upon which soil is spread out to a uniform depth. A counting period of approximately 30 minutes is used to obtain a full-spectrum analysis for the isotopes of interest. The LAGS is being tested on the soil that is being excavated from the Classified Waste Landfill

Solubility measurement of uranium in uranium-contaminated soils

International Nuclear Information System (INIS)

Lee, S.Y.; Elless, M.; Hoffman, F.

1993-08-01

A short-term equilibration study involving two uranium-contaminated soils at the Fernald site was conducted as part of the In Situ Remediation Integrated Program. The goal of this study is to predict the behavior of uranium during on-site remediation of these soils. Geochemical modeling was performed on the aqueous species dissolved from these soils following the equilibration study to predict the on-site uranium leaching and transport processes. The soluble levels of total uranium, calcium, magnesium, and carbonate increased continually for the first four weeks. After the first four weeks, these components either reached a steady-state equilibrium or continued linearity throughout the study. Aluminum, potassium, and iron, reached a steady-state concentration within three days. Silica levels approximated the predicted solubility of quartz throughout the study. A much higher level of dissolved uranium was observed in the soil contaminated from spillage of uranium-laden solvents and process effluents than in the soil contaminated from settling of airborne uranium particles ejected from the nearby incinerator. The high levels observed for soluble calcium, magnesium, and bicarbonate are probably the result of magnesium and/or calcium carbonate minerals dissolving in these soils. Geochemical modeling confirms that the uranyl-carbonate complexes are the most stable and dominant in these solutions. The use of carbonate minerals on these soils for erosion control and road construction activities contributes to the leaching of uranium from contaminated soil particles. Dissolved carbonates promote uranium solubility, forming highly mobile anionic species. Mobile uranium species are contaminating the groundwater underlying these soils. The development of a site-specific remediation technology is urgently needed for the FEMP site

Characterizing Soil Lead Contamination Near Streams in Oakland, California

Science.gov (United States)

Tanouye, D.

2017-12-01

Lead (Pb) contamination of soils, groundwater, and surface waters is a major concern because of the potential health risks related to accumulation of high levels of lead in blood. This is a pervasive issue in many low-income neighborhoods throughout the United States, and is documented to be particularly acute in West Oakland, California. The fate and transport of lead in the environment is largely dependent on how it will bind to various solids and compounds in solution. These adsorption mechanisms are a principal aspect of metal dissolution and chemical speciation. Stream channels are natural drainage areas for urban runoff, and may represent a hot spot for increased levels of lead. This study evaluates the environmental conditions at 15 sites near streams in West Oakland using in-situ soil sampling with the handheld X-Ray Fluorescence (XRF) analyzer to measure concentrations of lead in soil. Results from this study suggest that the levels of lead in soils near stream channels are generally lower than the regional regulatory screening level of 80 milligrams per kilogram (mg/kg), but the highest concentrations are found near stream banks. The spatial distribution can be explained by a contaminant transport process related to the presence of fluvial channels.

Management and re-use of contaminated soils

International Nuclear Information System (INIS)

Nowicki, V.K.; LeBlanc, M.

1993-01-01

The volume occupied by petroleum-contaminated soils in landfill facilities could be totally eliminated by treatment of these soils in separate facilities. Once treated, the soils could be recycled. In New Brunswick, one such treatment facility was opened in 1992 adjacent to the Fredericton regional landfill site; a second site was opened near Moncton in 1992. These facilities receive petroleum-contaminated soil from such users as gasoline stations, bulk plants, institutions, and transport companies, as well as from oil spill sites. The types of contaminants present range from gasoline to heavy fuel oils and greases, and the soils can vary from clays to gravels. Incoming soils are layered on treatment pads and treated by bioremediation. A bionutrient mixture containing fertilizers plus an amount of adapted, naturally-occurring petroleum hydrocarbon degrading microorganisms is sprayed onto the pile layer by layer. Aeration tubing is also installed during this layering process. When the piles are complete, they are covered with black plastic and aerated. Bioremediation times vary from 10 to 24 weeks. The facility has successfully decontaminated over 20,000 tonnes of soil to date. The resulting soil can be used for such purposes as soil cover and backfill. The bioremediation process itself is portable and can be initiated at landfill sites themselves to reduce transport and handling costs. 16 refs., 4 figs

Soil bioindicators as a usefull tools for land management and spatial planning processes: a case-study of prioritization of contaminated soil remediation

Science.gov (United States)

Grand, Cécile; Pauget, Benjamin; Villenave, Cécile; Le Guédard, Marina; Piron, Denis; Nau, Jean-François; Pérès, Guénola

2017-04-01

on the structuring of the soils. The results from 14 measurement points demonstrated the relatively low average transfers towards the plants and soil fauna although the transfers can be changing a lot in relation to heterogeneity of soil contamination. Results obtained from other bioindicators (nematodes, earthworms and bacterial biomass) showed that the different soils are on average of good biological quality and can benefit from a diversity and abundance of communities of soil organisms. The data obtained in this program underline that these tools can be used to evaluate soil functions (habitat for biodiversity, soil capacity to store contaminants, etc.) and, consequently, the services that the soil can give to humans. Moreover, these biological tools allowed to assess the biological quality of soils and their compatibility with the soil use and the necessity of soil remediation (excavation of hot-spots, surface cover etc ..).Taking into account not only the behavior of soil contaminants but also the environmental factors that influence the biological functioning of the soil, these tools can be useful for land management of large-scale sites and for brownfield conquest.

Biosensors for detection of mercury in contaminated soils

International Nuclear Information System (INIS)

Bontidean, Ibolya; Mortari, Alessia; Leth, Suzanne; Brown, Nigel L.; Karlson, Ulrich; Larsen, Martin M.; Vangronsveld, Jaco; Corbisier, Philippe; Csoeregi, Elisabeth

2004-01-01

Biosensors based on whole bacterial cells and on bacterial heavy metal binding protein were used to determine the mercury concentration in soil. The soil samples were collected in a vegetable garden accidentally contaminated with elemental mercury 25 years earlier. Bioavailable mercury was measured using different sensors: a protein-based biosensor, a whole bacterial cell based biosensor, and a plant sensor, i.e. morphological and biochemical responses in primary leaves and roots of bean seedlings grown in the mercury-contaminated soil. For comparison the total mercury concentration of the soil samples was determined by AAS. Whole bacterial cell and protein-based biosensors gave accurate responses proportional to the total amount of mercury in the soil samples. On the contrary, plant sensors were found to be less useful indicators of soil mercury contamination, as determined by plant biomass, mercury content of primary leaves and enzyme activities

Procedures for sampling radium-contaminated soils

International Nuclear Information System (INIS)

Fleischhauer, H.L.

1985-10-01

Two procedures for sampling the surface layer (0 to 15 centimeters) of radium-contaminated soil are recommended for use in remedial action projects. Both procedures adhere to the philosophy that soil samples should have constant geometry and constant volume in order to ensure uniformity. In the first procedure, a ''cookie cutter'' fashioned from pipe or steel plate, is driven to the desired depth by means of a slide hammer, and the sample extracted as a core or plug. The second procedure requires use of a template to outline the sampling area, from which the sample is obtained using a trowel or spoon. Sampling to the desired depth must then be performed incrementally. Selection of one procedure over the other is governed primarily by soil conditions, the cookie cutter being effective in nongravelly soils, and the template procedure appropriate for use in both gravelly and nongravelly soils. In any event, a minimum sample volume of 1000 cubic centimeters is recommended. The step-by-step procedures are accompanied by a description of the minimum requirements for sample documentation. Transport of the soil samples from the field is then addressed in a discussion of the federal regulations for shipping radioactive materials. Interpretation of those regulations, particularly in light of their application to remedial action soil-sampling programs, is provided in the form of guidance and suggested procedures. Due to the complex nature of the regulations, however, there is no guarantee that our interpretations of them are complete or entirely accurate. Preparation of soil samples for radium-226 analysis by means of gamma-ray spectroscopy is described

Electrokinetic remediation of fluorine-contaminated soil and its impact on soil fertility.

Science.gov (United States)

Zhou, Ming; Wang, Hui; Zhu, Shufa; Liu, Yana; Xu, Jingming

2015-11-01

Compared to soil pollution by heavy metals and organic pollutants, soil pollution by fluorides is usually ignored in China. Actually, fluorine-contaminated soil has an unfavorable influence on human, animals, plants, and surrounding environment. This study reports on electrokinetic remediation of fluorine-contaminated soil and the effects of this remediation technology on soil fertility. Experimental results showed that electrokinetic remediation using NaOH as the anolyte was a considerable choice to eliminate fluorine in contaminated soils. Under the experimental conditions, the removal efficiency of fluorine by the electrokinetic remediation method was 70.35%. However, the electrokinetic remediation had a significant impact on the distribution and concentrations of soil native compounds. After the electrokinetic experiment, in the treated soil, the average value of available nitrogen was raised from 69.53 to 74.23 mg/kg, the average value of available phosphorus and potassium were reduced from 20.05 to 10.39 mg/kg and from 61.31 to 51.58 mg/kg, respectively. Meanwhile, the contents of soil available nitrogen and phosphorus in the anode regions were higher than those in the cathode regions, but the distribution of soil available potassium was just the opposite. In soil organic matter, there was no significant change. These experiment results suggested that some steps should be taken to offset the impacts, after electrokinetic treatment.

Removal of residual contaminants in petroleum-contaminated soil by Fenton-like oxidation

Energy Technology Data Exchange (ETDEWEB)

Lu Mang [School of Material Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen, 333001, Jiangxi Province (China); State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Zhang Zhongzhi, E-mail: zzzhang1955@hotmail.com [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Qiao Wei; Guan Yueming; Xiao Meng; Peng Chong [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China)

2010-07-15

The degradation of bioremediation residues by hydrogen peroxide in petroleum-contaminated soil was investigated at circumneutral pH using a Fenton-like reagent (ferric ion chelated with EDTA). Batch tests were done on 20 g soil suspended in 60 mL aqueous solution containing hydrogen peroxide and Fe{sup 3+}-EDTA complex under constant stirring. A slurry reactor was used to treat the soil based on the optimal reactant conditions. Contaminants were characterized by Fourier transform infrared spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. The results showed that the optimal treatment condition was: the molar ratio of hydrogen peroxide to iron = 200:1, and pH 7.0. Under the optimum condition, total dichloromethane-extractable organics were reduced from 14,800 to 2300 mg kg{sup -1} soil when the accumulative H{sub 2}O{sub 2} dosage was 2.45 mol kg{sup -1} soil during the reactor treatment. Abundance of viable cells was lower in incubated Fenton-like treated soil than in untreated soil. Oxidation of contaminants produced remarkable compositional and structural modifications. A fused ring compound, identified as C{sub 34}H{sub 38}N{sub 1}, was found to exhibit the greatest resistance to oxidation.

Widespread arsenic contamination of soils in residential areas and public spaces: an emerging regulatory or medical crisis?

Science.gov (United States)

Belluck, D A; Benjamin, S L; Baveye, P; Sampson, J; Johnson, B

2003-01-01

A critical review finds government agencies allow, permit, license, or ignore arsenic releases to surface soils. Release rates are controlled or evaluated using risk-based soil contaminant numerical limits employing standardized risk algorithms, chemical-specific and default input values. United States arsenic residential soil limits, approximately 0.4- approximately 40 ppm, generally correspond to a one-in-one-million to a one-in-ten-thousand incremental cancer risk range via ingestion of or direct contact with contaminated residential soils. Background arsenic surface soil levels often exceed applicable limits. Arsenic releases to surface soils (via, e.g., air emissions, waste recycling, soil amendments, direct pesticide application, and chromated copper arsenic (CCA)-treated wood) can result in greatly elevated arsenic levels, sometimes one to two orders of magnitude greater than applicable numerical limits. CCA-treated wood, a heavily used infrastructure material at residences and public spaces, can release sufficient arsenic to result in surface soil concentrations that exceed numerical limits by one or two orders of magnitude. Although significant exceedence of arsenic surface soil numerical limits would normally result in regulatory actions at industrial or hazardous waste sites, no such pattern is seen at residential and public spaces. Given the current risk assessment paradigm, measured or expected elevated surface soil arsenic levels at residential and public spaces suggest that a regulatory health crisis of sizeable magnitude is imminent. In contrast, available literature and a survey of government agencies conducted for this paper finds no verified cases of human morbidity or mortality resulting from exposure to elevated levels of arsenic in surface soils. This concomitance of an emerging regulatory health crisis in the absence of a medical crisis is arguably partly attributable to inadequate government and private party attention to the issue.

Phytotoxicity of trace metals in spiked and field-contaminated soils: Linking soil-extractable metals with toxicity.

Science.gov (United States)

Hamels, Fanny; Malevé, Jasmina; Sonnet, Philippe; Kleja, Dan Berggren; Smolders, Erik

2014-11-01

Soil tests have been widely developed to predict trace metal uptake by plants. The prediction of metal toxicity, however, has rarely been tested. The present study was set up to compare 8 established soil tests for diagnosing phytotoxicity in contaminated soils. Nine soils contaminated with Zn or Cu by metal mining, smelting, or processing were collected. Uncontaminated reference soils with similar soil properties were sampled, and series of increasing contamination were created by mixing each with the corresponding soil. In addition, each reference soil was spiked with either ZnCl2 or CuCl2 at several concentrations. Total metal toxicity to barley seedling growth in the field-contaminated soils was up to 30 times lower than that in corresponding spiked soils. Total metal (aqua regia-soluble) toxicity thresholds of 50% effective concentrations (EC50) varied by factors up to 260 (Zn) or 6 (Cu) among soils. For Zn, variations in EC50 thresholds decreased as aqua regia > 0.43 M HNO3  > 0.05 M ethylenediamine tetraacetic acid (EDTA) > 1 M NH4 NO3  > cobaltihexamine > diffusive gradients in thin films (DGT) > 0.001 M CaCl2 , suggesting that the last extraction is the most robust phytotoxicity index for Zn. The EDTA extraction was the most robust for Cu-contaminated soils. The isotopically exchangeable fraction of the total soil metal in the field-contaminated soils markedly explained the lower toxicity compared with spiked soils. The isotope exchange method can be used to translate soil metal limits derived from soils spiked with metal salts to site-specific soil metal limits. © 2014 SETAC.

Bioremediation of Pyrene-Contaminated Soils Using Biosurfactant

OpenAIRE

Jorfi; Rezaee; Jaafarzadeh; Esrafili; Akbari; Moheb Ali

2014-01-01

Background Polycyclic aromatic hydrocarbons (PAHs) are persistence organic chemicals with proved carcinogenic and mutagenic hazards. These compounds are usually adsorbed in soils in vicinity of oil and gas industries. Bioremediation of PAHs contaminated soils is difficult due to hydrophobic nature of PAHs. Objectives The main purpose of the current study was to determine the pyrene removal efficiency in synthetically contaminated ...

Migration of radionuclides in sub-surface soil

International Nuclear Information System (INIS)

Bachhuber, H.; Bunzl, K.; Dietl, F.; Kretner, R.; Schimmack, W.; Schultz, W.

1981-08-01

The object of the investigations was to draw the most realistic conclusions about the spreading rate of the radionuclides Sr, I, Cs and Ce in a model accident contaminating the earth surface for various subsurface soils taken from the environment of the Gorleben salt done. The retardation factors were hence determined for these radionuclides in columntests in undisturbed soil samples and the distribution coefficients determined in disturbed soil samples by shaking tests (batch method). The following mobility series can be given very globally for the examined soil profiles where especially columnar-results had been used: Ranker (Trebel) J > Sr > Ce > Cs, Podsol (Gorleben) J > Cs > Sr > Ce, Braunerde (Bruenkendorf) J approx. >= Sr > Ce approx. >= Cs. Arable Soils: Podsol (Gorleben) J > Sr > Cs > Ce, Parabraunerde (Eschweiler) J > Sr > Ce approx. >= Cs. (orig./HP) [de

Restoration of contaminated soils in abandoned mine areas (Tuscany, Italy)

Science.gov (United States)

Bini, Claudio; Wahsha, Mohammad

2016-04-01

In Italy ore research and exploitation have been nearly exhausted since the end of the last century, and have left on the land a huge amount of mine waste, therefore provoking evident environmental damage including surface and groundwater, soils, vegetation and the food chain, and a potential threat to human health. The main processes occurring at these sites are: rock disgregation, fragments migration, dust dispersion, oxidation (Eh>250mV), acidification (pHhazard. The increasing environmental consciousness of general population compelled Public Administrators to set down effective legislation acts on this subject (e.g. D.L. 152/2006), and more generally on environmental contamination. In this work we present the results of a survey carried out at several mixed sulphides mine sites in Tuscany, exploited for at least a millennium, and closed in the last century. Biogeochemical analyses carried out on representative soil profiles (Spolic Technosols) and vegetation in the proximal and distal areas of ore exploitation show heavy metal concentrations (Cd, Cu, Fe, Pb, Zn) overcoming legislation limits on average. Ni, Cr and Mn concentrations, instead, are generally below the reference levels. The results obtained suggest that the abandoned mine sites represent actual natural laboratories where to experiment new opportunities for restoration of anthropogenically contaminated areas, and to study new pedogenetic trends from these peculiar parent materials. Moreover, plants growing on these substrates are genetically adapted to metal-enriched soils, and therefore may be utilized in phytoremediation of contaminated sites. Furthermore, the institution of natural parks in these areas could enhance their educational and scientific value, contributing in the meantime to general population amusement and recreation. Finally, it is the occasion for soil scientists to submit to the scientific community new classification proposals of this new kind of soils. Key-words: mine waste

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff.

Science.gov (United States)

Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Cahn, Michael

2017-05-15

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

Electrokinetic Amendment in Phytoremediation of Mixed Contaminated Soil

International Nuclear Information System (INIS)

Chirakkara, Reshma A.; Reddy, Krishna R.; Cameselle, Claudio

2015-01-01

This study examines the effects of electrokinetic amendments for phytoremediation of mixed contaminated soil where typical silty clay soil was spiked with organic contaminants (naphthalene and phenanthrene) and heavy metal (lead, cadmium and chromium). The contaminated soil was treated with compost and placed in electrokinetic cells, which were seeded with oat plant or sunflower. Thirty days after germination, 25 V alternating current was applied to selected cells using graphite electrodes for 3 h per day. The plants were harvested after a growth period of 61 days. One cell remained unplanted to evaluate the effect of the electric current on the soil, alone. The results confirm a significant reduction of heavy metals and organic contaminants in soil. However, there was no noticeable improvement of heavy metal phytoextraction or PAH degradation due to the application of electric field despite the increase in biomass production by the plants subjected to the electric current. The electric potential application time and frequency are suggested to be increased to have noticeable effects in heavy metal uptake and PAHs degradation.

Contact angles at the water-air interface of hydrocarbon-contaminated soils and clay minerals

Science.gov (United States)

Sofinskaya, O. A.; Kosterin, A. V.; Kosterina, E. A.

2016-12-01

Contact angles at the water-air interface have been measured for triturated preparations of clays and soils in order to assess changes in their hydrophobic properties under the effect of oil hydrocarbons. Tasks have been to determine the dynamics of contact angle under soil wetting conditions and to reveal the effect of chemical removal of organic matter from soils on the hydrophilicity of preparations. The potentialities of static and dynamic drop tests for assessing the hydrophilic-hydrophobic properties of soils have been estimated. Clays (kaolinite, gumbrine, and argillite) have been investigated, as well as plow horizons of soils from the Republic of Tatarstan: heavy loamy leached chernozem, medium loamy dark gray forest soil, and light loamy soddy-calcareous soil. The soils have been contaminated with raw oil and kerosene at rates of 0.1-3 wt %. In the uncontaminated and contaminated chernozem, capillary water capacity has been maintained for 250 days. The contact angles have been found to depend on the degree of dispersion of powdered preparation, the main type of clay minerals in the soil, the presence and amount of oxidation-resistant soil organic matter, and the soil-water contact time. Characteristic parameters of mathematical models for drop behavior on triturated preparations have been calculated. Contamination with hydrocarbons has resulted in a reliable increase in the contact angles of soil preparations. The hydrophobization of soil surface in chernozem is more active than in soils poorer in organic matter. The complete restoration of the hydrophilic properties of soils after hydrocarbon contamination is due to the oxidation of easily oxidizable organic matter at the low content of humus, or to wetting during several months in the absence of the mazut fraction.

Surfactant-enhanced bioremediation of PAH- and PCB-contaminated soils

International Nuclear Information System (INIS)

Ghosh, M.M.; Yeom, I.T.; Shi, Z.; Cox, C.D.; Robinson, K.G.

1995-01-01

The role of surfactants in the desorption of soil-bound polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) was investigated. The solubilization of individual PAHs in an extract of a weathered, coal tar-contaminated soil containing a mixture of PAHs and other petroleum derivatives was found to be significantly less than that for pure compounds. Batch soil washing with Triton X-100 (a commercial, nonionic alkyl phenol ethoxylate) was found to increase the effective diffusion rate of PAHs from the contaminated soil by four orders of magnitude compared to that obtained by gas purging when the results were analyzed using a radial diffusion model. At concentrations of up to 24 times its critical micelle concentration (CMC), Triton X-100 did not seem to enhance hydrocarbon degradation in the coal tar-contaminated soil; however, the biosurfactant rhamnolipid R1, at a concentration of 50x CMC, increased the rate of mineralization of 4,4'-chlorinated biphenyl mobilized from a laboratory-contaminated soil by more than 60 times

Remediation Of Radioactive Contaminated Soil in Oil Fields

International Nuclear Information System (INIS)

Taha, A.A.; Hassib, G.M.; Ibrahim, Z.A.

2011-01-01

Radioactive contamination by naturally occurring radioactive materials (NORM) in evaporation pond has been evaluated. At several onshore oil field locations, the produced water is discharged to form artificial lagoons or ponds. Subsequently, the released waters drain to the ground leaving radioactive deposits associated with the soil that eventually require remedial action in accordance with radiation protection principles. The present study aims to investigate the remediation of contaminated soil in some oil fields and in this concern, two scenarios were proposed. The first scenario is studying the feasibility of using soil washing technique (a physical-chemical separation process) for removing radium-226 from the contaminated soil samples collected from an evaporating pond. The size/activity distribution analyses were carried out. The data obtained showed that almost 68 % of the investigated soil was coarse sand (≥ 300 μm), 28 % was medium and fine sand (≤300 μm and (≥75 μm) and only small fraction of 4 % was silt and clay (≤75 μm). A series of mild acids such as HCl and mild NaCl/HCl (chloride washing) were used for washing the investigated soil fractions. The obtained data showed that the coarse fraction ≥ 300 μm can be re mediated below a regulatory level of 1Bq/g. and the radium from this coarse fraction could be easily removed by screening and chloride washing. For the remediation of (≤ 300 μm and (≥ 75 μm soil fractions, a series of mild chloride washing experiments also showed that the chloride base (NaCl/HCl) was found to be potentially useful. However, there was a difficulty in achieving a low radium value in the fine (≥ 75 μm size fractions using chloride washing. The second scenario is to get rid of all contaminated soil and store it in a concrete basin through the program of radiological protection of personnel and environment. Preliminary gamma survey of contaminated soil showed that the significant area of the investigated

An evaluation of different soil washing solutions for remediating arsenic-contaminated soils.

Science.gov (United States)

Wang, Yiwen; Ma, Fujun; Zhang, Qian; Peng, Changsheng; Wu, Bin; Li, Fasheng; Gu, Qingbao

2017-04-01

Soil washing is a promising way to remediate arsenic-contaminated soils. Most research has mostly focused on seeking efficient extractants for removing arsenic, but not concerned with any changes in soil properties when using this technique. In this study, the removal of arsenic from a heavily contaminated soil employing different washing solutions including H 3 PO 4 , NaOH and dithionite in EDTA was conducted. Subsequently, the changes in soil physicochemical properties and phytotoxicity of each washing technique were evaluated. After washing with 2 M H 3 PO 4 , 2 M NaOH or 0.1 M dithionite in 0.1 M EDTA, the soil samples' arsenic content met the clean-up levels stipulated in China's environmental regulations. H 3 PO 4 washing decreased soil pH, Ca, Mg, Al, Fe, and Mn concentrations but increased TN and TP contents. NaOH washing increased soil pH but decreased soil TOC, TN and TP contents. Dithionite in EDTA washing reduced soil TOC, Ca, Mg, Al, Fe, Mn and TP contents. A drastic color change was observed when the soil sample was washed with H 3 PO 4 or 0.1 M dithionite in 0.1 M EDTA. After adjusting the soil pH to neutral, wheat planted in the soil sample washed by NaOH evidenced the best growth of all three treated soil samples. These results will help with selecting the best washing solution when remediating arsenic-contaminated soils in future engineering applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrokinetic remediation of anionic contaminants from unsaturated soils

International Nuclear Information System (INIS)

Lindgren, E.R.; Kozak, M.W.; Mattson, E.D.

1992-01-01

Heavy-metal contamination of soil and groundwater is a widespread problem in the DOE weapons complex, and for the nation as a whole. Electrokinetic remediation is one possible technique for in situ removal of such contaminants from unsaturated soils. In previous studies at Sandia National Laboratories, the electromigration of chromate ions and anionic dye ions have been demonstrated. This paper reports on a series of experiments that were conducted to study the effect of moisture content on the electromigration rate of anionic contaminants in unsaturated soil and determine the limiting moisture content for which electromigration occurs

Ex-situ bioremediation of petroleum contaminated soil

International Nuclear Information System (INIS)

Minier, M.R.

1994-01-01

The use of stress acclimated bacteria and nutrient supplements to enhance the biodegradation of petroleum contaminated soil can be a cost effective and reliable treatment technology to reduce organic contaminant levels to below established by local, state, and federal regulatory clean-up criteria. This paper will summarize the results of a field study in which 12,000 yds 3 of petroleum contaminated soil was successfully treated via ex-situ bioremediation and through management of macro and micronutrient concentrations, as well as, other site specific environmental factors that are essential for optimizing microbial growth

CLOPYRALID DISSIPATION IN THE SOIL CONTAMINATED WITH HEAVY METALS

Directory of Open Access Journals (Sweden)

Mariusz Kucharski

2014-12-01

Full Text Available The aim of the studies was to determine the influence of copper and zinc contamination on clopyralid dissipation in soil. The experiment was carried out in laboratory conditions (plant growth chamber. Clopyralid was applied to three different soils [similar textures, pH, organic carbon content and contrasting copper and zinc content: soil natural contaminated with Cu and Zn (S1, soil with natural low Cu and Zn concentration (S2 and soil S21 prepared in the laboratory (S2 soil additionally contaminated with Cu and Zn salts in the amounts equivalent to contamination level of S1 soil]. Soil samples were taken for analyses for 1 hour (initial concentration and 2, 4, 8, 16, 32, 64 and 96 days after treatment. Clopyralid residue was analysed using GC/ECD (gas chromatography with electron capture detector. Good linearity was found between logarithmic concentration of clopyralid residues and time. The differences in Cu and Zn content influenced the clopyralid decay in soil. The values of DT50 obtained in the experiment ranged from 21 to 27 days. A high concentration of Cu and Zn in soil slowed down clopyralid degradation (the DT50 value was higher – 25–27 days.

Production of non-constructive concrete blocks using contaminated soil

NARCIS (Netherlands)

de Korte, A.C.J.; Brouwers, Jos

2009-01-01

In this research, a heavily contaminated humus-rich peat soil and a lightly contaminated humus-poor sand soil, extracted from a field location in the Netherlands, are immobilized. These two types of soil are very common in the Netherlands. The purpose is to develop financial feasible, good quality

Influence of plant roots upon the mobility of radionuclides in soil, with respect to location of contamination below the surface

International Nuclear Information System (INIS)

Harvey, N.W.; Shaw, G.; Bell, N.J.B.

1997-01-01

The movement of 85 Sr, 137 Cs, 54 Mn and 60 Co in the 50 cm soil profile was studied with and without the presence of plant roots (triticum aestivum) in order to investigate the influence of roots and depth contamination upon the migration of radionuclides. The water table was maintained manually at 3 cm from the bottom. The physicochemical characteristics (E h Fe -2 , NH 4 + , pH and moisture content) as well as the total and extractable radioactivity were investigated. In the discrete contamination, where the location of contamination varied within the soil profile (0-5, 25-30 or 45-50 cm from the top), the influence of location upon the movement of these radionuclides was also studied. It was found that the changes in the soil physicochemical characteristics influenced the mobility of the four radionuclides. The extractability of 54 Mn and 60 Co was significantly increased in the reducing region of the soil, whereas that of 85 Sr, 137 Cs was not. Plant roots excerted significant effects upon the soil characteristics, via, reducing the E h pH and moisture content of the soil; increasing the extractability of both 54 Mn and 60 Co from the depth of 35 cm downwards. Radionuclide migration occurred via physicochemical and biological transport. The biological transport via plant roots was of particular importance for 137 Cs. Location of contamination had a significant influence upon the mobility of radionuclides. The migration of radionuclides was in the sequence of contamination in middle > bottom > top. The degree of the influence varied with radionuclides concerned. In the top layer contamination, the rank of the migration from the contamination layers, on the other hand 54 Mn, 60 Co and 137 Cs were more mobile and the movement was: 85 Sr ∼ 54 Mn ∼ 60 Co > 137 Cs. In the middle and bottom contamination layers, on the other hand, 54 Mn and 60 Co and 137 Cs were more mobile and the movement was 85 Sr ∼ 54 Mn ∼ 60 Co ∼ 137 Cs. (author)

Phyto remediation of PAH contaminated soil

International Nuclear Information System (INIS)

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

2005-01-01

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

Bioremediation of petroleum hydrocarbon contaminated soils using soil vapor extraction: Case study

International Nuclear Information System (INIS)

Roth, R.J.; Peterson, R.M.

1994-01-01

Soils contaminated with petroleum hydrocarbons are being remediated in situ at a site in Lakewood, New Jersey by bioremediation in conjunction with soil vapor extractions (SVE) and nutrient addition. The contaminants were from hydraulic oils which leaked from subsurface hydraulic lifts, waste oil from leaking underground storage tanks (USTs), an aboveground storage tank, and motor oil from a leaking UST. The oils contaminated subsurface soils at the site to a depth of 25 feet. Approximately 900 cubic yards of soil were contaminated. Soil sample analyses showed total petroleum hydrocarbon (TPH) concentrations up to 31,500 ppm. The design of the remedial system utilized the results of a treatability study which showed that TPH degrading microorganisms, when supplied with oxygen and nutrients, affected a 14% reduction in TPH in 30 days. A SVE system was installed which used three wells, each installed to a depth of 25 feet below grade. The SVE system was operated to achieve an extracted air flow of approximately 20 to 30 scfm from each well. Bioremediation of the TPH was monitored by measuring CO 2 and O 2 concentrations at the wellheads and vapor monitoring probes. After four months of remediation, CO 2 concentrations were at a minimum, at which point the subsurface soils were sampled and analyzed for TPH. The soil analyses showed a removal of TPH by biodegradation of up to 99.8% after four months of remediation

Remediation of lead contaminated soil

International Nuclear Information System (INIS)

Urban, W.; Krishnamurthy, S.

1992-01-01

Lead contaminated soil in urban area is of major concern because of the potential health risk to children. Many studies have established a direct correlation between lead in soil and elevated blood lead levels in children. In Minneapolis, Minnesota, Mielke et al. (1983) reported that 50% of the Hmong children with lead poisioning were in areas where soil lead levels were between 500 and 1000 micrograms per gram (ug/g), and 40% of the children suffering from lead poisioning lived in areas where soil lead levels exceeded 1000 ug/g. In urban areas, lead pollution in soil has come from many different sources. The sources include lead paint, lead batteries and automobile exhaust. Olson and Skogerbee (1975) found the following lead compounds in soils where the primary source of pollution was from automobiles: lead sulfate, lead oxide, lead dioxide, lead sulfide, and metallic lead. The primary form of lead found was lead sulfate. Lead sulfate, lead tetraoxide, white lead, and other forms of lead have been used in the manufacture of paints for houses. At present, two remediation techniques, solidification and Bureau of Mines fluosilicic acid leaching, are available for lead-contaminated sites. The objective of the present investigation at the Risk Reduction Engineering Laboratory (RREL), Edison, was to try to solubilize the lead species by appropriate reagents and then recover the contaminants by precipitation as lead sulfate, using environmentally acceptable methods. The apparatus used for mixing was a LabMaster mixer, with variable speed and high-shear impeller. Previous work had used nitric acid for dissolving metallic lead. Owing to the environmental concerns, it was decided to use acetic acid in the presence of oxygen. The theoretical justification for this approach is the favorable redox potential for the reaction between metallic lead, acetic acid, and gaseous oxygen

The Effects of Subsurface Bioremediation on Soil Structure, Colloid Formation, and Contaminant Transport

Science.gov (United States)

Wang, Y.; Liang, X.; Zhuang, J.; Radosevich, M.

2016-12-01

Anaerobic bioremediation is widely applied to create anaerobic subsurface conditions designed to stimulate microorganisms that degrade organic contaminants and immobilize toxic metals in situ. Anaerobic conditions that accompany such techniques also promotes microbially mediated Fe(III)-oxide mineral reduction. The reduction of Fe(III) could potentially cause soil structure breakdown, formation of clay colloids, and alternation of soil surface chemical properties. These processes could then affect bioremediation and the migration of contaminants. Column experiments were conducted to investigate the impact of anaerobic bioreduction on soil structure, hydraulic properties, colloid formation, and transport of three tracers (bromide, DFBA, and silica shelled silver nanoparticles). Columns packed with inoculated water stable soil aggregates were placed in anaerobic glovebox, and artificial groundwater media was pumped into the columns to simulate anaerobic bioreduction process for four weeks. Decent amount of soluble Fe(II) accompanied by colloids were detected in the effluent from bioreduction columns a week after initiation of bioreduction treatment, which demonstrated bioreduction of Fe(III) and formation of colloids. Transport experiments were performed in the columns before and after bioreduction process to assess the changes of hydraulic and surface chemical properties through bioreduction treatment. Earlier breakthrough of bromide and DFBA after treatment indicated alterations in flow paths (formation of preferential flow paths). Less dispersion of bromide and DFBA, and less tailing of DFBA after treatment implied breakdown of soil aggregates. Dramatically enhanced transport and early breakthrough of silica shelled silver nanoparticles after treatment supported the above conclusion of alterations in flow paths, and indicated changes of soil surface chemical properties.

Experimental Research Regarding the Application of Electro-Flushing Method on Diesel Contaminated Soils

Directory of Open Access Journals (Sweden)

Streche Constantin

2014-05-01

Full Text Available In 2011, as a result of the inventory conducted at the national level, The Ministry Of Environment concluded that the largest number of contaminated sites with hydrocarbons are due to the petroleum products distribution (nearly 400 sites, followed by the hydrocarbons extraction (about 310 sites. So, soil contamination with liquid petroleum products resulting from many industrial activities became an important issue of environment protection. Unfortunately not all local governments have provided a list of contaminated sites, which means that there is a possibility to have a bigger problem at the national level. All these surfaces are in a continuous growth due to industrial and social development and that is why it is necessary to study and improve decontamination methods of contaminated sites in order to regain one of our most important resources - the soil. In this paper, the main results obtained during a research that aimed to study two different treatment methods of contaminated soil in a combined solution, are presented. The newly developed method is called electro-flushing. Results proved that combining the two nominated methods could be a viable solution for treating diesel polluted soil with better performances comparing with using them separately. Concerning the electrochemical treatment of diesel contaminated soils an efficiency of 35-40 % could be obtained after 28 days; while using the flushing method up to 15-20% efficiency could be reached. On the other hand, if we combine these two methods, we can reach remediation efficiency up to 50%. So, the main interesting results of the present research is given by the fact that combining two known remediation methods, better performances could be achieved.

Bioremediation of crude oil contaminated tea plantation soil using ...

African Journals Online (AJOL)

Crude oil contamination of soil is a major concern for tea industry in Assam, India. Crude oil is a persistent organic contaminant which alters soil physical and biochemical characteristics and makes tea plants more susceptible against crude oil contamination. Therefore, two native bacterial strains designated as AS 03 and ...

Feasilbility of phytoextraction to remediate cadmium and zinc contaminated soils

NARCIS (Netherlands)

Koopmans, G.F.; Romkens, P.F.A.M.; Fokkema, M.J.; Song, J.; Luo, Y.M.; Japenga, J.; Zhao, F.J.

2008-01-01

A Cd and Zn contaminated soil was mixed and equilibrated with an uncontaminated, but otherwise similar soil to establish a gradient in soil contamination levels. Growth of Thlaspi caerulescens (Ganges ecotype) significantly decreased the metal concentrations in soil solution. Plant uptake of Cd and

Feasibility of phytoextraction to remediate cadmium and zinc contaminated soils

NARCIS (Netherlands)

Koopmans, G.F.; Romkens, P.F.A.M.; Fokkema, M.J.; Song, J.; Luo, Y.; Japenga, J.; Zhao, F.J.

2008-01-01

A Cd and Zn contaminated soil was mixed and equilibrated with an uncontaminated, but otherwise similar soil to establish a gradient in soil contamination levels. Growth of Thlaspi caerulescens (Ganges ecotype) significantly decreased the metal concentrations in soil solution. Plant uptake of Cd and

Pyrene removal from contaminated soil using electrokinetic process combined with surfactant

Directory of Open Access Journals (Sweden)

Seyed Enayat Hashemi

2015-07-01

Full Text Available Background: Pyrene is one of the stable polycyclic aromatic hydrocarbons that is considered as an important pollutants, because of extensive distribution in the environment and carcinogenic and mutagenic properties. Among the various treatment techniques, electrokinetic method is an environmental- friendly process for organic and mineral pollutants adsorbed to soil with fine pore size the same as clay and low hydraulic conductivity soils. For improving the efficiency of pyrene removal from soil, soulobilization of pyrene from soil could be used by surfactants. Materials and Methods : In this study, clay soil was selected as model because of the specific properties. Combined method using surfactant and electrokinetic was applied for pyrene removal from soil. Experiments were designed using response surface methodology (RSM, and effect of three variables includes surfactant concentration, voltage and surfactant type were evaluated for pyrene removal from contaminated soil. Results: Pyrene removal using anionic surfactants(SDS and nonionic surfactants(TX100 as a solubilizing agents has high removal efficiency. In the optimum condition with 95% confidence coefficient, utilizing mixed surfactants of sodium dodecyl sulfate and triton X-100 with the same volume, induced of 18.54 volt and 6.53 percent surfactant concentration have 94.6% pyrene removal efficiency. Conclusion:: Results of this study shows that electrokinetic process combined with surfactant as solubilizing agent could be applied as an efficient method for treating the pyrene-contaminated soils.

Soil mixing of stratified contaminated sands.

Science.gov (United States)

Al-Tabba, A; Ayotamuno, M J; Martin, R J

2000-02-01

Validation of soil mixing for the treatment of contaminated ground is needed in a wide range of site conditions to widen the application of the technology and to understand the mechanisms involved. Since very limited work has been carried out in heterogeneous ground conditions, this paper investigates the effectiveness of soil mixing in stratified sands using laboratory-scale augers. This enabled a low cost investigation of factors such as grout type and form, auger design, installation procedure, mixing mode, curing period, thickness of soil layers and natural moisture content on the unconfined compressive strength, leachability and leachate pH of the soil-grout mixes. The results showed that the auger design plays a very important part in the mixing process in heterogeneous sands. The variability of the properties measured in the stratified soils and the measurable variations caused by the various factors considered, highlighted the importance of duplicating appropriate in situ conditions, the usefulness of laboratory-scale modelling of in situ conditions and the importance of modelling soil and contaminant heterogeneities at the treatability study stage.

Bioremediation of diesel fuel contaminated soils

International Nuclear Information System (INIS)

Troy, M.A.; Jerger, D.E.

1992-01-01

Bioremediation techniques were successfully employed in the cost-effective cleanup of approximately 8400 gallons of diesel fuel which had been accidentally discharged at a warehouse in New Jersey. Surrounding soils were contaminated with the diesel fuel at concentrations exceeding 1,470 mg/kg total petroleum hydrocarbons as measured by infrared spectroscopy (TPH-IR, EPA method 418.1, modified for soils). This paper reports on treatment of the contaminated soils through enhanced biological land treatment which was chosen for the soil remediation pursuant to a New Jersey Pollutant Discharge Elimination System - Discharge to Ground Water (NJPDES-DGW) permit. Biological land treatment of diesel fuel focuses on the breakdown of the hydrocarbon fractions by indigenous aerobic microorganisms in the layers of soil where oxygen is made available. Metabolism by these microorganisms can ultimately reduce the hydrocarbons to innocuous end products. The purpose of biological land treatment was to reduce the concentration of the petroleum hydrocarbon constituents of the diesel fuel in the soil to 100 ppm total petroleum hydrocarbons (TPH)

Release behavior of triazine residues in stabilised contaminated soils

International Nuclear Information System (INIS)

Ying, G.G.; Kookana, R.S.; Mallavarpu, M.

2005-01-01

This paper reports the release behavior of two triazines (atrazine and simazine) in stabilised soils from a pesticide-contaminated site in South Australia. The soils were contaminated with a range of pesticides, especially with triazine herbicides. With multiple extractions of each soil sample with deionised water (eight in total), 15% of atrazine and 4% of simazine residues were recovered, resulting in very high concentrations of the two herbicides in leachate. The presence of small fractions of surfactants was found to further enhance the release of the residues. Methanol content up to 10% did not substantially influence the concentration of simazine and atrazine released. The study demonstrated that while the stabilisation of contaminated soil with particulate activated carbon (5%) and cement mix (15%) was effective in locking the residues of some pesticides, it failed to immobilise triazine herbicides residues completely. Given the higher water solubility of these herbicides than other compounds more effective strategies to immobilise their residues is needed. - Stabilisation of contaminated soil with a mix of activated carbon and cement may fail to immobilise some contaminants like triazines

Heavy metal contamination characteristic of soil in WEEE (waste electrical and electronic equipment) dismantling community: a case study of Bangkok, Thailand.

Science.gov (United States)

Damrongsiri, Seelawut; Vassanadumrongdee, Sujitra; Tanwattana, Puntita

2016-09-01

Sue Yai Utit is an old community located in Bangkok, Thailand which dismantles waste electrical and electronic equipment (WEEE). The surface soil samples at the dismantling site were contaminated with copper (Cu), lead (Pb), zinc (Zn), and nickel (Ni) higher than Dutch Standards, especially around the WEEE dumps. Residual fractions of Cu, Pb, Zn, and Ni in coarse soil particles were greater than in finer soil. However, those metals bonded to Fe-Mn oxides were considerably greater in fine soil particles. The distribution of Zn in the mobile fraction and a higher concentration in finer soil particles indicated its readily leachable character. The concentration of Cu, Pb, and Ni in both fine and coarse soil particles was mostly not significantly different. The fractionation of heavy metals at this dismantling site was comparable to the background. The contamination characteristics differed from pollution by other sources, which generally demonstrated the magnification of the non-residual fraction. A distribution pathway was proposed whereby contamination began by the deposition of WEEE scrap directly onto the soil surface as a source of heavy metal. This then accumulated, corroded, and was released via natural processes, becoming redistributed among the soil material. Therefore, the concentrations of both the residual and non-residual fractions of heavy metals in WEEE-contaminated soil increased.

Bioavailability assessment of contaminants in soils via respiration and nitrification tests

International Nuclear Information System (INIS)

Hund-Rinke, Kerstin; Simon, Markus

2008-01-01

For the assessment of contaminated soils ecotoxicological tests are used to estimate the bioavailability of contaminants in soil samples. Terrestrial tests reveal the habitat function of soils, and parameters applied in tests involving microorganisms include respiration activity and potential ammonium oxidation. For such tests, the threshold values needed to assess the results have already been established in guidelines ISO 17155 and ISO 15685. In this paper, we discuss about the respiration activity and potential ammonium oxidation results obtained from a wide variety of soils with different physico-chemical properties and levels of contamination. These results show that microbial respiration and potential ammonium oxidation have different sensitivities to various classes of contaminants. We demonstrated that both organic and inorganic contaminants influence potential ammonium oxidation, whereas microbial respiration is predominantly affected by biodegradable organic contaminants. These differences might be useful for more detailed assessments of soil contamination, leading to different recommended actions depending on which parameter is affected. - The paper provides a further criterion for a more detailed assessment of soil contamination, leading to different recommended actions depending on which parameter is affected

Bioavailability assessment of contaminants in soils via respiration and nitrification tests

Energy Technology Data Exchange (ETDEWEB)

Hund-Rinke, Kerstin [Fraunhofer Institute for Molecular Biology and Applied Ecology, Auf dem Aberg 1, 57392 Schmallenberg (Germany)], E-mail: kerstin.hund-rinke@ime.fraunhofer.de; Simon, Markus [Fraunhofer Institute for Molecular Biology and Applied Ecology, Auf dem Aberg 1, 57392 Schmallenberg (Germany)], E-mail: markus.simon@ime.fraunhofer.de

2008-05-15

For the assessment of contaminated soils ecotoxicological tests are used to estimate the bioavailability of contaminants in soil samples. Terrestrial tests reveal the habitat function of soils, and parameters applied in tests involving microorganisms include respiration activity and potential ammonium oxidation. For such tests, the threshold values needed to assess the results have already been established in guidelines ISO 17155 and ISO 15685. In this paper, we discuss about the respiration activity and potential ammonium oxidation results obtained from a wide variety of soils with different physico-chemical properties and levels of contamination. These results show that microbial respiration and potential ammonium oxidation have different sensitivities to various classes of contaminants. We demonstrated that both organic and inorganic contaminants influence potential ammonium oxidation, whereas microbial respiration is predominantly affected by biodegradable organic contaminants. These differences might be useful for more detailed assessments of soil contamination, leading to different recommended actions depending on which parameter is affected. - The paper provides a further criterion for a more detailed assessment of soil contamination, leading to different recommended actions depending on which parameter is affected.

SoilCAM: soil contamination: advanced integrated characterisation and time-lapse monitoring

NARCIS (Netherlands)

French, H.K.; Zee, van der S.E.A.T.M.; Meju, M.

2009-01-01

The SoilCAM project is aimed at improving current methods for monitoring contaminant distribution and biodegradation in the subsurface. Currently proven methods, based on invasive sampling of soil, soil water and gaseous phase, are unable to provide sufficiently accurate data with high enough

Urban community gardeners' knowledge and perceptions of soil contaminant risks.

Science.gov (United States)

Kim, Brent F; Poulsen, Melissa N; Margulies, Jared D; Dix, Katie L; Palmer, Anne M; Nachman, Keeve E

2014-01-01

Although urban community gardening can offer health, social, environmental, and economic benefits, these benefits must be weighed against the potential health risks stemming from exposure to contaminants such as heavy metals and organic chemicals that may be present in urban soils. Individuals who garden at or eat food grown in contaminated urban garden sites may be at risk of exposure to such contaminants. Gardeners may be unaware of these risks and how to manage them. We used a mixed quantitative/qualitative research approach to characterize urban community gardeners' knowledge and perceptions of risks related to soil contaminant exposure. We conducted surveys with 70 gardeners from 15 community gardens in Baltimore, Maryland, and semi-structured interviews with 18 key informants knowledgeable about community gardening and soil contamination in Baltimore. We identified a range of factors, challenges, and needs related to Baltimore community gardeners' perceptions of risk related to soil contamination, including low levels of concern and inconsistent levels of knowledge about heavy metal and organic chemical contaminants, barriers to investigating a garden site's history and conducting soil tests, limited knowledge of best practices for reducing exposure, and a need for clear and concise information on how best to prevent and manage soil contamination. Key informants discussed various strategies for developing and disseminating educational materials to gardeners. For some challenges, such as barriers to conducting site history and soil tests, some informants recommended city-wide interventions that bypass the need for gardener knowledge altogether.

Urban community gardeners' knowledge and perceptions of soil contaminant risks.

Directory of Open Access Journals (Sweden)

Brent F Kim

Full Text Available Although urban community gardening can offer health, social, environmental, and economic benefits, these benefits must be weighed against the potential health risks stemming from exposure to contaminants such as heavy metals and organic chemicals that may be present in urban soils. Individuals who garden at or eat food grown in contaminated urban garden sites may be at risk of exposure to such contaminants. Gardeners may be unaware of these risks and how to manage them. We used a mixed quantitative/qualitative research approach to characterize urban community gardeners' knowledge and perceptions of risks related to soil contaminant exposure. We conducted surveys with 70 gardeners from 15 community gardens in Baltimore, Maryland, and semi-structured interviews with 18 key informants knowledgeable about community gardening and soil contamination in Baltimore. We identified a range of factors, challenges, and needs related to Baltimore community gardeners' perceptions of risk related to soil contamination, including low levels of concern and inconsistent levels of knowledge about heavy metal and organic chemical contaminants, barriers to investigating a garden site's history and conducting soil tests, limited knowledge of best practices for reducing exposure, and a need for clear and concise information on how best to prevent and manage soil contamination. Key informants discussed various strategies for developing and disseminating educational materials to gardeners. For some challenges, such as barriers to conducting site history and soil tests, some informants recommended city-wide interventions that bypass the need for gardener knowledge altogether.

De-icing salt contamination reduces urban tree performance in structural soil cells.

Science.gov (United States)

Ordóñez-Barona, Camilo; Sabetski, Vadim; Millward, Andrew A; Steenberg, James

2018-03-01

Salts used for de-icing roads and sidewalks in northern climates can have a significant impact on water quality and vegetation. Sub-surface engineering systems, such as structural soil cells, can regulate water runoff and pollutants, and provide the necessary soil volume and irrigation to grow trees. However, the ability of such systems to manage de-icing salt contamination, and the impact of this contamination on the trees growing in them, have not been evaluated. We report on an field investigation of de-icing salt contamination in structural cells in two street-revitalization projects in Toronto, Canada, and the impact of this contamination on tree performance. We analyzed soil chemistry and collected tree attributes; these data were examined together to understand the effect of salinity on tree mortality rates and foliar condition. Data collected from continuous soil salinity loggers from April to June for one of the two sites were used to determine whether there was a long-term accumulation of salts in the soils. Results for both sites indicate that both sites displayed high salinity and alkalinity, with levels elevated beyond those suggested before those reported to cause negative tree effects. For one site, trees that were alive and trees that had a better foliar condition had significantly lower levels of soil salinity and alkalinity than other trees. High salinity and alkalinity in the soil were also associated with lower nutrient levels for both sites. Although tests for salinity accumulation in the soils of one site were negative, a longer monitoring of the soil conditions within the soil cells is warranted. Despite structural cells being increasingly utilized for their dual role in storm-water management and tree establishment, there may be a considerable trade-off between storm-water management and urban-forest function in northern climates where de-icing salt application continues to be commonplace. Copyright © 2017 Elsevier Ltd. All rights reserved.

Screening hydroxyapatite for cadmium and lead immobilization in aqueous solution and contaminated soil: The role of surface area.

Science.gov (United States)

Li, Hongying; Guo, Xisheng; Ye, Xinxin

2017-02-01

Hydroxyapatite (HAP) has been widely used to immobilize many cationic metals in water and soils. The specific reason why an increase in the surface area of HAP enhances cadmium (Cd) uptake, but has no effect on lead (Pb) uptake, is not clear. The aim of this study was to determine the factors causing the differences in sorption behavior between Cd and Pb by evaluating HAPs with different surface areas. We synthesized HAPs with two different surface areas, which were characterized by X-ray diffraction, N 2 adsorption, and scanning electron microscopy, and then evaluated them as sorbents for Cd and Pb removal by testing in single and binary systems. The sorption capacity of large surface area HAP (1.85mmol/g) for Cd in the single-metal system was higher than that of small surface area HAP (0.64mmol/g), but there were no differences between single- and binary-metal solutions containing Pb. After the Cd experiments, the HAP retained a stable structure and intact morphology, which promotes the accessibility of reactive sites for Cd. However, a newly formed precipitate covered the surface and blocked the channels in the presence of Pb, which reduced the number of potential adsorption sites on HAP for Cd and Pb. Remediation experiments using Cd- and Pb-contaminated soil produced similar results to the solution tests. These results indicate that alterations of the structure and morphology during the reaction is an important factor influencing metal sorption to HAP. Copyright © 2016. Published by Elsevier B.V.

Effect of soil texture on phytoremediation of arsenic-contaminated soils

Science.gov (United States)

Pallud, C. E.; Matzen, S. L.; Olson, A.

2015-12-01

Soil arsenic (As) contamination is a global problem, resulting in part from anthropogenic activities, including the use of arsenical pesticides and treated wood, mining, and irrigated agriculture. Phytoextraction using the hyperaccumulating fern Pteris vittata is a promising new technology to remediate soils with shallow arsenic contamination with minimal site disturbance. However, many challenges still lie ahead for a global application of phytoremediation. For example, remediation times using P. vittata are on the order of decades. In addition, most research on As phytoextraction with P. vittata has examined As removal from sandy soils, where As is more available, with little research focusing on As removal from clayey soils, where As is less available. The objective of this study is to determine the effects of soil texture and soil fertilization on As extraction by P. vittata, to optimize remediation efficiency and decrease remediation time under complex field conditions. A field study was established 2.5 years ago in an abandoned railroad grade contaminated with As (average 85.5 mg kg-1) with texture varying from sandy loam to silty clay loam. Organic N, inorganic N, organic P, inorganic P, and compost were applied to separate sub-plots; control ferns were grown in untreated soil. In a parallel greenhouse experiment, ferns were grown in sandy loam soil extracted from the field (180 mg As kg-1), with similar treatments as those used at the field site, plus a high phosphate treatment and treatments with arbuscular mycorrhizal fungi. In the field study, fern mortality was 24% higher in clayey soil than in sandy soil due to waterlogging, while As was primarily associated with sandy soil. Results from the sandy loam soil indicate that soil treatments did not significantly increase As phytoextraction, which was lower in phosphate-treated ferns than in control ferns, both in the field and greenhouse study. Under greenhouse conditions, ferns treated with organic N were

Comparative analysis of decision tree algorithms on quality of water contaminated with soil

Directory of Open Access Journals (Sweden)

Mara Andrea Dota

2015-02-01

Full Text Available Agriculture, roads, animal farms and other land uses may modify the water quality from rivers, dams and other surface freshwaters. In the control of the ecological process and for environmental management, it is necessary to quickly and accurately identify surface water contamination (in areas such as rivers and dams with contaminated runoff waters coming, for example, from cultivation and urban areas. This paper presents a comparative analysis of different classification algorithms applied to the data collected from a sample of soil-contaminated water aiming to identify if the water quality classification proposed in this research agrees with reality. The sample was part of a laboratory experiment, which began with a sample of treated water added with increasing fractions of soil. The results show that the proposed classification for water quality in this scenario is coherent, because different algorithms indicated a strong statistic relationship between the classes and their instances, that is, in the classes that qualify the water sample and the values which describe each class. The proposed water classification varies from excelling to very awful (12 classes

Surface and subsurface characterization of uranium contamination at the Fernald environmental management site

International Nuclear Information System (INIS)

Schilk, A.J.; Perkins, R.W.; Abel, K.H.; Brodzinski, R.L.

1993-04-01

The past operations of uranium production and support facilities at several Department of Energy (DOE) sites have occasionally resulted in the local contamination of some surface and subsurface soils, and the three-dimensional distribution of the uranium at these sites must be thoroughly characterized before any effective remedial protocols can be established. To this end, Pacific Northwest Laboratory (PNL) has been tasked by the DOE's Office of Technology Development with adapting, developing, and demonstrating technologies for the measurement of uranium in surface and subsurface soils at the Fernald Uranium in Soils Integrated Demonstration site. These studies are detailed in this report

Electrokinetic In Situ Treatment of Metal-Contaminated Soil

Science.gov (United States)

Quinn, Jacqueline; Clausen, Christian A., III; Geiger, Cherie; Reinhart, Debra

2004-01-01

An electrokinetic technique has been developed as a means of in situ remediation of soils, sludges, and sediments that are contaminated with heavy metals. Examples of common metal contaminants that can be removed by this technique include cadmium, chromium, zinc, lead, mercury, and radionuclides. Some organic contaminants can also be removed by this technique. In the electrokinetic technique, a low-intensity direct current is applied between electrodes that have been implanted in the ground on each side of a contaminated soil mass. The electric current causes electro-osmosis and migration of ions, thereby moving aqueous-phase subsurface contaminants from one electrode to the other. The half reaction at the anode yields H+, thereby generating an acid front that travels from the anode toward the cathode. As this acid front passes through a given location, the local increase in acidity increases the solubility of cations that were previously adsorbed on soil particles. Ions are transported towards one electrode or the other which one depending on their respective electric charges. Upon arrival at the electrodes, the ionic contaminants can be allowed to become deposited on the electrodes or can be extracted to a recovery system. Surfactants and other reagents can be introduced at the electrodes to enhance rates of removal of contaminants. Placements of electrodes and concentrations and rates of pumping of reagents can be adjusted to maximize efficiency. The basic concept of electrokinetic treatment of soil is not new. What is new here are some of the details of application and the utilization of this technique as an alternative to other techniques (e.g., flushing or bioremediation) that are not suitable for treating soils of low hydraulic conductivity. Another novel aspect is the use of this technique as a less expensive alternative to excavation: The cost advantage over excavation is especially large in settings in which contaminated soil lies near and/or under

Chelate-assisted phytoextraction of lead from contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Cooper, E.M.; Sims, J.T.; Cunningham, S.D.; Huang, J.W.; Berti, W.R.

1999-12-01

Phytoextraction, a remediation strategy for lead (Pb)-contaminated soils that removes soil Pb through plant uptake and harvest, may be enhanced by use of synthetic chelates. The authors evaluated Pb desorption from four contaminated soils by seven chelates (CDTA, DTPA, EDDHA, EFTA, HEDTA, HEIDA, and NTA) at three rates. The three most effective chelates (CDTA, DTPA, and HEDTA) were used in greenhouse studies with an uncontaminated soil and a Pb-contaminated soil to determine the effect of chelate type and rate on growth, Pb uptake, and plant elemental composition. Lead desorption varied with chelate and soil and increased with chelate rate, averaging 948 mg Pb kg{sup {minus}1} at the 20 mmol kg{sup {minus}1} rate vs. 28 mg Pb kg{sup {minus}1} by the control. The general ranking of chelate effectiveness, based on total Pb desorbed, was HEDTA > CDTA > DTPA > EGTA > HEIDA > EDDHA {approximately} NTA. Plant uptake of Pb from the contaminated soil was enhanced by CDTA, DTPA, and HEDTA, but with even the most effective treatment (corn, high CDTA rate), the amount of Pb extracted by plants was rather low. Lead extractable by the Toxicity Characteristic Leaching Procedure (TCLP) was increased from 9 mg L{sup {minus}1} in the control to from 47 to 174 mg L{sup {minus}1} in soils treated with 20 mmol kg{sup {minus}1} CDTA or DTPA and chelates generally caused a shift in Pb from resistant to more soluble chemical fractions.

Effective dielectric mixture model for characterization of diesel contaminated soil

International Nuclear Information System (INIS)

Al-Mattarneh, H.M.A.

2007-01-01

Human exposure to contaminated soil by diesel isomers can have serious health consequences like neurological diseases or cancer. The potential of dielectric measuring techniques for electromagnetic characterization of contaminated soils was investigated in this paper. The purpose of the research was to develop an empirical dielectric mixture model for soil hydrocarbon contamination application. The paper described the basic theory and elaborated in dielectric mixture theory. The analytical and empirical models were explained in simple algebraic formulas. The experimental study was then described with reference to materials, properties and experimental results. The results of the analytical models were also mathematically explained. The proposed semi-empirical model was also presented. According to the result of the electromagnetic properties of dry soil contaminated with diesel, the diesel presence had no significant effect on the electromagnetic properties of dry soil. It was concluded that diesel had no contribution to the soil electrical conductivity, which confirmed the nonconductive character of diesel. The results of diesel-contaminated soil at saturation condition indicated that both dielectric constant and loss factors of soil were decreased with increasing diesel content. 15 refs., 2 tabs., 9 figs

[Cd Runoff Load and Soil Profile Movement After Implementation of Some Typical Contaminated Agricultural Soil Remediation Strategies].

Science.gov (United States)

Liu, Xiao-li; Zeng, Zhao-xia; Tie, Bai-qing; Chen, Qiu-wen; Wei, Xiang-dong

2016-02-15

Owing to the strong ability to immobilize and hyperaccumulate some toxic heavy metals in contaminated soils, the biochar, lime and such as hyperaccumulator ramie received increasing interests from crops and environment safety in recent years. Outdoor pot experiment was conducted to compare the impacts of lime and biochar addition in paddy rice treatment, hyperaccumulator ramie and ramie combined with EDTA of plant Phytoremediation methods on soil available Cd dynamics in rainfall runoff and the mobility along soil profile, under both natural acid precipitation and acid soil conditions. The results showed that, biochar addition at a 2% mass ratio application amount significantly increased soil pH, while ramie with EDTA application obviously decreased soil pH compared to ramie monoculture. Within the same rainfall events, water soluble Cd concentration in surface runoff of ramie treatments was significantly higher than those of waterlogged rice treatments, and Cd concentration in runoff was obviously increased after EDTA addition, whereas lime at a 0.3% mass ratio application amount as additive had no obvious impact on soil pH and Cd speciation change, which may be due to the low application amount. During the whole experimental period , water soluble Cd concentration of rainfall runoff in spring was higher than that in summer, showing the same seasonal characteristics in all treatments. Biochar addition could significantly decrease available Cd content in 0-20 cm soil layer and with certain preferable persistency effects, whereas EDTA addition treatment obviously increased available Cd of 0-20 cm soil layer compared to other treatments, and obvious Cd element activation phenomenon in 20-40 cm soil layer was observed after EDTA addition. In conclusion, lime and biochar as environmental and friendly alkaline Cd immobilization materials showed lower environment risk to surface and ground receiving water, but attention should be paid to phytoremediation enhanced with

Geochemical cartography as a tool for assessing the degree of soil contamination with heavy metals in Poland

Science.gov (United States)

Szymon Borkowski, Andrzej; Kwiatkowska-Malina, Jolanta

2016-04-01

Spatial disposition of chemical elements including heavy metals in the soil environment is a very important information during preparation of the thematic maps for the environmental protection and/or spatial planning. This knowledge is also essential for the earth's surface and soil's monitoring, designation of areas requiring improvement including remediation. The main source of anthropogenic pollution of soil with heavy metals are industry related to the mining coal and liquid fuels, mining and metallurgy, chemical industry, energy production, waste management, agriculture and transport. The geochemical maps as a kind of specific thematic maps made on the basis of datasets obtained from the Polish Geological Institute's resources allow to get to know the spatial distribution of different chemical elements including heavy metals in soil. The results of the research carried out by the Polish Geological Institute showed strong contamination in some regions in Poland mainly with arsenic, cadmium, lead and nickel. For this reason it was the point to prepare geochemical maps showing contamination of soil with heavy metals, and determine main sources of contamination and zones where heavy metals concentration was higher than acceptable contents. It was also presented a summary map of soil contamination with heavy metals. Additionally, location of highly contaminated zones was compiled with predominant in those areas types of arable soils and then results were thoroughly analyzed. This information can provide a base for further detailed studies on the soil contamination with heavy metals.

Comparative plant uptake and microbial degradation of trichloroethylene in the rhizospheres of five plant species-- implications for bioremediation of contaminated surface soils

Energy Technology Data Exchange (ETDEWEB)

Anderson, T. A. [Tennessee Univ., Knoxville, TN (United States); Walton, B. T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

1992-01-01

The objective of this study was to collect data that would provide a foundation for the concept of using vegetation to enhance in situ bioremediation of contaminated surface soils. Soil and vegetation (Lespedeza cuneata, Paspalum notatum, Pinus taeda, and Solidago sp.) samples from the Miscellaneous Chemicals Basin (MCB) at the Savannah River Site were used in tests to identify critical plant and microbiological variables affecting the fate of trichloroethylene (TCE) in the root zone. Microbiological assays including phospholipid acid analyses, and 14C-acetate incorporation were conducted to elucidate differences in rhizosphere and nonvegetated soil microbial communities from the MCB. The microbial activity, biomass, and degradation of TCE in rhizosphere soils were significantly greater than corresponding nonvegetated soils. Vegetation had a positive effect on microbial degradation of 14C-TCE in whole-plant experiments. Soils from the MCB containing Lespedeza cuneata, Pinus taeda, and Glycine max mineralized greater than 25% of the 14C- TCE added compared with less than 20% in nonvegetated soils. Collectively, these results provide evidence for the positive role of vegetation in enhancing biodegradation.

Comparative plant uptake and microbial degradation of trichloroethylene in the rhizospheres of five plant species-- implications for bioremediation of contaminated surface soils

Energy Technology Data Exchange (ETDEWEB)

Anderson, T.A. (Tennessee Univ., Knoxville, TN (United States)); Walton, B.T. (Oak Ridge National Lab., TN (United States))

1992-01-01

The objective of this study was to collect data that would provide a foundation for the concept of using vegetation to enhance in situ bioremediation of contaminated surface soils. Soil and vegetation (Lespedeza cuneata, Paspalum notatum, Pinus taeda, and Solidago sp.) samples from the Miscellaneous Chemicals Basin (MCB) at the Savannah River Site were used in tests to identify critical plant and microbiological variables affecting the fate of trichloroethylene (TCE) in the root zone. Microbiological assays including phospholipid acid analyses, and {sup 14}C-acetate incorporation were conducted to elucidate differences in rhizosphere and nonvegetated soil microbial communities from the MCB. The microbial activity, biomass, and degradation of TCE in rhizosphere soils were significantly greater than corresponding nonvegetated soils. Vegetation had a positive effect on microbial degradation of {sup 14}C-TCE in whole-plant experiments. Soils from the MCB containing Lespedeza cuneata, Pinus taeda, and Glycine max mineralized greater than 25% of the {sup 14}C- TCE added compared with less than 20% in nonvegetated soils. Collectively, these results provide evidence for the positive role of vegetation in enhancing biodegradation.

[Phytoremediation of Petroleum Contaminated Soils with Iris pseudacorus L. and the Metabolic Analysis in Roots].

Science.gov (United States)

Wang, Ya-nan; Cheng, Li-juan; Zhou, Qi-xing

2016-04-15

In this study, we performed a greenhouse pot-culture experiment to investigate the potential of a wild ornamental plant Iris pseudacorus L. in remediating petroleum contaminated soils from the Dagang Oilfield in Tianjin, China. The results suggested that Iris pseudacorus L. had great resistance to ≤ 40,000 mg · kg(⁻¹ of total petroleum hydrocarbons (TPHs). The removal rate of TPHs with concentrations of 10,000 mg · kg⁻¹, 20,000 mg · kg⁻¹ and 40,000 mg · kg⁻¹ in soils by Iris pseudacorus L. was 42.1%, 33.1% 31.2%, respectively, much higher than those in the corresponding controls (31.8%, 21.3% 11.9%, respectively) (P 1.2) with the root specific surface area from the PLS-DA model analysis, including ethanedioic acid, lactic acid, 2-butenedioic acid, phosphate and propanedioic acid, were positively correlated with the root specific surface area, but the others, gluconic acid, uridine, butanoic acid, maltose, 9,12-octadecadienoic acid, phenylalanine, were negatively correlated with it. In conclusion, using Iris pseudacorus L. to remediate petroleum contaminated soils is feasible, and the metabolic analysis in roots is useful to better understand the metabolic response of plants exposure to petroleum contaminated soils, and then reveals its remediated mechanisms.

Bioremediation in soil contaminated with hydrocarbons in Colombia.

Directory of Open Access Journals (Sweden)

María Alejandra Trujillo Toro

2012-10-01

Full Text Available This study analyzes bioremediation processes of hydrocarbon contaminated soils in Colombia as a sustainable alternative to the deterioration of environmental quality by hydrocarbon spillage. According to national and international environmental law, all waste contaminated with hydrocarbons is considered dangerous waste, and therefore it cannot be released in the ground, water or be incinerated. Such legislation has motivated companies around the world to implement treatment processes for contaminated soils. Within Colombia, oil companies have been implementing the bioremediation of hydrocarbon contaminated soils in order to manage the waste coming from activities of oil drilling, refinement, transport and distribution.These practices must be considered viable for their ease of implementation, their low overhead costs, and for the benefits they provide towards environmental quality. Among the positive impacts that these practices have generated, it may consider the following: a solution for the problem of hydrocarbon contaminated soils, alternatives for the ultimate disposal of said waste without affecting ground, water or air resources, the low cost of the operation, and the technical experience of sustainable development which can continue to be implemented in companies dealing with dangerous waste.

Progress of research and utilization of soil amendments in phytoremediation of radioactive contamination soil

International Nuclear Information System (INIS)

Guo Yangrui; Song Gang; Chen Yongheng

2012-01-01

With the increasing of soil pollution and degradation, it becomes more important to research and apply soil amendments in agriculture. This paper reviewed different kinds of soil amendments and their impacts on phytostabilization and phytoextraction techniques, and summarized the application of soil amendments in the radio-contaminated soils as well as their effects on the phytoremediation. The main repair mechanisms of the soil amendments are involved in adsorption, ion exchange, chelation, and complexation. The potential applications in the phytoremediation on radio-contaminated soils, as well as the main repair mechanisms and the existing problems were discussed. (authors)

Vermiremediation of soils contaminated with mixture of petroleum ...

African Journals Online (AJOL)

In this paper, vermiremediation, a biological technique was utilized in order to clean-up soil contaminated with gasoline, diesel and spent engine oil using an earthworm - Eisenia fetida. The contaminated soils were analyzed for the total petroleum hydrocarbon (TPH) level every 24 hours over a period of 120 hours using ...

Optimization of surfactant-aided remediation of industrially contaminated soils

International Nuclear Information System (INIS)

Joshi, M.M.; Lee, S.

1996-01-01

Soil matrices contaminated with polycyclic aromatic hydrocarbons (PAHs) abound at the sites of coke-oven gas plants, refineries, and many other major chemical industries. The removal of PAHs from soil using pure water, via soil washing (ex situ) or soil flushing (in situ), is quite ineffective due to their low solubility and hydrophobicity. However, addition of suitable surfactant(s) has been shown to increase the removal efficiency several fold. For the present work, the removal of PAHs occurring in industrially contaminated soil was studied. The objective was to use a nonionic surfactant solution for in situ soil flushing and to evaluate the optimal range of process parameters that can significantly increase the removal efficiency. The process parameters chosen were surfactant concentration, ratio of washing solution volume to soil weight, and temperature of washing solution. These parameters were found to have a significant effect on PAH removal from the contaminated soil and an optimal range was determined for each parameter under given washing conditions

Heavy metal contamination of soil and sediment in Zambia

African Journals Online (AJOL)

USER

Key words: Heavy metal, contamination, mining, soil, sediment. INTRODUCTION ... drinking water and inhaling air or soil contaminated by mining activities and the ..... indicates that copper waste discharged into the upper reaches of the Kafue ...

Development of provisions for oil contaminated soil neutralizing in the conditions of Siberia and the Arctic

Science.gov (United States)

Shtripling, L. O.; Kholkin, E. G.

2017-08-01

Siberia and the Arctic zone of the Russian Federation occupy a large area of the country and they differ from other regions in special climatic conditions, in particular, a long period of freezing temperatures and relatively poor infrastructure. The main problem of neutralizing soils contaminated with oil products in conditions of negative ambient temperature is that the contaminated soil is in a frozen state, and it prevents the normal course of neutralization process, so additional energy is required for preparing the soil. There is proposed a technology adapted to the conditions of Siberia and the Arctic for the operational elimination of emergency situations consequences accompanied with oil spills. The technology for neutralizing soils contaminated with petroleum products is based on the encapsulation of a pollutant (reagent capsulation technology) using an alkaline calcium-based reagent. Powdered building quicklime is used as a reagent, and it is a product of roasting carbonate rocks or a mixture of this product with mineral additives (calcium oxide). The encapsulated material obtained as a result of neutralizing soils contaminated with petroleum products is resistant to natural and man-made factors such as moisture, temperature fluctuations, acid rain and high pressure. Energy use from the chemical detoxification exothermic process of soils contaminated with petroleum products in combination with the forced supply of carbon dioxide to the neutralization zone during the formation of a shell from calcium carbonate on the surface of the pollutant makes it possible to neutralize soils contaminated with oil products in the extreme climatic conditions of the Arctic using reagent Encapsulation. The principle of equipment operation that allows neutralizing soils contaminated with petroleum products in the natural and climatic conditions of the Arctic using reagent capsulation technology has been described. The results of experimental studies have been presented that

Biosurfactant Producing Microbes from Oil Contaminated Soil - Isolation, Screening and Characterization

OpenAIRE

, A Pandey; , D Nandi; , N Prasad; , S Arora

2016-01-01

Th1s paper bas1cally deals W1th 1solat10n, productıon and characterızatıon of biosurfactant producing microbes from oil contaminated soil sample. In this paper, we are comparing and discussing different methods to screen & characterize microbes from soil which can degrade oil due to their biosurfactant producing activity which helps in reduction of surface tension of oil. Oils used to check the biosurfactant activity of microbes, were engine oil and vegetable oil. Further isolation of...

Some aspects of remediation of contaminated soils

Science.gov (United States)

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

2014-05-01

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

Responses of microbial community from tropical pristine coastal soil to crude oil contamination

Directory of Open Access Journals (Sweden)

Daniel Morais

2016-02-01

Full Text Available Brazilian offshore crude oil exploration has increased after the discovery of new reservoirs in the region known as pré-sal, in a depth of 7.000 m under the water surface. Oceanic islands near these areas represent sensitive environments, where changes in microbial communities due oil contamination could stand for the loss of metabolic functions, with catastrophic effects to the soil services provided from these locations. This work aimed to evaluate the effect of petroleum contamination on microbial community shifts (Archaea, Bacteria and Fungi from Trindade Island coastal soils. Microcosms were assembled and divided in two treatments, control and contaminated (weathered crude oil at the concentration of 30 g kg−1, in triplicate. Soils were incubated for 38 days, with CO2 measurements every four hours. After incubation, the total DNA was extracted, purified and submitted for target sequencing of 16S rDNA, for Bacteria and Archaea domains and Fungal ITS1 region, using the Illumina MiSeq platform. Three days after contamination, the CO2 emission rate peaked at more than 20 × the control and the emissions remained higher during the whole incubation period. Microbial alpha-diversity was reduced for contaminated-samples. Fungal relative abundance of contaminated samples was reduced to almost 40% of the total observed species. Taxonomy comparisons showed rise of the Actinobacteria phylum, shifts in several Proteobacteria classes and reduction of the Archaea class Nitrososphaerales. This is the first effort in acquiring knowledge concerning the effect of crude oil contamination in soils of a Brazilian oceanic island. This information is important to guide any future bioremediation strategy that can be required.

A dual phased approach for bioremediation of petroleum contaminated soil and ground water

International Nuclear Information System (INIS)

Kennel, N.D.; Maher, A.; Buckallew, B.

1994-01-01

A case study will be presented to demonstrate an effective and timely method of site remediation which yields complete contaminant destruction rather than the contaminant transfer that traditional ground water extraction and treatment techniques result in. By utilizing bioremediation at this site, the client was able to completely degrade the contamination beneath the property, and in the process avoid future liability from transfer of the contamination to another party (i.e. landfill) or phase (i.e. liquid to vapor through air stripping). The provisions of a real estate transaction involving a former service station site in Central Iowa stipulated that the site be remediated prior to title transfer. Previous Environmental Investigative activities revealed significant soil and ground water contamination resulting from over 50 years of diesel and gasoline fuel storage and dispensing operations at the site. Microbial Environmental Services, Inc. (MES) utilized a dual phased bioremediation approach to meet regulatory clean-up guidelines in order for a timely property transfer to occur. To facilitate and expedite ground water remediation, contaminated soil was excavated and remediated via Advanced Biological Surface Treatment (ABST) techniques. ABST techniques are utilized by MES to treat excavated soil in closed cell to control emissions and treatment conditions. Following contaminant source removal, ground water was extracted and treated in a submerged, fixed film, flow through 1,000 gallon fixed film bioreactor at a rate of 2.5 gallons per minute

Uptake of Organic Contaminants from Soil into Vegetables and Fruits

DEFF Research Database (Denmark)

Trapp, Stefan; Legind, Charlotte Nielsen

2011-01-01

Contaminants may enter vegetables and fruits by several pathways: by uptake with soil pore water, by diffusion from soil or air, by deposition of soil or airborne particles, or by direct application. The contaminant-specific and plantspecific properties that determine the importance of these path......Contaminants may enter vegetables and fruits by several pathways: by uptake with soil pore water, by diffusion from soil or air, by deposition of soil or airborne particles, or by direct application. The contaminant-specific and plantspecific properties that determine the importance...... of these pathways are described in this chapter. A variety of models have been developed, specific for crop types and with steady-state or dynamic solutions. Model simulations can identify sensitive properties and relevant processes. Persistent, polar (log KOW ... particles, or from air. Volatile contaminants have a low potential for accumulation because they quickly escape to air. Experimental data are listed that support these model predictions, but underline also the high variability of accumulation under field conditions. Plant uptake predictions are uncertain...

Natural revegetation of hydrocarbon-contaminated soil in semi-arid grasslands

International Nuclear Information System (INIS)

Bizecki Robson, D.; Knight, J. D.; Farrell, R. E.; Germida, J. J.

2004-01-01

Phytoremediation, or the use of plants to degrade and contain soil contaminants is considered a cost-effective decontaminant for sites contaminated by spills in the oil and gas producing areas of Western Canada. The objective of this study was to determine if contamination by hydrocarbons changes soil properties, species composition, and species abundance when compared with uncontaminated plots, and to identify species and functional groups unique to contaminated sites that may be further screened for their hydrocarbon-degrading ability. In pursuit of these objectives the effect of contamination on coverage, litter and bare ground was examined, differences in species composition between contaminated and uncontaminated sites were assessed, and the ability to fix nitrogen, and form mycorrhiza, life form, pollination mode, seed dispersal and reproduction mode of each species was determined. Results showed less vegetation and litter cover in contaminated plots, and significantly higher soil carbon to nitrogen ratios. Species diversity was also lower on contaminated sites, although species richness was not significantly different. Self-pollinated species were significantly more common on contaminated sites. Five grasses and three forbs were identified as tolerant of hydrocarbon-contaminated soils, with two grasses -- Agropyron smithii, and Agropyron trachycaulum -- being the most promising for reclamation. The low vegetation cover on contaminated plots is attributed to high pH and carbon to nitrogen ratios, and low nitrogen and phosphorus that results from soil disturbance. High electrical conductivity is also considered to adversely affect vegetation and litter cover on contaminated sites. 54 refs., 3 tabs., 1 fig

Natural revegetation of hydrocarbon-contaminated soil in semi-arid grasslands

Energy Technology Data Exchange (ETDEWEB)

Bizecki Robson, D.; Knight, J. D.; Farrell, R. E.; Germida, J. J. [University of Saskatchewan, Dept. of Soil Science, Saskatoon, SK (Canada)

2004-01-01

Phytoremediation, or the use of plants to degrade and contain soil contaminants is considered a cost-effective decontaminant for sites contaminated by spills in the oil and gas producing areas of Western Canada. The objective of this study was to determine if contamination by hydrocarbons changes soil properties, species composition, and species abundance when compared with uncontaminated plots, and to identify species and functional groups unique to contaminated sites that may be further screened for their hydrocarbon-degrading ability. In pursuit of these objectives the effect of contamination on coverage, litter and bare ground was examined, differences in species composition between contaminated and uncontaminated sites were assessed, and the ability to fix nitrogen, and form mycorrhiza, life form, pollination mode, seed dispersal and reproduction mode of each species was determined. Results showed less vegetation and litter cover in contaminated plots, and significantly higher soil carbon to nitrogen ratios. Species diversity was also lower on contaminated sites, although species richness was not significantly different. Self-pollinated species were significantly more common on contaminated sites. Five grasses and three forbs were identified as tolerant of hydrocarbon-contaminated soils, with two grasses -- Agropyron smithii, and Agropyron trachycaulum -- being the most promising for reclamation. The low vegetation cover on contaminated plots is attributed to high pH and carbon to nitrogen ratios, and low nitrogen and phosphorus that results from soil disturbance. High electrical conductivity is also considered to adversely affect vegetation and litter cover on contaminated sites. 54 refs., 3 tabs., 1 fig.

Stabilizing lead bullets in shooting range soil by phosphate-based surface coating

Directory of Open Access Journals (Sweden)

Bin Hua

2016-08-01

Full Text Available Soil lead (Pb is well known as a threat to human health and ecosystem. Although relatively insoluble, lead bullets in shooting range soil can be readily released into soluble forms through natural weathering processes and thus pose significant human and environmental risks. In this study, laboratory experiments were conducted to investigate if the Pb bullets in shooting range soil can be stabilized through surface coating of phosphate-based materials. Results indicated that FePO4 or AlPO4 coatings, insoluble metal phosphates, have been successfully formed on the surface of the Pb bullets. The EPA Toxicity Characteristic Leaching Procedure (TCLP test showed that FePO4 or AlPO4 surface coating would effectively reduce the Pb solubility or leachability of the bullets. The surface coating under pH of <5.5 for 7 days could achieve 92–100% reduction, with 85–98% by FePO4 coating and 77–98% by AlPO4 coating as compared with the non-coating. Leachable Pb concentration in the contaminated shooting range soil was reduced by 85–98% or 77–98% as a result of the FePO4 or AlPO4 solution treatment. This study demonstrated that the FePO4 or AlPO4–based surface coating on lead bullets can effectively inhibit the Pb weathering and significantly reduce the Pb release from soil through in situ chemical stabilization, which could be potentially applicable as a cost-effective and environmental-sound technology for the remediation of Pb-contaminated shooting range soil.

Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analyses of contaminated soils by XRF

Science.gov (United States)

Mucke, D.

2012-04-01

Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analysis of contaminated soils by XRF Dieter Mucke, Rolf Kumann, Sebastian Baldauf GEOMONTAN Gesellschaft für Geologie und Bergbau mbH&Co.KG, Muldentalstrasse 56, 09603 Rothenfurth, Saxony/Germany For hundreds of years in the Ore Mountains between Bohemia and Saxony silver and other ores are produced and smelted. Sulphide- and sulpharsenide-ores needed to be roasted first. In doing so the sulphide sulphur was oxidised under formation of sulphur dioxide SO2 and arsenide conversed into elemental arsenic and arsenide trioxide As2O3 respectively. Also the metals lead, cadmium and zinc are components of hut smokes, in the field of nickel foundries also nickel. The contents of soils basically reflect the geogenic conditions, which are caused by decomposition- and relocation-effects of the mineralisations, in the area of foundries also with influences by with the hut smokes anthropogenic mobilised elements. The Saxonian Agency for Environment and Geology drafted in 1992 a Soil Investigation Program with the aim of investigation of the contamination of Saxonian soils with arsenic and toxic heavy metals. In order of this Agency GEOMONTAN investigated 1164 measuring points in the grid 4 * 4 km.soil profiles and extracted soil samples for analysis. In the result of the laboratory examinations the Agency edited the "Soil atlas of the Free State of Saxony". 27 elements, pH and PAK are shown in detailed maps and allow in whole Saxony the first assessment of the contamination of soils with arsenic and toxic heavy metals. Each of the investigated soil profiles represent an area of 16 km2. Already by the different use of the districts (agricultural, industrial, urban) restricts representative values. GEOMONTAN in the meantime used at the exploration of a copper deposit in Brandenburg/Germany with approx. 50,000 single tests at drill cores a very fast low-cost method: the X Ray fluorescence

Compound washing remediation and response surface analysis of lead-contaminated soil in mining area by fermentation broth and saponin.

Science.gov (United States)

Zhang, Hongjiao; Wang, Zhengwei; Gao, Yuntao

2018-03-01

The development of eluent is the key to soil washing remediation, and a compound eluent was constructed using the prepared citric acid fermentation broth and saponin in this study. It displayed a good washing performance for Pb, Cu, Cr, and Cd in red soil, and the removal rates, especially Pb, gained an improvement compared with a single eluent. Based on this, the compound eluent was applied to remediation of Pb-contaminated soil in mining area; the desorption of Pb is a heterogeneous diffusion process, and Pb in large particle size soil is relatively easy to remove. An available response surface analysis model was established; its P  washing time > saponin concentration, and liquid-to-solid ratio and washing time show interaction. Moreover, the Pb removal rate can reach 56.20% under the optimized conditions: 0.25% saponin concentration, 20 mL/g liquid-to-solid ratio, and 320-min washing time, which is close to the predicted value of 56.20% with a difference of 1.41%. In addition, most of the active Pb was removed and environmental risks were lowered after washing.

Fluorescence Imaging Reveals Surface Contamination

Science.gov (United States)

Schirato, Richard; Polichar, Raulf

1992-01-01

In technique to detect surface contamination, object inspected illuminated by ultraviolet light to make contaminants fluoresce; low-light-level video camera views fluorescence. Image-processing techniques quantify distribution of contaminants. If fluorescence of material expected to contaminate surface is not intense, tagged with low concentration of dye.

Decontamination of Uranium-Contaminated Soil Sand Using Supercritical CO2 with a TBP–HNO3 Complex

Directory of Open Access Journals (Sweden)

Kwangheon Park

2015-09-01

Full Text Available An environmentally friendly decontamination process for uranium-contaminated soil sand is proposed. The process uses supercritical CO2 as the cleaning solvent and a TBP–HNO3 complex as the reagent. Four types of samples (sea sand and coarse, medium, and fine soil sand were artificially contaminated with uranium. The effects of the amount of the reagent, sand type, and elapsed time after the preparation of the samples on decontamination were examined. The extraction ratios of uranium in all of the four types of sand samples were very high when the time that elapsed after preparation was less than a few days. The extraction ratio of uranium decreased in the soil sand with a higher surface area as the elapsed time increased, indicating the possible formation of chemisorbed uranium on the surface of the samples. The solvent of supercritical CO2 seemed to be very effective in the decontamination of soil sand. However, the extraction of chemisorbed uranium in soil sand may need additional processes, such as the application of mechanical vibration and the addition of bond-breaking reagents.

Zinc and lead transfer in a contaminated roadside soil: Experimental study and modeling

International Nuclear Information System (INIS)

Hanna, K.; Lassabatere, L.; Bechet, B.

2009-01-01

The application of a surface complexation model to simulate the sorption of metals on single sorbents is very well investigated, but very little is known regarding the use of surface complexation modeling to simulate the metal mobility in contaminated roadside soils. The overall objective of this study was to examine whether the use of the surface complexation model (SCM) could correctly describe the migration of zinc and lead in roadside soil under various physicochemical conditions. The release and transport of Zn and Pb was studied by means of batch reactors and saturated chromatography columns. Soil batch experiments were conducted to evaluate the effects of pH variation and ionic strength on the metal mobility from soil. Elution of Pb and Zn was examined in column experiments by using acetic acid at pH5 and EDTA at pH7. The modeling work has focused on the development of a SCM using MINTEQ2 database incorporated in PHREEQC-2 to describe the interactions between trace metals and the main mineral soil components (quartz, iron and aluminum oxides). In this study, it was found that the SCM was able to simulate the mobility of metals from soil by assuming one mononuclear surface reaction between one solution species (Me 2+ ) and one type of site on the surface of soil dominant sorbents

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

Science.gov (United States)

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

2017-04-01

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

Restoration of contaminated soils; Restauracion de suelos contaminados

Energy Technology Data Exchange (ETDEWEB)

Miranda J, Jose Eduardo

2009-07-01

A great variety of techniques are used for the restoration of contaminated soils. The contamination is present by both organic and inorganic pollutants. Environmental conditions and soil characteristics should take into account in order to implement a remedial technique. The bioremediation technologies are showed as help to remove a variety of soil contaminants. (author) [Spanish] Una gran variedad de tecnicas son utilizadas para la restauracion de suelos contaminados. La contaminacion se presenta tanto por contaminantes organicos como inorganicos. Las condiciones ambientales y caracteristicas del suelo se deben de tomar en cuenta para poder implementar una tecnica remediadora. Las tecnologias de biorremediacion son mostradas como ayuda para remover una gran variedad de contaminantes del suelo. (autor)

Electromigration of Contaminated Soil by Electro-Bioremediation Technique

Science.gov (United States)

Azhar, A. T. S.; Nabila, A. T. A.; Nurshuhaila, M. S.; Shaylinda, M. Z. N.; Azim, M. A. M.

2016-07-01

Soil contamination with heavy metals poses major environmental and human health problems. This problem needs an efficient method and affordable technological solution such as electro-bioremediation technique. The electro-bioremediation technique used in this study is the combination of bacteria and electrokinetic process. The aim of this study is to investigate the effectiveness of Pseudomonas putida bacteria as a biodegradation agent to remediate contaminated soil. 5 kg of kaolin soil was spiked with 5 g of zinc oxide. During this process, the anode reservoir was filled with Pseudomonas putida while the cathode was filled with distilled water for 5 days at 50 V of electrical gradient. The X-Ray Fluorescent (XRF) test indicated that there was a significant reduction of zinc concentration for the soil near the anode with 89% percentage removal. The bacteria count is high near the anode which is 1.3x107 cfu/gww whereas the bacteria count at the middle and near the cathode was 5.0x106 cfu/gww and 8.0x106 cfu/gww respectively. The migration of ions to the opposite charge of electrodes during the electrokinetic process resulted from the reduction of zinc. The results obtained proved that the electro-bioremediation reduced the level of contaminants in the soil sample. Thus, the electro-bioremediation technique has the potential to be used in the treatment of contaminated soil.

Evaluation the Phytoremediation of Oil-contaminated Soils Around Isfahan Oil Refinery

Directory of Open Access Journals (Sweden)

Farida Iraji-Asiabadi

2016-07-01

Full Text Available Petroleum compounds are pollutants that most commonly occur in soils around oil refineries and that often find their ways into groundwater resources. Phytoremediation is a cost-effective alternative to physicochemical methods for oil-contaminated soil remediation, where feasible. In this study, a greenhouse experiment was conducted to evaluate the phytoremediation of oil-contaminated soils around Isfahan Oil Refinery. Four different plants (namely, sorghum, barley, agropyron, and festuca were initially evaluated in terms of their germinability in both contaminated and control (non-contaminated soils. Sorghum and barley (recording the highest germinability values were chosen as the species for use in the phytoremediation experiments. Shoot and root dry weights, total and oil-degrading bacteria counts, microbial activity, and total concentrations of petroleum hydrocarbons (TPHs were determined at harvest 120 days after planting. A significant difference was observed in the bacterial counts (total and oil-degrading bacteria between the planted soils and the control. In contaminated soils, a higher microbial activity was observed in the rhizosphere of the sorghum soil than in that of barley. TPHs concentration decreased by 52%‒64% after 120 days in contaminated soil in which sorghum and barley had been cultivated. This represented an improvement of 30% compared to the contaminated soil without plants. Based on the results obtained, sorghum and barley may be recommended for the removal of petro-contaminants in areas close to Isfahan Oil Refinery. Nevertheless, caution must be taken as such cultivated lands may need to be protected against grazing animals.

Optimization of sampling for the determination of the mean Radium-226 concentration in surface soil

International Nuclear Information System (INIS)

Williams, L.R.; Leggett, R.W.; Espegren, M.L.; Little, C.A.

1987-08-01

This report describes a field experiment that identifies an optimal method for determination of compliance with the US Environmental Protection Agency's Ra-226 guidelines for soil. The primary goals were to establish practical levels of accuracy and precision in estimating the mean Ra-226 concentration of surface soil in a small contaminated region; to obtain empirical information on composite vs. individual soil sampling and on random vs. uniformly spaced sampling; and to examine the practicality of using gamma measurements in predicting the average surface radium concentration and in estimating the number of soil samples required to obtain a given level of accuracy and precision. Numerous soil samples were collected on each six sites known to be contaminated with uranium mill tailings. Three types of samples were collected on each site: 10-composite samples, 20-composite samples, and individual or post hole samples; 10-composite sampling is the method of choice because it yields a given level of accuracy and precision for the least cost. Gamma measurements can be used to reduce surface soil sampling on some sites. 2 refs., 5 figs., 7 tabs

Plant tolerance to diesel minimizes its impact on soil microbial characteristics during rhizoremediation of diesel-contaminated soils

International Nuclear Information System (INIS)

Barrutia, O.; Garbisu, C.; Epelde, L.; Sampedro, M.C.; Goicolea, M.A.; Becerril, J.M.

2011-01-01

Soil contamination due to petroleum-derived products is an important environmental problem. We assessed the impacts of diesel oil on plants (Trifolium repens and Lolium perenne) and soil microbial community characteristics within the context of the rhizoremediation of contaminated soils. For this purpose, a diesel fuel spill on a grassland soil was simulated under pot conditions at a dose of 12,000 mg diesel kg -1 DW soil. Thirty days after diesel addition, T. repens (white clover) and L. perenne (perennial ryegrass) were sown in the pots and grown under greenhouse conditions (temperature 25/18 o C day/night, relative humidity 60/80% day/night and a photosynthetic photon flux density of 400 μmol photon m -2 s -1 ) for 5 months. A parallel set of unplanted pots was also included. Concentrations of n-alkanes in soil were determined as an indicator of diesel degradation. Seedling germination, plant growth, maximal photochemical efficiency of photosystem II (F v /F m ), pigment composition and lipophylic antioxidant content were determined to assess the impacts of diesel on the studied plants. Soil microbial community characteristics, such as enzyme and community-level physiological profiles, were also determined and used to calculate the soil quality index (SQI). The presence of plants had a stimulatory effect on soil microbial activity. L. perenne was far more tolerant to diesel contamination than T. repens. Diesel contamination affected soil microbial characteristics, although its impact was less pronounced in the rhizosphere of L. perenne. Rhizoremediation with T. repens and L. perenne resulted in a similar reduction of total n-alkanes concentration. However, values of the soil microbial parameters and the SQI showed that the more tolerant species (L. perenne) was able to better maintain its rhizosphere characteristics when growing in diesel-contaminated soil, suggesting a better soil health. We concluded that plant tolerance is of crucial importance for the

Tracing contamination sources in soils with Cu and Zn isotopic ratios.

Science.gov (United States)

Fekiacova, Z; Cornu, S; Pichat, S

2015-06-01

Copper (Cu) and zinc (Zn) are naturally present and ubiquitous in soils and are important micronutrients. Human activities contribute to the input of these metals to soils in different chemical forms, which can sometimes reach a toxic level for soil organisms and plants. Isotopic signatures could be used to trace sources of anthropogenic Cu and Zn pollution. The aim of this paper is to determine whether it is possible to identify (i) Cu and Zn contamination in soils and their sources, on the basis of their isotopic signatures, and (ii) situations that are a priori favorable or not for tracing Cu and Zn pollution using the isotopic approach. Therefore, we compiled data from the literature on Cu and Zn isotopes in soils, rocks and pollutants and added to this database the results of our own research. As only a few studies have dealt with agricultural contamination, we also studied a soil toposequence from Brittany, France, that experienced spreading of pig slurry for tens of years. In the surface horizons of the natural soils, the δ(65)Cu values vary from -0.15 to 0.44‰ and the δ(66)Zn from -0.03 to 0.43‰. Furthermore, vertical variations along soil profiles range from -0.95 to 0.44‰ for δ(65)Cu and from -0.53 to 0.64‰ for δ(66)Zn values. We concluded that pedogenetic processes can produce isotopic fractionation, yet, it is not always discernible and can be overprinted by an exogenous isotopic signature. Furthermore, some contaminants are enriched in heavy Cu or in light Zn compared to the rock or soil, but no generalization can be made. The anthropogenic inputs can be identified based on stable Cu and Zn isotope ratios if the isotope ratios of the sources are different from those of the soil, which needs to be tested for each individual case. Copyright © 2015 Elsevier B.V. All rights reserved.

Leaching of Contamination from Stabilization/Solidification Remediated Soils of Different Texture

Science.gov (United States)

Burlakovs, Juris; Kasparinskis, Raimonds; Klavins, Maris

2012-09-01

Development of soil and groundwater remediation technologies is a matter of great importance to eliminate historically and currently contaminated sites. Stabilization/solidification (S/S) refers to binding of waste contaminants to a more chemically stable form and thus diminishing leaching of contamination. It can be performed using cement with or without additives in order to stabilize and solidify soil with the contamination in matrix. A series of experiments were done to determine leaching properties of spiked soils of different texture bound with cement. Results of experiments showed, that soil texture (content of sand, silt and clay particles) affects the leaching of heavy metals from stabilized soils.

Bioremediation of petroleum contaminated soil using vegetation--A technology transfer project

International Nuclear Information System (INIS)

Banks, M.K.; Schwab, A.P.; Govindaraju, R.S.; Chen, Z.

1994-01-01

A common environmental problem associated with the pumping and refining of crude oil is the disposal of petroleum sludge. Unfortunately, the biodegradation fate of more recalcitrant and potentially toxic contaminants, such as the polynuclear aromatic hydrocarbons (PNAs), is rapid at first but declines quickly. Biodegradation of these compounds is limited by their strong adsorption potential and low solubility. Recent research has suggested that vegetation may play an important role in the biodegradation of toxic organic chemicals, such as PNAs, in soil. The establishment of vegetation on hazardous waste sites may be an economic, effective, low maintenance approach to waste remediation and stabilization. Completed greenhouse studies have indicated that vegetative remediation is a feasible method for clean-up of surface soil contaminated with petroleum products. However, a field demonstration is needed to exhibit this new technology to the industrial community. In this project, several petroleum contaminated field sites will be chosen in collaboration with three industrial partners. These sites will be thoroughly characterized for chemical properties, physical properties, and initial PNA concentrations. A variety of plant species will be established on the sites, including warm and cool season grasses and alfalfa. Soil analyses for the target compounds over time will allow them to assess the efficiency and applicability of this remediation method

Degradation of tetraethyllead in leaded gasoline contaminated and uncontaminated soils

International Nuclear Information System (INIS)

Ou, L.; Jing, W.; Thomas, J.; Mulroy, P.

1995-01-01

For over 50 years, since its introduction in 1923 by General Motors, tetraethyllead (TEL) was the major antiknock agent used in leaded gasoline. Since the middle of 1970, use of leaded gasoline in automobiles was gradually phased out. The main objective of this study is to determine the degradation rates and metabolites of TEL in gasoline contaminated and uncontaminated soils. TEL in uncontaminated soils disappeared rapidly. Ionic triethyllead (TREL) was the major organolead metabolite in these soils, with ionic diethyllead (DEL) being the minor product. Nonsterile soils, but not autoclaved soils, had limited capacity to mineralize 14 C-TEL to 14 CO 2 , H 2 0, and Pb 2+ . Unlike TEL in uncontaminated soils, petroleum hydrocarbons protected TEL in leaded gasoline contaminated soils from being degraded. Both disappearance and mineralization rates of TEL in leaded gasoline contaminated soils decreased with the increase in gasoline concentration. It appears that TEL in leaded gasoline contaminated soils is relatively stable until the level of petroleum hydrocarbons falls below a critical value. TEL is then rapidly degraded. Hydrocarbon degrading microorganisms may be involved, to some extent, in the degradation of TEL

Aerobic and anaerobic biosynthesis of nano-selenium for remediation of mercury contaminated soil.

Science.gov (United States)

Wang, Xiaonan; Zhang, Daoyong; Pan, Xiangliang; Lee, Duu-Jong; Al-Misned, Fahad A; Mortuza, M Golam; Gadd, Geoffrey Michael

2017-03-01

Selenium (Se) nanoparticles are often synthesized by anaerobes. However, anaerobic bacteria cannot be directly applied for bioremediation of contaminated top soil which is generally aerobic. In this study, a selenite-reducing bacterium, Citrobacter freundii Y9, demonstrated high selenite reducing power and produced elemental nano-selenium nanoparticles (nano-Se 0 ) under both aerobic and anaerobic conditions. The biogenic nano-Se 0 converted 45.8-57.1% and 39.1-48.6% of elemental mercury (Hg 0 ) in the contaminated soil to insoluble mercuric selenide (HgSe) under anaerobic and aerobic conditions, respectively. Addition of sodium dodecyl sulfonate enhanced Hg 0 remediation, probably owing to the release of intracellular nano-Se 0 from the bacterial cells for Hg fixation. The reaction product after remediation was identified as non-reactive HgSe that was formed by amalgamation of nano-Se 0 and Hg 0 . Biosynthesis of nano-Se 0 both aerobically and anaerobically therefore provides a versatile and cost-effective remediation approach for Hg 0 -contaminated surface and subsurface soils, where the redox potential often changes dramatically. Copyright © 2016. Published by Elsevier Ltd.

Levels of concern for radioactive contaminations in soil according to soil protection standards

International Nuclear Information System (INIS)

Gellermann, R.; Barkowski, D.; Machtolf, M.

2016-01-01

In the paper the question is examined whether the established soil protection standards for carcinogenic substances are also applicable to the assessment of radioactive soil contamination. Referring to the methods applied in soil protection for evaluation of dose-effectrelations and estimations of carcinogenic risks as well as the calculation methods for test values in soil protection ''levels of concern'' for soil contamination by artificial radionuclides are derived. The values obtained are significantly larger than the values for unrestricted clearance of ground according to the German Radiation Protection Ordinance (StrlSchV). The thesis that soil is protected according to environmental standards provided that radiation protection requirements are met needs further checks but can be probably confirmed if the radiation protection requirements are clearly defined.

Uptake of radionuclides by wheat roots with respect to location of contamination below the surface

International Nuclear Information System (INIS)

Suvornmongkhol, Narumon.

1996-01-01

The behaviour of 85 Sr, 137 Cs, 54 Mn and 60 Co in terms of plant availability in near surface soil and their root uptake was studied as a function of the location of contamination in the soil profile. Wheat (Triticum aestivum) was employed and the study programme involved both column and hydroponic studies. In the column studies, columns were packed with sandy soil, and either homogeneously or discretely contaminated with the radionuclides, and the water table maintained manually at 3 cm from the bottom. In the discrete contamination, the location of contamination was varied (0-5, 25-30 or 45-50 cm from the top). Wheat plants were grown to maturity in these columns, and harvested at different growth stages to examine radioactivity uptake and its subsequent translocation within the plants. The movement of radionuclides within the soil as well as the soil physicochemical properties were also investigated. The short term uptake kinetics of the hydroponically grown plants during ontogenesis were also studied, both with excised roots and intact plants. The excised root experiment was aimed at investigating the radionuclide by roots of different orders. (author)

[Improving Agricultural Safety of Soils Contaminated with Polycyclic Aromatic Hydrocarbons by In Situ Bioremediation].

Science.gov (United States)

Jiao, Hai-huan; Pan, Jian-gang; Xu, Shena-jun; Bai, Zhi-hui; Wang, Dong; Huang, Zhan-bin

2015-08-01

In order to reduce the risk of enrichment of polycyclic aromatic hydrocarbons (PAHs) in crops, reduce the potential hazards of food-sourced PAHs to human and increase the agricultural safety of PAHs contaminated soils, the bio-augmented removal of polycyclic aromatic hydrocarbons (PAHs) was investigated through in situ remediation by introducing Rhodobacter sphaeroides (RS) into the agricultural soil contaminated by PAHs. The 50-times diluted RS was sprayed on leaf surface (in area B) or irrigated to roots (in area D). The treatment of spraying water of the equal amount was taken as the control (A) and the wheat field without any treatment as the blank (CK). Treatments were conducted since wheat seeding. Soil and wheat samples were collected in the mature period to analyze the changes of community structure of the soil microorganisms and the concentration of PAHs in soils and investigate the strengthening and restoration effects of RS on PAHs contaminated soils. Compared to the CK Area, the areas B and D revealed that the variation ratio of phospholipid fatty acids (PLFAs) that were the biomarker of soil microorganisms was 29.6%, and the ratio of total PAHs removed was increased 1.59 times and 1.68 times, respectively. The dry weight of wheat grain of 50 spikes was increased by 8.95% and 12.5%, respectively, and the enrichment factor of total PAHs was decreased by 58.9% and 62.2% respectively in the wheat grains. All the results suggested that RS reduced enrichment of PAHs in wheat grains and increased wheat yield, which had great exploitation and utilization potentiality in repairing and improving the agricultural safety of the soils contaminated with PHAs.

Enrichment of arbuscular mycorrhizal fungi in a contaminated soil after rehabilitation.

Science.gov (United States)

Lopes Leal, Patrícia; Varón-López, Maryeimy; Gonçalves de Oliveira Prado, Isabelle; Valentim Dos Santos, Jessé; Fonsêca Sousa Soares, Cláudio Roberto; Siqueira, José Oswaldo; de Souza Moreira, Fatima Maria

Spore counts, species composition and richness of arbuscular mycorrhizal fungi, and soil glomalin contents were evaluated in a soil contaminated with Zn, Cu, Cd and Pb after rehabilitation by partial replacement of the contaminated soil with non-contaminated soil, and by Eucalyptus camaldulensis planting with and without Brachiaria decumbens sowing. These rehabilitation procedures were compared with soils from contaminated non-rehabilitated area and non-contaminated adjacent soils. Arbuscular mycorrhizal fungi communities attributes were assessed by direct field sampling, trap culture technique, and by glomalin contents estimate. Arbuscular mycorrhizal fungi was markedly favored by rehabilitation, and a total of 15 arbuscular mycorrhizal fungi morphotypes were detected in the studied area. Species from the Glomus and Acaulospora genera were the most common mycorrhizal fungi. Number of spores was increased by as much as 300-fold, and species richness almost doubled in areas rehabilitated by planting Eucalyptus in rows and sowing B. decumbens in inter-rows. Contents of heavy metals in the soil were negatively correlated with both species richness and glomalin contents. Introduction of B. decumbens together with Eucalyptus causes enrichment of arbuscular mycorrhizal fungi species and a more balanced community of arbuscular mycorrhizal fungi spores in contaminated soil. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

In situ vitrification: Test results for a contaminated soil melting process

International Nuclear Information System (INIS)

Buelt, J.L.; Bonner, W.F.

1989-04-01

Pacific Northwest Laboratory (PNL) is developing in situ vitrification (ISV), a remedial action process for treating contaminated soils. In situ vitrification is a thermal treatment process that converts contaminated soil into a chemically inert and stable glass and crystalline product. Figure 1 depicts the process. A square array of four molybdenum/graphite electrodes is inserted into the ground to the desired treatment depth. Because soil is not electrically conductive when the moisture has been driven off, a conductive mixture of flaked graphite and glass frit is placed between the pairs of electrodes as a starter path. An electrical potential is applied to the electrodes to establish an electric current in the starter path. The resultant power heats the starter path and surrounding soil to 2000 degree C, well above the initial soil-melting temperature of 1100 to 1400 degree C. The graphite starter path is eventually consumed by oxidation, and the current is transferred to the molten soil, which is electrically conductive. As the molten or vitrified zone grows, it incorporates radionuclides and nonvolatile hazardous elements, such as heavy metals, and destroys organic components by pyrolysis. The pyrolyzed byproducts migrate to the surface of the vitrified zone, where they burn in the presence of oxygen. A hood placed over the area being vitrified directs the gaseous effluents to an off-gas treatment system. 5 refs., 1 fig., 1 tab

Clean-up criteria for remediation of contaminated soils

International Nuclear Information System (INIS)

Nguyen, H.D.; Wilson, J.R.; Sato, Chikashi

1997-01-01

'How clean is clean?' is a question commonly raised in the remediation of contaminated soils. To help with the answer, criteria are proposed to serve as guidelines for remedial actions and to define a clean-up level such that the remaining contaminant residuals in the soil will not violate the Drinking Water Standards (DWS). The equations for computing those criteria are developed from the principle of conservation of mass and are functions of the maximum concentration level in the water (MCL) and the sorption coefficient. A multiplier, ranging from 10 to 1000, is also factored into the soil standard equation to reflect the effectiveness of various remediation techniques. Maximum allowable concentration in the soil (MSCL) is presented for several contaminants which are being regulated at the present time. Future modifications are recommended for better estimates of the MSCLs as additional transport mechanisms are incorporated to account for other potentially dominant effects

Managing long-term polycyclic aromatic hydrocarbon contaminated soils: a risk-based approach.

Science.gov (United States)

Duan, Luchun; Naidu, Ravi; Thavamani, Palanisami; Meaklim, Jean; Megharaj, Mallavarapu

2015-06-01

Polycyclic aromatic hydrocarbons (PAHs) are a family of contaminants that consist of two or more aromatic rings fused together. Soils contaminated with PAHs pose significant risk to human and ecological health. Over the last 50 years, significant research has been directed towards the cleanup of PAH-contaminated soils to background level. However, this achieved only limited success especially with high molecular weight compounds. Notably, during the last 5-10 years, the approach to remediate PAH-contaminated soils has changed considerably. A risk-based prioritization of remediation interventions has become a valuable step in the management of contaminated sites. The hydrophobicity of PAHs underlines that their phase distribution in soil is strongly influenced by factors such as soil properties and ageing of PAHs within the soil. A risk-based approach recognizes that exposure and environmental effects of PAHs are not directly related to the commonly measured total chemical concentration. Thus, a bioavailability-based assessment using a combination of chemical analysis with toxicological assays and nonexhaustive extraction technique would serve as a valuable tool in risk-based approach for remediation of PAH-contaminated soils. In this paper, the fate and availability of PAHs in contaminated soils and their relevance to risk-based management of long-term contaminated soils are reviewed. This review may serve as guidance for the use of site-specific risk-based management methods.

Soil microbial effects of smelter induced heavy metal contamination

Energy Technology Data Exchange (ETDEWEB)

Nordgren, A

1986-01-01

The soil concentrations of Cu and Zn at the secondary smelter were 20 00 mu g/g dry soil. Close to the primary smelter the soil was contaminated with more than ten elements including Pb, Zn, Cu and As at levels ranging between 6000 and 1000 mu g/g dry soil. The correlations between the concentrations of the metals were high at both smelters. Soil respiration rate decreased by about 75% close to both smelters. Total and fluorescein diacetate stained mycelial lengths decrease with increasing heavy metal pollution at the secondary but not at the primary smelter. The fungal community structure was strongly affected by the contamination. General common in coniferous forest soils such as Penicillium and Oidiodendron virtually vanished, while less frequent species like Paecilomyces farinosus and Geomyces pannorum dominated the site close to the smelter. Colony forming units of a number of functional groups of bacteria were found to be very sensitive to metal contamination. The urease activity of the soil was inhibited. Multivariate statistical analyses showed that the metal contamination was the major environmental influence on the microbiotain the soils studied. A study of about 200 decomposition curves resulting from glutamic acid additions to the different soils produced four microbially related parameters: basal respiration rate, initial respiration rate after the addition of the glutamic acid, specific respiration rate during the exponential increase of the respiration rate and the lag time before the exponential phase. With 53 refs.

Pollution Status of Pakistan: A Retrospective Review on Heavy Metal Contamination of Water, Soil, and Vegetables

Directory of Open Access Journals (Sweden)

Amir Waseem

2014-01-01

Full Text Available Trace heavy metals, such as arsenic, cadmium, lead, chromium, nickel, and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. In addition to these metals, copper, manganese, iron, and zinc are also important trace micronutrients. The presence of trace heavy metals in the atmosphere, soil, and water can cause serious problems to all organisms, and the ubiquitous bioavailability of these heavy metal can result in bioaccumulation in the food chain which especially can be highly dangerous to human health. This study reviews the heavy metal contamination in several areas of Pakistan over the past few years, particularly to assess the heavy metal contamination in water (ground water, surface water, and waste water, soil, sediments, particulate matter, and vegetables. The listed contaminations affect the drinking water quality, ecological environment, and food chain. Moreover, the toxicity induced by contaminated water, soil, and vegetables poses serious threat to human health.

Waste management of actinide contaminated soil

International Nuclear Information System (INIS)

Navratil, J.D.; Thompson, G.H.; Kochen, R.L.

1978-01-01

Waste management processes have been developed to reduce the volume of Rocky Flats soil contaminated with plutonium and americium and to prepare the contaminated fraction for terminal storage. The primary process consists of wet-screening. The secondary process uses attrition scrubbing and wet screening with additives. The tertiary process involves volume reduction of the contaminated fraction by calcination, or fixation by conversion to glass. The results of laboratory scale testing of the processes are described

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

Science.gov (United States)

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

2009-01-01

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

Diversity of biosurfactant producing microorganisms isolated from soils contaminated with diesel oil.

Science.gov (United States)

Menezes Bento, Fátima; de Oliveira Camargo, Flavio A; Okeke, Benedict C; Frankenberger, William T

2005-01-01

Biosurfactant production is a desirable property of hydrocarbon-degrading microorganisms (HDM). We characterized biosurfactant producing microbial populations from a Long Beach soil, California (USA) and a Hong Kong soil (China), contaminated with diesel oil. A total of 33 hydrocarbon-utilizing microorganisms were isolated from the soils. Twelve isolates and three defined consortia were tested for biosurfactant production and emulsification activity. The highest reduction of surface tension was achieved with a consortium of L1, L2 and L3 isolates from a Long Beach soil (41.4mN m(-1)). Isolate L1 (Acinetobacter junii) displayed the highest reduction of surface tension (46.5 mN m(-1)). The emulsifying capacity evaluated by the E24 emulsification index was highest in the culture of isolate L5 (74%). No substantial emulsification was achieved with the cell-free extracts, indicating that the emulsifying activity was not extracellular. Based on surface tension and the E24 index results, isolates F1, F2, F3, F4, L1, L2, L3 and L4 were identified by 16S rRNA gene sequencing as Bacillus cereus, Bacillus sphaericus, B. fusiformis, Acinetobacter junii, a non-cultured bacterium, Pseudomonas sp. and B. pumilus, respectively. Cluster analyses of 16S rRNA gene sequences of the bacterial isolates revealed 70% similarity amongst hydrocarbon-degrading bacterial community present in both soils. Five isolates (isolates F1, F2, F3, F4 and L4) belong to the Firmicutes order, two isolates (L1 and L3) belong to the Proteobacteria order and one isolate (L2) is an Actinomyces sp. Simpson's index (1 - D) and the Shannon-Weaver index (H) revealed more diversity of HDM in the Hong Kong soil, while evenness (E) and the equitability (J) data indicated that there was not a dominant population. Bacterial isolates displaying substantial potential for production of biosurfactants can be applied in the bioremediation of soils contaminated with petroleum hydrocarbons.

In situ vadose zone remediation of petroleum-contaminated soils

International Nuclear Information System (INIS)

Greacen, J.R.; Finkel, D.J.

1991-01-01

This paper discusses a pilot-scale system treating vadose zone soils contaminated with petroleum products constructed and operated at a former petroleum bulk storage terminal in New England. A site investigation following decommissioning activities identified more than 100,000 yds of soil at the site contaminated by both No. 2 fuel oil and gasoline. Soil cleanup criteria of 50 ppm TPH and 0.25 ppm BTEX were established. A pilot-scale treatment unit with dimensions of 125 ft x 125 ft x 6 ft was constructed to evaluate the potential for in situ treatment of vadose zone soils. Contaminant levels in pilot cell soils ranged from 0 to 5,250 ppm TPH and 0.0 to 4.2 ppm BTEX. Two soil treatment methods n the pilot system were implemented; venting to treat the lighter petroleum fractions and bioremediation to treat the nonvolatile petroleum constituents. Seven soil gas probes were installed to monitor pressure and soil gas vapor concentrations in the subsurface. Changes in soil gas oxygen and carbon dioxide concentrations were used as an indirect measure of enhanced bioremediation of pilot cell soils. After operating the system for a period of 2.5 months, soil BTEX concentrations were reduced to concentrations below the remediation criteria for the site

Remediation of Cd-contaminated soil around metal sulfide mines

Science.gov (United States)

Lu, Xinzhe; Hu, Xuefeng; Kang, Zhanjun; Luo, Fan

2017-04-01

The mines of metal sulfides are widely distributed in the southwestern part of Zhejiang Province, Southeast China. The activities of mining, however, often lead to the severe pollution of heavy metals in soils, especially Cd contamination. According to our field investigations, the spatial distribution of Cd-contaminated soils is highly consistent with the presence of metal sulfide mines in the areas, further proving that the mining activities are responsible for Cd accumulation in the soils. To study the remediation of Cd-contaminated soils, a paddy field nearby large sulfide mines, with soil pH 6 and Cd more than 1.56 mg kg-1, five times higher than the national recommended threshold, was selected. Plastic boards were deeply inserted into soil to separate the field and make experimental plots, with each plot being 4 m×4 m. Six treatments, TK01˜TK06, were designed to study the effects of different experimental materials on remediating Cd-contaminated soils. The treatment of TK01 was the addition of 100 kg zeolites to the plot; TK02, 100 kg apatites; TK03, 100 kg humid manure; TK04, 50 kg zeolites + 50 kg apatites; TK05, 50 kg zeolites + 50 kg humid manure; TK06 was blank control (CK). One month after the treatments, soil samples at the plots were collected to study the possible change of chemical forms of Cd in the soils. The results indicated that these treatments reduced the content of available Cd in the soils effectively, by a decreasing sequence of TK04 (33%) > TK02 (25%) > TK01 (23%) > TK05 (22%) > TK03 (15%), on the basis of CK. Correspondingly, the treatments also reduced the content of Cd in rice grains significantly, by a similar decreasing sequence of TK04 (83%) > TK02 (77%) > TK05 (63%) > TK01 (47%) > TK03 (27%). The content of Cd in the rice grains was 0.071 mg kg-1, 0.094 mg kg-1, 0.159 mg kg-1, 0.22 mg kg-1 and 0.306 mg kg-1, respectively, compared with CK, 0.418 mg kg-1. This experiment suggested that the reduction of available Cd in the soils is

Application of Ultrasonic for Decontamination of Contaminated Soil - 13142

International Nuclear Information System (INIS)

Vasilyev, A.P.; Lebedev, N.M.; Savkin, A.E.

2013-01-01

The trials of soil decontamination were carried out with the help of a pilot ultrasonic installation in different modes. The installation included a decontamination bath equipped with ultrasonic sources, a precipitator for solution purification from small particles (less than 80 micrometer), sorption filter for solution purification from radionuclides washing out from soil, a tank for decontamination solution, a pump for decontamination solution supply. The trials were carried out on artificially contaminated sand with specific activity of 4.5 10 5 Bk/kg and really contaminated soil from Russian Scientific Center 'Kurchatovsky Institute' (RSC'KI') with specific activity of 2.9 10 4 Bk/kg. It was established that application of ultrasonic intensify the process of soil reagent decontamination and increase its efficiency. The decontamination factor for the artificially contaminated soil was ∼200 and for soil from RSC'KI' ∼30. The flow-sheet diagram has been developed for the new installation as well as determined the main technological characteristics of the equipment. (authors)

Air separation of heavy metal contaminants from soil

International Nuclear Information System (INIS)

Nelson, M.E.; Harper, M.J.; Buckon, A.D.

1995-01-01

Several heavy metal separation techniques are currently being developed for soil remediation at various Department of Defense and Department of Energy (DOE) Facilities. The majority of these techniques involve a wet process using water, pH modifiers or other compounds. The US Naval Academy (USNA) has developed a dry process for heavy metal separation. The process uses air classification technology to concentrate the metal contaminant into a fraction of the soil. The advantages of this dry process are that it creates no contaminated byproduct and uses commercially available technology. The USNA process is based on using a Gayco-Reliance air classifier. Tests have been conducted with the system at the Naval Academy and the University of Nevada-Reno (UNR). The USNA tests used soil from the Nevada Test Site mixed with bismuth at a concentration of 500--1,000 ppm. The UNR tests used soil from four DOE sites mixed with uranium oxides and plutonium at an activity level of 100--700 pCi per gram. Concentration of activities and volume reduction percentages are presented for the various soils and contaminants tested

A Study on the Removal of Cesium in Soil Contaminated with Radiation Using a Soil Washing Process

International Nuclear Information System (INIS)

Park, Ukryang; Kim, Gyenam; Kim, Seungsoo; Park, Hyemin; Kim, Wansuk; Moon, Jaikwon

2013-01-01

The first principle is related with the washing process which is carried out to transfer the contaminated mass from the soil to water by dissolving it with a cleansing solution. The second is concerned with the size of the separation process which focuses on the reduction of the volume by separating the subject matters based on the different sizes of the soil. The complex agents used in the soil washing process include HCl, Oxalic acid, Citric acid, CaCl 2 , BaCl 2 , NH 4 NO 3 , and NaOH. It is known that the complex-forming capacity of such complex agents and radionuclides influences the decontamination from the soil. Also, since the forms of the chemical species related with the complex agents and the surface potential of the soil vary based on the changes of acidity observed in the cleansing solution, the level of acidity in the cleansing solution can be regarded as a factor that influences the decontamination. Therefore, in this study, H 2 SO 4 was selected as the complex agent and used to check the influence of the temperature when the subject contaminated soil was washed. Then, by applying the sieve grading process with a sieve-shaker, the size separation process was carried out to measure the level of radiation for each size. By washing the contaminated soil separated into different sizes with the complex agent H 2 SO 4 , the different removal tendencies for each size were considered. After selecting the complex agent H 2 SO 4 and checking the influence of temperature when the contaminated soil was washed based on the solid-liquid ratio of 1g:2ml, it was found that the heat washing process at a temperature of 95 .deg. C showed a higher level of efficiency for the removal of Cs compared to the case of the non-heat washing process. Also, according to the results given by the process of considering the different removal tendencies for each size based on the heat washing process after the sieve grading process was applied with the sieve-shaker prior for the size

Electrokinetic treatment of contaminated soils, sludges, and lagoons. Final report

Energy Technology Data Exchange (ETDEWEB)

Wittle, J.K. [Electro-Petroleum, Inc., Wayne, PA (United States); Pamukcu, S. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Civil Engineering

1993-04-01

The electrokinetic process is an emerging technology for in-situ soil decontamination, in which chemical species, both ionic and nonionic are transported to an electrode site in soil. These products are subsequently removed from the ground via collection systems engineered for each specific application. Electrokinetics refer to movement of water, ions and charged particles relative to one another under the action of an applied direct current electric field. In a porous compact matrix of surface charged particles such as soil, the ion containing pore fluid may be made to flow to collection sites under the applied field. This report describes the effort undertaken to investigate electrokinetically enhanced transport of soil contaminants in synthetic systems. These systems consisted of clay or clay-sand mixtures containing known concentration of a selected heavy metal salt solution or an organic compound. Metals, surrogate radio nuclides and organic compounds evaluated in the program were representatives of those found at a majority of DOE sites. Degree of removal of these metals from soil by the electrokinetic treatment process was assessed through the metal concentration profiles generated across the soil between the electrodes. The best removals, from about 85 to 95% were achieved at the anode side of the soil specimens. Transient pH change had an effect on the metal movement via transient creation of different metal species with different ionic mobilities, as well as changing of the surface characteristics of the soil medium.

Phytoremediation of soil contaminated with low concentrations of radionuclides

Energy Technology Data Exchange (ETDEWEB)

Entry, J A; Vance, N C; Hamilton, M A; Zabowski, D; Watrud, L S; Adriano, D C [Auburn University, Auburn, AL (United States). Dept. of Agronomy and Soils

1996-03-01

Ecsosytems throughout the world have been contaminated with radionuclides by above-ground nuclear testing, nuclear reactor accidents and nuclear power generation. Radioisotopes characteristics of nuclear fission, such as {sup 137}Cs and {sup 90}Sr, that are released into the environment can become more concentrated as they move up the food chain often becoming human health hazards. Natural environmental processes will redistribute long lived radionuclides that are released into the environment among soil, plants and wildlife. Numerous studies have shown that {sup 137}Cs and {sup 90}Sr are not removed from the top 0.4 metres of soil even under high rainfall, and migration rate from the top few centimetres of soil is slow. The top 0.4 meters of the soil is where plant roots actively accumulate elements. Since plants are known to take up and accumulate {sup 137}Cs and {sup 90}Sr, removal of these radionuclides from contaminated soils by plants could provide a reliable and economical method of remediation. One approach is to use fast growing plants inoculated with mycorrhizal fungi combined with soil organic amendments to maximize the plant accumulation and removal of radionuclides from contaminated soils, followed by harvest of above-ground portion of the plants. High temperature combustion would be used to oxidize plant material concentrating {sup 137}Cs and {sup 90}Sr in ash for disposal. When areas of land have been contaminated with radionuclides are large, using energy intensive engineering solutions to mediate huge volumes of soil is not feasible or economical. Plants are proposed as a viable and cost effective method to remove radionuclides from the soils that have been contaminated by nuclear testing and nuclear reactor accidents. 40 refs.

Microbial interactions with organic contaminants in soil: Definitions, processes and measurement

International Nuclear Information System (INIS)

Semple, Kirk T.; Doick, Kieron J.; Wick, Lukas Y.; Harms, Hauke

2007-01-01

There has been and continues to be considerable scientific interest in predicting bioremediation rates and endpoints. This requires the development of chemical techniques capable of reliably predicting the bioavailability of organic compounds to catabolically active soil microbes. A major issue in understanding the link between chemical extraction and bioavailability is the problem of definition; there are numerous definitions, of varying degrees of complexity and relevance, to the interaction between organic contaminants and microorganisms in soil. The aim of this review is to consider the bioavailability as a descriptor for the rate and extent of biodegradation and, in an applied sense, bioremediation of organic contaminants in soil. To address this, the review will (i) consider and clarify the numerous definitions of bioavailability and discuss the usefulness of the term 'bioaccessibility'; (ii) relate definition to the microbiological and chemical measurement of organic contaminants' bioavailability in soil, and (iii) explore the mechanisms employed by soil microorganisms to attack organic contaminants in soil. - Understanding organic contaminant's behaviour in soil is key to chemically predicting biodegradation

A compendium of results from long-range alpha detector soil surface monitoring: June 1992--May 1994

International Nuclear Information System (INIS)

Garner, S.E.; Bounds, J.A.; Allander, K.S.; Johnson, J.D.; MacArthur, D.W.; Caress, R.W.

1994-11-01

Soil surface monitors based on long-range alpha detector (LRAD) technology are being used to monitor alpha contamination at various sites in the Department of Energy complex. These monitors, the large soil-surface monitor (LSSM) and the small soil-surface monitor (SSSM), were used to help characterize sites at Fernald, Ohio, and active or inactive firing sites at Sandia National Laboratories and Los Alamos National Laboratory. Monitoring results are presented herein in chronological order

Feasibility Process for Remediation of the Crude Oil Contaminated Soil

Science.gov (United States)

Keum, H.; Choi, H.; Heo, H.; Lee, S.; Kang, G.

2015-12-01

More than 600 oil wells were destroyed in Kuwait by Iraqi in 1991. During the war, over 300 oil lakes with depth of up to 2m at more than 500 different locations which has been over 49km2. Therefore, approximately 22 million m3was crude oil contaminated. As exposure of more than 20 years under atmospheric conditions of Kuwait, the crude oil has volatile hydrocarbons and covered heavy oily sludge under the crude oil lake. One of crude oil contaminated soil which located Burgan Oilfield area was collected by Kuwait Oil Company and got by H-plus Company. This contaminated soil has about 42% crude oil and could not biodegraded itself due to the extremely high toxicity. This contaminated soil was separated by 2mm sieve for removal oil sludge ball. Total petroleum hydrocarbons (TPH) was analysis by GC FID and initial TPH concentration was average 48,783 mg/kg. Ten grams of the contaminated soil replaced in two micro reactors with 20mL of bio surfactant produce microorganism. Reactor 1 was added 0.1g powder hemoglobin and other reactor was not added hemoglobin at time 0 day. Those reactors shake 120 rpm on the shaker for 7 days and CO2 produced about 150mg/L per day. After 7 days under the slurry systems, the rest days operated by hemoglobin as primary carbon source for enhanced biodegradation. The crude oil contaminated soil was degraded from 48,783mg/kg to 20,234mg/kg by slurry process and final TPH concentration degraded 11,324mg/kg for 21days. Therefore, highly contaminated soil by crude oil will be combined bio slurry process and biodegradation process with hemoglobin as bio catalytic source. Keywords: crude-oil contaminated soil, bio slurry, biodegradation, hemoglobin ACKOWLEDGEMENTS This project was supported by the Korea Ministry of Environment (MOE) GAIA Program

Experimental increase in availability of a PAH complex organic contamination from an aged contaminated soil: Consequences on biodegradation

International Nuclear Information System (INIS)

Cébron, Aurélie; Faure, Pierre; Lorgeoux, Catherine; Ouvrard, Stéphanie; Leyval, Corinne

2013-01-01

Although high PAH content and detection of PAH-degraders, the PAH biodegradation is limited in aged-contaminated soils due to low PAH availability (i.e., 1%). Here, we tried to experimentally increase the soil PAH availability by keeping both soil properties and contamination composition. Organic extract was first removed and then re-incorporated in the raw soil as fresh contaminants. Though drastic, this procedure only allowed a 6-time increase in the PAH availability suggesting that the organic constituents more than ageing were responsible for low availability. In the re-contaminated soil, the mineralization rate was twice more important, the proportion of 5–6 cycles PAH was higher indicating a preferential degradation of lower molecular weight PAH. The extraction treatment induced bacterial and fungal community structures modifications, Pseudomonas and Fusarium solani species were favoured, and the relative quantity of fungi increased. In re-contaminated soil the percentage of PAH-dioxygenase gene increased, with 10 times more Gram negative representatives. -- Highlights: ► Re-incorporation of soil organic extract increased 6-times the PAH availability. ► Complexity of organic contamination is the main driver of PAH availability. ► Biodegradation of PAH with less than 5-cycles increased with increasing PAH availability. ► Pseudomonas and Fusarium species are favoured when PAH availability increased. -- More than ageing, the complexity of organic contamination is the main driver of PAH availability