Humic substances as a washing agent for Cd-contaminated soils.

Science.gov (United States)

Meng, Fande; Yuan, Guodong; Wei, Jing; Bi, Dongxue; Ok, Yong Sik; Wang, Hailong

2017-08-01

Cost-effective and eco-friendly washing agents are in demand for Cd contaminated soils. Here, we used leonardite-derived humic substances to wash different types of Cd-contaminated soils, namely, a silty loam (Soil 1), a silty clay loam (Soil 2), and a sandy loam (Soil 3). Washing conditions were investigated for their effects on Cd removal efficiency. Cadmium removal was enhanced by a high humic substance concentration, long washing time, near neutral pH, and large solution/soil ratio. Based on the tradeoff between efficiency and cost, an optimum working condition was established as follows: humic substance concentration (3150 mg C/L), solution pH (6.0), washing time (2 h) and a washing solution/soil ratio (5). A single washing removed 0.55 mg Cd/kg from Soil 1 (1.33 mg Cd/kg), 2.32 mg Cd/kg from Soil 2 (6.57 mg Cd/kg), and 1.97 mg Cd/kg from Soil 3 (2.63 mg Cd/kg). Cd in effluents was effectively treated by adding a small dose of calcium hydroxide, reducing its concentration below the discharge limit of 0.1 mg/L in China. Being cost-effective and safe, humic substances have a great potential to replace common washing agents for the remediation of Cd-contaminated soils. Besides being environmentally benign, humic substances can improve soil physical, chemical, and biological properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Combined soil washing and CDEO for the removal of atrazine from soils

Energy Technology Data Exchange (ETDEWEB)

Vieira dos Santos, Elisama [Institute of Chemistry, Federal University of Rio Grande do Norte, Lagoa Nova CEP 59078-970, Natal, RN (Brazil); Sáez, Cristina [Department of Chemical Engineering, Universidad de Castilla – La Mancha, Enrique Costa Building, Campus Universitario s/n, 13071 Ciudad Real (Spain); Martínez-Huitle, Carlos Alberto [Institute of Chemistry, Federal University of Rio Grande do Norte, Lagoa Nova CEP 59078-970, Natal, RN (Brazil); Cañizares, Pablo; Rodrigo, Manuel Andres [Department of Chemical Engineering, Universidad de Castilla – La Mancha, Enrique Costa Building, Campus Universitario s/n, 13071 Ciudad Real (Spain)

2015-12-30

Highlights: • Sequential soil washing-waste electrolysis is an efficient treatment for removing atrazine. • Ratio surfactant/soil influences on the size of micelles and organic load. • Electrolysis with diamond anodes oxidizes pollutants from soils washing wastes. • Electrolysis of soil washing fluids promotes the reduction in size of micelles. • Sulphate ions release from the oxidation of SDS participates in the oxidation process. - Abstract: In this work, it is studied the removal of atrazine from spiked soils by soil washing using surfactant fluids, followed by the treatment of the resulting washing waste by electrolysis with boron doped diamond (BDD) anode. Results confirm that combination of both technologies is efficient for the removal and total mineralization of atrazine. Ratio surfactant/soil is a key parameter for the removal of atrazine from soil and influences significantly in the characteristic of the wastewater produced, affecting not only to the total organic load but also to the mean size of micelles. The higher the ratio surfactant soil, the lower is the size of the particles. Electrolyses of this type of waste attain the complete mineralization. TOC and COD are removed from the start of the treatment but the key of the treatment is the reduction in size of the micelles, which lead to a higher negative charge in the surface and to the faster depletion of the surfactant as compared with the pesticide.

Decontamination of electronic waste-polluted soil by ultrasound-assisted soil washing.

Science.gov (United States)

Chen, Fu; Yang, Baodan; Ma, Jing; Qu, Junfeng; Liu, Gangjun

2016-10-01

Laboratorial scale experiments were performed to evaluate the efficacy of a washing process using the combination of methyl-β-cyclodextrin (MCD) and tea saponin (TS) for simultaneous desorption of hydrophobic organic contaminants (HOCs) and heavy metals from an electronic waste (e-waste) site. Ultrasonically aided mixing of the field contaminated soil with a combination of MCD and TS solutions simultaneously mobilizes most of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and the analyte metal (Pb, Cu, and Ni) burdens. It is found that 15 g/L MCD and 10 g/L TS is an efficient reagent combination reconciling extraction performance and reagent costs. Under these conditions, the removal efficiencies of HOCs and heavy metals are 93.5 and 91.2 %, respectively, after 2 cycles of 60-min ultrasound-assisted washing cycles. By contrast, 86.3 % of HOCs and 88.4 % of metals are removed from the soil in the absence of ultrasound after 3 cycles of 120-min washing. The ultrasound-assisted soil washing could generate high removal efficiency and decrease the operating time significantly. Finally, the feasibility of regenerating and reusing the spent washing solution in extracting pollutants from the soil is also demonstrated. By application of this integrated technology, it is possible to recycle the washing solution for a purpose to reduce the consumption of surfactant solutions. Collectively, it has provided an effective and economic treatment of e-waste-polluted soil.

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...

SOIL-WASHING TECHNOLOGY AND PRACTICE

Science.gov (United States)

Soil washing in the United States has been studied and evaluated with increasing thoroughness during the last 15 to 20 years. It is now entering a phase of actual use and acceptance as its applicability and economics become clearer. This paper reviews the principles behind soil...

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

100 Area soil washing treatability test plan

International Nuclear Information System (INIS)

1993-03-01

This test plan describes specifications, responsibilities, and general methodology for conducting a soil washing treatability study as applied to source unit contamination in the 100 Area. The objective ofthis treatability study is to evaluate the use of physical separation systems and chemical extraction methods as a means of separating chemically and radioactively contaminated soil fractions from uncontaminated soil fractions. The purpose of separating these fractions is to minimize the volume of soil requiring permanent disposal. It is anticipated that this treatability study will be performed in two phases of testing, a remedy screening phase and a remedy selection phase. The remedy screening phase consists of laboratory- and bench-scale studies performed by Battelle Pacific Northwest laboratories (PNL) under a work order issued by Westinghouse Hanford Company (Westinghouse Hanford). This phase will be used to provide qualitative evaluation of the potential effectiveness of the soil washing technology. The remedy selection phase, consists of pilot-scale testing performed under a separate service contract to be competitively bid under Westinghouse Hanford direction. The remedy selection phase will provide data to support evaluation of the soil washing technology in future feasibility studies for Interim Remedial Measures (IRMs) or final operable unit (OU) remedies. Performance data from these tests will indicate whether applicable or relevant and appropriate requirements (ARARs) or cleanup goals can be met at the site(s) by application of soil washing. The remedy selection tests wig also allow estimation of costs associated with implementation to the accuracy required for the Feasibility Study

The source of groundwater and solutes to Many Devils Wash at a former uranium mill site in Shiprock, New Mexico

Science.gov (United States)

Robertson, Andrew J.; Ranalli, Anthony J.; Austin, Stephen A.; Lawlis, Bryan R.

2016-04-21

The Shiprock Disposal Site is the location of the former Navajo Mill (Mill), a uranium ore-processing facility, located on a terrace overlooking the San Juan River in the town of Shiprock, New Mexico. Following the closure of the Mill, all tailings and associated materials were encapsulated in a disposal cell built on top of the former Mill and tailings piles. The milling operations, conducted at the site from 1954 to 1968, created radioactive tailings and process-related wastes that are now found in the groundwater. Elevated concentrations of constituents of concern—ammonium, manganese, nitrate, selenium, strontium, sulfate, and uranium—have also been measured in groundwater seeps in the nearby Many Devils Wash arroyo, leading to the inference that these constituents originated from the Mill. These constituents have also been reported in groundwater that is associated with Mancos Shale, the bedrock that underlies the site. The objective of this report is to increase understanding of the source of water and solutes to the groundwater beneath Many Devils Wash and to establish the background concentrations for groundwater that is in contact with the Mancos Shale at the site. This report presents evidence on three working hypotheses: (1) the water and solutes in Many Devils Wash originated from the operations at the former Mill, (2) groundwater in deep aquifers is upwelling under artesian pressure to recharge the shallow groundwater beneath Many Devils Wash, and (3) the groundwater beneath Many Devils Wash originates as precipitation that infiltrates into the shallow aquifer system and discharges to Many Devils Wash in a series of springs on the east side of the wash. The solute concentrations in the shallow groundwater of Many Devils Wash would result from the interaction of the water and the Mancos Shale if the source of water was upwelling from deep aquifers or precipitation.In order to compare the groundwater from various wells to groundwater that has been

Removal of uranium from gravel using soil washing method

Energy Technology Data Exchange (ETDEWEB)

Kim, Ilgook; Kim, Kye-Nam; Kim, Seung-Soo; Choi, Jong-Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

The development of nuclear technology has led to increasing radioactive waste containing uranium being released and disposed in the nuclear sites. Fine grained soils with a size of less than 4 mm are normally decontaminated using soil washing and electro-kinetic technologies. However, there have been few studies on the decontamination of gravels with a size of more than 4 mm. Therefore, it is necessary to study the decontamination of gravel contaminated with radionuclides. The main objective of the present study on soil washing was to define the optimal condition for acid treatment of uranium-polluted gravel. In this study, soil washing method was applied to remove uranium from gravel. The gravel was crushed and classified as particle sizes. The gravel particles were treated with sulfuric acid in a shaking incubator at 60 .deg. C and 150 rpm for 3 h. The optimal particle size of gravel for soil washing in removal of uranium was between 0.45 and 2.0 mm.

100 Area soil washing bench-scale test procedures

International Nuclear Information System (INIS)

Freeman, H.D.; Gerber, M.A.; Mattigod, S.V.; Serne, R.J.

1993-03-01

This document describes methodologies and procedures for conducting soil washing treatability tests in accordance with the 100 Area Soil Washing Treatability Test Plan (DOE-RL 1992, Draft A). The objective of this treatability study is to evaluate the use of physical separation systems and chemical extraction methods as a means of separating chemically and radioactively contaminated soil fractions from uncontaminated soil fractions. These data will be primarily used for determining feasibility of the individual unit operations and defining the requirements for a system, or systems, for pilot-scale testing

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

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

An overview of the Department of Energy's soil washing workshop

International Nuclear Information System (INIS)

1991-09-01

The Soil Washing Workshop was convened in Las Vegas, Nevada, on August 28--29, 1990 at the request of C.W. Frank, Associate Director, Office of Technology Development, US Department of Energy (DOE). The purpose of the workshop was to determine the status of existing soil washing technologies and their applicability to specific soil contamination problems at DOE sites and at Superfund sites of the US Environmental Protection Agency (EPA). From the workshop deliberations, a course of action would be recommended in developing soil washing technologies. Presentations were given describing the soil contamination problems at various DOE sites. The factors addressed for each site included: type of contamination (organic, heavy metals, radionuclides, etc.), sources of contamination (leaking tanks, ponds, soil columns, pipes, etc.), types of soils that are contaminated, magnitude of the problem, current site activities (remediation), other considerations that impact the use of soil washing technology (e.g., environmental, site policies, etc.), and regulations and standards the sites are required to meet. Major findings and presentations of the workshop are presented

The integration of innovative technologies into a physical-separation-based soil washing system

International Nuclear Information System (INIS)

Krstich, M.A.

1995-01-01

An innovative system's approach to the treatment of soils at the Fernald Environmental Management Project (FEMP) has been proposed to effectively and cost competitively treat a significant mass of soil. The use of an integrated soil treatment system to decontaminate FEMP soils is a unique application of the soil washing technology. Due to the unfavorable soil particle size distribution and the ubiquitous distribution of uranium among these particle size fractions, conventional soil washing processes commonly used on predominantly sandy soils alone may not achieve the desirable waste minimization level without the inclusion of innovative technologies. This objective of this paper is to briefly describe the physical separation and chemical extraction process commonly used in soil washing operation and to present the baseline soil washing approach used on FEMP soils. Noting the successful and not-so-successful processes within the soil washing operation at the FEMP, a proposed innovative system's approach to treating FEMP soils will be described. This system's approach will integrate a conventional soil washing operation with proposed innovative technologies

Ground-water recharge in Fortymile Wash near Yucca Mountain, Nevada, 1992--1993

International Nuclear Information System (INIS)

Savard, C.S.

1994-01-01

Quantification of the ground-water recharge from streamflow in the Fortymile Wash watershed will contribute to regional ground-water studies. Regional ground-water studies are an important component in the studies evaluating the ground-water flow system as a barrier to the potential migration of radionuclides from the potential underground high-level nuclear waste repository. Knowledge gained in understanding the ground-water recharge mechanisms and pathways in the Pah Canyon area, which is 10 km to the northeast of Yucca Mountain, may transfer to Yucca site specific studies. The current data collection network in Fortymile Canyon does not permit quantification of ground-water recharge, however a qualitative understanding of ground-water recharge was developed from these data

Impact of electrochemical treatment of soil washing solution on PAH degradation efficiency and soil respirometry

International Nuclear Information System (INIS)

Mousset, Emmanuel; Huguenot, David; Hullebusch, Eric D. van; Oturan, Nihal; Guibaud, Gilles; Esposito, Giovanni; Oturan, Mehmet A.

2016-01-01

The remediation of a genuinely PAH-contaminated soil was performed, for the first time, through a new and complete investigation, including PAH extraction followed by advanced oxidation treatment of the washing solution and its recirculation, and an analysis of the impact of the PAH extraction on soil respirometry. The study has been performed on the remediation of genuine PAH-contaminated soil, in the following three steps: (i) PAH extraction with soil washing (SW) techniques, (ii) PAH degradation with an electro-Fenton (EF) process, and (iii) recirculation of the partially oxidized effluent for another SW cycle. The following criteria were monitored during the successive washing cycles: PAH extraction efficiency, PAH oxidation rates and yields, extracting agent recovery, soil microbial activity, and pH of soil. Two representative extracting agents were compared: hydroxypropyl-beta-cyclodextrin (HPCD) and a non-ionic surfactant, Tween"® 80. Six PAH with different numbers of rings were monitored: acenaphthene (ACE), phenanthrene (PHE), fluoranthene (FLA), pyrene (PYR), benzo(a)pyrene (BaP), and benzo(g,h,i)perylene (BghiP). Tween"® 80 showed much better PAH extraction efficiency (after several SW cycles) than HPCD, regardless of the number of washing cycles. Based on successive SW experiments, a new mathematical relation taking into account the soil/water partition coefficient (Kd*) was established, and could predict the amount of each PAH extracted by the surfactant with a good correlation with experimental results (R"2 > 0.975). More HPCD was recovered (89%) than Tween"® 80 (79%), while the monitored pollutants were completely degraded (>99%) after 4 h and 8 h, respectively. Even after being washed with partially oxidized solutions, the Tween"® 80 solutions extracted significantly more PAH than HPCD and promoted better soil microbial activity, with higher oxygen consumption rates. Moreover, neither the oxidation by-products nor the acidic media (p

The Development of Treatment Process Technology for Uranium Soil washing Leachate

Energy Technology Data Exchange (ETDEWEB)

Shon, Dong Bin; Kim, Gye Nam; Park, Hye Min; Kim, Ki Hong; Lee, Ki Won; Moon, Jeik won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2011-05-15

Electrokinetic treatment technology is a good method for removing radioactive substances such as U, Co, Cs: but it has a weakness. It takes a long time to get high removal efficiency. The Soil washing method compensates for this weak point with its short reaction time and with this method it is possible to remove a lot of uranium-contaminated soil. But a great deal of leachate is generated. That is, about more amounts of leachate are generated for the decontamination of the same volume of radioactive soil using the electrokinetic equipment. Therefore, the development of a treatment process for The Soil washing leachate is important so that there is a reduction of leachate waste volume and a choice of process. Previously, studies for liquid radioactive waste were in process at various nuclear facilities. Nuclear fuel plant survey appropriate cohesion quantity of liquid waste of radioactive. Nuclear power plants manage liquid radioactive waste with centrifugation equipment. In this study, the treatment technology for uranium Soil washing leachate generated on Soil washing decontamination for the soil contaminated with uranium was developed. A treatment process suitable to the contamination characteristics of Soil washing leachate was proposed

Soil Chemistry Effect on Feasibility of Cr-decontamination by Acid-Washing

OpenAIRE

Isoyama, Masahiro; Wada, Shin-Ichiro

2006-01-01

Soil washing with sample acid jas been proven to be effective for removal of cationic heavy metals from contaminated soils. Since the obsorption of anitonic heavy metals is enhanced in acidic medium, the efficiency of acid-washing may not be guaranteed for soils that are doubly contaminated with cationic and anitonic heavy metals. To evaluate the efficiensy of acid-washing, nine soils are artifically contaminated with chromate and chromium was extracted with hydrochrolic acid of 0.5 mmol L[-1...

Overview of JGC soil washing and site stabilization (SWSS) concept

International Nuclear Information System (INIS)

Goetsch, S.; Fujimura, Y.; Sauda, K.; Yagi, T.; Suzuki, K.

1991-01-01

The JGC Soil Washing and Site Stabilization (SWSS) concept is to wash heavy metal and uranium-contaminated soils using well demonstrated techniques, and to follow that process with its innovative stabilization process, to fix the remaining contaminates within a stable matrix. In addition, the solution used to wash the soil is stripped of contaminates, so that it can be reused. This process reduces the total amount of wastes generated from washing the soil, since not only can the solution be reused, but often the extracted contaminates can be recovered for industrial use. The stabilization portion of the concept is based on a family of proprietary fixing agents which can render the remaining contaminates insoluble. These agents are significantly different from other (generally silicate) agents used for stabilizing contaminated soils in that they appear to bond more strongly to heavy metal contaminants than the silicate-based reagents, resulting in improved leach-rate performance when combined with bentonite or portland cement stabilization

Soil physical characteristics after EDTA washing and amendment with inorganic and organic additives

International Nuclear Information System (INIS)

Zupanc, Vesna; Kastelec, Damijana; Lestan, Domen; Grcman, Helena

2014-01-01

Soil washing has been established as suitable remediation technology, with most research focused on metal removing efficiency and toxic effect on plants, less on the influence on soil physical characteristics, which was the focus of this study. In soil column experiment highly contaminated soil and soil washed with EDTA, mixed with additives (gypsum, hydrogel, manure, peat) were tested. White clover was used as a soil cover. Yield, metal concentration in soil and plant, aggregate fractionation and stability, saturated hydraulic conductivity and soil water retention of the soil were measured. Soil washing decreased metal concentration in soil and plants, but yield of white clover on remediated soil was significantly lower compared to the original soil. Significant differences in water retention characteristics, aggregate fractionation and stability between original and remediated soil have been determined. Gypsum, hydrogel and peat increased plant available water, manure and peat increased yield on remediated soil. -- Highlights: • Clover yield on washed soil was significantly lower than on original soil. • Organic additives increased yield on remediated soils. • Soil washing changed soil water retention and soil structure. • Hydrogen, gypsum and peat increased plant available water of remediated soil. -- The study critically examines yield, plant metal uptake and possible changes in soil physical characteristics as a consequence of soil washing procedure for metal pollution remediation

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

100 Area soil washing: Bench scale tests on 116-F-4 pluto crib soil

International Nuclear Information System (INIS)

Field, J.G.

1994-01-01

The Pacific Northwest Laboratory conducted a bench-scale treatability study on a pluto crib soil sample from 100 Area of the Hanford Site. The objective of this study was to evaluate the use of physical separation (wet sieving), treatment processes (attrition scrubbing, and autogenous surface grinding), and chemical extraction methods as a means of separating radioactively-contaminated soil fractions from uncontaminated soil fractions. The soil washing treatability study was conducted on a soil sample from the 116-F-4 Pluto Crib that had been dug up as part of an excavation treatability study. Trace element analyses of this soil showed no elevated concentrations above typically uncontaminated soil background levels. Data on the distribution of radionuclide in various size fractions indicated that the soil-washing tests should be focused on the gravel and sand fractions of the 116-F-4 soil. The radionuclide data also showed that 137 Cs was the only contaminant in this soil that exceeded the test performance goal (TPG). Therefore, the effectiveness of subsequent soil-washing tests for 116-F-4 soil was evaluated on the basis of activity attenuation of 137 Cs in the gravel- and sand-size fractions

100 Area soil washing: Bench scale tests on 116-F-4 pluto crib soil

Energy Technology Data Exchange (ETDEWEB)

Field, J.G.

1994-06-10

The Pacific Northwest Laboratory conducted a bench-scale treatability study on a pluto crib soil sample from 100 Area of the Hanford Site. The objective of this study was to evaluate the use of physical separation (wet sieving), treatment processes (attrition scrubbing, and autogenous surface grinding), and chemical extraction methods as a means of separating radioactively-contaminated soil fractions from uncontaminated soil fractions. The soil washing treatability study was conducted on a soil sample from the 116-F-4 Pluto Crib that had been dug up as part of an excavation treatability study. Trace element analyses of this soil showed no elevated concentrations above typically uncontaminated soil background levels. Data on the distribution of radionuclide in various size fractions indicated that the soil-washing tests should be focused on the gravel and sand fractions of the 116-F-4 soil. The radionuclide data also showed that {sup 137}Cs was the only contaminant in this soil that exceeded the test performance goal (TPG). Therefore, the effectiveness of subsequent soil-washing tests for 116-F-4 soil was evaluated on the basis of activity attenuation of {sup 137}Cs in the gravel- and sand-size fractions.

Washing enhanced electrokinetic remediation for removal cadmium from real contaminated soil

International Nuclear Information System (INIS)

Giannis, Apostolos; Gidarakos, Evangelos

2005-01-01

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

Extraction agents for the removal of polycyclic aromatic hydrocarbons (PAHs) from soil in soil washing technologies

International Nuclear Information System (INIS)

Lau, Ee Von; Gan, Suyin; Ng, Hoon Kiat; Poh, Phaik Eong

2014-01-01

Polycyclic aromatic hydrocarbons (PAHs) in soil have been recognised as a serious health and environmental issue due to their carcinogenic, mutagenic and teratogenic properties. One of the commonly employed soil remediation techniques to clean up such contamination is soil washing or solvent extraction. The main factor which governs the efficiency of this process is the solubility of PAHs in the extraction agent. Past field-scale soil washing treatments for PAH-contaminated soil have mainly employed organic solvents or water which is either toxic and costly or inefficient in removing higher molecular weight PAHs. Thus, the present article aims to provide a review and discussion of the alternative extraction agents that have been studied, including surfactants, biosurfactants, microemulsions, natural surfactants, cyclodextrins, vegetable oil and solution with solid phase particles. These extraction agents have been found to remove PAHs from soil at percentages ranging from 47 to 100% for various PAHs. -- Highlights: • The alternative and advancement in extraction agents to remove PAHs from soil using soil washing technology is summarised. • The soil regulations for PAH level in various countries are summarized for reference to researchers. • The concentration levels of PAHs in soil at present and the need for soil remediation is presented. -- The efficiency of the extraction agent plays a significant role in soil washing of PAH-contaminated soil

Coagulation-flocculation process applied to wastewaters generated in hydrocarbon-contaminated soil washing

International Nuclear Information System (INIS)

Torres, L. g.; Belloc, C.; Iturbe, R.; Bandala, E.

2009-01-01

A wastewater produced in the contaminated soil washing was treated by means of coagulation-flocculation (CF) process. the wastewater treatment in this work continued petroleum hydrocarbons, a surfactant, i. e., sodium dodecyl sulphate (SDS) as well as salts, humic acids and other constituents that were lixiviated rom the soil during the washing process. The aim of this work was to develop a process for treating the wastewaters generated when washing hydrocarbon-contaminated soils in such a way that it could be recycled to the washing process, and at the end of the cleaning up, the waters could be disposed properly. (Author)

Remediation of multiple heavy metal-contaminated soil through the combination of soil washing and in situ immobilization.

Science.gov (United States)

Zhai, Xiuqing; Li, Zhongwu; Huang, Bin; Luo, Ninglin; Huang, Mei; Zhang, Qiu; Zeng, Guangming

2018-09-01

The remediation of heavy metal-contaminated soils is a great challenge for global environmental sciences and engineering. To control the ecological risks of heavy metal-contaminated soil more effectively, the present study focused on the combination of soil washing (with FeCl 3 ) and in situ immobilization (with lime, biochar, and black carbon). The results showed that the removal rate of Cd, Pb, Zn, and Cu was 62.9%, 52.1%, 30.0%, and 16.7%, respectively, when washed with FeCl 3 . After the combined remediation (immobilization with 1% (w/w) lime), the contaminated soils showed 36.5%, 73.6%, 70.9%, and 53.4% reductions in the bioavailability of Cd, Cu, Pb, and Zn (extracted with 0.11M acetic acid), respectively, than those of the soils washed with FeCl 3 only. However, the immobilization with 1% (w/w) biochar or 1% (w/w) carbon black after washing exhibited low effects on stabilizing the metals. The differences in effects between the immobilization with lime, biochar, and carbon black indicated that the soil pH had a significant influence on the lability of heavy metals during the combined remediation process. The activity of the soil enzymes (urease, sucrase, and catalase) showed that the addition of all the materials, including lime, biochar, and carbon black, exhibited positive effects on microbial remediation after soil washing. Furthermore, lime was the most effective material, indicating that low soil pH and high acid-soluble metal concentrations might restrain the activity of soil enzymes. Soil pH and nutrition were the major considerations for microbial remediation during the combined remediation. These findings suggest that the combination of soil washing and in situ immobilization is an effective method to amend the soils contaminated with multiple heavy metals. Copyright © 2018 Elsevier B.V. All rights reserved.

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

Impact of electrochemical treatment of soil washing solution on PAH degradation efficiency and soil respirometry.

Science.gov (United States)

Mousset, Emmanuel; Huguenot, David; van Hullebusch, Eric D; Oturan, Nihal; Guibaud, Gilles; Esposito, Giovanni; Oturan, Mehmet A

2016-04-01

The remediation of a genuinely PAH-contaminated soil was performed, for the first time, through a new and complete investigation, including PAH extraction followed by advanced oxidation treatment of the washing solution and its recirculation, and an analysis of the impact of the PAH extraction on soil respirometry. The study has been performed on the remediation of genuine PAH-contaminated soil, in the following three steps: (i) PAH extraction with soil washing (SW) techniques, (ii) PAH degradation with an electro-Fenton (EF) process, and (iii) recirculation of the partially oxidized effluent for another SW cycle. The following criteria were monitored during the successive washing cycles: PAH extraction efficiency, PAH oxidation rates and yields, extracting agent recovery, soil microbial activity, and pH of soil. Two representative extracting agents were compared: hydroxypropyl-beta-cyclodextrin (HPCD) and a non-ionic surfactant, Tween(®) 80. Six PAH with different numbers of rings were monitored: acenaphthene (ACE), phenanthrene (PHE), fluoranthene (FLA), pyrene (PYR), benzo(a)pyrene (BaP), and benzo(g,h,i)perylene (BghiP). Tween(®) 80 showed much better PAH extraction efficiency (after several SW cycles) than HPCD, regardless of the number of washing cycles. Based on successive SW experiments, a new mathematical relation taking into account the soil/water partition coefficient (Kd*) was established, and could predict the amount of each PAH extracted by the surfactant with a good correlation with experimental results (R(2) > 0.975). More HPCD was recovered (89%) than Tween(®) 80 (79%), while the monitored pollutants were completely degraded (>99%) after 4 h and 8 h, respectively. Even after being washed with partially oxidized solutions, the Tween(®) 80 solutions extracted significantly more PAH than HPCD and promoted better soil microbial activity, with higher oxygen consumption rates. Moreover, neither the oxidation by-products nor the acidic media (p

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)

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...

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

Energy Technology Data Exchange (ETDEWEB)

Park, Ukryang; Kim, Gyenam; Kim, Seungsoo; Park, Hyemin; Kim, Wansuk; Moon, Jaikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

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{sub 2}, BaCl{sub 2}, NH{sub 4}NO{sub 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{sub 2}SO{sub 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{sub 2}SO{sub 4}, the different removal tendencies for each size were considered. After selecting the complex agent H{sub 2}SO{sub 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

Particle Separation of Non-Decontamination Soil using Attrition and Washing

International Nuclear Information System (INIS)

Koo, Daeseo; Sung, Hyun-Hee; Kim, Seung-Soo; Hong, Sang Bum; Seo, Bum Kyoung; Choi, Jong-Won

2017-01-01

In this study, to improve the decontamination efficiency of uranium soil, a preliminary experiment on the particle separation of non-decontamination soil was carried out using attrition and washing. The characteristics of the attrition and washing system are investigated. A conditional experiment on particle separation of non-decontamination soil will be performed. A preliminary experiment on the particle separation of non-decontamination soil was carried out to improve the decontamination efficiency of uranium soil. This experiment was performed with the ratio of soil to water (1:4) for the particle separation of non-decontamination soil. The operations of all equipment such as attrition scrubber, ultrasonic reaction, vibrating screen, and hydro-cyclone were conducted and confirmed. In the future, the additional experiments will be conducted for optimal experimental condition.

Copper removal from contaminated soils by soil washing process using camellian-derived saponin

Science.gov (United States)

Reyes, Arturo; Fernanda Campos, Maria; Videla, Álvaro; Letelier, María Victoria; Fuentes, Bárbara

2015-04-01

Antofagasta Region in North of Chile has been the main copper producer district in the world. As a consequence of a lack of mining closure regulation, a large number of abandon small-to-medium size metal-contaminated sites have been identified in the last survey performed by the Chilean Government. Therefore, more research development on sustainable reclamation technologies must be made in this extreme arid-dry zone. The objective of this study is to test the effectiveness of soil remediation by washing contaminated soil using camellian-derived saponin for the mobilization of copper. Soil samples were taken from an abandoned copper mine site located at 30 km North Antofagasta city. They were dried and sieved at 75 µm for physico-chemical characterization. A commercial saponin extracted from camellias seed was used as biosurfactant. The soil used contains 67.4 % sand, 26.3 % silt and 6.3 % clay. The soil is highly saline (electric conductivity, 61 mScm-1), with low organic matter content (0.41%), with pH 7.30, and a high copper concentration (2200 mg Kg-1 soil). According to the sequential extraction procedure of the whole soil, copper species are mainly as exchangeable fraction (608.2 mg Kg-1 soil) and reducible fraction (787.3 mg Kg-1 soil), whereas the oxidizable and residual fractions are around 205.7 and 598.8 mg Kg-1 soil, respectively. Soil particles under 75 µm contain higher copper concentrations (1242 mg Kg-1 soil) than the particle fraction over 75 µm (912 mg Kg-1 soil). All washing assays were conducted in triplicate using a standard batch technique with and without pH adjustment. The testing protocols includes evaluation of four solid to liquid ratio (0.5:50; 1.0:50; 2.0:50, and 5.0:50) and three saponin concentrations (0, 1, and 4 mg L-1). After shaking (24 h, 20±1 °C) and subsequently filtration (0.45 µm), the supernatants were analyzed for copper and pH. The removal efficiencies of copper by saponin solutions were calculated in according to the

Copper Recovery from Polluted Soils Using Acidic Washing and Bioelectrochemical Systems

Directory of Open Access Journals (Sweden)

Karin Karlfeldt Fedje

2015-07-01

Full Text Available Excavation followed by landfilling is the most common method for treating soils contaminated by metals. However, as this solution is not sustainable, alternative techniques are required. Chemical soil washing is one such alternative. The aim of this experimental lab-scale study is to develop a remediation and metal recovery method for Cu contaminated sites. The method is based on the washing of soil or ash (combusted soil/bark with acidic waste liquids followed by electrolytic Cu recovery by means of bioelectrochemical systems (BES. The results demonstrate that a one- or two-step acidic leaching process followed by water washing removes >80 wt. % of the Cu. Copper with 99.7–99.9 wt. % purity was recovered from the acidic leachates using BES. In all experiments, electrical power was generated during the reduction of Cu. This clearly indicates that Cu can also be recovered from dilute solutions. Additionally, the method has the potential to wash co-pollutants such as polycyclic aromatic hydrocarbons (PAHs and oxy-PAHs.

Volume reduction system by soil classifying. Soil-washing system and problems to be solved

International Nuclear Information System (INIS)

Oshino, Yoshio

2016-01-01

Radioactive contamination of ground surfaces, buildings and forests in a broad area was caused by the accident at the Fukushima Daiichi Nuclear Power Plant in Japan. The national government and municipalities have still been carrying out the decontamination works for livelihood areas after five years from the accident. The government estimated that the amounts of soils and wastes removed by the decontamination works would be about 28,000,000 cubic meters maximum including 20,000,000 cubic meters maximum of soils. The removed soils will be stored in “Interim Storage Facility” then will be finally disposed outside of Fukushima prefecture within 30 years. On the other hand, shortage of the soils as materials needed for the revitalization in Fukushima prefecture is expected. Technical Advisory Council on Remediation and Waste Management, which consists of about 90 companies, started a working group to investigate solutions to these problems. The working group focused on the investigation of the possibility to recycle the soils by washing and classification to use them as the materials for civil engineering works, and to reduce the volume of the interim storage. In the first part of this report, we have evaluated the applicability of various technologies for purification and volume reduction of the removed soils, and have researched usages, required quantities and specifications of the recycled soils. In the second part, we have made trial calculations of the volume reduction effects and costs using the washing and classification system. The calculated results showed the possibilities of reducing the storage capacity of the interim storage facility, as well as the construction and the operation costs by recycling the removed soils with the washing and classification system inside the interim storage facility. At the end of this report, we proposed problems to be solved in order to adopt the washing and classification system. (author)

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

Science.gov (United States)

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

2015-01-01

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

Minimum Additive Waste Stabilization (MAWS), Phase I: Soil washing final report

International Nuclear Information System (INIS)

1995-08-01

As a result of the U.S. Department of Energy's environmental restoration and technology development activities, GTS Duratek, Inc., and its subcontractors have demonstrated an integrated thermal waste treatment system at Fernald, OH, as part the Minimum Additive Waste Stabilization (MAWS) Program. Specifically, MAWS integrates soil washing, vitrification of mixed waste streams, and ion exchange to recycle and remediate process water to achieve, through a synergistic effect, a reduction in waste volume, increased waste loading, and production of a durable, leach-resistant, stable waste form suitable for disposal. This report summarizes the results of the demonstration/testing of the soil washing component of the MAWS system installed at Fernald (Plant 9). The soil washing system was designed to (1) process contaminated soil at a rate of 0.25 cubic yards per hour; (2) reduce overall waste volume and provide consistent-quality silica sand and contaminant concentrates as raw material for vitrification; and (3) release clean soil with uranium levels below 35 pCi/g. Volume reductions expected ranged from 50-80 percent; the actual volume reduction achieved during the demonstration reached 66.5 percent. The activity level of clean soil was reduced to as low as 6 pCi/g from an initial average soil activity level of 17.6 pCi/g (the highest initial level of soil provided for testing was 41 pCi/g). Although the throughput of the soil washing system was inconsistent throughout the testing period, the system was online for sufficient periods to conclude that a rate equivalent to 0.25 cubic yards per hour was achieved

Remediation of soils polluted with lindane using surfactant-aided soil washing and electrochemical oxidation.

Science.gov (United States)

Muñoz-Morales, M; Braojos, M; Sáez, C; Cañizares, P; Rodrigo, M A

2017-10-05

In this work the complete treatment of soil spiked with lindane is studied using surfactant-aided soil-washing (SASW) to exhaust lindane from soil and electrolysis with diamond anodes to mineralize lindane from the soil washing fluid (SWF) waste. Results demonstrated that this technological approach is efficient and allow to remove this hazardous pollutant from soil. They also pointed out the significance of the ratio surfactant/soil in the efficiency of the SASW process and in the performance of the later electrolysis used to mineralize the pollutant. Larger values of this parameter lead to effluents that undergo a very efficient treatment which allows the depletion of lindane for applied charges lower than 15AhL -1 and the recovery of more than 70% of the surfactant for the regeneration of the SWF. Copyright © 2017 Elsevier B.V. All rights reserved.

Soil remediation using a coupled process: soil washing with surfactant followed by photo-Fenton oxidation

International Nuclear Information System (INIS)

Villa, Ricardo D.; Trovo, Alam G.; Nogueira, Raquel F. Pupo

2010-01-01

In the present work the use of a coupled process, soil washing and photo-Fenton oxidation, was investigated for remediation of a soil contaminated with p,p'-DDT (DDT) and p,p'-DDE (DDE), and a soil artificially contaminated with diesel. In the soil washing experiments, Triton X-100 (TX-100) aqueous solutions were used at different concentrations to obtain wastewaters with different compositions. Removal efficiencies of 66% (DDT), 80% (DDE) and 100% (diesel) were achieved for three sequential washings using a TX-100 solution strength equivalent to 12 times the effective critical micelle concentration of the surfactant (12 CMC eff ). The wastewater obtained was then treated using a solar photo-Fenton process. After 6 h irradiation, 99, 95 and 100% degradation efficiencies were achieved for DDT, DDE and diesel, respectively. In all experiments, the concentration of dissolved organic carbon decreased by at least 95%, indicating that residual concentration of contaminants and/or TX-100 in the wastewater was very low. The co-extraction of metals was also evaluated. Among the metals analyzed (Pb, Cr, Ni, Cu, Cd, Mn and Co), only Cr and Mn were detected in the wastewater at concentrations above the maximum value permitted by current Brazilian legislation. The effective removal of contaminants from soil by the TX-100 washing process, together with the high degradation efficiency of the solar photo-Fenton process, suggests that this procedure could be a useful option for soil remediation.

Soil remediation using a coupled process: soil washing with surfactant followed by photo-Fenton oxidation

Energy Technology Data Exchange (ETDEWEB)

Villa, Ricardo D., E-mail: ricardovilla@ufmt.br [UNESP - Sao Paulo State University, Institute of Chemistry of Araraquara, Department of Analytical Chemistry, P.O. Box 355, 14801-970 Araraquara, SP (Brazil); Trovo, Alam G., E-mail: alamtrovo@smail.ufsm.br [UNESP - Sao Paulo State University, Institute of Chemistry of Araraquara, Department of Analytical Chemistry, P.O. Box 355, 14801-970 Araraquara, SP (Brazil); Nogueira, Raquel F. Pupo, E-mail: nogueira@iq.unesp.br [UNESP - Sao Paulo State University, Institute of Chemistry of Araraquara, Department of Analytical Chemistry, P.O. Box 355, 14801-970 Araraquara, SP (Brazil)

2010-02-15

In the present work the use of a coupled process, soil washing and photo-Fenton oxidation, was investigated for remediation of a soil contaminated with p,p'-DDT (DDT) and p,p'-DDE (DDE), and a soil artificially contaminated with diesel. In the soil washing experiments, Triton X-100 (TX-100) aqueous solutions were used at different concentrations to obtain wastewaters with different compositions. Removal efficiencies of 66% (DDT), 80% (DDE) and 100% (diesel) were achieved for three sequential washings using a TX-100 solution strength equivalent to 12 times the effective critical micelle concentration of the surfactant (12 CMC{sub eff}). The wastewater obtained was then treated using a solar photo-Fenton process. After 6 h irradiation, 99, 95 and 100% degradation efficiencies were achieved for DDT, DDE and diesel, respectively. In all experiments, the concentration of dissolved organic carbon decreased by at least 95%, indicating that residual concentration of contaminants and/or TX-100 in the wastewater was very low. The co-extraction of metals was also evaluated. Among the metals analyzed (Pb, Cr, Ni, Cu, Cd, Mn and Co), only Cr and Mn were detected in the wastewater at concentrations above the maximum value permitted by current Brazilian legislation. The effective removal of contaminants from soil by the TX-100 washing process, together with the high degradation efficiency of the solar photo-Fenton process, suggests that this procedure could be a useful option for soil remediation.

Physical separations soil washing system cold test results

Energy Technology Data Exchange (ETDEWEB)

McGuire, J.P.

1993-07-28

This test summary describes the objectives, methodology, and results of a physical separations soil-washing system setup and shakedown test using uncontaminated soil. The test is being conducted in preparation for a treatability test to be conducted in the North Pond of the 300-FF-1 Operable Unit. It will be used to assess the feasibility of using a physical separations process to reduce the volume of contaminated soils in the 300-FF-1 Operable Unit. The test is described in DOE-RL (1993). The setup test was conducted at an uncontrolled area located approximately 3.2 km northwest of the 300-FF-1 Operable Unit. The material processed was free of contamination. The physical separation equipment to be used in the test was transferred to the US Department of Energy (DOE) by the US Environmental Protection Agency (EPA) Risk Reduction Engineering Laboratory. On May 13, 1993, soil-washing equipment was moved to the cold test location. Design assistance and recommendation for operation was provided by the EPA.

Optimizing the molarity of a EDTA washing solution for saturated-soil remediation of trace metal contaminated soils

International Nuclear Information System (INIS)

Andrade, M.D.; Prasher, S.O.; Hendershot, W.H.

2007-01-01

Three experiments were conducted to optimize the use of ethylenediaminetetraacetic acid (EDTA) for reclaiming urban soils contaminated with trace metals. As compared to Na 2 EDTA (NH 4 ) 2 EDTA extracted 60% more Zn and equivalent amounts of Cd, Cu and Pb from a sandy loam. When successively saturating and draining loamy sand columns during a washing cycle, which submerged it once with a (NH 4 ) 2 EDTA wash and four times with deionised water, the post-wash rinses largely contributed to the total cumulative extraction of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn. Both the washing solution and the deionised water rinses were added in a 2:5 liquid to soil (L:S) weight ratio. For equal amounts of EDTA, concentrating the washing solution and applying it and the ensuing rinses in a smaller 1:5 L:S weight ratio, instead of a 2:5 L:S weight ratio, increased the extraction of targeted Cr, Cu, Ni, Pb and Zn. - A single EDTA addition is best utilised in a highly concentrated washing solution given in a small liquid to soil weight ratio

Heavy metal removal by GLDA washing: Optimization, redistribution, recycling, and changes in soil fertility.

Science.gov (United States)

Wang, Guiyin; Zhang, Shirong; Xu, Xiaoxun; Zhong, Qinmei; Zhang, Chuer; Jia, Yongxia; Li, Ting; Deng, Ouping; Li, Yun

2016-11-01

Soil washing, an emerging method for treating soils contaminated by heavy metals, requires an evaluation of its efficiency in simultaneously removing different metals, the quality of the soil following remediation, and the reusability of the recycled washing agent. In this study, we employed N,N-bis (carboxymethyl)-l-glutamic acid (GLDA), a novel and readily biodegradable chelator to remove Cd, Pb, and Zn from polluted soils. We investigated the influence of washing conditions, including GLDA concentration, pH, and contact time on their removal efficiencies. The single factor experiments showed that Cd, Pb, and Zn removal efficiencies reached 70.62, 74.45, and 34.43% in mine soil at a GLDA concentration of 75mM, a pH of 4.0, and a contact time of 60min, and in polluted farmland soil, removal efficiencies were 69.12, 78.30, and 39.50%, respectively. We then employed response surface methodology to optimize the washing parameters. The optimization process showed that the removal efficiencies were 69.50, 88.09, and 40.45% in mine soil and 71.34, 81.02, and 50.95% in polluted farmland soil for Cd, Pb, and Zn, respectively. Moreover, the overall highly effective removal of Cd and Pb was connected mainly to their highly effective removal from the water-soluble, exchangeable, and carbonate fractions. GLDA-washing eliminated the same amount of metals as EDTA-washing, while simultaneously retaining most of the soil nutrients. Removal efficiencies of recycled GLDA were no >5% lower than those of the fresh GLDA. Therefore, GLDA could potentially be used for the rehabilitation of soil contaminated by heavy metals. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of radiocaesium wash-off by soil erosion from various land uses using USLE plots

International Nuclear Information System (INIS)

Yoshimura, Kazuya; Onda, Yuichi; Kato, Hiroaki

2015-01-01

Radiocaesium wash-off associated with soil erosion in different land use was monitored using USLE plots in Kawamata, Fukushima Prefecture, Japan after the Fukushima Dai-ichi Nuclear Power Plant accident. Parameters and factors relating to soil erosion and 137 Cs concentration in the eroded soil were evaluated based on the field monitoring and presented. The erosion of fine soil, which is defined as the fraction of soil overflowed along with discharged water from a sediment-trap tank, constituted a large proportion of the discharged radiocaesium. This indicated that the quantitative monitoring of fine soil erosion is greatly important for the accurate evaluation of radiocaesium wash-off. An exponential relationship was found between vegetation cover and the amount of eroded soil. Moreover, the radiocaesium concentrations in the discharged soil were greatly affected by the land use. These results indicate that radiocaesium wash-off related to vegetation cover and land use is crucially important in modelling radiocaesium migration. - Highlights: • Fine soil erosion showed large impact on radiocaesium wash-off. • Exponential relationship was found between vegetation cover and eroded soil. • Radiocaesium concentration in the discharged soil was depending on land use

Combination of surfactant enhanced soil washing and electro-Fenton process for the treatment of soils contaminated by petroleum hydrocarbons.

Science.gov (United States)

Huguenot, David; Mousset, Emmanuel; van Hullebusch, Eric D; Oturan, Mehmet A

2015-04-15

In order to improve the efficiency of soil washing treatment of hydrocarbon contaminated soils, an innovative combination of this soil treatment technique with an electrochemical advanced oxidation process (i.e. electro-Fenton (EF)) has been proposed. An ex situ soil column washing experiment was performed on a genuinely diesel-contaminated soil. The washing solution was enriched with surfactant Tween 80 at different concentrations, higher than the critical micellar concentration (CMC). The impact of soil washing was evaluated on the hydrocarbons concentration in the leachates collected at the bottom of the soil columns. These eluates were then studied for their degradation potential by EF treatment. Results showed that a concentration of 5% of Tween 80 was required to enhance hydrocarbons extraction from the soil. Even with this Tween 80 concentration, the efficiency of the treatment remained very low (only 1% after 24 h of washing). Electrochemical treatments performed thereafter with EF on the collected eluates revealed that the quasi-complete mineralization (>99.5%) of the hydrocarbons was achieved within 32 h according to a linear kinetic trend. Toxicity was higher than in the initial solution and reached 95% of inhibition of Vibrio fischeri bacteria measured by Microtox method, demonstrating the presence of remaining toxic compounds even after the complete degradation. Finally, the biodegradability (BOD₅/COD ratio) reached a maximum of 20% after 20 h of EF treatment, which is not enough to implement a combined treatment with a biological treatment process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biodegradation and speciation of residual SS-ethylenediaminedisuccinic acid (EDDS) in soil solution left after soil washing.

Science.gov (United States)

Tandy, Susan; Ammann, Adrian; Schulin, Rainer; Nowack, Bernd

2006-07-01

This paper aims to investigate the degradation and speciation of EDDS-complexes (SS-ethylenediaminedisuccinic acid) in soil following soil washing. The changes in soil solution metal and EDDS concentrations were investigated for three polluted soils. EDDS was degraded after a lag phase of 7-11 days with a half-life of 4.18-5.60 days. No influence of EDDS-speciation on the reaction was observed. The decrease in EDDS resulted in a corresponding decrease in solubilized metals. Changes in EDDS speciation can be related to (1) initial composition of the soil, (2) temporarily anoxic conditions in the soil slurry after soil washing, (3) exchange of EDDS complexes with Cu even in soils without elevated Cu and (4) formation of NiEDDS. Dissolved organic matter is important for metal speciation at low EDDS concentrations. Our results show that even in polluted soils EDDS is degraded from a level of several hundred micromoles to below 1 microM within 50 days.

European soil washing for U.S. applications

Energy Technology Data Exchange (ETDEWEB)

Mann, Michael J [Geraghty and Miller, Inc., Tampa, PL (United States)

1992-07-01

The purpose of this paper is to present the details of the introduction of a new soil treatment technology to the U.S. market. For the purposes of this presentation, I would like to introduce a concept of three tiers of contaminated soil treatment; traditional treatment technologies, alternative treatment technologies and emerging treatment technologies. Traditional treatment consists of landfilling, incineration, and stabilization. Alternative technologies consist of low-temperature thermal treatment, bioremediation, vapor extraction, and physical screening and separation to achieve volume reduction...the essence of soil washing. Emerging technologies currently include in-situ vitrification, RF processes, dechlorination, and possibly some extraction techniques. This paper focuses on the alternative soil technologies. One of the most important lessons we have learned over the past decade is that no single technology provides a broad enough capability to solve all the soil situations that we encounter - the key to feasible and cost-effective site solutions is the ability to optimize the use of reasonable alternatives in a site-specific matrix of use. The Environmental Protection Agency (EPA) has recognized this need and particularly with SARA, emphasized the importance of 'on-site' treatment technologies. This policy was initially stimulated through the development of the SITES program and most recently expanded by the formation of the Technology Innovation Office. Still, all technologies have their limitations. The limitations that are most commonly encountered are: The volume of soil is too big or too small; The contaminants species and/or concentration is not process-compatible; Organics and inorganics cannot be handled in the same treatment train; The process has little or no commercial operations experience. This document is intended to provide a description of a commercial soil-washing facility operating in Holland for the past seven years and to demonstrate

The sequential use of washing and an electrochemical reduction process for the remediation of lead-contaminated soils.

Science.gov (United States)

Demir, Aydeniz; Köleli, Nurcan

2013-01-01

A two-step method for the remediation of three different types of lead (Pb)-contaminated soil was evaluated. The first step included soil washing with ethylenediaminetetraacetic acid (EDTA) to remove Pb from soils. The washing experiments were performed with 0.05 M Na2EDTA at 1:10 soil to liquid ratio. Following the washing, Pb removal efficiency from soils ranged within 50-70%. After the soil washing process, Pb2+ ions in the washing solution were reduced electrochemically in a fixed-bed reactor. Lead removal efficiency with the electrochemical reduction at -2.0 V potential ranged within 57-76%. The overall results indicate that this two-step method is an environmentally-friendly and effective technology to remediate Pb-contaminated soils, as well as Pb-contaminated wastewater treatment due to the transformation of toxic Pb2+ ions into a non-hazardous metallic form (Pb(0)).

Possibilities of soil washing for decontamination at Belgoprocess

Energy Technology Data Exchange (ETDEWEB)

Aerts, Wouter [Belgoprocess, Dessel, Antwerp (Belgium); De Bruecker, Thomas; Lytek, Anna [DEC - DEME Environmental Contractor, Zwijndrecht, Antwerp (Belgium)

2013-07-01

Contaminated soils form a large part of the nuclear waste arising from decommissioning activities. The storage and disposal of these large volumes of waste is costly. For this reason techniques which can decontaminate this waste stream to free release levels are economically very interesting. A feasibility study of the possibilities of soil washing to decontaminate such soils was ordered by NIRAS/ONDRAF and performed at Belgoprocess in collaboration with DEC. Initial contamination level and particle size distributions of contaminated soils from three different sources were determined. The main isotopes detected with gamma spectrometry contained in the waste were {sup 241}Am, {sup 137}Cs, {sup 226}Ra, {sup 60}Co and {sup 232}Th. The particle size distribution revealed that more than half of the mass of the quartz sand that makes up the soil has a particle size between 125 and 212 μm. This fraction is less contaminated than the fractions containing smaller particles. However, separation of the fines fraction (< 125 μm) was not enough to achieve the free release limit. Soil attrition was tested as an extra decontamination step for the sand fraction. The removal efficiencies for the different radionuclides contained in the soil were measured. The process conditions were optimized to achieve maximum removal and a treatment method for the secondary waste coming from this process step was determined. The soil washing process was not only performed with water but also with nitric acid to assess the possibilities of a combination of a mechanical and a chemical decontamination process. Reduction efficiencies of 60-80% for the most relevant radionuclides were recorded. (authors)

Regional analysis of groundwater phosphate concentrations under acidic sandy soils: Edaphic factors and water table strongly mediate the soil P-groundwater P relation.

Science.gov (United States)

Mabilde, Lisa; De Neve, Stefaan; Sleutel, Steven

2017-12-01

Historic long-term P application to sandy soils in NW-Europe has resulted in abundant sorption, saturation and eventually leaching of P from soil to the groundwater. Although many studies recognize the control of site-specific factors like soil texture and phosphate saturation degree (PSD), the regional-scaled relevance of effects exerted by single factors controlling P leaching is unclear. Very large observational datasets of soil and groundwater P content are furthermore required to reveal indirect controls of soil traits through mediating soil variables. We explored co-variation of phreatic groundwater orthophosphate (o-P) concentration and soil factors in sandy soils in Flanders, Belgium. Correlation analyses were complemented with an exploratory model derived using 'path analysis'. Data of oxalate-extractable Al, Fe, P and pH KCl , phosphate sorption capacity (PSC) and PSD in three depth layers (0-30, 30-60, 60-90 cm), topsoil SOC, % clay and groundwater depth (fluctuation) were interpolated to predict soil properties on exact locations of a very extensive net of groundwater monitoring wells. The mean PSD was only poorly correlated to groundwater o-P concentration, indicating the overriding control of other factors in the transport of P to the groundwater. A significant (P soil pH and groundwater table depth than by PSD indicates the likely oversimplification of the latter index to measure the long-term potential risk of P leaching. Accounting for controls on leaching not included in PSD via an alternative index, however, seems problematic as in Flanders for example groundwater o-P turned out to be higher in finer textured soils or soils with higher pedogenic Fe content, probably because of their lower pedogenic Al content and higher soil pH. Path analysis of extensive soil and groundwater datasets seems a viable way to identify prime local determinants of soil P leaching and could be further on used for 'ground-truthing' more complex P-migration simulation

Removal of oxyfluorfen from ex-situ soil washing fluids using electrolysis with diamond anodes.

Science.gov (United States)

dos Santos, Elisama Vieira; Sáez, Cristina; Martínez-Huitle, Carlos Alberto; Cañizares, Pablo; Rodrigo, Manuel Andres

2016-04-15

In this research, firstly, the treatment of soil spiked with oxyfluorfen was studied using a surfactant-aided soil-washing (SASW) process. After that, the electrochemical treatment of the washing liquid using boron doped diamond (BDD) anodes was performed. Results clearly demonstrate that SASW is a very efficient approach in the treatment of soil, removing the pesticide completely by using dosages below 5 g of sodium dodecyl sulfate (SDS) per Kg of soil. After that, complete mineralization of organic matter (oxyflourfen, SDS and by-products) was attained (100% of total organic carbon and chemical oxygen demand removals) when the washing liquids were electrolyzed using BDD anodes, but the removal rate depends on the size of the particles in solution. Electrolysis of soil washing fluids occurs via the reduction in size of micelles until their complete depletion. Lower concentrations of intermediates are produced (sulfate, chlorine, 4-(trifluoromethyl)-phenol and ortho-nitrophenol) during BDD-electrolyzes. Finally, it is important to indicate that, sulfate (coming from SDS) and chlorine (coming from oxyfluorfen) ions play an important role during the electrochemical organic matter removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Arsenic bioavailability in soils before and after soil washing: the use of Escherichia coli whole-cell bioreporters.

Science.gov (United States)

Yoon, Youngdae; Kang, Yerin; Chae, Yooeun; Kim, Sunghoon; Lee, Youngshim; Jeong, Seung-Woo; An, Youn-Joo

2016-02-01

We investigated the quantification of bioavailable arsenic in contaminated soils and evaluation of soil-washing processes in the aspect of bioavailability using a novel bacterial bioreporter developed in present study. The whole-cell bioreporter (WCB) was genetically engineered by fusing the promoter of nik operon from Escherichia coli and green fluorescent protein as a sensing domain and reporter domain. Among eight well-known hazardous heavy metals and metalloid, this system responded specifically to arsenic, thereby inferring association of As(III) with NikR inhibits the repression. Moreover, the response was proportional to the concentration of As(III), thereby it was capable to determine the amount of bioavailable arsenic quantitatively in contaminated soils. The bioavailable portion of arsenic was 5.9 (3.46-10.96) and 0.9 (0.27-1.74) % of total from amended and site soils, respectively, suggesting the bioavailability of arsenic in soils was related to the soil properties and duration of aging. On the other hand, only 1.37 (0.21-2.97) % of total arsenic was extracted into soil solutions and 19.88 (11.86-28.27) % of arsenic in soil solution was bioavailable. This result showed that the soluble arsenic is not all bioavailable and most of bioavailable arsenic in soils is water non-extractable. In addition, the bioavailable arsenic was increased after soil-washing while total amount was decreased, thereby suggesting the soil-washing processes release arsenic associated with soil materials to be bioavailable. Therefore, it would be valuable to have a tool to assess bioavailability and the bioavailability should be taken into consideration for soil remediation plans.

Evaluation of radiocaesium wash-off by soil erosion from various land uses using USLE plots.

Science.gov (United States)

Yoshimura, Kazuya; Onda, Yuichi; Kato, Hiroaki

2015-01-01

Radiocaesium wash-off associated with soil erosion in different land use was monitored using USLE plots in Kawamata, Fukushima Prefecture, Japan after the Fukushima Dai-ichi Nuclear Power Plant accident. Parameters and factors relating to soil erosion and (137)Cs concentration in the eroded soil were evaluated based on the field monitoring and presented. The erosion of fine soil, which is defined as the fraction of soil overflowed along with discharged water from a sediment-trap tank, constituted a large proportion of the discharged radiocaesium. This indicated that the quantitative monitoring of fine soil erosion is greatly important for the accurate evaluation of radiocaesium wash-off. An exponential relationship was found between vegetation cover and the amount of eroded soil. Moreover, the radiocaesium concentrations in the discharged soil were greatly affected by the land use. These results indicate that radiocaesium wash-off related to vegetation cover and land use is crucially important in modelling radiocaesium migration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Recovery of MSWI and soil washing residues as concrete aggregates.

Science.gov (United States)

Sorlini, Sabrina; Abbà, Alessandro; Collivignarelli, Carlo

2011-02-01

The aim of the present work was to study if municipal solid waste incinerator (MSWI) residues and aggregates derived from contaminated soil washing could be used as alternative aggregates for concrete production. Initially, chemical, physical and geometric characteristics (according to UNI EN 12620) of municipal solid waste incineration bottom ashes and some contaminated soils were evaluated; moreover, the pollutants release was evaluated by means of leaching tests. The results showed that the reuse of pre-treated MSWI bottom ash and washed soil is possible, either from technical or environmental point of view, while it is not possible for the raw wastes. Then, the natural aggregate was partially and totally replaced with these recycled aggregates for the production of concrete mixtures that were characterized by conventional mechanical and leaching tests. Good results were obtained using the same dosage of a high resistance cement (42.5R calcareous Portland cement instead of 32.5R); the concrete mixture containing 400 kg/m(3) of washed bottom ash and high resistance cement was classified as structural concrete (C25/30 class). Regarding the pollutants leaching, all concrete mixtures respected the limit values according to the Italian regulation. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effects of lead mineralogy on soil washing enhanced by ferric salts as extracting and oxidizing agents.

Science.gov (United States)

Yoo, Jong-Chan; Park, Sang-Min; Yoon, Geun-Seok; Tsang, Daniel C W; Baek, Kitae

2017-10-01

In this study, we evaluated the feasibility of using ferric salts including FeCl 3 and Fe(NO 3 ) 3 as extracting and oxidizing agents for a soil washing process to remediate Pb-contaminated soils. We treated various Pb minerals including PbO, PbCO 3 , Pb 3 (CO 3 ) 2 (OH) 2 , PbSO 4 , PbS, and Pb 5 (PO 4 ) 3 (OH) using ferric salts, and compared our results with those obtained using common washing agents of HCl, HNO 3 , disodium-ethylenediaminetetra-acetic acid (Na 2 -EDTA), and citric acid. The use of 50 mM Fe(NO 3 ) 3 extracted significantly more Pb (above 96% extraction) from Pb minerals except PbSO 4 (below 55% extraction) compared to the other washing agents. In contrast, washing processes using FeCl 3 and HCl were not effective for extraction from Pb minerals because of PbCl 2 precipitation. Yet, the newly formed PbCl 2 could be dissolved by subsequent wash with distilled water under acidic conditions. When applying our washing method to remediate field-contaminated soil from a shooting range that had high concentrations of Pb 3 (CO 3 ) 2 (OH) 2 and PbCO 3 , we extracted more Pb (approximately 99% extraction) from the soil using 100 mM Fe(NO 3 ) 3 than other washing agents at the same process conditions. Our results show that ferric salts can be alternative washing agents for Pb-contaminated soils in view of their extracting and oxidizing abilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrodialytic versus acid extraction of heavy metals from soil washing residue

DEFF Research Database (Denmark)

Jensen, Pernille E.; Ottosen, Lisbeth M.; Allard, Bert

2012-01-01

The feasibility of electrodialytic remediation (EDR) for treatment of suspended sludge after soil washing is in focus in the present paper. Five industrially contaminated soils were treated in laboratory scale remediation experiments, and the toxic elements of the investigation were: As, Cd, Cu, ...

Following of erosive wash of soil in variants with different intercrops

Directory of Open Access Journals (Sweden)

Barbora Badalíková

2010-01-01

Full Text Available In a pilot experiment established in a sugar beet growing region the erosive washing away of soil was studied in the years 2006 to 2008. The area is located at an altitude of 246 m with the long-term mean precipitation of 500 mm and the mean annual temperature of 8.4 °C. The soils are classified as Chernozem, moderately heavy, loamy, with a good supply of nutrients, humus content of 2.30 % and an alkaline soil reaction. Slope gradient is 12 %, exposition is NE. To study the role of intercrops in erosion control, three variants were established after the harvest of the main crop, two variants with different intercrops and one (control with no intercrop. These were Variant 1 with Secale cereale L. var. multicaule METZG. ex ALEF., a non-freezing intercrop, Variant 2 with cluster mallow (Malva verticillata L., a freezing intercrop, and a control variant with no intercrop. In Variant 1 Secale cereale L. var. multicaule was desiccated with the herbicide Roundup in early spring. All the variants involved maize as the main crop. In variants 1 and 2, maize was sown in intercrop residues after seedbed preparation by Vario and a compactor. In Variant 3 maize was sown after conventional seedbed preparation. For assessment of soil conditions soil samples were taken to determine soil physical and chemical properties and water content in the soil. Soil loss by erosion was determined using specially-designed pockets. Erosive washing away of soil was monitored during the entire growing season of maize. The variants in which intercrops were used were found very effective in soil erosion control. In Variant 3 (control without surface crop residues, the washing away of soil was recorded with each heavy torrential rain. During the all years the total amount of soil loss by erosion in this treatment was 2.25 t . ha−1.

Remediation of cadmium- and lead-contaminated agricultural soil by composite washing with chlorides and citric acid.

Science.gov (United States)

Li, Yu-jiao; Hu, Peng-jie; Zhao, Jie; Dong, Chang-xun

2015-04-01

Composite washing of cadmium (Cd)- and lead (Pb)-contaminated agricultural soil from Hunan province in China using mixtures of chlorides (FeCl3, CaCl2) and citric acid (CA) was investigated. The concentrations of composite washing agents for metal removal were optimized. Sequential extraction was conducted to study the changes in metal fractions after soil washing. The removal of two metals at optimum concentration was reached. Using FeCl3 mixed with CA, 44% of Cd and 23% of Pb were removed, and 49 and 32% by CaCl2 mixed with CA, respectively. The mechanism of composite washing was postulated. A mixture of chlorides and CA enhanced metal extraction from soil through the formation of metal-chloride and metal-citrate complexes. CA in extract solutions promoted the formation of metal-chloride complexes and reduced the solution pH. Composite washing reduced Cd and Pb in Fe-Mn oxide forms significantly. Chlorides and CA exerted a synergistic effect on metal extraction during composite washing.

Ultrasonic and mechanical soil washing processes for the remediation of heavy-metal-contaminated soil

Science.gov (United States)

Kim, Seulgi; Lee, Wontae; Son, Younggyu

2016-07-01

Ultrasonic/mechanical soil washing process was investigated and compared with ultrasonic process and mechanical process using a relatively large lab-scale sonoreactor. It was found that higher removal efficiencies were observed in the combined processes for 0.1 and 0.3 M HCl washing liquids. It was due to the combination effects of macroscale removal for the overall range of slurry by mechanical mixing and microscale removal for the limited zone of slurry by cavitational actions.

Removal of Pb, Zn, and Cd from contaminated soil by new washing agent from plant material.

Science.gov (United States)

Cao, Yaru; Zhang, Shirong; Wang, Guiyin; Huang, Qinling; Li, Ting; Xu, Xiaoxun

2017-03-01

Soil washing is an effective approach to remove soil heavy metals, and the washing agent is generally regarded as one of the primary factors in the process, but there is still a lack of efficient and eco-friendly agents for this technique. Here, we showed that four plant washing agents-from water extracts of Coriaria nepalensis (CN), Clematis brevicaudata (CB), Pistacia weinmannifolia (PW), and Ricinus communis (RC)-could be feasible agents for the removal of soil lead (Pb), zinc (Zn), and cadmium (Cd). The metal removal efficiencies of the agents increased with their concentrations from 20 to 80 g L -1 , decreased with the increasing solution pH, and presented different trends with the reaction time increasing. CN among the four agents had the highest removal efficiencies of soil Pb (62.02%) and Zn (29.18%) but owned the relatively low Cd removal efficiencies (21.59%). The Fourier transform infrared spectroscopy showed that the abilities of plant washing agents for the removal of soil heavy metals may result from bioactive substances with specific functional groups such as -COOH, -NH 2 , and -OH. Our study provided CN as the best washing agents for the remediation of contaminated soil by heavy metals.

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

Selective dissolution followed by EDDS washing of an e-waste contaminated soil: Extraction efficiency, fate of residual metals, and impact on soil environment.

Science.gov (United States)

Beiyuan, Jingzi; Tsang, Daniel C W; Valix, Marjorie; Zhang, Weihua; Yang, Xin; Ok, Yong Sik; Li, Xiang-Dong

2017-01-01

To enhance extraction of strongly bound metals from oxide minerals and organic matter, this study examined the sequential use of reductants, oxidants, alkaline solvents and organic acids followed by a biodegradable chelating agent (EDDS, [S,S]-ethylene-diamine-disuccinic-acid) in a two-stage soil washing. The soil was contaminated by Cu, Zn, and Pb at an e-waste recycling site in Qingyuan city, China. In addition to extraction efficiency, this study also examined the fate of residual metals (e.g., leachability, bioaccessibility, and distribution) and the soil quality parameters (i.e., cytotoxicity, enzyme activities, and available nutrients). The reductants (dithionite-citrate-bicarbonate and hydroxylamine hydrochloride) effectively extracted metals by mineral dissolution, but elevated the leachability and bioaccessibility of metals due to the transformation from Fe/Mn oxides to labile fractions. Subsequent EDDS washing was found necessary to mitigate the residual risks. In comparison, prior washing by oxidants (persulphate, hypochlorite, and hydrogen peroxide) was marginally useful because of limited amount of soil organic matter. Prior washing by alkaline solvents (sodium hydroxide and sodium bicarbonate) was also ineffective due to metal precipitation. In contrast, prior washing by low-molecular-weight organic acids (citrate and oxalate) improved the extraction efficiency. Compared to hydroxylamine hydrochloride, citrate and oxalate induced lower cytotoxicity (Microtox) and allowed higher enzyme activities (dehydrogenase, acid phosphatase, and urease) and soil nutrients (available nitrogen and phosphorus), which would facilitate reuse of the treated soil. Therefore, while sequential washing proved to enhance extraction efficacy, the selection of chemical agents besides EDDS should also include the consideration of effects on metal leachability/bioaccessibility and soil quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Soil washing physical separations test procedure - 300-FF-1 operable unit

Energy Technology Data Exchange (ETDEWEB)

Belden, R.D.

1993-10-08

This procedure provides the operations approach, a field sampling plan, and laboratory procedures for a soil washing test to be conducted by Alternative Remedial Technologies, Inc. (ART) in the 300-FF-1 area at the Hanford site. The {open_quotes}Quality Assurance Project Plan for the Soil Washing Physical Separations Test, 300-FF-1 Operable Unit,{close_quotes} Hanford, Washington, Alternative Remedial Technologies, Inc., February 1994 (QAPP) is provided in a separate document that presents the procedural and organizational guidelines for this test. This document describes specifications, responsibilities, and general procedures to be followed to conduct physical separation soil treatability tests in the North Process Pond of the 300-FF-1 Operable Unit (OU) at the Hanford Site. These procedures are based on the {open_quotes}300-FF-1 Physical Separations CERCLA Treatability Test Plan, DOE/RL 92-2l,{close_quotes} (DOE-RL 1993).

Soil washing physical separations test procedure - 300-FF-1 operable unit

International Nuclear Information System (INIS)

Belden, R.D.

1993-01-01

This procedure provides the operations approach, a field sampling plan, and laboratory procedures for a soil washing test to be conducted by Alternative Remedial Technologies, Inc. (ART) in the 300-FF-1 area at the Hanford site. The open-quotes Quality Assurance Project Plan for the Soil Washing Physical Separations Test, 300-FF-1 Operable Unit,close quotes Hanford, Washington, Alternative Remedial Technologies, Inc., February 1994 (QAPP) is provided in a separate document that presents the procedural and organizational guidelines for this test. This document describes specifications, responsibilities, and general procedures to be followed to conduct physical separation soil treatability tests in the North Process Pond of the 300-FF-1 Operable Unit (OU) at the Hanford Site. These procedures are based on the open-quotes 300-FF-1 Physical Separations CERCLA Treatability Test Plan, DOE/RL 92-2l,close quotes (DOE-RL 1993)

Integrating EDDS-enhanced washing with low-cost stabilization of metal-contaminated soil from an e-waste recycling site.

Science.gov (United States)

Beiyuan, Jingzi; Tsang, Daniel C W; Ok, Yong Sik; Zhang, Weihua; Yang, Xin; Baek, Kitae; Li, Xiang-Dong

2016-09-01

While chelant-enhanced soil washing has been widely studied for metal extraction from contaminated soils, there are concerns about destabilization and leaching of residual metals after remediation. This study integrated 2-h soil washing enhanced by biodegradable ethylenediaminedisuccinic acid (EDDS) and 2-month stabilization using agricultural waste product (soybean stover biochar pyrolyzed at 300 and 700 °C), industrial by-product (coal fly ash (CFA)), and their mixture. After integration with 2-month stabilization, the leachability and mobility of residual metals (Cu, Zn, and Pb) in the field-contaminated soil were significantly reduced, especially for Cu, in comparison with 2-h EDDS washing alone. This suggested that the metals destabilized by EDDS-washing could be immobilized by subsequent stabilization with biochar and CFA. Moreover, when the remediation performance was evaluated for phytoavailability and bioaccessibility, prior EDDS washing helped to achieve a greater reduction in the bioavailable fraction of metals than sole stabilization treatment. This was probably because the weakly-bound metals were first removed by EDDS washing before stabilization. Both individual and combined applications of biochar and CFA showed comparable effectiveness regardless of the difference in material properties, possibly due to the high level of amendments (150 ton ha(-1)). Based on the mobility and bioaccessibility results, the estimated human health risk (primarily resulting from Pb) could be mitigated to an acceptable level in water consumption pathway or reduced by half in soil ingestion pathway. These results suggest that an integration of EDDS washing with soil stabilization can alleviate post-remediation impacts of residual metals in the treated soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genesis Eco Systems, Inc. soil washing process

International Nuclear Information System (INIS)

Cena, R.J.

1994-01-01

The Genesis soil washing system is an integrated system of modular design allowing for maximum material handling capabilities, with optimized use of space for site mobility. The Surfactant Activated Bio-enhanced Remediation Equipment-Generation 1 (SABRE-1, Patent Applied For) modification was developed specifically for removing petroleum byproducts from contaminated soils. Scientifically formulated surfactants, introduced by high pressure spray nozzles, displace the contaminant from the surface of the soil particles into the process solution. Once the contaminant is dispersed into the liquid fraction of the process, it is either mechanically removed, chemically oxidized, or biologically oxidized. The contaminated process water is pumped through the Genesis Biosep (Patent Applied For) filtration system where the fines portion is flocculated, and the contaminant-rich liquid portion is combined with an activated mixture of nutrients and carefully selected bacteria to decompose the hydrocarbon fraction. The treated soil and dewatered fines are transferred to a bermed stockpile where bioremediation continues during drying. The process water is reclaimed, filtered, and recycled within the system

Chelator induced phytoextraction and in situ soil washing of Cu

International Nuclear Information System (INIS)

Kos, Bostjan; Lestan, Domen

2004-01-01

In a soil column experiment, we investigated the effect of 5 mmol kg -1 soil addition of citric acid, ethylenediamine tetraacetate (EDTA), diethylenetriamine-pentaacetate (DTPA) and [S,S]-stereoisomer of ethylenediamine-disuccinate (EDDS) on phytoextraction of Cu from a vineyard soil with 162.6 mg kg -1 Cu, into the test plant Brassica rapa var. pekinensis. We also examined the use of a horizontal permeable barrier, composed of layers of nutrient enriched sawdust and apatite, for reduction of chelator induced Cu leaching. The addition of all chelators, except citric acid, enhanced Cu mobility and caused leaching of 19.5-23% of initial total Cu from the soil column. However, Cu plant uptake did not increase accordingly; the most effective was the EDDS treatment, in which plant Cu concentration reached 37.8±1.3 mg kg -1 Cu and increased by 3.3-times over the control treatment. The addition of none of the chelators in the concentration range from 5 to 15 mmol kg -1 exerted any toxic effect on respiratory soil microorganisms. When EDDS was applied into the columns with horizontal permeable barriers, only 0.53±0.32% of the initial total Cu was leached. Cu (36.7%) was washed from the 18 cm soil layer above the barrier and accumulated in the barrier. Our results indicate that rather than for a reduction of Cu leaching during rather ineffective chelate induced Cu phytoextraction, horizontal permeable barriers could be more effective in a new remediation technique of controlled in situ soil washing of Cu with biodegradable chelates

Investigation of washing and storage strategy on aging Of Mg-aminoclay (MgAC) coated nanoscale zero-valent iron (nZVI) particles

DEFF Research Database (Denmark)

Hwang, Yuhoon; Lee, Young-Chul; Mines, Paul D.

2014-01-01

The tendency towards agglomeration and oxidation of nanoscale zero-valent iron (nZVI) particles limits its application for in situ groundwater and soil remediation. Although the effect of surface coatings on nanoparticle stabilization has been commonly practiced, the effect of preparation...... correlations (r2 > 0.95, p one another. Pre-storage washing, followed by addition of MgAC, exhibits high stability as pre-storage washing, as well as high reactivity as post-storage washing. Here, it is found that the proper washing procedure is crucial in coated nZVI preparation...

Removal of heavy metals from polluted soil using the citric acid fermentation broth: a promising washing agent.

Science.gov (United States)

Zhang, Hongjiao; Gao, Yuntao; Xiong, Huabin

2017-04-01

The citric acid fermentation broth was prepared and it was employed to washing remediation of heavy metal-polluted soil. A well-defined washing effect was obtained, the removal percentages using citric acid fermentation broth are that 48.2% for Pb, 30.6% for Cu, 43.7% for Cr, and 58.4% for Cd and higher than that using citric acid solution. The kinetics of heavy metals desorption can be described by the double constant equation and Elovich equation and is a heterogeneous diffusion process. The speciation analysis shows that the citric acid fermentation broth can effectively reduce bioavailability and environmental risk of heavy metals. Spectroscopy characteristics analysis suggests that the washing method has only a small effect on the mineral composition and does not destroy the framework of soil system. Therefore, the citric acid fermentation broth is a promising washing agent and possesses a potential practical application value in the field of remediation of soils with a good washing performance.

The Decline of Soil Infiltration Capacity Due To High Elevation Groundwater

OpenAIRE

Isri Ronald Mangangka

2008-01-01

Infiltration capacity of soil mainly depends on two factors; the particle size and the moisture content of the soil. Groundwater increases the soil moisture, not only below the water table but also within the capillary zone, above the water table. Field experiment in a high groundwater area was conducted to understand the relationship among the groundwater, soil moisture and infiltration capacity. Using a single ring infiltrometer, the effect of groundwater in the infiltration rate was observ...

100 Areas soil washing tradeoff study

International Nuclear Information System (INIS)

Belden, R.D.

1995-11-01

The complex nature of cost analysis and systems work demands a level of effort to ensure that decisions made support the best interests of all parties. This tradeoff study will act as a formal decision analysis method for the evaluation of many variables. The documentation of the decision rationale and system design is essential for successful planning and implementation of any system. The Hanford Site offers unique problems for economic analysis of remediation alternatives. The variations in the size of sites, geographic locations, and possible cleanup scenarios all add to the complexity of the tradeoff analysis. A thorough examination of all alternatives must be held to a level of detail appropriate to current regulatory and budgetary considerations. This study will compare the economics of two specific alternatives for remediation of soils at the Hanford Site. Remove and dispose is compared to remove, treat, and dispose. The treatment analyzed in this study is volume reduction through soil washing

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.

Metal (Cu, Cd and Zn) removal and stabilization during multiple soil washing by saponin.

Science.gov (United States)

Gusiatin, Zygmunt Mariusz; Klimiuk, Ewa

2012-01-01

The influence of multiple saponin washing on copper, cadmium and zinc removal and stability in three types of soils (loamy sand, loam, silty clay) was investigated. Distribution of metals and their mobility measured as the ratio of exchangeable form to the sum of all fractions in soils was differential. After single washing the highest efficiency of metal removal was obtained in loamy sand (82-90%) and loam (67-88%), whereas the lowest in silty clay (39-62%). In loamy sand and loam metals had higher mobility factors (44-61% Cu, 60-76% Cd, and 68-84% Zn) compared to silty clay (9% Cu, 28% Cd and 36% Zn). Triplicate washing led to increase both efficiency of metal removal and percentage content of their stable forms. In consequence, fractional patterns for metals before and after treatment changed visibly as a result of their redistribution. Based on the redistribution index, the most stable metal (mainly in residual and organic fractions) after triplicate washing was Cu in loamy sand and loam. For silty clay contaminated with Cd, effective metal removal and its stabilization required a higher number of washings. Copyright © 2011 Elsevier Ltd. All rights reserved.

Study of electroflotation method for treatment of wastewater from washing soil contaminated by heavy metals

OpenAIRE

de Oliveira da Mota, Izabel; de Castro, José Adilson; de Góes Casqueira, Rui; de Oliveira Junior, Angelo Gomes

2015-01-01

Electroflotation method (EFM) for treatment of synthetic solutions simulating wastewater from washing soil contaminated by drilling fluids from oil wells was investigated in this paper. Experiments were carried out to examine the effects of the operating conditions on the removal of lead, barium and zinc from solutions containing 15 mg dm−3 for each metal representing a typical concentration of wastewater generated in the washing soil in this treatment. The experimental results showed that it...

Vulnerability to diffuse pollution of European soils and groundwater

NARCIS (Netherlands)

Meinardi CR; Beusen AHW; Bollen MJS; Klepper O; LBG; CWM

1994-01-01

From the Atlantic Ocean to the Ural Mountains, European soils and groundwater are threatened by diffuse pollution derived from various chemicals used in modern agriculture and by increased atmospheric deposition of pollutants. The investigated vulnerability of soils (including groundwater) to

Soil and groundwater remediation using dual-phase extraction technology

International Nuclear Information System (INIS)

Miller, A.W.; Gan, D.R.

1995-01-01

A gasoline underground storage tank (UST) was formerly used to fuel vehicles for a hospital in Madison, Wisconsin. Elevated concentrations of gasoline range organics (GRO) were observed in soils and groundwater at the site during the tank removal and a subsequent site investigation. Based on the extent of soil and groundwater contamination, a dual-phase extraction technology was selected as the most cost effective alternative to remediate the site. The dual-phase extraction system includes one extraction well functioning both as a soil vapor extraction (SVE) and groundwater recovery well. After six months of operation, samples collected from the groundwater monitoring wells indicated that the groundwater has been cleaned up to levels below the Wisconsin preventative action limits. The dual-phase extraction system effectively remediated the site in a short period of time, saving both operation and maintenance costs and overall project cost

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.

Selective Removal of Uranium from the Washing Solution of Uranium-Contaminated Soil

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Soo; Han, G. S.; Kim, G. N.; Koo, D. S.; Jeong, J. W.; Choi, J. W. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

This study examined selective removal methods of uranium from the waste solution by ion exchange resins or solvent extraction methods to reduce amount of the 2{sup nd} waste. Alamine-336, known as an excellent extraction reagent of uranium from the leaching solution of uranium ore, did not remove uranium from the acidic washing solution of soil. Uranyl ions in the acidic waste solution were sorbed on ampholyte resin with a high sorption efficiency, and desorbed from the resin by a washing with 0.5 M Na{sub 2}CO{sub 3} solution at 60 .deg. C. However, the uranium dissolved in the sulfuric acid solution was not sorbed onto the strong anion exchanger resins. A great amount of uranium-contaminated (U-contaminated) soil had been generated from the decommissioning of a uranium conversion plant. Our group has developed a decontamination process with washing and electrokinetic methods to decrease the amount of waste to be disposed of. However, this process generates a large amount of waste solution containing various metal ions.

Soil washing in combination with homogeneous Fenton-like oxidation for the removal of 2,4,4'-trichlorodiphenyl from soil contaminated with capacitor oil.

Science.gov (United States)

Ma, Xiao-Hong; Zhao, Ling; Lin, Zhi-Rong; Dong, Yuan-Hua

2016-04-01

Detoxification by chemical oxidation of polychlorinated biphenyls (PCBs) in contaminated soils is very difficult and inefficient because PCBs typically associate with the solid phase or exist as non-aqueous-phase liquids due to their low solubility and slow desorption rates, and thus, they are difficult to remove from soils by using traditional, water-based elution techniques. Surfactant can enhance washing efficiency of PCBs from contaminated soils. This study used Brij 58, Brij 30, Tween 80, and 2-hydroxypropyl-β-cyclodextrin (HPCD) to solubilize 2,4,4'-trichlorodiphenyl (PCB28) from soil contaminated with capacitor oil into solution. The feasibility of PCB28 oxidation in soil washing wastewater through a Fe(3+)-catalyzed Fenton-like reaction was subsequently examined. Washing with 10 g L(-1) Brij 58 solution showed the highest extraction efficiency (up to 61.5 %) compared with that of the three other surfactants. The total concentration of PCB28 in contaminated soil at 25 °C after 48-h extraction was 286 mg L(-1). In contrast to conditions in which no washing agent was added, addition of the four washing agents decreased the efficiency of PCB28 degradation by the Fenton-like reaction, with the decrease due to addition of 10 g L(-1) Brij 58 solution being the smallest. The optimal concentration of H2O2 for preventing its useless decomposition was found to be 50 mM. The efficiency of PCB28 removal was lower when the initial concentration of PCB28 treated in the Fenton-like reaction was higher. The degradation efficiencies of PCB28 at initial concentrations of 0.1, 10, and 176 mg L(-1) in 10 g L(-1) Brij 58 solution at 25 °C and pH 3.0 and 9 h of reaction using 50 mM H2O2 were 64.1, 42.0, and 34.6 %, respectively. This result indicates that soil washing combined with Fenton-like oxidation may be a practical approach for the remediation of PCB-contaminated soil.

Occurrence of perchlorate in groundwater, paired farmland soil, lettuce, and rhizosphere soil from Chengdu, China.

Science.gov (United States)

Tang, Yulu; Zhong, Bifeng; Qu, Bing; Feng, Shujin; Ding, Sanglan; Su, Shijun; Li, Zhi; Gan, Zhiwei

2017-05-24

A total of 28 groundwater, paired farmland soil, lettuce, and its rhizosphere soil samples were collected from Chengdu, China to detect perchlorate levels and to evaluate the relationships of perchlorate concentrations among these matrices. The perchlorate concentrations in the groundwater, farmland soil, lettuce, and rhizosphere soil samples ranged from below detection limit to 60.2 μg L -1 , from below detection limit to 249 μg kg -1 dry weight (dw), from 2.07 to 1010 μg kg -1 wet weight, and from below detection limit to 314 μg kg -1 dw, respectively. Significant correlation was found in the perchlorate levels among the farmland soil, lettuce, and rhizosphere soil, suggesting that they have common pollution sources, or perchlorate might transfer from farmland soil-rhizosphere soil-plant. However, there is no significant correlation between groundwater and the other three matrices, indicating that infiltration from perchlorate contaminated farmland soil was not the predominant source for groundwater pollution in Chengdu. The perchlorate concentrations in the farmland soil and lettuce samples were significantly higher than those in the rhizosphere soil, primarily due to uptake of perchlorate through the rhizosphere micro-environment by lettuce, or accelerated degradation by rhizospheric microorganisms, which contributed more needs further investigation.

Potential Groundwater Recharge and the Effects of Soil Heterogeneity on Flow at Two Radioactive Waste Management Sites at the Nevada Test Site

International Nuclear Information System (INIS)

Yucel, V.; Levitt, D. G.

2001-01-01

Two low-level Radioactive Waste Management Sites (RWMSs), consisting of shallow land burial disposal units at the Nevada Test Site (NTS), are managed by Bechtel Nevada for the U.S. Department of Energy, National Nuclear Security Administration. The NTS has an arid climate with annual average precipitation of about 17 cm at the Area 3 RWMS and about 13 cm at the Area 5 RWMS. The vadose zone is about 490 m thick at the Area 3 RWMS, and about 235 m thick at the Area 5 RWMS. Numerous studies indicate that under current climatic conditions, there is generally no groundwater recharge at these sites. Groundwater recharge may occur at isolated locations surrounding the RWMSs, such as in large drainage washes. However, groundwater recharge scenarios (and radionuclide transport) at the RWMSs are modeled in support of Performance Assessment (PA) documents required for operation of each RWMS. Recharge scenarios include conditions of massive subsidence and flooding, and recharge resulting from deep infiltration through bare-soil waste covers. This paper summarizes the groundwater recharge scenarios and travel time estimates that have been conducted in support of the PAs, and examines the effects of soil hydraulic property heterogeneity on flow

Behaviour of cyanides in soil and groundwater

DEFF Research Database (Denmark)

Kjeldsen, P.

1999-01-01

contamination in soils and groundwater are discussed. Toxicological and analytical aspects of cyanide containing compounds are briefly touched. The behaviour of cyanide compounds in soil and groundwater is governed by many interacting chemical and microbial processes. Redox conditions and pH are of importance...... is evaluated. At gas work sites, where cyanide is mainly present as iron cyanide complexes, the risk for effects on humans from exposure to cyanide compounds seems to be of minor relevance....

Countercurrent soil washing system for remediation of viscous hydrocarbons, heavy metals, radionuclides

International Nuclear Information System (INIS)

Kuhlman, M.I.; Karlsson, M.K.; Downie, C.A.

1995-01-01

Drying augers and multicell DAF tanks are excellent machines in which to countercurrently wash soil and remove hazardous hydrocarbons, metals or radionuclides. An auger works well because it preferentially moves soil along one side of its trough. Thus, when enough high pressure and temperature water jets are placed along that path, contaminants can be melted, or dissolved and scoured from the soil. Contaminants and fines flow down the opposite side of the auger and out for extraction in a series of flotation tanks. Countercurrent washing of the silt results when soil settles in tanks through rising water and air bubbles then is pumped through cyclones placed above the next DAF tank of the series. LNAPLs, DNAPLs, or metallic contaminants made hydrophobic by chemicals in the system are removed at the overflow of the cyclones or by flotation in the tanks. The overflow from the cyclones and DAF tanks flows into the previous tank of the series. Examples of contaminants remediated include; arsenic, cadmium, lead and mercury, Naturally Occurring Radioactive Materials (NORM), uranium, solid oils, polyaromatic hydrocarbons in creosote and coal tars, and polychlorinated hydrocarbons

Advanced oxidation for groundwater remediation and for soil decontamination

International Nuclear Information System (INIS)

Gehringer, P.; Eschweiler, H.

2001-01-01

The advanced oxidation process (AOP) used in this paper is based on EB irradiation of water in the presence and absence of ozone. The paper describes two distinct sets of experiments, one dealing with groundwater contaminated with perchloroethylene (PCE) and some genotoxic compounds, and the other dealing with soil contaminated with polycyclic aromatic hydrocarbons (PAHs). The combination of ozone and EB irradiation has shown to be able to mineralize trace amounts of PCE contained in groundwater in a single stage process without formation of any by-product to be disposed of. Moreover, experiments performed with real groundwater have demonstrated that the combined ozone/EB irradiation process is also apt for total removal of some genotoxic compounds detected in groundwater contaminated with PCE. The design of an ozone/EB irradiation plant for treating 108 m 3 /h is presented. The issue concerning both the occurrences of genotoxic compounds in oxygen containing groundwater and possible processes for their removal is discussed. In the second part soil contaminated with PAHs has been treated in aqueous suspension using ozone and EB irradiation, respectively. Experiments were performed with low contaminated soil (total PAHs about 332 mg/kg soil). With an ozone consumption of 10 g C) 3 /kg soil a total PAH decomposition of about 21% was recorded. EB irradiation with a reasonable radiation dose of 100 kGy results in about 7% total PAH decomposition at room temperature and about 16%, respectively at 55-60 deg. C. It was recorded that almost no transfer of the PAH takes place from the soil into the water when soil is merely suspended in water. Ozone mainly attacked the high molecular fraction (i.e. consisting of 5 or 6 aromatic rings) of the PAHs investigated while EB irradiation of the aqueous soil suspension mostly decomposed the lower fraction (i.e. consisting up to 4 aromatic rings). (author)

The removal of Cs-137 from soil using washing-electrokinetic decontamination equipment

International Nuclear Information System (INIS)

Kim, Gyenam; Kim, Seungsoo; Kim, Geunho; Park, Hyemin; Kim, Wansuk; Park, Ukryang; Kwon, Hyeokju; Ryu, Ohha; Moon, Jeikwon

2012-01-01

The radioactive soil at the KAERI radioactive waste storage facility has slightly high hydro-conductivity, and was mainly contaminated with 137 Cs 30-35 years ago. Recently, a soil washing method has been applied to remove 137 Cs from radioactive soil, but it appears that the removal efficiency of 137 Cs had low and a lot of waste solution was generated. Meanwhile, an electrokinetic decontamination method provides high removal efficiency of 137 Cs and generates little waste effluent. Thus, it is suggested that an electrokinetic decontamination method is a suitable technology in consideration of the soil characteristics near South Korean nuclear facilities

Innovative approaches for the remediation of arsenic and mercury pollution via soil washing

International Nuclear Information System (INIS)

Sierra, C.; Gonzalez-Coto, F.; Villa, R.; Menendez-Aguado, J. M.; Gallego, J. R.

2009-01-01

Soil washing techniques are ex situ remediation procedures to remove contaminants concentrating them into a minor volume through particle size separation, gravity separation, and attrition scrubbing; with or without the utilization of chemical additives. Systems incorporating these removal techniques offer possibilities for application to soils contaminated with a wide variety of heavy metal, radionuclides, and organic contaminants. (Author)

Potential of activated carbon to recover randomly-methylated-β-cyclodextrin solution from washing water originating from in situ soil flushing.

Science.gov (United States)

Sniegowski, K; Vanhecke, M; D'Huys, P-J; Braeken, L

2014-07-01

Despite the overall high efficacy of cyclodextrins to accelerate the treatment of soil aquifer remediation by in-situ soil flushing, the use in practice remains limited because of the high costs of cyclodextrin and high concentrations needed to significantly reduce the treatment time. The current study tested the potential of activated carbon to treat washing water originating from soil flushing in order to selectively separate hydrocarbon contaminants from washing water containing cyclodextrin and subsequently reuse the cyclodextrin solution for reinfiltration. A high recovery of the cyclodextrin from the washing water would reduce the costs and would make the technique economically feasible for soil remediation. This study aimed to investigate whether cyclodextrin can pass through the activated carbon filter without reducing the cyclodextrin concentration when the contaminated washing water is treated and whether the presence of cyclodextrin negatively affects the purification potential of activated carbon to remove the organic pollutants from the pumped soil water. Lab-scale column experiments showed that with the appropriate activated carbon 100% of cyclodextrin (randomly-methylated-β-cyclodextrin) can be recovered from the washing water and that the effect on the efficiency of activated carbon to remove the hydrocarbon contaminants remains limited. These results show that additional field tests are useful to make in-situ soil flushing with cyclodextrin both a technical and an economical interesting technique. These results might stimulate the application of cyclodextrin in soil treatment technology. Copyright © 2013 Elsevier B.V. All rights reserved.

The removal of Cs-137 from soil using washing-electrokinetic decontamination equipment

Energy Technology Data Exchange (ETDEWEB)

Kim, Gyenam; Kim, Seungsoo; Kim, Geunho; Park, Hyemin; Kim, Wansuk; Park, Ukryang; Kwon, Hyeokju; Ryu, Ohha; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-10-15

The radioactive soil at the KAERI radioactive waste storage facility has slightly high hydro-conductivity, and was mainly contaminated with {sup 137}Cs 30-35 years ago. Recently, a soil washing method has been applied to remove {sup 137}Cs from radioactive soil, but it appears that the removal efficiency of {sup 137}Cs had low and a lot of waste solution was generated. Meanwhile, an electrokinetic decontamination method provides high removal efficiency of {sup 137}Cs and generates little waste effluent. Thus, it is suggested that an electrokinetic decontamination method is a suitable technology in consideration of the soil characteristics near South Korean nuclear facilities.

Development of a combined soil-wash/in-furnace vitrification system for soil remediation at DOE sites

International Nuclear Information System (INIS)

Pegg, I.L.; Guo, Y.; Lahoda, E.J.; Lai, Shan-Tao; Muller, I.S.; Ruller, J.; Grant, D.C.

1993-01-01

This report addresses research and development of technologies for treatment of radioactive and hazardous waste streams at DOE sites. Weldon Spring raffinate sludges were used in a direct vitrification study to investigate their use as fluxing agents in glass formulations when blended with site soil. Storm sewer sediments from the Oak Ridge, TN, Y-12 facility were used for soil washing followed by vitrification of the concentrates. Both waste streams were extensively characterized. Testing showed that both mercury and uranium could be removed from the Y-12 soil by chemical extraction resulting in an 80% volume reduction. Thermal desorption was used on the contaminant-enriched minority fraction to separate the mercury from the uranium. Vitrification tests demonstrated that high waste loading glasses could be produced from the radioactive stream and from the Weldon Spring wastes which showed very good leach resistance, and viscosities and electrical conductivities in the range suitable for joule-heated ceramic melter (JHCM) processing. The conceptual process described combines soil washing, thermal desorption, and vitrification to produce clean soil (about 90% of the input waste stream), non-radioactive mercury, and a glass wasteform; the estimated processing costs for that system are about $260--$400/yd 3 . Results from continuous melter tests performed using Duratek's advanced JHCM (Duramelter) system are also presented. Since life cycle cost estimates are driven largely by volume reduction considerations, the large volume reductions possible with these multi-technology, blended waste stream approaches can produce a more leach resistant wasteform at a lower overall cost than alternative technologies such as cementation

Removal of Uranium by Exchanger Resins from Soil Washing Solution

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Soo; Han, G. S.; Kim, G. N.; Koo, D. S.; Jeong, J. W.; Moon, J. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

Uranyl ions in the acidic waste solution were sorbed on AM-resin resin with a high sorption efficiency, and desorbed from the resin by a batch-type washing with a 60 .deg. C heated 0.5 M Na{sub 2}CO{sub 3} solution. However, the uranium dissolved in the sulfuric acid solution was not sorbed onto the strong anion exchanger resins. Our group has developed a decontamination process with washing and electrokinetic methods for uranium-contaminated (U-contaminated) soil. However, this process generates a large amount of waste solution containing various metal ions. If the uranium selectively removed from the waste solution, a very small amount of the 2nd waste would be generated. Thus, selective sorption of uranium by ion exchange resins was examined in this study.

Soil and groundwater remediation guidelines for methanol

International Nuclear Information System (INIS)

2010-12-01

Methanol is used by oil and gas operators to inhibit hydrate formation in the recovery of heavy oils, in natural gas production and transport, as well as in various other production applications. Emissions from methanol primary occur from miscellaneous solvent usage, methanol production, end-product manufacturing, and storage and handling losses. This document provided soil and groundwater remediation guidelines for methanol releases into the environment. The guidelines were consistent with the Alberta Environment tier 1 soil and groundwater framework. The chemical and physical properties of methanol were reviewed. The environmental fate and behavior of methanol releases was discussed, and the behaviour and effects of methanol in terrestrial and aquatic biota were evaluated. The toxicity of methanol and its effects in humans and mammalian species were reviewed. Soil quality and ground water quality guidelines were presented. Surface water and soil guideline calculation methods were provided, and ecological exposure and ground water pathways were discussed. Management limits for methanol concentrations were also provided. 162 refs., 18 tabs., 4 figs.

Isotope geochemistry of sulfur in forest soils and in new groundwater below forest soils

International Nuclear Information System (INIS)

Mayer, B.

1993-04-01

The isotope geochemistry of sulphur in aerobic forest soils and new groundwater below forest soils was investigated for the purpose of investigating the transport and transformation behaviour of sulfate in the water-unsaturated zone. The effects of hydrodynamic and biogeochemical processes on the development of seepage water sulfate isotopes between depositions and groundwater were investigated by means of laboratory experiments, profile studies, lysimeter experiments, and field studies in order to determine the sulphur conversion processes. Dissolved sulphur from precipitates, seepage water, creek water and groundwater, as well as sulphur extracted from soil samples, were precipitated in the form of BaSO 4 or AgS 2 , decomposed thermally into SO 2 or CO 2 , and the 34 S/ 32 S and 18 O/ 16 O isotope ratios were determined by mass spectrometry. (orig.) [de

In-Situ Bioremediation of Perchlorate in Groundwater and Soil

OpenAIRE

Jin, Liyan

2012-01-01

Historical, uncontrolled disposal practices have made perchlorate a significant threat to drinking water supplies in the United States. In-situ bioremediation (ISB) technologies are cost effective and provide an environmental friendly solution for treating contaminated groundwater and soil. In situ bioremediation was considered as an option for treatment of perchlorate in groundwater and soil in Lockheed Martin Corporation's Beaumont Site 2 (Beaumont, CA). Based on the perchlorate distribu...

Application of remedy studies to the development of a soil washing pilot plant that uses mineral processing technology: a practical experience

International Nuclear Information System (INIS)

Richardson, W.S.; Phillips, C.R.; Hicks, R.; Luttrell, J.; Cox, C.

1999-01-01

Soil washing employing mineral processing technology to treat radionuclide-contaminated soils has been examined as a remedy alternative to the exclusive excavation, transportation, and disposal of the soil. Successful application depends on a thorough remedy study, employing a systematic tiered approach that is efficient, self-limiting, and cost effective. The study includes: (1) site and soil characterization to determine the basic mineral and physical properties of both the soil and contaminants and to identify their relative associations; (2) treatment studies to evaluate the performance of process units for contaminant separation; (3) conceptual process design to develop a treatment pilot plant; and (4) engineering design to construct, test, and optimize the actual full-scale plant. A pilot plant using soil washing technology for the treatment of radium-contaminated soil was developed, tested, and demonstrated. The plant used particle-size separation to produced a remediated product that represented approximately 50% of the contaminated soil. Subsequently, it was modified for more effective performance and application to soil with alternate characteristics; it awaits further testing. The economic analysis of soil washing using the pilot plant as a model indicates that a remedy plan based on mineral processing technology is very competitive with the traditional alternative employing excavation, transportation, and disposal exclusively, even when disposal costs are modest or when recovery of remediated soil during treatment is low. This paper reviews the tiered approach as it applies to mineral processing technology to treat radionuclide-contaminated soils and a pilot plant developed to test the soil washing process. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Soils washing for removal of heavy oil: Naval Air Engineering Center, Lakehurst, NJ

International Nuclear Information System (INIS)

Nash, J.H.; Traver, R.P.

1991-01-01

With the recognition that large tracts of land are currently unusable as a result of either accidental spills or past industrial practices (such as oil field development), the USEPA Office of Research and Development evaluated soil washing as an alternative remedial technology for heavy oil contaminated soil at a site located on the Naval Air Engineering Center (NAEC), Lakehurst, New Jersey. The researchers used a self-contained, 100-pound-per-hour soil washer. Electrical, pneumatic, and fluid-pumping capabilities were provided by the trailer-mounted system at a remote No. 6 type oil spill site at the Navy base. Chloroform extracts of the contaminated sandy soil recovered a 0.91 gram/milliliter, 950 centistoke viscosity, dark brown, non-PCB oil. By using a surfactant/solvent solution at ambient temperatures, contaminant levels on the soil were reduced from 3.8% (38,000 milligram/kilogram-RCRA hazardous waste designation) to as low as 0.035% (350 milligram/kilogram) oil concentration. Supplemental laboratory evaluations extending the pilot field evaluations showed at elevated temperatures (120F) that residual oil contamination was less than 0.01% (100 milligram/kilogram). This final oil concentration in the treated soil would be defined as clean under the New Jersey Environmental Cleanup and Responsibilities Act (ECRA). A continuous belt press filter was used to recover the oil in a 47% solids cake that could be used as a secondary fuel feed to a waste boiler. The wash water solution was treated and recycled permitting economical operations

Headcut erosive regimes influenced by groundwater on disturbed agricultural soils.

Science.gov (United States)

Rockwell, D L

2011-02-01

A series of simulated rainfall experiments, testing several soils and slope gradients in a 10 m x 0.8m laboratory flume, displayed close correlations between initial development of a water table at a 10 cm depth and highly erosive headcut formation. On some soils and gradients, highly erosive headcuts formed consistently and predictably within minutes or seconds of initial water table rise. However, headcuts alone were not good indicators of increased erosion. In most experiments some headcuts formed early, often when surface hydraulic parameter values reached established rill initiation thresholds, but resulted in little or no erosion increase. Later, at initial water table rise, other headcuts formed coincident with major erosion increase, often with surface hydraulic values then less than rill initiation thresholds. On the four soils tested, highly erosive headcuts never formed without groundwater development, except on steep 9 ° slopes. Common visual indicators such as headcut morphology and headcut advance rates were not effective means of determining either erosion or the existence of groundwater. Only local monitoring of subsurface moisture conditions with micro-standpipes and TDR aided in determining headcut processes and erosive regimes. Groundwater-influenced headcut formation was likely caused by increased soil pore-water pressures and decreased soil shear strengths in surface rainflow, not by sapping or seepage from the soil matrix. Highly erosive headcuts can thus form under common agricultural conditions where reductions in permeability, such as plow pans, exist near the surface--without the need for saturated soils. Headcut erosive regimes were also significantly influenced by soil type and slope gradient, with the greatest effects of groundwater on moderate slopes and fairly permeable soils. Copyright © 2010. Published by Elsevier Ltd.

Contamination valuation of soil and groundwater source at anaerobic municipal solid waste landfill site.

Science.gov (United States)

Aziz, Shuokr Qarani; Maulood, Yousif Ismael

2015-12-01

The present work aimed to determine the risks that formed landfill leachate from anaerobic Erbil Landfill Site (ELS) poses on groundwater source and to observe the effects of disposed municipal solid waste (MSW) on soil properties. The study further aims to fill the gap in studies on the effects of disposed MSW and produced leachate on the groundwater characteristics and soil quality at ELS, Iraq. Soil, leachate, and groundwater samples were collected from ELS for use as samples in this study. Unpolluted groundwater samples were collected from an area outside of the landfill. Field and laboratory experiments for the soil samples were conducted. Chemical analyses for the soil samples such as organic matter, total salts, and SO4 (=) were also performed. Raw leachate and groundwater samples were analyzed using physical and chemical experiments. The yields for sorptivity, steady-state infiltration rate, and hydraulic conductivity of the soil samples were 0.0006 m/√s, 0.00004 m/s, and 2.17 × 10(-5) m/s, respectively. The soil at ELS was found to be light brown clayey gravel with sand and light brown gravely lean clay layers with low permeability. Unprocessed leachate analysis identified the leachate as stabilized. Findings showed that the soil and groundwater at the anaerobic ELS were contaminated.

Case studies illustrating in-situ remediation methods for soil and groundwater contaminated with petrochemicals

Energy Technology Data Exchange (ETDEWEB)

Dixon, Robert A; Lance, P E; Downs, A; Kier, Brian P [EMCON Northwest Inc., Portland, OR (United States)

1994-12-31

Four case studies of successful in-situ remediation are summarized illustrating cost-effective methods to remediate soil and groundwater contaminated with volatile and non-volatile petrochemicals. Each site is in a different geologic environment with varying soil types and with and without groundwater impact. The methods described include vadose zone vapor extraction, high-vacuum vapor extraction combined with groundwater tab.le depression, air sparging with groundwater recovery and vapor extraction, and bio remediation of saturated zone soils using inorganic nutrient and oxygen addition

Case studies illustrating in-situ remediation methods for soil and groundwater contaminated with petrochemicals

Energy Technology Data Exchange (ETDEWEB)

Dixon, Robert A.; Lance, P.E.; Downs, A.; Kier, Brian P. [EMCON Northwest Inc., Portland, OR (United States)

1993-12-31

Four case studies of successful in-situ remediation are summarized illustrating cost-effective methods to remediate soil and groundwater contaminated with volatile and non-volatile petrochemicals. Each site is in a different geologic environment with varying soil types and with and without groundwater impact. The methods described include vadose zone vapor extraction, high-vacuum vapor extraction combined with groundwater tab.le depression, air sparging with groundwater recovery and vapor extraction, and bio remediation of saturated zone soils using inorganic nutrient and oxygen addition

Using electrocoagulation for metal and chelant separation from washing solution after EDTA leaching of Pb, Zn and Cd contaminated soil.

Science.gov (United States)

Pociecha, Maja; Lestan, Domen

2010-02-15

Electrocoagulation with an Al sacrificial anode was tested for the separation of chelant and heavy metals from a washing solution obtained after leaching Pb (3200 mg kg(-1)), Zn (1100 mg kg(-1)), and Cd (21 mg kg(-1)) contaminated soil with EDTA. In the electrochemical process, the sacrificial anode corroded to release Al(3+) which served as coagulant for precipitation of chelant and metals. A constant current density of 16-128 mAc m(-2) applied between the Al anode and the stainless-steel cathode removed up to 95% Pb, 68% Zn and 66% Cd from the soil washing solution. Approximately half of the initial EDTA remained in the washing solution after treatment, up to 16.3% of the EDTA was adsorbed on Al coagulant and precipitated, the rest of the EDTA was degraded by anodic oxidation. In a separate laboratory-scale remediation experiment, we leached a soil with 40 mmol EDTA per kg of soil and reused the washing solution (after electrocoagulation) in a closed loop. It removed 53% of Pb, 26% of Zn and 52% of Cd from the soil. The discharge solution was clear and colourless, with pH 7.52 and 170 mg L(-1) Pb, 50 mg L(-1) Zn, 1.5 mg L(-1) Cd and 11 mM EDTA.

Pollution potential of oil-contaminated soil on groundwater resources in Kuwait

International Nuclear Information System (INIS)

Literathy, P.; Quinn, M.; Al-Rashed, M.

2003-01-01

The only natural freshwater resource of Kuwait occurs as lenses floating on the saline groundwater in the northern part of the country, near to the oil fields. Rainwater is the only means of recharge of this limited groundwater resource. This groundwater is used as bottled drinking water and the fresh groundwater aquifer is considered as a strategic drinking water reserve for Kuwait. As a result of the 1991 Gulf War, the upper soil layer has been widely contaminated with crude oil and crude oil combustion products, which are potential pollutants likely affecting the groundwater resources. Significant efforts have been made to assess this pollution. These included: (a) a soil survey for assessing the soil contamination, and (b) leaching experiments to characterise the mobilization of the soil-associated pollutants. Fluorescence measurement techniques were used during field surveys as well as for laboratory testing. In addition, determination of the total extractable matter (TEM), total petroleum hydrocarbons (TPH), and GC/MS measurement of polyaromatic hydrocarbons (PAHs) were performed for the assessments. The laser induced fluorescence (LIF) measurement, having good correlation with the other laboratory measurements, was proved to provide necessary information for the assessment of the oil-contamination level in the desert soil. The subsequent leaching test with water demonstrated the mobilization of the fluorescing compounds (e.g. PAHs), and the alteration in the leaching characteristics of the contamination during the long term environmental weathering of the oil. (author)

Feasibility study on the use of soil washing to remediate the As-Hg contamination at an ancient mining and metallurgy area.

Science.gov (United States)

Sierra, C; Menéndez-Aguado, J M; Afif, E; Carrero, M; Gallego, J R

2011-11-30

Soils in abandoned mining sites generally present high concentrations of trace elements, such as As and Hg. Here we assessed the feasibility of washing procedures to physically separate these toxic elements from soils affected by a considerable amount of mining and metallurgical waste ("La Soterraña", Asturias, NW Spain). After exhaustive soil sampling and subsequent particle-size separation via wet sieving, chemical and mineralogical analysis revealed that the finer fractions held very high concentrations of As (up to 32,500 ppm) and Hg (up to 1600 ppm). These elements were both associated mainly with Fe/Mn oxides and hydroxides. Textural and geochemical data were correlated with the geological substrate by means of a multivariate statistical analysis. In addition, the Hg liberation size (below 200 μm) was determined to be main factor conditioning the selection of suitable soil washing strategies. These studies were finally complemented with a specific-gravity study performed with a C800 Mozley separator together with a grindability test, both novel approaches in soil washing feasibility studies. The results highlighted the difficulties in treating "La Soterraña" soils. These difficulties are attributed to the presence of contaminants embedded in the soil and spoil heap aggregates, caused by the meteorization of gangue and ore minerals. As a result of these two characteristics, high concentrations of the contaminants accumulate in all grain-size fractions. Therefore, the soil washing approach proposed here includes the grinding of particles above 125 μm. Copyright © 2011 Elsevier B.V. All rights reserved.

Tailoring Water, Sanitation, and Hygiene (WASH) Targets for Soil-Transmitted Helminthiasis and Schistosomiasis Control.

Science.gov (United States)

Campbell, Suzy J; Biritwum, Nana-Kwadwo; Woods, Geordie; Velleman, Yael; Fleming, Fiona; Stothard, J Russell

2018-01-01

The World Health Organization's (WHO) 2015-2020 Global Strategy on water, sanitation, and hygiene (WASH) and neglected tropical diseases (NTDs) encourages integration, whilst maintaining existing structured NTD investments, and acceleration towards Sustainable Development Goal (SDG) targets. Accordingly, SDG-associated and WASH-NTD indicators have been developed, commencing important intersectoral dialogue, alongside opportunities for future disease-specific refinements. The rationale for soil-transmitted helminthiasis (STH)- and schistosomiasis-specific WASH considerations, and a traffic-light figure, are presented here to indicate where current international definitions may, or may not, suffice. Certain unique aspects in control dynamics and parasitic lifecycles, however, necessitate additional implementation research with more appropriate measurement indicators developed to record programmatic interventions and to define strategic priorities more effectively. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Critical assessment of the available technologies for sanitation of contaminated soil and their limits of application

International Nuclear Information System (INIS)

Nussbaumer, M.; Glaeser, E.

1993-01-01

Sanitation of polluted land comprises safety measures and soil purification measures. Soil purification can take place either in situ, or on-site or off-site after digging up the contaminated soil. In-situ processes are soil deaeration, groundwater purification and biological methods. Soil deaeration is suited for volatile pollutants in the unsaturated zone of loose soils, while groundwater purification is commonly applied for water-soluble pollutants in the saturated zone of soils with a high k f value. On-site or off-site purification of contaminated soils can take place by thermal processes, by soil washing, by microorganisms, or by physical processes. Thermal processes have the widest range of applications; they are suited for most soils polluted with mostly organic pollutants, and the residual contamination is lowest. Soil washing is limited to sandy and noncohesive soils and for emulsifiable or elutable pollutants. Biological on-site and off-line methods are limited to biodegradable pollutants which are not in phase. Loosening agents may be added in order to overcome geotechnical limitations. Physical purification of soils is limited to specific applications e.g. removal of volatile hydrocarbons. (orig.) [de

Soil washing of chromium- and cadmium-contaminated sludge using acids and ethylenediaminetetra acetic acid chelating agent.

Science.gov (United States)

Gitipour, Saeid; Ahmadi, Soheil; Madadian, Edris; Ardestani, Mojtaba

2016-01-01

In this research, the effect of soil washing in the removal of chromium- and cadmium-contaminated sludge samples collected from Pond 2 of the Tehran Oil Refinery was investigated. These metals are considered as hazardous substances for human health and the environment. The carcinogenicity of chromate dust has been established for a long time. Cadmium is also a potential environmental toxicant. This study was carried out by collecting sludge samples from different locations in Pond 2. Soil washing was conducted to treat the samples. Chemical agents, such as acetic acid, ethylenediaminetetra acetic acid (EDTA) and hydrochloric acid, were used as washing solutions to remove chromium and cadmium from sludge samples. The results of this study indicated that the highest removal efficiencies from the sludge samples were achieved using a 0.3 M HCl solution with 82.69% and 74.47% for chromium and cadmium, respectively. EDTA (0.1 M) in the best condition extracted 66.81% of cadmium and 72.52% of chromium from the sludges. The lowest efficiency values for the samples, however, were achieved using 3 M acetic acid with 41.7% and 46.96% removals for cadmium and chromium, respectively. The analysis of washed sludge indicated that the heavy metals removal decreased in the order of 3 M acetic acid < 0.1 M EDTA<0.3 M HCl, thus hydrochloric acid appears to offer a greater potential as a washing agent in remediating the sludge samples.

Groundwater Availability Alters Soil-plant Nutrient Cycling in a Stand of Invasive, N-fixing Phreatophytes

Science.gov (United States)

Dudley, B. D.; Miyazawa, Y.; Hughes, F.; Ostertag, R.; Kettwich, S. K.; MacKenzie, R.; Dulaiova, H.; Waters, C. A.; Bishop, J.; Giambelluca, T. W.

2013-12-01

N-fixing phreatophytic trees are common in arid and semi-arid regions worldwide, and can play significant roles in modifying hydrology and soil-plant nutrient cycling where they are present. In light of reductions in groundwater levels in many arid regions we estimated annual transpiration rates at a stand level, and alterations to C, N and P accretion in soils as a function of groundwater depth in a ca.120 year old stand of Prosopis pallida along an elevation gradient in coastal leeward Hawaii. We measured sapflow and stand level sapwood area to quantify transpiration, and calculated groundwater transpiration rates using P. pallida stem water δ18O values. By measuring soil resistivity, we were able to compare the volume of groundwater transpired by these trees to groundwater depth across the stand. We examined nutrient deposition and accretion in soils in lowland areas of the stand with accessible shallow groundwater, compared to upland areas with no groundwater access, as indicated by stem water δ18O values. Resistivity results suggested that groundwater was at a height close to sea level throughout the stand. Transpiration was around 1900 m3 ha-1 year-1 in the areas of the stand closest to the sea (where groundwater was at around 1-4 m below ground level) and decreased to around a tenth of that volume where groundwater was not accessible. Litterfall rates over the course of the year studied were 17 times greater at lowland sites, but this litterfall contributed ca. 24 times the N, and 35 times the P of upland sites. Thus, groundwater access contributed to the total mass of nitrogen and phosphorus deposited in the form of litter through higher litter quantity and quality. Total N content of soils was 4.7 times greater and inorganic N pools were eight times higher at lowland plots. These results suggest that groundwater depth can have strong effects on soil-plant nutrient cycling, so that reductions in the availability of shallow groundwater are likely to impact

100-FR-3 groundwater/soil gas supplemental limited field investigation report

International Nuclear Information System (INIS)

1996-04-01

In 1993, a Limited Field Investigation (LFI) was conducted for the 100-FR-3 Operable Unit which identified trichloroethylene (TCE) as a contaminant of potential concern (COPC) (DOE-RL 1994). In groundwater samples collected for the LFI, TCE was detected in well 199-177-1 at a concentration exceeding the U.S. Environmental Protection Agency (EPA) maximum contaminant level (5 μg/L) and Washington State groundwater criteria (3 μg/L). With the concurrence of the EPA and the Washington State Department of Ecology (Ecology), a supplemental LFI was conducted to determine the extent and potential source of TCE groundwater contamination associated with the 100-FR-3 Operable Unit. This report summarizes the activities and results of the groundwater/soil gas supplemental LFI for the 100-FR-3 Operable Unit. The primary objective of this investigation was to assess the lateral distribution of TCE in shallow (3 to 5 ft below the water table) groundwater associated with the 100-FR-3 Operable Unit. The second objective was to assess soil gas (3 to 5 concentrations in the study area in an attempt to identify potential sources of TCE and develop a correlation between soil gas and groundwater concentrations). Finally, the third objective of the investigation was to refine the site conceptual model

Pyraclostrobin wash-off from sugarcane leaves and aerobic dissipation in agricultural soil.

Science.gov (United States)

Fulcher, James M; Wayment, Darcey G; White, Paul M; Webber, Charles L

2014-03-12

To mitigate damage from the fungal sugarcane pathogen brown rust (Puccinia melanocephala), a Section 18 Emergency Use Label was put in place by the United States Environmental Protection Agency (U.S. EPA) for the application of pyraclostrobin (trade name Headline SC, produced by BASF, Research Triangle Park, NC) on sugarcane in 2008. To assess the dynamics of this fungicide in Louisiana soil, samples (n = 24) from a non-treated field were spiked with pyraclostrobin (3.1 μg g(-1)) and analyzed in laboratory conditions over the course of 63 days using quick, easy, cheap, effective, rugged, and safe (QuEChERS) dispersive solid-phase extraction/high-performance liquid chromatography with ultraviolet-visible detection (dSPE/HPLC-UV). Modeling was performed using Microsoft Excel to predict DTx values. Pyraclostrobin was found to follow biphasic kinetics with DT50 and DT90 values of 60 and 282 days, suggesting that it is moderately persistent to persistent in soils. Wash-off studies on sugarcane indicate that very little fungicide is in the wash-off after 48 h. If applied to sugarcane according to label recommendations, the fungicide should have minimal dissipation from rainfall events.

Feed Forward Artificial Neural Network Model to Estimate the TPH Removal Efficiency in Soil Washing Process

Directory of Open Access Journals (Sweden)

Hossein Jafari Mansoorian

2017-01-01

Full Text Available Background & Aims of the Study: A feed forward artificial neural network (FFANN was developed to predict the efficiency of total petroleum hydrocarbon (TPH removal from a contaminated soil, using soil washing process with Tween 80. The main objective of this study was to assess the performance of developed FFANN model for the estimation of   TPH removal. Materials and Methods: Several independent repressors including pH, shaking speed, surfactant concentration and contact time were used to describe the removal of TPH as a dependent variable in a FFANN model. 85% of data set observations were used for training the model and remaining 15% were used for model testing, approximately. The performance of the model was compared with linear regression and assessed, using Root of Mean Square Error (RMSE as goodness-of-fit measure Results: For the prediction of TPH removal efficiency, a FANN model with a three-hidden-layer structure of 4-3-1 and a learning rate of 0.01 showed the best predictive results. The RMSE and R2 for the training and testing steps of the model were obtained to be 2.596, 0.966, 10.70 and 0.78, respectively. Conclusion: For about 80% of the TPH removal efficiency can be described by the assessed regressors the developed model. Thus, focusing on the optimization of soil washing process regarding to shaking speed, contact time, surfactant concentration and pH can improve the TPH removal performance from polluted soils. The results of this study could be the basis for the application of FANN for the assessment of soil washing process and the control of petroleum hydrocarbon emission into the environments.

Sustainable Soil Washing: Shredded Card Filtration of Potentially Toxic Elements after Leaching from Soil Using Organic Acid Solutions.

Directory of Open Access Journals (Sweden)

Christopher Ash

Full Text Available Shredded card (SC was assessed for use as a sorbent of potentially toxic elements (PTE carried from contaminated soil in various leachates (oxalic acid, formic acid, CaCl2, water. We further assessed SC for retention of PTE, using acidified water (pH 3.4. Vertical columns and a peristaltic pump were used to leach PTE from soils (O and A/B horizons before passing through SC. Sorption onto SC was studied by comparing leachates, and by monitoring total PTE contents on SC before and after leaching. SC buffers against acidic soil conditions that promote metals solubility; considerable increases in solution pH (+4.49 were observed. Greatest differences in solution PTE content after leaching with/without SC occurred for Pb. In oxalic acid, As, Cd, Pb showed a high level of sorption (25, 15, and 58x more of the respective PTE in leachates without SC. In formic acid, Pb sorption was highly efficient (219x more Pb in leachate without SC. In water, only Pb showed high sorption (191x more Pb in leachate without SC. In desorption experiments, release of PTE from SC varied according to the source of PTE (organic/mineral soil, and type of solvent used. Arsenic was the PTE most readily leached in desorption experiments. Low As sorption from water was followed by fast release (70% As released from SC. A high rate of Cd sorption from organic acid solutions was followed by strong retention (~12% Cd desorption. SC also retained Pb after sorption from water, with subsequent losses of ≤8.5% of total bound Pb. The proposed use of this material is for the filtration of PTE from extract solution following soil washing. Low-molecular-mass organic acids offer a less destructive, biodegradable alternative to strong inorganic acids for soil washing.

Sustainable Soil Washing: Shredded Card Filtration of Potentially Toxic Elements after Leaching from Soil Using Organic Acid Solutions

Science.gov (United States)

Ash, Christopher; Drábek, Ondřej; Tejnecký, Václav; Jehlička, Jan; Michon, Ninon; Borůvka, Luboš

2016-01-01

Shredded card (SC) was assessed for use as a sorbent of potentially toxic elements (PTE) carried from contaminated soil in various leachates (oxalic acid, formic acid, CaCl2, water). We further assessed SC for retention of PTE, using acidified water (pH 3.4). Vertical columns and a peristaltic pump were used to leach PTE from soils (O and A/B horizons) before passing through SC. Sorption onto SC was studied by comparing leachates, and by monitoring total PTE contents on SC before and after leaching. SC buffers against acidic soil conditions that promote metals solubility; considerable increases in solution pH (+4.49) were observed. Greatest differences in solution PTE content after leaching with/without SC occurred for Pb. In oxalic acid, As, Cd, Pb showed a high level of sorption (25, 15, and 58x more of the respective PTE in leachates without SC). In formic acid, Pb sorption was highly efficient (219x more Pb in leachate without SC). In water, only Pb showed high sorption (191x more Pb in leachate without SC). In desorption experiments, release of PTE from SC varied according to the source of PTE (organic/mineral soil), and type of solvent used. Arsenic was the PTE most readily leached in desorption experiments. Low As sorption from water was followed by fast release (70% As released from SC). A high rate of Cd sorption from organic acid solutions was followed by strong retention (~12% Cd desorption). SC also retained Pb after sorption from water, with subsequent losses of ≤8.5% of total bound Pb. The proposed use of this material is for the filtration of PTE from extract solution following soil washing. Low-molecular-mass organic acids offer a less destructive, biodegradable alternative to strong inorganic acids for soil washing. PMID:26900684

Simulation of large-scale soil water systems using groundwater data and satellite based soil moisture

Science.gov (United States)

Kreye, Phillip; Meon, Günter

2016-04-01

Complex concepts for the physically correct depiction of dominant processes in the hydrosphere are increasingly at the forefront of hydrological modelling. Many scientific issues in hydrological modelling demand for additional system variables besides a simulation of runoff only, such as groundwater recharge or soil moisture conditions. Models that include soil water simulations are either very simplified or require a high number of parameters. Against this backdrop there is a heightened demand of observations to be used to calibrate the model. A reasonable integration of groundwater data or remote sensing data in calibration procedures as well as the identifiability of physically plausible sets of parameters is subject to research in the field of hydrology. Since this data is often combined with conceptual models, the given interfaces are not suitable for such demands. Furthermore, the application of automated optimisation procedures is generally associated with conceptual models, whose (fast) computing times allow many iterations of the optimisation in an acceptable time frame. One of the main aims of this study is to reduce the discrepancy between scientific and practical applications in the field of hydrological modelling. Therefore, the soil model DYVESOM (DYnamic VEgetation SOil Model) was developed as one of the primary components of the hydrological modelling system PANTA RHEI. DYVESOMs structure provides the required interfaces for the calibrations made at runoff, satellite based soil moisture and groundwater level. The model considers spatial and temporal differentiated feedback of the development of the vegetation on the soil system. In addition, small scale heterogeneities of soil properties (subgrid-variability) are parameterized by variation of van Genuchten parameters depending on distribution functions. Different sets of parameters are operated simultaneously while interacting with each other. The developed soil model is innovative regarding concept

Use of Additives in Bioremediation of Contaminated Groundwater and Soil

Science.gov (United States)

This chapter reviews application of additives used in bioremediation of chlorinated solvents and fuels for groundwater and soil remediation. Soluble carbon substrates are applicable to most site conditions except aquifers with very high or very low groundwater flow. Slow-release ...

Radon occurrence in soil-gas and groundwater around an active landslide

Energy Technology Data Exchange (ETDEWEB)

Ramola, R.C. [Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal -249 199 (India)], E-mail: rcramola@gmail.com; Choubey, V.M. [Wadia Institute of Himalayan Geology, Dehradun 248 001 (India); Negi, M.S.; Prasad, Yogesh; Prasad, Ganesh [Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal -249 199 (India)

2008-01-15

This paper presents the results of investigation of radon levels in the soil-gas and groundwater of Uttarkashi, India within the distance of 5 km in vertical and horizontal directions from the landslide of Varunawat hill. Radon release from the soil and groundwater was found higher than the normal values. Radon concentration in groundwater over and around the landslide was found to vary from 0.51 to 86kBqm{sup -3}. The soil-gas radon concentration was found to vary from 219 to 3kBqm{sup -3} along the slope of landslide. Radon exhalation rate in collected soil samples was found to vary from 2.28x10{sup -5} to 9.01x10{sup -5}Bqkg{sup -1}h{sup -1}. Radon values were not found correlated with major and trace element contents in the upper soil of the area, which indicate that the migration of radon from deeper part of the earth along with landslide contribute to the surface radon concentration. Recorded values show a close association with local geology and Varunawat eruptions.

Radon occurrence in soil-gas and groundwater around an active landslide

International Nuclear Information System (INIS)

Ramola, R.C.; Choubey, V.M.; Negi, M.S.; Prasad, Yogesh; Prasad, Ganesh

2008-01-01

This paper presents the results of investigation of radon levels in the soil-gas and groundwater of Uttarkashi, India within the distance of 5 km in vertical and horizontal directions from the landslide of Varunawat hill. Radon release from the soil and groundwater was found higher than the normal values. Radon concentration in groundwater over and around the landslide was found to vary from 0.51 to 86kBqm -3 . The soil-gas radon concentration was found to vary from 219 to 3kBqm -3 along the slope of landslide. Radon exhalation rate in collected soil samples was found to vary from 2.28x10 -5 to 9.01x10 -5 Bqkg -1 h -1 . Radon values were not found correlated with major and trace element contents in the upper soil of the area, which indicate that the migration of radon from deeper part of the earth along with landslide contribute to the surface radon concentration. Recorded values show a close association with local geology and Varunawat eruptions

Removal of heavy metals and arsenic from a co-contaminated soil by sieving combined with washing process.

Science.gov (United States)

Liao, Xiaoyong; Li, You; Yan, Xiulan

2016-03-01

Batch experiments were conducted with a heavy metals and arsenic co-contaminated soil from an abandoned mine to evaluate the feasibility of a remediation technology that combines sieving with soil washing. Leaching of the arsenic and heavy metals from the different particle size fractions was found to decrease in the order: 2mm. With increased contact time, the concentration of heavy metals in the leachate was significantly decreased for small particles, probably because of adsorption by the clay soil component. For the different particle sizes, the removal efficiencies for Pb and Cd were 75%-87%, and 61%-77% for Zn and Cu, although the extent of removal was decreased for As and Cr at 2mm, although good metal removal efficiencies were also achieved in the small particle size fractions. Through SEM-EDS observations and correlation analysis, the leaching regularity of the heavy metals and arsenic was found to be closely related to Fe, Mn, and Ca contents of the soil fractions. The remediation of heavy metal-contaminated soil by sieving combined with soil washing was proven to be efficient, and practical remediation parameters were also recommended. Copyright © 2015. Published by Elsevier B.V.

Monitoring the Perturbation of Soil and Groundwater Microbial Communities Due to Pig Production Activities

KAUST Repository

Hong, Pei-Ying

2013-02-08

This study aimed to determine if biotic contaminants originating from pig production farms are disseminated into soil and groundwater microbial communities. A spatial and temporal sampling of soil and groundwater in proximity to pig production farms was conducted, and quantitative PCR (Q-PCR) was utilized to determine the abundances of tetracycline resistance genes (i.e., tetQ and tetZ) and integrase genes (i.e., intI1 and intI2). We observed that the abundances of tetZ, tetQ, intI1, and intI2 in the soils increased at least 6-fold after manure application, and their abundances remained elevated above the background for up to 16 months. Q-PCR further determined total abundances of up to 5.88 × 109 copies/ng DNA for tetZ, tetQ, intI1, and intI2 in some of the groundwater wells that were situated next to the manure lagoon and in the facility well used to supply water for one of the farms. We further utilized 16S rRNA-based pyrosequencing to assess the microbial communities, and our comparative analyses suggest that most of the soil samples collected before and after manure application did not change significantly, sharing a high Bray-Curtis similarity of 78.5%. In contrast, an increase in Bacteroidetes and sulfur-oxidizing bacterial populations was observed in the groundwaters collected from lagoon-associated groundwater wells. Genera associated with opportunistic human and animal pathogens, such as Acinetobacter, Arcobacter, Yersinia, and Coxiella, were detected in some of the manure-treated soils and affected groundwater wells. Feces-associated bacteria such as Streptococcus, Erysipelothrix, and Bacteroides were detected in the manure, soil, and groundwater ecosystems, suggesting a perturbation of the soil and groundwater environments by invader species from pig production activities.

Plutonium mobility studies in soil sediment decontaminated by means of a soil-washing technology

International Nuclear Information System (INIS)

Negri, M.C.; Orlandini, K.A.; Swift, N.; Carfagno, D.

1995-01-01

The ACT*DE*CON SM process extracts plutonium from contaminated soils/sediments by means of a series of washings with a blend of chemicals, that includes a chelating agent, an oxidant, and carbonates. At the end of the process, the Pu level in the soil is lowered to 25-30 pCi/g from an initial contamination level averaging 500 pCi/g. The radionuclide still present in the soil at the end of the treatment must be strongly immobilized in or onto the soil particles to minimize the risk of its percolation to the aquifer and/or uptake by vegetation. This paper reports the investigation of residual Pu mobility as K d (distribution coefficient) in the treated soil/sediment. Six batches of contaminated soil were treated simultaneously by means of the ACT*DE*CON SM process. Some batches of the treated soil were amended with a standard fertilizer treatment of compost and nutrient and brought to pH 8.5. The treated soil, treated and fertilized soil, and the untreated controls were then incubated at 18 degrees C for 90 days. At four different times, a small aliquot of soil was retrieved from each of the batches and contacted with rainwater for six days to determine the Pu solid/liquid distribution and K d . Results indicated that a higher total amount of Pu was leached from the untreated soil, probably as a consequence of the higher content of available/exchangeable Pu in this soil compared with the treated ones. Treated/fertilized soils showed Pu leaching at intermediate levels between those for treated and untreated soils, at least for the first 30 days of incubation. K d values at the beginning of the incubation period were significantly lower in the untreated and treated/fertilized soils compared with those for the treated-only, but at 90 days, these values were substantially equal among the three different soils. Traces of the chelant were detectable only in treated, unfertilized soil

Estimation of groundwater recharge to chalk and sandstone aquifers using simple soil models

Science.gov (United States)

Ragab, R.; Finch, J.; Harding, R.

1997-03-01

On the assumption that the water draining below the root zone is potentially available for groundwater recharge, two current UK methods for estimating annual groundwater recharge have been compared with a new soil model using data from four sites under permanent grass in the UK: two sites representative of the Chalk aquifer at Bridgest Farm (Hampshire) and Fleam Dyke (Cambridgeshire), and two sites on the Triassic sandstone at Bicton College (Devon) and Bacon Hall (Shropshire). A Four Root Layers Model (FRLM), the Penman-Grindley model and the UK Meteorological Office Rainfall and Evaporation Calculation System (MORECS) were used. The new soil model was run with potential evaporation as input both from the MORECS and from the Penman-Monteith equation. The models were run for the Chalk sites both with and without a bypass flow of 15% of rainfall. Bypass was not considered for the sandstone sites. The performance of the models was tested against neutron probes measurements of soil moisture deficits. In addition, the annual groundwater recharge estimated from the models was compared with the published values obtained from the 'zero flux plane' method. Generally, the Penman-Grindley model was more successful in predicting the time for soil to return to its field capacity than in predicting the magnitude of the soil moisture deficit. The annual groundwater recharge was predicted with reasonable accuracy. The MORECS relatively tended to overestimate the soil moisture deficits and to delay the time at which the soil returns to its field capacity. The consequences were underestimates of annual groundwater recharge, owing either to the higher values of potential evaporation calculated from the MORECS or tothe high available water capacity values associated with the soils under consideration. The new soil model (FRLM) predicts the soil moisture deficits successfully and hence is reliable in estimating the annual groundwater recharge. The model is capable of doing this with

Remediation of organochlorine pesticides (OCPs) contaminated site by successive methyl-β-cyclodextrin (MCD) and sunflower oil enhanced soil washing - Portulaca oleracea L. cultivation.

Science.gov (United States)

Ye, Mao; Sun, Mingming; Hu, Feng; Kengara, Fredrick Orori; Jiang, Xin; Luo, Yongming; Yang, Xinlun

2014-06-01

An innovative ex situ soil washing technology was developed in this study to remediate organochlorine pesticides (OCPs)-contaminated site. Elevated temperature (50 °C) combined with ultrasonication (35 kHz, 30 min) at 25 g L(-1) methyl-β-cyclodextrin and 100 mL L(-1) sunflower oil were effective in extracting OCPs from the soil. After four successive washing cycles, the removal efficiency for total OCPs, DDTs, endosulfans, 1,2,3,4,5,6-hexachlorocyclohexanes, heptachlors, and chlordanes were all about 99%. The 4th washed soil with 3 months cultivation of Portulaca oleracea L. and nutrient addition significantly increase (p<0.05) the number, biomass carbon, nitrogen, and functioning diversity of soil microorganisms. This implied that the microbiological functioning of the soil was at least partially restored. This combined cleanup strategy proved to be effective and environmental friendly. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modelling Technique for the Assessment of the Sub-Soil Drain for Groundwater Seepage Remediation

Directory of Open Access Journals (Sweden)

Tajul Baharuddin Mohamad Faizal

2017-01-01

Full Text Available Groundwater simulation technique was carried out for examining the performance of sub-soil drain at problematic site area. Subsoil drain was proposed as one of solution for groundwater seepage occurred at the slope face by reducing groundwater table at Taman Botani Park Kuala Lumpur. The simulation technique used Modular Three-Dimensional Finite Difference Groundwater Flow (MODFLOW software. In transient conditions, the results of simulation showed that heads increases surpass 1 to 2 m from the elevation level of the slope area that caused groundwater seepage on slope face. This study attempt to decrease the heads increase surpass by using different sub-soil drain size in simulation technique. The sub-soil drain capable to decline the heads ranges of 1 to 2 m.

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

Coagulation-flocculation process applied to wastewaters generated in hydrocarbon-contaminated soil washing: Interactions among coagulant and flocculant concentrations and pH value.

Science.gov (United States)

Torres, Luis G; Belloc, Claudia; Vaca, Mabel; Iturbe, Rosario; Bandala, Erick R

2009-11-01

Wastewater produced in the contaminated soil washing was treated by means of coagulation-flocculation (CF) process. The wastewater contained petroleum hydrocarbons, a surfactant, i.e., sodium dodecyl sulfate (SDS) as well as salts, brownish organic matter and other constituents that were lixiviated from the soil during the washing process. The main goal of this work was to develop a process for treating the wastewaters generated when washing hydrocarbon-contaminated soils in such a way that it could be recycled to the washing process, and also be disposed at the end of the process properly. A second objective was to study the relationship among the coagulant and flocculant doses and the pH at which the CF process is developed, for systems where methylene blue active substances (MBAS) as well as oil and greases were present. The results for the selection of the right coagulant and flocculant type and dose, the optimum pH value for the CF process and the interactions among the three parameters are detailed along this work. The best coagulant and flocculant were FeCl(3) and Tecnifloc 998 at doses of 4,000 and 1 mg/L, correspondingly at pH of 5. These conditions gave color, turbidity, chemical oxygen demand (COD) and conductivity removals of 99.8, 99.6, 97.1 and 35%, respectively. It was concluded that it is feasible to treat the wastewaters generated in the contaminated soil washing process through CF process, and therefore, wastewaters could be recycled to the washing process or disposed to drainage.

Washing technology development for gravel contaminated with uranium

Energy Technology Data Exchange (ETDEWEB)

Park, Uk Ryang; Kim, Gye Nam; Kim, Seung Soo; Kim, Wan Suk; Moon, Jai Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

The soil washing method has a short decontamination time and is economical. In addition, methods including phytoremediation, solidification/stabilization and bioremediation exist. Phytoremediation and bioremediation are economical, but have low remedial efficiency. In addition, bioremediation causes washing wastewater because it requires a washing process for the separation of microorganisms from the soils. In addition, solidification/stabilization is a commonly used methods, but eventually increases the volume of wastes. As mentioned above, many researches involved in the decontamination of radioactively contaminated soils have been actively processed. On the other hand, researches for decontaminating radioactively contaminated gravels are not being currently processed. In this study, we performed basic experiments using decontamination methods to decontaminate radioactively contaminated gravel. First, we measured the concentration of uranium in gravel included in uranium-contaminated soils and performed a washing experiment to monitor the tendency of uranium removal. In addition, when managing gravel with a low uranium-decontamination rate, we tried to satisfy the radioactivity concentration criteria for self-disposal in the wastes (0.4Bq/g or less) by performing a washing experiment after only a physical crushing process. We performed washing experiments to satisfy the radioactivity concentration criteria for self-disposal (0.4 Bq/g or less) in gravel included in radioactively contaminated soil. We performed washing experiments for gravel whose initial average concentration of uranium was 1.3Bq/g. In addition, the average concentration of uranium was 0.8Bq/g. Too increase the decontamination rate, we crushed the gravel with a jaw crusher and performed the washing experiments. The results were similar to the results without crushing. In addition, it was determined that the smaller the size of the gravel particles, the more efficient the uranium decontamination

Monitoring of Nitrate and Pesticide Pollution in Mnasra, Morocco Soil and Groundwater.

Science.gov (United States)

Marouane, Bouchra; Dahchour, Abdelmalek; Dousset, Sylvie; El Hajjaji, Souad

2015-06-01

This study evaluates the levels of nitrates and pesticides occurring in groundwater and agricultural soil in the Mnasra, Morocco area, a zone with intensive agricultural activity. A set of 108 water samples and 68 soil samples were collected from ten selected sites in the area during agricultural seasons, from May 2010 to September 2012. The results reveal that 89.7% of water samples exceeded the standard limit of nitrate concentrations for groundwater (50 mg/L). These results can be explained by the prevailing sandy nature of the soil in the area, the frequency of fertilizer usage, and the shallow level of the water table, which favors the leaching of nitrate from field to groundwater. In contrast, the selected pesticide molecules were not detected in the analysed soil and water samples; levels were below the quantification limit in all samples. This situation could be explained by the probable partial or total transformation of the molecules in soil.

Dissipation of the herbicide oxyfluorfen in subtropical soils and its potential to contaminate groundwater.

Science.gov (United States)

Yen, Jui-Hung; Sheu, Wey-Shin; Wang, Yei-Shung

2003-02-01

The dissipation and mobility of the herbicide oxyfluorfen (2-chloro-alpha,alpha,alpha-trifluoro-p-tolyl 3-ethoxy-4-nitrophenyl ether) in field soil of Taiwan were investigated in the laboratory with six tea garden soils. The dissipation coefficients of oxyfluorfen in soils of different moisture content (30%, 60%, and 90% of soil field capacity) and soil temperature (10 degrees C, 25 degrees C, and 40 degrees C) were studied. Results indicate that the half-life of oxyfluorfen ranged from 72 to 160 days for six tea garden soils. It was found that if the temperature is high, the dissipation rate is rapid, and there is almost no dissipation at 10 degrees C. Possible contamination of groundwater by the herbicide oxyfluorfen was assessed using the behavior assessment model and the groundwater pollution-potential (GWP) model. The results obtained after evaluating the residue and travel time using the GWP model illustrated that oxyfluorfen is not very mobile in soil and may not contaminate groundwater under normal conditions. But in the case of soil of extremely low organic carbon content and coarse texture, oxyfluorfen has the potential to contaminate groundwater less than 3m deep.

Evaluation of short-term tracer fluctuations in groundwater and soil air in a two year study

Science.gov (United States)

Jenner, Florian; Mayer, Simon; Aeschbach, Werner; Weissbach, Therese

2016-04-01

The application of gas tracers like noble gases (NGs), SF6 or CFCs in groundwater studies such as paleo temperature determination requires a detailed understanding of the dynamics of reactive and inert gases in the soil air with which the infiltrating water equilibrates. Due to microbial gas consumption and production, NG partial pressures in soil air can deviate from atmospheric air, an effect that could bias noble gas temperatures estimates if not taken into account. So far, such an impact on NG contents in groundwater has not been directly demonstrated. We provide the first long-term study of the above mentioned gas tracers and physical parameters in both the saturated and unsaturated soil zone, sampled continuously for more than two years near Mannheim (Germany). NG partial pressures in soil air correlate with soil moisture and the sum value of O2+CO2, with a maximal significant enhancement of 3-6% with respect to atmospheric air during summer time. Observed seasonal fluctuations result in a mass dependent fractionation of NGs in soil air. Concentrations of SF6 and CFCs in soil air are determined by corresponding fluctuations in local atmospheric air, caused by industrial emissions. Arising concentration peaks are damped with increasing soil depth. Shallow groundwater shows short-term NG fluctuations which are smoothed within a few meters below the water table. A correlation between NG contents of soil air and of groundwater is observable during strong recharge events. However, there is no evidence for a permanent influence of seasonal variations of soil air composition on shallow groundwater. Fluctuating NG contents in shallow groundwater are rather determined by variations of soil temperature and water table level. Our data gives evidence for a further temperature driven equilibration of groundwater with entrapped air bubbles within the topmost saturated zone, which permanently occurs even some years after recharge. Local subsurface temperature fluctuations

Monitoring the Perturbation of Soil and Groundwater Microbial Communities Due to Pig Production Activities

KAUST Repository

Hong, Pei-Ying; Yannarell, A. C.; Dai, Q.; Ekizoglu, M.; Mackie, R. I.

2013-01-01

This study aimed to determine if biotic contaminants originating from pig production farms are disseminated into soil and groundwater microbial communities. A spatial and temporal sampling of soil and groundwater in proximity to pig production farms

Pore Pressure Response to Groundwater Fluctuations in Saturated Double-Layered Soil

Directory of Open Access Journals (Sweden)

Hongwei Ying

2015-01-01

Full Text Available Analytical solutions are developed for one-dimensional consolidation of double-layered saturated soil subjected to groundwater fluctuations. The solutions are derived by an explicit mathematical procedure using Duhamel’s theorem in conjunction with a Fourier series, when groundwater fluctuation is described by a general time-dependent function and assumed to be the pore water pressure variations at the upper boundary. Taking as an example the harmonic groundwater fluctuation, the relevant response of the excess pore water pressure is discussed in detail, and the main influencing factors of the excess pore pressure distribution are analyzed. A dimensionless parameter θ has been introduced because it significantly affects the phase and the amplitude of excess pore pressures. The influences of the coefficients of permeability and compressibility of soil on the excess pore pressure distribution are different and cannot be incorporated into the coefficient of consolidation in double-layered soil. The relative permeability ratio of two clayey soils also plays an important role on the curves of the distributions of the excess pore pressures. The effects of the thickness of the soil layer on the excess pore pressure distribution should be considered together with the dimensionless parameter θ and the permeability and compressibility of the double-layered soil system.

Soil treatment and groundwater control for No. 6 fuel oil and PCB contamination

International Nuclear Information System (INIS)

Girioni, M.J.; St. Hilaire, W.J.

1991-01-01

This paper reports that as part of a Short-Term Measure ordered by the Massachusetts Department of Environmental Protection (DEP), soil contaminated by No. 6 fuel oil and low-level polychlorinated biphenyls (PCBs) was excavated, treated and recycled on-site as an asphalt base course for a parking lot at an industrial complex in New Bedford, Massachusetts. Approximately 300 cubic yards of contaminated soil were treated with an asphalt emulsion and utilized as a aggregate component for asphalt processed at ambient temperatures during the month of December 1990. In order to determine if the contaminated soils to be recycled would be classified as a hazardous waste (as defined by the Massachusetts Hazardous Waste Regulations, 310 CMR 30.000), or if the soil to be recycled would pose a significant risk to health, safety or the environment, analytical testing of the contaminated soil was conducted prior, during and after treatment. Analytical testing included Toxicity Characteristics Leaching Procedure (TCLP) analyses of the untreated and treated soil. An alternative solution to the standard groundwater pump-and-treat method was designed and constructed to control and recover the highly viscous floating petroleum product. A series of precast leaching galleys (oil collection chambers) and a precast leach pit (groundwater discharge structure) were constructed to alter the local groundwater table to induce groundwater flow by gravity into the leaching chambers. Passive (i.e., nonpumping) groundwater flow to the leaching chambers was induced by placing of the groundwater discharge structure hydraulically downgradient of the leaching chambers. Collected oil, separated by gravity, will be periodically vacuumed, as necessary, for proper off-site disposal. Excess water discharges to the downgradient leach pit

Groundwater influence on soil moisture memory and land-atmosphere interactions over the Iberian Peninsula

Science.gov (United States)

Martinez-de la Torre, Alberto; Miguez-Macho, Gonzalo

2017-04-01

We investigate the memory introduced in soil moisture fields by groundwater long timescales of variation in the semi-arid regions of the Iberian Peninsula with the LEAFHYDRO soil-vegetation-hydrology model, which includes a dynamic water table fully coupled to soil moisture and river flow via 2-way fluxes. We select a 10-year period (1989-1998) with transitions from wet to dry to again wet long lasting conditions and we carry out simulations at 2.5 km spatial resolution forced by ERA-Interim and a high-resolution precipitation analysis over Spain and Portugal. The model produces a realistic water table that we validate with hundreds of water table depth observation time series (ranging from 4 to 10 years) over the Iberian Peninsula. Modeled river flow is also compared to observations. Over shallow water table regions, results highlight the groundwater buffering effect on soil moisture fields over dry spells and long-term droughts, as well as the slow recovery of pre-drought soil wetness once climatic conditions turn wetter. Groundwater sustains river flow during dry summer periods. The longer lasting wet conditions in the soil when groundwater is considered increase summer evapotranspiration, that is mostly water-limited. Our results suggest that groundwater interaction with soil moisture should be considered for climate seasonal forecasting and climate studies in general over water-limited regions where shallow water tables are significantly present and connected to land surface hydrology.

Record of Decision Tank Farm Soil and INTEC Groundwater

Energy Technology Data Exchange (ETDEWEB)

L. S. Cahn

2007-05-01

This decision document presents the selected remedy for Operable Unit (OU) 3-14 tank farm soil and groundwater at the Idaho Nuclear Technology and Engineering Center (INTEC), which is located on the Idaho National Laboratory (INL) Site. The tank farm was initially evaluated in the OU 3-13 Record of Decision (ROD), and it was determined that additional information was needed to make a final decision. Additional information has been obtained on the nature and extent of contamination in the tank farm and on the impact of groundwater. The selected remedy was chosen in accordance with the Comprehensive Environmental Response, Liability and Compensation Act of 1980 (CERCLA) (42 USC 9601 et seq.), as amended by the Superfund Amendments and Reauthorization Act of 1986 (Public Law 99-499) and the National Oil and Hazardous Substances Pollution Contingency Plan (40 CFR 300). The selected remedy is intended to be the final action for tank far soil and groundwater at INTEC.

Proceedings of the 2010 PTAC soil and groundwater forum and poster session

International Nuclear Information System (INIS)

2010-01-01

This conference focused on emerging environmental issues and advances in soil and groundwater remediation research. It provided a forum to discuss current research and environmental regulations pertaining to the remediation and reclamation of oil and gas production sites as well as soils along pipeline routes. Methods for accurately identifying the source of hydrocarbon contamination in soils and wetlands were also presented. Recent advances in technological solutions for soil and groundwater remediation were reviewed along with methods for addressing salts, petroleum hydrocarbons, and process chemicals. The conference featured 18 presentations, of which 3 have been catalogued separately for inclusion in this database. refs., tabs., figs.

Decontamination of soil washing wastewater using solar driven advanced oxidation processes.

Science.gov (United States)

Bandala, Erick R; Velasco, Yuridia; Torres, Luis G

2008-12-30

Decontamination of soil washing wastewater was performed using two different solar driven advanced oxidation processes (AOPs): the photo-Fenton reaction and the cobalt/peroxymonosulfate/ultraviolet (Co/PMS/UV) process. Complete sodium dodecyl sulphate (SDS), the surfactant agent used to enhance soil washing process, degradation was achieved when the Co/PMS/UV process was used. In the case of photo-Fenton reaction, almost complete SDS degradation was achieved after the use of almost four times the actual energy amount required by the Co/PMS/UV process. Initial reaction rate in the first 15min (IR15) was determined for each process in order to compare them. Highest IR15 value was determined for the Co/PMS/UV process (0.011mmol/min) followed by the photo-Fenton reaction (0.0072mmol/min) and the dark Co/PMS and Fenton processes (IR15=0.002mmol/min in both cases). Organic matter depletion in the wastewater, as the sum of surfactant and total petroleum hydrocarbons present (measured as chemical oxygen demand, COD), was also determined for both solar driven processes. It was found that, for the case of COD, the highest removal (69%) was achieved when photo-Fenton reaction was used whereas Co/PMS/UV process yielded a slightly lower removal (51%). In both cases, organic matter removal achieved was over 50%, which can be consider proper for the coupling of the tested AOPs with conventional wastewater treatment processes such as biodegradation.

EPA RREL's mobile volume reduction unit advances soil washing at four Superfund sites

International Nuclear Information System (INIS)

Gaire, R.; Borst, M.

1994-01-01

Research testing of the US. Environmental Protection Agency (EPA) Risk Reduction Engineering Laboratory's (RREL) Volume Reduction Unit (VRU), produced data helping advance soil washing as a remedial technology for contaminated soils. Based on research at four Superfund sites, each with a different matrix of organic contaminants, EPA evaluated the soil technology and provided information to forecast realistic, full-scale remediation costs. Primarily a research tool, the VRU is RREL's mobile test unit for investigating the breadth of this technology. During a Superfund Innovative Technology Evaluation (SITE) Demonstration at Escambia Wood Treating Company Site, Pensacola, FL, the VRU treated soil contaminated with pentachlorophenol (PCP) and polynuclear aromatic hydrocarbon-laden creosote (PAH). At Montana Pole and Treatment Plant Site, Butte, MT, the VRU treated soil containing PCP mixed with diesel oil (measured as total petroleum hydrocarbons) and a trace of dioxin. At Dover Air Force Base Site, Dover, DE, the VRU treated soil containing JP-4 jet fuel, measured as TPHC. At Sand Creek Site, Commerce City, CO, the feed soil at this site was contaminated with two pesticides: heptachlor and dieldrin. Less than 10 percent of these pesticides remained in the treated coarse soil fractions

Effect of EDTA washing of metal polluted garden soils. Part I: Toxicity hazards and impact on soil properties.

Science.gov (United States)

Jelusic, Masa; Lestan, Domen

2014-03-15

We applied a multi-level approach assessing the quality, toxicity and functioning of Pb, Zn and Cd contaminated/remediated soil from a vegetable garden in Meza Valley, Slovenia. Contaminated soil was extracted with EDTA and placed into field experimental plots equipped with lysimeters. Soil properties were assessed by standard pedological analysis. Fractionation and leachability of toxic metals were analyzed by sequential extraction and TCLP and metal bioaccessibility by UBM tests. Soil respiration and enzyme activities were measured as indicators of soil functioning. Remediation reduced the metal burden by 80, 28 and 72% for Pb, Zn and Cd respectively, with a limited impact on soil pedology. Toxic metals associated with labile soil fractions were largely removed. No shifts between labile and residual fractions were observed during the seven months of the experiment. Initial metal leaching measured through lysimeters eventually ceased. However, remediation significantly diminished potential soil enzyme activity and no trends were observed of the remediated soil recovering its biological properties. Soil washing successfully removed available forms of Pb, Zn and Cd and thus lowered the human and environmental hazards of the remediated soil; however, remediation also extracted the trace elements essential for soil biota. In addition to reduced water holding capacity, soil health was not completely restored. Copyright © 2013 Elsevier B.V. All rights reserved.

Interactions Between Wind Erosion, Vegetation Structure, and Soil Stability in Groundwater Dependent Plant Communities

Science.gov (United States)

Vest, K. R.; Elmore, A. J.; Okin, G. S.

2009-12-01

Desertification is a human induced global phenomenon causing a loss of biodiversity and ecosystem productivity. Semi-arid grasslands are vulnerable to anthropogenic impacts (i.e., groundwater pumping and surface water diversion) that decrease vegetation cover and increase bare soil area leading to a greater probability of soil erosion, potentially enhancing feedback processes associated with desertification. To enhance our understanding of interactions between anthropogenic, physical, and biological factors causing desertification, this study used a combination of modeling and field observations to examine the relationship between chronic groundwater pumping and vegetation cover change and its effects on soil erosion and stability. The work was conducted in Owens Valley California, where a long history of groundwater pumping and surface water diversion has lead to documented vegetation changes. The work examined hydrological, ecological and biogeochemical factors across thirteen sites in Owens Valley. We analyzed soil stability, vegetation and gap size, soil organic carbon, and we also installed Big Spring Number Eight (BSNE) catchers to calculate mass transport of aeolian sediment across sites. Mass transport calculations were used to validate a new wind erosion model that represents the effect of porous vegetation on surface windshear velocity. Results across two field seasons show that the model can be used to predict mass transport, and areas with increased groundwater pumping show a greater susceptibility to erosion. Sediment collected in BSNE catchers was positively correlated with site gap size. Additionally, areas with larger gap sizes have a greater threshold shear velocity and soil stability, yet mass transport was greater at these sites than at sites with smaller gap sizes. Although modeling is complicated by spatial variation in multiple model parameters (e.g., gap size, threshold shear velocity in gaps), our results support the hypothesis that soils

Application of soil washing system to the volume reduction of radioactively contaminated soils and automated treatment of sludge cake

International Nuclear Information System (INIS)

Mouri, Mitsuo; Tsuchida, Mitsuru; Baba, Naoki; Nakajima, Takuma

2013-01-01

The pilot plant study was intended to evaluate; a) the removal efficiency of radioactive Cs, b) the volume reduction rate of feed soils, c) the volumetric rate and concentration rate of discharged sludge cake, and d) the effect of radiation exposure reduction by automated filter press unit and automated packing unit of sludge cake. As a result of this study, following observations were made; 1) the radioactive Cs content of clean sands ranged 882∼2,940 Bq/kg as compared to the feed soils of 8,790 to 26,270 Bq/kg, 2) the removal efficiency of radioactive Cs ranged 84∼92% of feed soils, 3) the volume reduction rate of feed soils ranged 70∼86% (ave. 82%), and 4) the automated filter press unit and the automated packing system of sludge cake were helpful for workers in reducing radiation exposure. It is concluded that soil washing system can effectively reduce volume of radioactively contaminated soils and can be practically used in Fukushima for remediation of soils. (author)

A new separation and treatment method for soil and groundwater restoration

Energy Technology Data Exchange (ETDEWEB)

Hitchens, G.D. [Lynntech, Inc., College Station, TX (United States)

1997-10-01

Soil and groundwater contamination by organic compounds is a widespread environmental pollution problem. In many cases, contaminated soil is excavated and transported to a landfill or is incinerated to remove contaminants. These remediation practices are expensive, environmentally disruptive, require extensive permitting, and only move contamination from one location to another. Onsite and in situ treatment techniques offer a safer, more cost-effective, and permanent solution. Many soil and groundwater contaminants are highly volatile, enabling the use of methods such as in situ vacuum extraction and air injection for their removal. However, these methods are often difficult to use because of slow volatilization rates and the lack of effective methods to treat the extracted hazardous material. This Phase I Small Business Innovation Research program focuses on developing an in situ soil and groundwater remediation technique that is effective against volatile as well as nonvolatile compounds and that will shorten treatment times. The technique forms the basis of a new catalytic process to degrade extracted contaminants onsite. Key hardware elements on which the new technique is based have been proven in preliminary research. The method has a high potential for public and regulatory acceptance because of its low environment impact.

A new separation and treatment method for soil and groundwater restoration

International Nuclear Information System (INIS)

Hitchens, G.D.

1997-01-01

Soil and groundwater contamination by organic compounds is a widespread environmental pollution problem. In many cases, contaminated soil is excavated and transported to a landfill or is incinerated to remove contaminants. These remediation practices are expensive, environmentally disruptive, require extensive permitting, and only move contamination from one location to another. Onsite and in situ treatment techniques offer a safer, more cost-effective, and permanent solution. Many soil and groundwater contaminants are highly volatile, enabling the use of methods such as in situ vacuum extraction and air injection for their removal. However, these methods are often difficult to use because of slow volatilization rates and the lack of effective methods to treat the extracted hazardous material. This Phase I Small Business Innovation Research program focuses on developing an in situ soil and groundwater remediation technique that is effective against volatile as well as nonvolatile compounds and that will shorten treatment times. The technique forms the basis of a new catalytic process to degrade extracted contaminants onsite. Key hardware elements on which the new technique is based have been proven in preliminary research. The method has a high potential for public and regulatory acceptance because of its low environment impact

In situ air sparging for bioremediation of groundwater and soils

International Nuclear Information System (INIS)

Lord, D.; Lei, J.; Chapdelaine, M.C.; Sansregret, J.L.; Cyr, B.

1995-01-01

Activities at a former petroleum products depot resulted in the hydrocarbon contamination of soil and groundwater over a 30,000-m 2 area. Site remediation activities consisted of three phases: site-specific characterization and treatability study, pilot-scale testing, and full-scale bioremediation. During Phase 1, a series of site/soil/waste characterizations was undertaken to ascertain the degree of site contamination and to determine soil physical/chemical and microbiological characteristics. Treatability studies were carried out to simulate an air sparging process in laboratory-scale columns. Results indicated 42% mineral oil and grease removal and 94% benzene, toluene, ethylbenzene, and xylenes (BTEX) removal over an 8-week period. The removal rate was higher in the unsaturated zone than in the saturated zone. Phase 2 involved pilot-scale testing over a 550-m 2 area. The radius of influence of the air sparge points was evaluated through measurements of dissolved oxygen concentrations in the groundwater and of groundwater mounding. A full-scale air sparging system (Phase 3) was installed on site and has been operational since early 1994. Physical/chemical and microbiological parameters, and contaminants were analyzed to evaluate the system performance

Environmental hazard of cadmium, copper, lead and zinc in metal-contaminated soils remediated by sulfosuccinamate formulation.

Science.gov (United States)

del Carmen Hernández-Soriano, Maria; Peña, Aránzazu; Mingorance, M Dolores

2011-10-01

Accumulation of metals in soil at elevated concentrations causes risks to the environmental quality and human health for more than one hundred million people globally. The rate of metal release and the alteration of metal distribution in soil phases after soil washing with a sulfosuccinamate surfactant solution (Aerosol 22) were evaluated for four contaminated soils. Furthermore, a sequential extraction scheme was carried out using selective extractants (HAcO, NH(2)OH·HCl, H(2)O(2) + NH(4)AcO) to evaluate which metal species are extracted by A22 and the alteration in metal distribution upon surfactant-washing. Efficiency of A22 to remove metals varied among soils. The washing treatment released up to 50% of Cd, 40% of Cu, 20% of Pb and 12% of Zn, mainly from the soluble and reducible soil fractions, therefore, greatly reducing the fraction of metals readily available in soil. Metal speciation analysis for the solutions collected upon soil washing with Aerosol 22 further confirmed these results. Copper and lead in solution were mostly present as soluble complexes, while Cd and Zn were present as free ions. Besides, redistribution of metals in soil was observed upon washing. The ratios of Zn strongly retained in the soil matrix and Cd complexed with organic ligands increased. Lead was mobilized to more weakly retained forms, which indicates a high bioavailability of the remaining Pb in soil after washing. Comprehensive knowledge on chemical forms of metals present in soil allows a feasible assessment of the environmental impact of metals for a given scenario, as well as possible alteration of environmental conditions, and a valuable prediction for potential leaching and groundwater contamination.

Proceedings (of the) first annual groundwater and soil remediation R, D and D (research, development and demonstration) symposium

Energy Technology Data Exchange (ETDEWEB)

1991-01-01

A symposium was held to present results of research on the remediation of contamination of groundwater and soils. Papers were presented on groundwater/soil remediation research and demonstration programs, in-situ bioremediation, remediation of groundwater contaminated by gasoline-derived aromatics, solvent extraction of petroleum hydrocarbons from soil, bioreactors for cleaning hydrocarbon- and salt-contaminated soils, in-situ volatilization technologies, evaluations of spill cleanup technologies, remediating subsurface contamination around sour gas processing plants, and the influence of gasoline oxygenates on the persistence of aromatics in groundwater. Separate abstracts have been prepared for 9 papers from this symposium.

Groundwater chemistry of Al under Dutch sandy soils: Effects of land use and depth

NARCIS (Netherlands)

Fest, E.P.M.J.; Temminghoff, E.J.M.; Griffioen, J.; Grift, B. van der; Riemsdijk, W.H. van

2007-01-01

Aluminium has received great attention in the second half of the 20th century, mainly in the context of the acid rain problem mostly in forest soils. In this research the effect of land use and depth of the groundwater on Al, pH and DOC concentration in groundwater under Dutch sandy soils has been

Study of electroflotation method for treatment of wastewater from washing soil contaminated by heavy metals

Directory of Open Access Journals (Sweden)

Izabel de Oliveira da Mota

2015-04-01

Full Text Available Electroflotation method (EFM for treatment of synthetic solutions simulating wastewater from washing soil contaminated by drilling fluids from oil wells was investigated in this paper. Experiments were carried out to examine the effects of the operating conditions on the removal of lead, barium and zinc from solutions containing 15 mg dm−3 for each metal representing a typical concentration of wastewater generated in the washing soil in this treatment. The experimental results showed that it is possible to remove these heavy metals by electrocoagulation/electroflotation (ECF attaining 97% of removal using stainless steel mesh electrodes with a power consumption of 14 kWh m−3. The optimal conditions of treatment were sodium dodecyl sulfate (SDS in a molar ratio 3:1, current density around 350 A m−2, ionic strength 3.2 × 10−3 M, pH = 10.0 and 20 min of ECF. This study newly indicated that the proposed method is adequate to simultaneously treat the common heavy metals found in the drilling fluids oil wells.

Data of heavy metals in soil and groundwater at Kiwi gardens of Amlash in Guilan Province, Iran

Directory of Open Access Journals (Sweden)

Dariush Naghipour

2018-06-01

Full Text Available Data on this paper describe the concentrations of arsenic, cadmium, copper, nickel, lead and zinc in the surface soils and groundwater's of Kiwi gardens and its relation to chemical fertilizers in Amlash city, Guilan Province, in Iran. The results of this study showed that the average concentration of heavy metals in groundwater and soils of the studied areas was less than the national standards of Iran for irrigation water, Dutch MPA for soils (except Cu and Ni and Canadian MAC for inorganic fertilizers. Considering that after fertilizing to soils used in gardening, the concentration of heavy metals in groundwater and soil can be increased significantly, so that chemical fertilizers can be considered as an effective factor in increasing the amount of heavy metals in water and soil. The results of this research can be used by who concern about water and soil quality related to fertilizing and also can be used by Rural Water and Wastewater Company and Ministry of Jahad Agriculture of Iran. Keywords: Heavy metals, Chemical fertilizer, Soil & groundwater pollution, Amlash

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

Feasibility of phytoremediation for common soil and groundwater pollutants

DEFF Research Database (Denmark)

Clausen, Lauge Peter Westergaard

During the past two to three decades numerous studies reporting highly efficient remediation of contaminated soil and groundwater by plants have been published. The promises of phytoremediation has been great but till now the technology has not been widely applied and recognized, commercially...... and in a regulatory context, on par with other conventional soil and groundwater remediation technologies. This thesis elucidates the field of phytoremediation and addresses the lack of recognition of the technology. It aims to assesses the overall feasibility of phytoremediation and identify obstacles within...... the field. Further, it provides examples and suggestions of how to overcome these obstacles. The first part of the thesis scrutinizes the literature for data and experiences regarding application of phytoremediation and uncovers potential barriers and where the existing knowledge is insufficient. Further...

Soil and ground-water remediation techniques

International Nuclear Information System (INIS)

Beck, P.

1996-01-01

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

Biosphere modelling for a deep radioactive waste repository: treatment of the groundwater-soil pathway

International Nuclear Information System (INIS)

Baeyens, B.; Grogan, H.A.; Dorp, F. van

1991-07-01

The effect of radionuclide transfer from near-surface groundwater to the rooting zone soil, via a deep soil layer, is modelled in this report. The possible extent of upward solute movement is evaluated for a region in northern Switzerland. The concentration of 237 Np and 129 I in the deep and top soil, and hence growing crops, are evaluated assuming a constant unit activity concentration in the groundwater. A number of parameter variations are considered, namely variable soil sorption coefficients, reduced infiltration of rain water and decreased groundwater flow. A release to an alternative smaller recipient region in northern Switzerland is also evaluated. For the parameter ranges considered uncertainty in the solid-liquid distribution coefficient has the largest effect on overall uncertainty. These calculations have been presented within the international Biosphere Model Validation Study (BIOMOVS). A description of the test scenario, and the model calculations submitted, have been included in this report for completeness. To place the groundwater-soil-crop-man pathway in context, its contribution to the total dose to man is evaluated for the 237 Np- 233 U- 229 Th decay chain. The results obtained using the two-layer soil model, described in this report, are compared with the single-layer soil model used during Project Gewaehr 1985. The more realistic two-layer soil model indicated an increase in importance of the drinking water pathway. It should be noted, however, that not all the critical pathways have been treated in this study with the same degree of conservatism. (author) 16 figs., 15 tabs., 31 refs

DEPARTMENT OF ENERGY SOIL AND GROUNDWATER SCIENCE AND TECHNOLOGY NEEDS, PLANS AND INITIATIVES

Energy Technology Data Exchange (ETDEWEB)

Aylward, B; V. ADAMS, V; G. M. CHAMBERLAIN, G; T. L. STEWART, T

2007-12-12

This paper presents the process used by the Department of Energy (DOE) Environmental Management (EM) Program to collect and prioritize DOE soil and groundwater site science and technology needs, develop and document strategic plans within the EM Engineering and Technology Roadmap, and establish specific program and project initiatives for inclusion in the EM Multi-Year Program Plan. The paper also presents brief summaries of the goals and objectives for the established soil and groundwater initiatives.

Biosphere modelling for a deep radioactive waste repository: site-specific consideration of the groundwater-soil pathway

International Nuclear Information System (INIS)

Grogan, H.A.; Baeyens, B.; Mueller, H.; Dorp, F. van

1991-07-01

Scenario evaluations indicate that groundwater is the most probable pathway for released radionuclides to reach the biosphere from a deep underground nuclear waste repository. This report considers a small valley in northern Switzerland where the transport of groundwater to surface soil might be possible. The hydrological situation has been examined to allow a system of compartments and fluxes for modelling this pathway with respect to the release of radionuclides from an underground repository to be produced. Assuming present day conditions the best estimate surface soil concentrations are calculated by dividing the soil into two layers (deep soil, surface soil) and assuming an annual upward flux of 10 mm from the groundwater through the two soil layers. A constant unit activity concentration is assumed for the radionuclides in the groundwater. It is concluded that the resultant best estimate values must still be considered to be biased on the conservative side, in view of the fact that the more typical situation is likely to be that no groundwater reaches the surface soil. Upper and lower estimates for the surface soil radionuclide concentrations are based on the parameter perturbation results which were carried out for three key parameters, i.e. precipitation surplus, upward flux and solid-liquid distribution coefficients (K d ). It is noted that attention must be given to the functional relationships which exist between various model parameters. Upper estimates for the surface soil concentration are determined assuming a higher annual upward flux (100 mm) as well as a more conservative K d value compared with the base case. This gives rise to surface soil concentrations more than two orders of magnitude higher than the best estimate values. The lower estimated are more easily assigned assuming that no activity reaches the surface soil via this pathway. (author) 18 figs., 4 tabs., refs

Spray washing, absorbent cornstarch powder, and dry time to reduce bacterial numbers on soiled transport cage flooring

Science.gov (United States)

Broiler transport cages are often used repeatedly without washing and fecal matter deposited on the floor surface can transfer Campylobacter from one flock to another. Allowing feces to dry is an effective but slow and logistically impractical means to kill Campylobacter in soiled transport cages. ...

Feasibility of phytoremediation of common soil and groundwater pollutants

DEFF Research Database (Denmark)

Trapp, Stefan; Rein, Arno; Clause, Lauge

2014-01-01

This report is the D eliverable D 4.3 and was done within the Timbre project WP4. It introduces into the various clean - up techniques that apply plants, evaluates the feasibility of phytoremediation of common soil and groundwater pollutants, and the knowle dge collected for this purpose was appl......This report is the D eliverable D 4.3 and was done within the Timbre project WP4. It introduces into the various clean - up techniques that apply plants, evaluates the feasibility of phytoremediation of common soil and groundwater pollutants, and the knowle dge collected for this purpose...... was applied to the two Timbre sites : Hunedoara (Romania) and Szprotawa (Poland). Phytoremediation is the technique to clean up (remediate) contaminated sites using plants, typically trees. The principles of the data were deta iled, with focus on obstacles (phytotoxicity) and factors stimulating success...

Update on the National Groundwater and Soil Remediation Program (GASReP)

International Nuclear Information System (INIS)

Lye, A.

1992-01-01

The national Groundwater and Soil Remediation Program (GASReP), supported jointly by government and the petroleum industry, targets research on innovative ways to clean up groundwater and soil contaminated with petroleum hydrocarbons, and conducts technology transfer sessions. Within its broad context as an initiative for research, development and demonstration of innovative cleanup technologies, GASReP now targets basic applied research and/or technology development only. Industry partners and other government programs will be encouraged to extend GASReP research findings to the final stage of technology demonstration. During 1991-92 GASReP shifted its attention from starting new projects to evaluating the program, setting a new direction, and establishing a better way to seek ideas for projects. Unlike previous years, only three projects began during this period. Two technology development projects are iron and manganese pre-treatment for pump and treat clean-up systems, and surface bioreactor to clean soil/waste contaminated with petroleum hydrocarbons. The one technology assessment project dealt with a review of six technologies for in-situ bioremediation of BTEX (benzene, toluene, ethylbenzene, xylene) in groundwater. Current program direction, interests, and research needs are summarized, and candidate proposals for project selection in 1992-93 are listed

Comparison of point-source pollutant loadings to soil and groundwater for 72 chemical substances.

Science.gov (United States)

Yu, Soonyoung; Hwang, Sang-Il; Yun, Seong-Taek; Chae, Gitak; Lee, Dongsu; Kim, Ki-Eun

2017-11-01

Fate and transport of 72 chemicals in soil and groundwater were assessed by using a multiphase compositional model (CompFlow Bio) because some of the chemicals are non-aqueous phase liquids or solids in the original form. One metric ton of chemicals were assumed to leak in a stylized facility. Scenarios of both surface spills and subsurface leaks were considered. Simulation results showed that the fate and transport of chemicals above the water table affected the fate and transport of chemicals below the water table, and vice versa. Surface spill scenarios caused much less concentrations than subsurface leak scenarios because leaching amounts into the subsurface environment were small (at most 6% of the 1 t spill for methylamine). Then, simulation results were applied to assess point-source pollutant loadings to soil and groundwater above and below the water table, respectively, by multiplying concentrations, impact areas, and durations. These three components correspond to the intensity of contamination, mobility, and persistency in the assessment of pollutant loading, respectively. Assessment results showed that the pollutant loadings in soil and groundwater were linearly related (r 2  = 0.64). The pollutant loadings were negatively related with zero-order and first-order decay rates in both soil (r = - 0.5 and - 0.6, respectively) and groundwater (- 1.0 and - 0.8, respectively). In addition, this study scientifically defended that the soil partitioning coefficient (K d ) significantly affected the pollutant loadings in soil (r = 0.6) and the maximum masses in groundwater (r = - 0.9). However, K d was not a representative factor for chemical transportability unlike the expectation in chemical ranking systems of soil and groundwater pollutants. The pollutant loadings estimated using a physics-based hydrogeological model provided a more rational ranking for exposure assessment, compared to the summation of persistency and transportability scores in

Influence of multi-step washing using Na2EDTA, oxalic acid and phosphoric acid on metal fractionation and spectroscopy characteristics from contaminated soil.

Science.gov (United States)

Wei, Meng; Chen, Jiajun

2016-11-01

A multi-step soil washing test using a typical chelating agent (Na 2 EDTA), organic acid (oxalic acid), and inorganic weak acid (phosphoric acid) was conducted to remediate soil contaminated with heavy metals near an arsenic mining area. The aim of the test was to improve the heavy metal removal efficiency and investigate its influence on metal fractionation and the spectroscopy characteristics of contaminated soil. The results indicated that the orders of the multi-step washing were critical for the removal efficiencies of the metal fractions, bioavailability, and potential mobility due to the different dissolution levels of mineral fractions and the inter-transformation of metal fractions by XRD and FT-IR spectral analyses. The optimal soil washing options were identified as the Na 2 EDTA-phosphoric-oxalic acid (EPO) and phosphoric-oxalic acid-Na 2 EDTA (POE) sequences because of their high removal efficiencies (approximately 45 % for arsenic and 88 % for cadmium) and the minimal harmful effects that were determined by the mobility and bioavailability of the remaining heavy metals based on the metal stability (I R ) and modified redistribution index ([Formula: see text]).

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

International Nuclear Information System (INIS)

Werner, P.; Stieber, M.

1997-01-01

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

The Soils and Groundwater – EM-20 S&T Roadmap Quality Assurance Project Plan

Energy Technology Data Exchange (ETDEWEB)

Fix, N. J.

2008-02-11

The Soils and Groundwater – EM-20 Science and Technology Roadmap Project is a U.S. Department of Energy, Office of Environmental Management-funded initiative designed to develop new methods, strategies and technology for characterizing, modeling, remediating, and monitoring soils and groundwater contaminated with metals, radionuclides, and chlorinated organics. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by EM-20 Roadmap Project staff.

Evidence for groundwater contamination by heavy metals through soil passage under acidifying conditions

NARCIS (Netherlands)

Wilkens, B.J.

1995-01-01

The research reported here is aimed at improving the knowledge of the mobility of the heavy metals cadmium and zinc in vulnerable soil types. We use the term vulnerable with reference to vulnerability of groundwater for contamination by soil leaching. At diffuse soil immissions of heavy metals,

Evidence for groundwater contamination by heavy metals through soil passage under acidifying conditions

NARCIS (Netherlands)

Wilkens, B.J,

1995-01-01

The research reported here is aimed at improving the knowledge of the mobility of the heavy metals cadmium and zinc in vulnerable soil types. We use the term vulnerable with reference to vulnerability of groundwater for contamination by soil leaching. At diffuse soil immissions of heavy

Change of physical and chemical composition of soil washing out during vegetation season from differently used fields

Science.gov (United States)

Baryła, A.; Pierzgalski, E.; Karczmarczyk, A.

2009-04-01

oil losses due to water erosion not only decrease of soil fertility but also influence on pollution of water bodies. One of the method for limitation of water erosion process is protected soil management and choose suitable plants which requires knowledge about effect and mechanism of erosion under different environmental conditions. The results of measurements of quantity and quality of soil losses from three experimental plots are given in the article. Plots were located in Experimental Agricultural Station Puczniew in central part of Poland. Surface soil layer on the plots had mechanical composition of medium loam soil. On two plots grass and barley were planted. Third plot was used as fallow and tilled land. Measurements were carried out four times in the period May-October 2007. Physical and chemical composition of washed soil material was analyzed.

Abacus to determine soils salinity in presence of saline groundwater in arid zones case of the region of Ouargla

Science.gov (United States)

Fergougui, Myriam Marie El; Benyamina, Hind; Boutoutaou, Djamel

2018-05-01

In order to remedy the limit of salt intake to the soil surface, it is necessary to study the causes of the soil salinity and find the origin of these salts. The arid areas in the region of Ouargla lie on excessively mineralized groundwater whose level is near the soil surface (0 - 1.5 m). The topography and absence of a reliable drainage system led to the rise of the groundwater beside the arid climatic conditions contributed to the salinization and hydromorphy of the soils. The progress and stabilization of cultures yields in these areas can only occur if the groundwater is maintained (drained) to a depth of 1.6 m. The results of works done to the determination of soil salinity depend mainly on the groundwater's salinity, its depth and the climate.

Soil, Groundwater, Surface Water, and Sediments of Kennedy Space Center, Florida: Background Chemical and Physical Characteristics

Science.gov (United States)

Shmalzer, Paul A.; Hensley, Melissa A.; Mota, Mario; Hall, Carlton R.; Dunlevy, Colleen A.

2000-01-01

This study documented background chemical composition of soils, groundwater, surface; water, and sediments of Kennedy Space Center. Two hundred soil samples were collected, 20 each in 10 soil classes. Fifty-one groundwater wells were installed in 4 subaquifers of the Surficial Aquifer and sampled; there were 24 shallow, 16 intermediate, and 11 deep wells. Forty surface water and sediment samples were collected in major watershed basins. All samples were away from sites of known contamination. Samples were analyzed for organochlorine pesticides, aroclors, chlorinated herbicides, polycyclic aromatic hydrocarbons (PAH), total metals, and other parameters. All aroclors (6) were below detection in all media. Some organochlorine pesticides were detected at very low frequencies in soil, sediment, and surface water. Chlorinated herbicides were detected at very low frequencies in soil and sediments. PAH occurred in low frequencies in soiL, shallow groundwater, surface water, and sediments. Concentrations of some metals differed among soil classes, with subaquifers and depths, and among watershed basins for surface water but not sediments. Most of the variation in metal concentrations was natural, but agriculture had increased Cr, Cu, Mn, and Zn.

Investigation of the mobilizability of persistent pollutants in the system groundwater/soil/plant of a former fen

International Nuclear Information System (INIS)

Hein, D.; Goertz, W.; Leisner-Saaber, J.; Rathje, M.

1993-01-01

For a former fen situated at the eastern border of the Lower terraces of the river Rhine in the close neighbourhood of densely populated urban districts a biotope-managementplan suggests the rewetting and restauration of typical landscape forms. High concentrations of heavy metals and low pH-values of the soil imply a potential danger especially for the groundwater. In order to solve this conflict between the aims of protecting rare biotopes and of saving groundwater-resources investigations were carried out considering all environmental compartments concerned: groundwater, surfacewater, soil and plants. The results demonstate that a step-by-step rewetting of the area is possible without a previous exchange of soil. In addition, careful groundwater control has to be carried out. (orig.) [de

Methodology of determining soil structure in important groundwater areas: case studies in Kauvonkangas, Finnish Lapland

Science.gov (United States)

Kupila, Juho

2016-04-01

Finland is fully self-sufficient in clean groundwater and even has a capacity of exportation. There are approx. 6000 groundwater areas with a total yield of 5.4 million m3/day. Currently only 10% of this groundwater resource is in use. For the efficient and safe exploitation of these areas in the future, detailed modeling of soil structure is an important method in groundwater surveys. 3D -models improve the general knowledge of linkage between land use planning and groundwater protection. Results can be used as a base information in water supply service development and when performing the measures needed in case of environmental accidents. Also, when creating the groundwater flow models the collected information is utilized and is usually the main data source. Geological Survey of Finland has carried out soil structure studies in co-operation with authorities, municipalities and the local water suppliers. The main objectives of these projects are to determine the geological structure of groundwater area for estimating the validity of the present exclusion area, the quantity of ground water volume and recharge capability and possible risks to the groundwater. Research areas are usually under an active water supply service. Kauvonkangas groundwater area is located in the municipality of Tervola, in Southern part of Finnish Lapland. Extent of the area is 7.9 km2 and it is an important water source for the local and nearby population centers. There are two active water supply companies in the area. Field studies in the project will include general geological and hydrological mapping, soil drilling with observation pipe installation, test pumping and water sampling. Geophysical measures will play a key-role, including ground penetrating radar (GPR) and gravimetric measurements. Studies will be carried out in spring and summer 2016. The main results will be the models of the bedrock and groundwater level and main characteristics of the soil layers in the area. Results

Soil, groundwater cleanup takes the gamble out of casino operation

International Nuclear Information System (INIS)

Anon.

1993-01-01

Colorado's rich stores of gold and silver sparked development of towns like Black Hawk and Central City in the 1890s. Today, these communities are the homes of limited-stakes gaming operations. However casino operators are discovering that having gold and silver underground in the form of tailings is not as desirable as collecting it aboveground in slot machines. A unique environmental engineering approach allowed construction of two new casinos and reclamation of the tailings, as well as cleanup of petroleum-saturated soils and groundwater. A treatment system was designed and constructed to treat groundwater at the Black Hawk site. The most economical alternative for disposing treated groundwater was to discharge it into nearby North Clear Creek. An NPDES permit was obtained requiring treatment of the groundwater for petroleum, heavy metals and pH before discharging it

Connecting carbon and nitrogen storage in rural wetland soil to groundwater abstraction for urban water supply.

Science.gov (United States)

Lewis, David Bruce; Feit, Sharon J

2015-04-01

We investigated whether groundwater abstraction for urban water supply diminishes the storage of carbon (C), nitrogen (N), and organic matter in the soil of rural wetlands. Wetland soil organic matter (SOM) benefits air and water quality by sequestering large masses of C and N. Yet, the accumulation of wetland SOM depends on soil inundation, so we hypothesized that groundwater abstraction would diminish stocks of SOM, C, and N in wetland soils. Predictions of this hypothesis were tested in two types of subtropical, depressional-basin wetland: forested swamps and herbaceous-vegetation marshes. In west-central Florida, >650 ML groundwater day(-1) are abstracted for use primarily in the Tampa Bay metropolis. At higher abstraction volumes, water tables were lower and wetlands had shorter hydroperiods (less time inundated). In turn, wetlands with shorter hydroperiods had 50-60% less SOM, C, and N per kg soil. In swamps, SOM loss caused soil bulk density to double, so areal soil C and N storage per m(2) through 30.5 cm depth was diminished by 25-30% in short-hydroperiod swamps. In herbaceous-vegetation marshes, short hydroperiods caused a sharper decline in N than in C. Soil organic matter, C, and N pools were not correlated with soil texture or with wetland draining-reflooding frequency. Many years of shortened hydroperiod were probably required to diminish soil organic matter, C, and N pools by the magnitudes we observed. This diminution might have occurred decades ago, but could be maintained contemporarily by the failure each year of chronically drained soils to retain new organic matter inputs. In sum, our study attributes the contraction of hydroperiod and loss of soil organic matter, C, and N from rural wetlands to groundwater abstraction performed largely for urban water supply, revealing teleconnections between rural ecosystem change and urban resource demand. © 2014 John Wiley & Sons Ltd.

Assessment of groundwater and soil quality degradation using multivariate and geostatistical analyses, Dakhla Oasis, Egypt

Science.gov (United States)

Masoud, Alaa A.; El-Horiny, Mohamed M.; Atwia, Mohamed G.; Gemail, Khaled S.; Koike, Katsuaki

2018-06-01

Salinization of groundwater and soil resources has long been a serious environmental hazard in arid regions. This study was conducted to investigate and document the factors controlling such salinization and their inter-relationships in the Dakhla Oasis (Egypt). To accomplish this, 60 groundwater samples and 31 soil samples were collected in February 2014. Factor analysis (FA) and hierarchical cluster analysis (HCA) were integrated with geostatistical analyses to characterize the chemical properties of groundwater and soil and their spatial patterns, identify the factors controlling the pattern variability, and clarify the salinization mechanism. Groundwater quality standards revealed emergence of salinization (av. 885.8 mg/L) and extreme occurrences of Fe2+ (av. 17.22 mg/L) and Mn2+ (av. 2.38 mg/L). Soils were highly salt-affected (av. 15.2 dS m-1) and slightly alkaline (av. pH = 7.7). Evaporation and ion-exchange processes governed the evolution of two main water types: Na-Cl (52%) and Ca-Mg-Cl (47%), respectively. Salinization leads the chemical variability of both resources. Distinctive patterns of slight salinization marked the northern part and intense salinization marked the middle and southern parts. Congruence in the resources clusters confirmed common geology, soil types, and urban and agricultural practices. Minimizing the environmental and socioeconomic impacts of the resources salinization urges the need for better understanding of the hydrochemical characteristics and prediction of quality changes.

Paleotemperatures derived from noble gases dissolved in groundwater and in relation to soil temperature

International Nuclear Information System (INIS)

Stute, M.; Sonntag, C.

1992-01-01

Measurements of He, Ne, Ar, Kr and Xe dissolved in groundwater at two sites (Bocholt, Germany, and the Great Hungarian Plain) were taken to prove the reliability of noble gas temperatures as indicators of paleotemperatures. Noble gas temperatures of groundwater of Holocene age were found to reflect the annual mean soil temperature in the recharge are with an accuracy close to the precision of measurement (1σ approx. ±0.5 deg. C). Noble gas temperature data demonstrate the influence of vegetation cover on the soil temperature in the infiltration area. Groundwater formed in forests at the Bocholt site shows noble gas temperatures that are 2.2 deg. C lower than the groundwater formed in fields or meadows. The temperature data obtained from groundwater of the Great Hungarian Plain for the last glaciation are ≥ 8.6 deg. C lower than data from recent groundwater for maximum glaciation (approx. 18,000 years ago) and 4.7 ± 1 deg. C lower for the preceding interstadial (approx. 28,000-35,000 years ago). These data permit independent reconstruction of paleoclimatic conditions. (author). 19 refs, 3 figs, 1 tab

Little Puerco Wash-Catalpa Canyon Floodplain Management Study

Data.gov (United States)

Earth Data Analysis Center, University of New Mexico — The City of Gallup requested the Soil Conservation Service, through the McKinley Soil and Water Conservation District, to conduct a study of the Little Puerco Wash...

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.

In-situ remediation system for groundwater and soils

Science.gov (United States)

Corey, John C.; Kaback, Dawn S.; Looney, Brian B.

1993-01-01

A method and system for in-situ remediation of contaminated groundwater and soil where the contaminants, such as toxic metals, are carried in a subsurface plume. The method comprises selection and injection into the soil of a fluid that will cause the contaminants to form stable, non-toxic compounds either directly by combining with the contaminants or indirectly by creating conditions in the soil or changing the conditions of the soil so that the formation of stable, non-toxic compounds between the contaminants and existing substances in the soil are more favorable. In the case of non-toxic metal contaminants, sulfides or sulfates are injected so that metal sulfides or sulfates are formed. Alternatively, an inert gas may be injected to stimulate microorganisms in the soil to produce sulfides which, in turn, react with the metal contaminants. Preferably, two wells are used, one to inject the fluid and one to extract the unused portion of the fluid. The two wells work in combination to create a flow of the fluid across the plume to achieve better, more rapid mixing of the fluid and the contaminants.

Recovery of soil water, groundwater, and streamwater from acidification at the Swedish integrated monitoring catchments.

Science.gov (United States)

Löfgren, Stefan; Aastrup, Mats; Bringmark, Lage; Hultberg, Hans; Lewin-Pihlblad, Lotta; Lundin, Lars; Karlsson, Gunilla Pihl; Thunholm, Bo

2011-12-01

Recovery from anthropogenic acidification in streams and lakes is well documented across the northern hemisphere. In this study, we use 1996-2009 data from the four Swedish Integrated Monitoring catchments to evaluate how the declining sulfur deposition has affected sulfate, pH, acid neutralizing capacity, ionic strength, aluminum, and dissolved organic carbon in soil water, groundwater and runoff. Differences in recovery rates between catchments, between recharge and discharge areas and between soil water and groundwater are assessed. At the IM sites, atmospheric deposition is the main human impact. The chemical trends were weakly correlated to the sulfur deposition decline. Other factors, such as marine influence and catchment features, seem to be as important. Except for pH and DOC, soil water and groundwater showed similar trends. Discharge areas acted as buffers, dampening the trends in streamwater. Further monitoring and modeling of these hydraulically active sites should be encouraged.

Arsenic and metallic trace elements cycling in the surface water-groundwater-soil continuum down-gradient from a reclaimed mine area: Isotopic imprints

Science.gov (United States)

Khaska, Mahmoud; Le Gal La Salle, Corinne; Sassine, Lara; Cary, Lise; Bruguier, Olivier; Verdoux, Patrick

2018-03-01

One decade after closure of the Salsigne mine (SW France), As contamination persisted in surface water, groundwater and soil near and down-gradient from the reclaimed ore processing site (OPS). We assess the fate of As and other associated chalcophilic MTEs, and their transport in the surface-water/groundwater/soil continuum down-gradient from the reclaimed OPS, using Sr-isotopic fingerprinting. The Sr-isotope ratio was used as a tracer of transfer processes in this hydro-geosystem and was combined to sequential extraction of soil samples to evaluate the impact of contaminated soil on the underlying phreatic groundwater. The contrast in Sr isotope compositions of the different soil fractions reflects several Sr sources in the soil. In the complex hydro-geosystem around the OPS, the transport of As and MTEs is affected by a succession of factors, such as (1) Existence of a reducing zone in the aquifer below the reclaimed OPS, where groundwater shows relatively high As and MTEs contents, (2) Groundwater discharge into the stream near the reclaimed OPS causing an increase in As and MTE concentrations in surface water; (3) Partial co-precipitation of As with Fe-oxyhydroxides, contributing to some attenuation of As contents in surface water; (4) Infiltration of contaminated stream water into the unconfined aquifer down-gradient from the reclaimed OPS; (5) Accumulation of As and MTEs in soil irrigated with contaminated stream- and groundwater; (6) Release of As and MTEs from labile soil fractions to underlying the groundwater.

Impact of groundwater levels on evaporation and water-vapor fluxes in highly saline soils

Science.gov (United States)

Munoz, J. F.; Hernández, M. F.; Braud, I.; Gironas, J. A.; Suarez, F. I.

2012-12-01

In aquifers of arid and hyper-arid zones, such as those occurring in the Chilean Andes high plateau, it is important to determine both the quantity and location of water discharges at the temporal scales of interest to close the basin's water budget and thus, to manage the water resource properly. In zones where shallow aquifers are the main source of water, overexploitation of the water resource changes the dynamics of water, heat and solute transport in the vadose zone. As aquifers are exploited, fluctuations in depth to groundwater are exacerbated. These fluctuations modify both soil structure and evaporation from the ground, which is typically the most important discharge from the water budget and is very difficult to estimate. Therefore, a correct quantification of evaporation from these soils is essential to improve the accuracy of the water balance estimation. The objective of this study was to investigate the evaporation processes and water-vapor fluxes in a soil column filled with a saline soil from the Salar del Huasco basin, Chile. Water content, electrical conductivity and temperature at different depths in the soil profile were monitored to determine the liquid and vapor fluxes within the soil column. The results showed that evaporation is negligible when the groundwater table is deeper than 1 m. For shallower groundwater levels, evaporation increases in an exponential fashion reaching a value of 3 mm/day when the groundwater table is near the surface of the ground. These evaporation rates are on the same order of magnitude than the field measurements, but slightly lower due to the controlled conditions maintained in the laboratory. Isothermal fluid fluxes were predominant over the non-isothermal fluid and water vapor fluxes. The net flux for all the phreatic levels tested in the laboratory showed different behaviors, with ascending or descending flows as a consequence of changes in water content and temperature distribution within the soil. It was

Radionuclide content of Las Vegas wash sediments

International Nuclear Information System (INIS)

Rudin, M.J.; Meyers, A.M.; Johnson, W.H.

1996-01-01

The Las Vegas Wash is an excavated waterway channel which drains all surface water and effluent discharge from sewage-treatment facilities from the greater Las Vegas Metropolitan Area to Lake Mead. Runoff and erosion processes are expected to transport man-made radioactivity that was deposited over the past several decades in the Las Vegas Valley. Additionally, radionuclides disposed of via the city's sanitary system are expected to accumulate in the Wash sediments. Fine and coarse sediment samples were collected at 100 m intervals and analyzed to determine the distribution of alpha- and gamma-emitting radionuclides in the lower 5,500 in of the Las Vegas Wash. Results indicate little accumulation of long-lived fission products in upstream Wash sediments. However, trace amounts of fission products measured in downstream sediments suggest the resuspension and transport of radioactive particulate matter within the Wash. Levels of naturally-occurring radionuclides found in Wash sediments were found to be consistent with levels typically found in southeast Nevada soils

Impact of groundwater capillary rises as lower boundary conditions for soil moisture in a land surface model

Science.gov (United States)

Vergnes, Jean-Pierre; Decharme, Bertrand; Habets, Florence

2014-05-01

Groundwater is a key component of the global hydrological cycle. It sustains base flow in humid climate while it receives seepage in arid region. Moreover, groundwater influences soil moisture through water capillary rise into the soil and potentially affects the energy and water budget between the land surface and the atmosphere. Despite its importance, most global climate models do not account for groundwater and their possible interaction with both the surface hydrology and the overlying atmosphere. This study assesses the impact of capillary rise from shallow groundwater on the simulated water budget over France. The groundwater scheme implemented in the Total Runoff Integrated Pathways (TRIP) river routing model in a previous study is coupled with the Interaction between Soil Biosphere Atmosphere (ISBA) land surface model. In this coupling, the simulated water table depth acts as the lower boundary condition for the soil moisture diffusivity equation. An original parameterization accounting for the subgrid elevation inside each grid cell is proposed in order to compute this fully-coupled soil lower boundary condition. Simulations are performed at high (1/12°) and low (0.5°) resolutions and evaluated over the 1989-2009 period. Compared to a free-drain experiment, upward capillary fluxes at the bottom of soil increase the mean annual evapotranspiration simulated over the aquifer domain by 3.12 % and 1.54 % at fine and low resolutions respectively. This process logically induces a decrease of the simulated recharge from ISBA to the aquifers and contributes to enhance the soil moisture memory. The simulated water table depths are then lowered, which induces a slight decrease of the simulated mean annual river discharges. However, the fully-coupled simulations compare well with river discharge and water table depth observations which confirms the relevance of the coupling formalism.

The impact of groundwater level on soil seed bank survival

NARCIS (Netherlands)

Bekker, RM; Oomes, MJM; Bakker, JP

Seed longevity of plant species is an important topic in restoration management, and little is known about the effects of environmental conditions on seed survival and longevity under natural conditions. Therefore, the effect of groundwater level on the survival of seeds in the soil seed bank of a

Responses of Water and Salt Parameters to Groundwater Levels for Soil Columns Planted with Tamarix chinensis

Science.gov (United States)

Xia, Jiangbao; Zhao, Ximei; Chen, Yinping; Fang, Ying; Zhao, Ziguo

2016-01-01

Groundwater is the main water resource for plant growth and development in the saline soil of the Yellow River Delta in China. To investigate the variabilities and distributions of soil water and salt contents at various groundwater level (GL), soil columns with planting Tamarix chinensis Lour were established at six different GL. The results demonstrated the following: With increasing GL, the relative soil water content (RWC) declined significantly, whereas the salt content (SC) and absolute soil solution concentration (CS) decreased after the initial increase in the different soil profiles. A GL of 1.2 m was the turning point for variations in the soil water and salt contents, and it represented the highest GL that could maintain the soil surface moist within the soil columns. Both the SC and CS reached the maximum levels in these different soil profiles at a GL of 1.2 m. With the raise of soil depth, the RWC increased significantly, whereas the SC increased after an initial decrease. The mean SC values reached 0.96% in the top soil layer; however, the rates at which the CS and RWC decreased with the GL were significantly reduced. The RWC and SC presented the greatest variations at the medium (0.9–1.2 m) and shallow water levels (0.6 m) respectively, whereas the CS presented the greatest variation at the deep water level (1.5–1.8 m).The RWC, SC and CS in the soil columns were all closely related to the GL. However, the correlations among the parameters varied greatly within different soil profiles, and the most accurate predictions of the GL were derived from the RWC in the shallow soil layer or the SC in the top soil layer. A GL at 1.5–1.8 m was moderate for planting T. chinensis seedlings under saline groundwater conditions. PMID:26730602

Responses of Water and Salt Parameters to Groundwater Levels for Soil Columns Planted with Tamarix chinensis.

Science.gov (United States)

Xia, Jiangbao; Zhao, Ximei; Chen, Yinping; Fang, Ying; Zhao, Ziguo

2016-01-01

Groundwater is the main water resource for plant growth and development in the saline soil of the Yellow River Delta in China. To investigate the variabilities and distributions of soil water and salt contents at various groundwater level (GL), soil columns with planting Tamarix chinensis Lour were established at six different GL. The results demonstrated the following: With increasing GL, the relative soil water content (RWC) declined significantly, whereas the salt content (SC) and absolute soil solution concentration (CS) decreased after the initial increase in the different soil profiles. A GL of 1.2 m was the turning point for variations in the soil water and salt contents, and it represented the highest GL that could maintain the soil surface moist within the soil columns. Both the SC and CS reached the maximum levels in these different soil profiles at a GL of 1.2 m. With the raise of soil depth, the RWC increased significantly, whereas the SC increased after an initial decrease. The mean SC values reached 0.96% in the top soil layer; however, the rates at which the CS and RWC decreased with the GL were significantly reduced. The RWC and SC presented the greatest variations at the medium (0.9-1.2 m) and shallow water levels (0.6 m) respectively, whereas the CS presented the greatest variation at the deep water level (1.5-1.8 m).The RWC, SC and CS in the soil columns were all closely related to the GL. However, the correlations among the parameters varied greatly within different soil profiles, and the most accurate predictions of the GL were derived from the RWC in the shallow soil layer or the SC in the top soil layer. A GL at 1.5-1.8 m was moderate for planting T. chinensis seedlings under saline groundwater conditions.

Responses of Water and Salt Parameters to Groundwater Levels for Soil Columns Planted with Tamarix chinensis.

Directory of Open Access Journals (Sweden)

Jiangbao Xia

Full Text Available Groundwater is the main water resource for plant growth and development in the saline soil of the Yellow River Delta in China. To investigate the variabilities and distributions of soil water and salt contents at various groundwater level (GL, soil columns with planting Tamarix chinensis Lour were established at six different GL. The results demonstrated the following: With increasing GL, the relative soil water content (RWC declined significantly, whereas the salt content (SC and absolute soil solution concentration (CS decreased after the initial increase in the different soil profiles. A GL of 1.2 m was the turning point for variations in the soil water and salt contents, and it represented the highest GL that could maintain the soil surface moist within the soil columns. Both the SC and CS reached the maximum levels in these different soil profiles at a GL of 1.2 m. With the raise of soil depth, the RWC increased significantly, whereas the SC increased after an initial decrease. The mean SC values reached 0.96% in the top soil layer; however, the rates at which the CS and RWC decreased with the GL were significantly reduced. The RWC and SC presented the greatest variations at the medium (0.9-1.2 m and shallow water levels (0.6 m respectively, whereas the CS presented the greatest variation at the deep water level (1.5-1.8 m.The RWC, SC and CS in the soil columns were all closely related to the GL. However, the correlations among the parameters varied greatly within different soil profiles, and the most accurate predictions of the GL were derived from the RWC in the shallow soil layer or the SC in the top soil layer. A GL at 1.5-1.8 m was moderate for planting T. chinensis seedlings under saline groundwater conditions.

The use of in-situ dual vacuum extraction for remediation of soil and groundwater

International Nuclear Information System (INIS)

Trowbridge, B.E.; Ott, D.E.

1992-01-01

Dual Extraction provides a rapid and cost-effective method of remediating soil and groundwater impacted by volatile organic compounds (VOC's). Dual Extraction is the removal of both water and vapors through the same borehole using entrainment. This technology provides for the remediation of the vadose zone, capillary fringe, smear zone, and existing water table. The effectiveness of this technology is shown in a case study. A release from an Underground Storage Tank (UST) was responsible for a hydrocarbon plume spreading over approximately 50,000 square feet. The release produced vadose zone contamination in the silty and sandy clays from 10 - 30 feet below ground surface with TPH concentrations up to 1,400 mg/kg. A layer of free floating liquid hydrocarbon was present on a shallow aquifer located at 30 feet bgs in thicknesses ranging from 0.5 feet to 3.0 feet. An in-situ dual-extraction system was installed to remediate the soils and groundwater to levels as required by the Los Angeles Regional Water Quality Control Board (RWQCB). The system operated 24 hours/day for 196 days with an operating efficiency of over 99%. After 196 days, over 17,000 pounds of hydrocarbons had been extracted from the soils. Seven confirmatory soil borings were advanced in the area of highest initial hydrocarbon concentrations and indicated that TPH and BTEX concentrations had decreased over 99% from initial soil concentrations. Three confirmatory groundwater samples were obtained from monitoring wells initially exhibiting up to 3 feet of floating product. Confirmatory samples exhibited non-detectable (ND) concentrations of TPH and BTEX. Based upon the positive confirmatory results, site closure was obtained from the RWQCB in May of 1991. In only 28 weeks of operation, the groundwater contamination was reduced from free floating product to non-detectable concentrations of TPH using Dual Vacuum Extraction

The use of soil moisture - remote sensing products for large-scale groundwater modeling and assessment

NARCIS (Netherlands)

Sutanudjaja, E.H.

2012-01-01

In this thesis, the possibilities of using spaceborne remote sensing for large-scale groundwater modeling are explored. We focus on a soil moisture product called European Remote Sensing Soil Water Index (ERS SWI, Wagner et al., 1999) - representing the upper profile soil moisture. As a test-bed, we

Biodegradation of cyanide in groundwater and soils from gasworks sites in south-eastern Australia

Energy Technology Data Exchange (ETDEWEB)

Meehan, S.M.E.; Weaver, T.R.; Lawrence, C.R. [University of Melbourne, Parkvills, Vic. (Australia). School of Earth Sciences

1999-07-01

Groundwater from a gasworks site in south-eastern Australia has been found to contain high concentrations of cyanide (total), sulphate, and ammonia (1400 mg L{sup -1}, 6500 mg L{sup -1}, and 580 mg L{sup -1} respectively). Soil from another gasworks site has been found to contain 587 mg kg{sup -1} of cyanide (total), with concentrations of cyanide in the groundwater at this site being relatively low ({lt} 21 mgL{sup -1} CN(Total)). Experiments were conducted to determine the biodegradation rates of cyanide in groundwater and soils using samples from both sites. Column experiments and bioreactors were constructed to produce both aerobic and anaerobic conditions for the groundwater containing high concentrations of cyanide. Samples of water were taken periodically to analyse the pH, redox potential, temperature, and concentrations of cyanide (free and total), sulphate, ammonia, nitrate and dissolved organic carbon (DOC). Initial results indicate that concentrations of cyanide are declining in both aerobic and anaerobic conditions, with biodegradation one process producing degradation. 9 refs., 4 figs., 2 tabs.

Preliminary study of depleted uranium aerosol migration in soils

International Nuclear Information System (INIS)

Guo Zhiying; Yu Shui; Zheng Yonghong; Liang Yueqin; Liu Liping; Song Zhanjun; Zhao Fa

2007-01-01

Objective: To explore the depth of depleted uranium (DU) migration in six main kinds of Chinese soils and the pollution of the groundwater made by DU migration. Methods: With the circulating column model and the inductively coupled plasma-mass spectrometry (ICP-MS), concentration of uranium and the ratio of 235 U/ 238 U in different depth soils and in the corresponding filter liquids had been determined. Results: In the acid rain of pH 3.0, the migration depth of DU in the washed soil and brown soil were 6-8 cm and 4-6 cm, respectively. And with the increment of the acidity of the acid rain, the migration depth of DU in the soils was increased. The migration depth of DU in the 6 types soils was 0-4 cm. The distributed factor between the liquids and soils was lower than 0.004, and the concentration of uranium in the filter liquids was 0.05-10.33 μg/L. Conclusions: The migration depth of DU in soils can be increased by the acid rain, and the majority of DU was stayed in the upper soils and DU pollution might exist for long time, but the probability of groundwater pollution was low. The migration capability of DU was interrelated with the concentration of organic compound in the soils. (authors)

PHYTOREMEDIATION: USING PLANTS TO CLEAN UP CONTAMINATED SOIL, GROUNDWATER, AND WASTEWATER

Science.gov (United States)

Phytoremediation is an emerging cleanup technology for contaminated soils, groundwater, and wastewater that is both low-tech and low-cost. The cleanup technology is defined as the use of green plants to remove, contain, or render harmless such environmental contaminants as heavy ...

Washing of Cloth Contaminated with Radionuclides Using a Detergent-free Laundry System

Energy Technology Data Exchange (ETDEWEB)

Yim, Sung Paal

2005-07-01

In this study, a new laundry system to wash clothes without using detergent (detergent-free) was applied to wash clothes contaminated with radionuclides at the RWTF of KAERI. If the clothes contaminated with radionuclides and soil decontaminated and cleaned by washing without using detergent, the problem caused by the detergent could be solved naturally. The experiment was performed in two stages. In the first stage, washability of the processed water from the detergent=free laundry system was investigated with regard to its decontamination efficiency for the radionuclides and the detergency for the soil by using the test cloth specimens. In the second stage, real working clothes contaminated with radionuclides from the RWTF were washed by using a laundry machine equipped with a detergent-free system. Decontamination and detergency of the clothes were estimated after washing and the wastewater was also analyzed for its properties.

Shifts in pore connectivity from precipitation versus groundwater rewetting increases soil carbon loss after drought

Energy Technology Data Exchange (ETDEWEB)

Smith, Ashly P.; Bond-Lamberty, Benjamin; Benscoter, Brian W.; Tfaily, Malak M.; Hinkle, Ross; Liu, Chongxuan; Bailey, Vanessa L.

2017-11-06

Droughts and other extreme precipitation events are predicted to increase in intensity, duration and extent, with uncertain implications for terrestrial carbon (C) sequestration. Soil wetting from above (precipitation) results in a characteristically different pattern of pore-filling than wetting from below (groundwater), with larger, well-connected pores filling before finer pore spaces, unlike groundwater rise in which capillary forces saturate the finest pores first. Here we demonstrate that pore-scale wetting patterns interact with antecedent soil moisture conditions to alter pore-, core- and field-scale C dynamics. Drought legacy and wetting direction are perhaps more important determinants of short-term C mineralization than current soil moisture content in these soils. Our results highlight that microbial access to C is not solely limited by physical protection, but also by drought or wetting-induced shifts in hydrologic connectivity. We argue that models should treat soil moisture within a three-dimensional framework emphasizing hydrologic conduits for C and resource diffusion.

ERC hazard classification matrices for above ground structures and groundwater and soil remediation activities

International Nuclear Information System (INIS)

Curry, L.R.

1997-01-01

This document provides the status of the preliminary hazard classification (PHC) process for the Environmental Restoration Contractor (ERC) above ground structures and groundwater and soil remediation activities currently underway for planned for fiscal year (FY) 1997. This classification process is based on current US Department of Energy (DOE), Richland Operations Office (RL) guidance for the classification of facilities and activities containing radionuclide and nonradiological hazardous material inventories. The above ground structures presented in the matrices were drawn from the Bechtel Hanford, Inc. (BHI) Decontamination and Decommissioning (D and D) Project Facility List (DOE 1996), which identifies the facilities in the RL-Environmental Restoration baseline contract in 1997. This document contains the following two appendices: (1) Appendix A, which consists of a matrix identifying PHC documents that have been issued for BHI's above ground structures and groundwater and soil remediation activities underway or planned for FY 1997, and (2) Appendix B, which consists of a matrix showing anticipated PHCs for above ground structures, and groundwater and soil remediation activities underway or planned for FY 1997. Appendix B also shows the schedule for finalization of PHCs for above ground structures with an anticipated classification of Nuclear

Toxicity test of the F-Area seep soils by laboratory lettuce seed germination and seedling growth

International Nuclear Information System (INIS)

Eaton, D.; Murphy, C.E.

1993-09-01

This study is a follow-up of a similar study done by Loehle (1990). The objectives of the original study were to: (1) measure the toxicity of groundwater contaminated by the F-Area seepage basins where this water surfaces in a seepline along Fourmile Branch and (2) to evaluate the effectiveness of rainwater for washing contaminants from the soil. Results of seed germination tests show no significant difference between water extracted from one extraction of F-Area seepline soil, soil from a control area, the sixth consecutive extraction from F-Area soil, and a deionized water control. A root-growth assay on the same seeds shows a significant effect with the order of growth, first extraction of F-Area soil< control site< deionized watersoil at the F-Area seepline, but there is still some evidence of phytotoxicity in this soil. As shown previously, the cause of the toxicity is removed by soil washing, suggesting that continued improvement should be expected

In-situ remediation of brine impacted soils and groundwater using hydraulic fracturing, desalinization and recharge wells

Energy Technology Data Exchange (ETDEWEB)

Robertson, C. [Wiebe Environmental Services Inc., Calgary, AB (Canada); Ratiu, I. [GeoGrid Environmental Inc., Calgary, AB (Canada)

2006-07-01

This conference presentation focused on the in-stu remediation of brine impacted soils and groundwater using hydraulic fracturing, desalinization and recharge wells. A former oil battery was established in the 1940s, decommissioned in the late 1960s with a reclamation certificate issued in 1972. The land owner reported poor vegetative growth in the former battery area. The purpose of the study was to investigate the cause of poor growth and delineate contaminants of concern and to remediate impacted soil and groundwater associated with the former battery site. The investigation involved agrological, geophysical and hydrogeological investigation into the extent of anthropogenic impacts as well as the development of remediation options and plans to deal with issues of concern. The presentation provided the results of the investigation, options identified, and discussed limitation on salt remediation and treatment of saline soils. Other topics included hydraulic fracturing, injection wells that were installed to re-circulate treated groundwater though the salt plume, desalinization processes, and next steps. figs.

Treating soil-washing fluids polluted with oxyfluorfen by sono-electrolysis with diamond anodes.

Science.gov (United States)

Vieira Dos Santos, E; Sáez, C; Cañizares, P; Martínez-Huitle, C A; Rodrigo, M A

2017-01-01

This works is focused on the treatment by sono-electrolysis of the liquid effluents produced during the Surfactant-Aided Soil-Washing (SASW) of soils spiked with herbicide oxyfluorfen. Results show that this combined technology is very efficient and attains the complete mineralization of the waste, regardless of the surfactant/soil radio applied in the SASW process (which is the main parameter of the soil remediation process and leads to very different wastes). Both the surfactant and the herbicide are completely degraded, even when single electrolysis is used; and only two intermediates are detected by HPLC in very low concentrations. Conversely, the efficiency of single sonolysis approach, for the oxidation of pollutant, is very low and just small changes in the herbicides and surfactant concentrations are observed during the tests carried out. Sono-electrolysis with diamond electrodes achieved higher degradation rates than those obtained by single sonolysis and/or single electrolysis with diamond anodes. A key role of sulfate is developed, when it is released after the electrochemical degradation of surfactant. The efficient catalytic effect observed which can be explained by the anodic formation of persulfate and the later, a sono-activation is attained to produce highly efficient sulfate radicals. The effect of irradiating US is more importantly observed in the pesticide than in the surfactant, in agreement with the well-known behavior of these radicals which are known to oxidize more efficiently aromatic compounds than aliphatic species. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessment of groundwater and soil quality for agricultural purposes in Kopruoren basin, Kutahya, Turkey

Science.gov (United States)

Arslan, Sebnem

2017-07-01

This research evaluated the irrigation water and agricultural soil quality in the Kopruoren Basin by using hierarchical cluster analysis. Physico-chemical properties and major ion chemistry of 19 groundwater samples were used to determine the irrigation water quality indices. The results revealed out that the groundwaters are in general suitable for irrigation and have low sodium hazard, although they are very hard in nature due to the dominant presence of Ca+2, Mg+2 and HCO3- ions. Water samples contain arsenic in concentrations below the recommended guidelines for irrigation (59.7 ± 14.7 μg/l), however, arsenic concentrations in 89% of the 9 soil samples exceed the maximum allowable concentrations set for agricultural soils (81 ± 24.3 mg/kg). Nickel element, albeit not present in high concentrations in water samples, is enriched in all of the agricultural soil samples (390 ± 118.2 mg/kg). Hierarchical cluster analysis studies conducted to identify the sources of chemical constituents in water and soil samples elicited that the chemistry of the soils in the study area are highly impacted by the soil parent material and both geogenic and anthropogenic pollution sources are responsible for the metal contents of the soil samples. On the other hand, water chemistry in the area is affected by water-rock interactions, anthropogenic and agricultural pollution.

Selected hydrologic data from Fortymile Wash in the Yucca Mountain area, Nevada, water years 1993--94

Energy Technology Data Exchange (ETDEWEB)

Savard, C.S.

1996-09-01

The Yucca Mountain area is being evaluated by the US Department of Energy for its suitability to store high-level nuclear waste in a mined, underground repository. Hydrologic data are being collected by the US Geological Survey throughout a 150 Km{sup 2} study area about 15- Km northwest of Las Vegas in southern Nevada for site characterization studies. Ongoing hydrologic studies are investigating atmospheric precipitation, stream-flow, movement of water through the unsaturated zone, movement of water through the saturated zone, and paleohydrology. This study at Fortymile Wash involves some components of each of these studies. Fortymile Wash is an ephemeral stream near Yucca Mountain with tributaries draining the east side of Yucca Mountain and then forming a distributary system in the Amargosa Desert. An objective of the study is to determine the amount of recharge from Fortymile Wash to the ground-water flow system that has been proposed. Understanding the ground-water flow system is important because it is a possible mechanism for radionuclide migration from the repository to the accessible environment. An adequate understanding of the ground-water flow system is necessary for an evaluation of the safety issues involved in siting the potential repository.

Complementary effects of surface water and groundwater on soil moisture dynamics in a degraded coastal floodplain forest

Science.gov (United States)

Kaplan, D.; Muñoz-Carpena, R.

2011-02-01

SummaryRestoration of degraded floodplain forests requires a robust understanding of surface water, groundwater, and vadose zone hydrology. Soil moisture is of particular importance for seed germination and seedling survival, but is difficult to monitor and often overlooked in wetland restoration studies. This research hypothesizes that the complex effects of surface water and shallow groundwater on the soil moisture dynamics of floodplain wetlands are spatially complementary. To test this hypothesis, 31 long-term (4-year) hydrological time series were collected in the floodplain of the Loxahatchee River (Florida, USA), where watershed modifications have led to reduced freshwater flow, altered hydroperiod and salinity, and a degraded ecosystem. Dynamic factor analysis (DFA), a time series dimension reduction technique, was applied to model temporal and spatial variation in 12 soil moisture time series as linear combinations of common trends (representing shared, but unexplained, variability) and explanatory variables (selected from 19 additional candidate hydrological time series). The resulting dynamic factor models yielded good predictions of observed soil moisture series (overall coefficient of efficiency = 0.90) by identifying surface water elevation, groundwater elevation, and net recharge (cumulative rainfall-cumulative evapotranspiration) as important explanatory variables. Strong and complementary linear relationships were found between floodplain elevation and surface water effects (slope = 0.72, R2 = 0.86, p < 0.001), and between elevation and groundwater effects (slope = -0.71, R2 = 0.71, p = 0.001), while the effect of net recharge was homogenous across the experimental transect (slope = 0.03, R2 = 0.05, p = 0.242). This study provides a quantitative insight into the spatial structure of groundwater and surface water effects on soil moisture that will be useful for refining monitoring plans and developing ecosystem restoration and management scenarios

Electrochemical remediation technologies for soil and groundwater

Energy Technology Data Exchange (ETDEWEB)

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

2001-07-01

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

A Geochemical Reaction Model for Titration of Contaminated Soil and Groundwater at the Oak Ridge Reservation

Science.gov (United States)

Zhang, F.; Parker, J. C.; Gu, B.; Luo, W.; Brooks, S. C.; Spalding, B. P.; Jardine, P. M.; Watson, D. B.

2007-12-01

This study investigates geochemical reactions during titration of contaminated soil and groundwater at the Oak Ridge Reservation in eastern Tennessee. The soils and groundwater exhibits low pH and high concentrations of aluminum, calcium, magnesium, manganese, various trace metals such as nickel and cobalt, and radionuclides such as uranium and technetium. The mobility of many of the contaminant species diminishes with increasing pH. However, base additions to increase pH are strongly buffered by various precipitation/dissolution and adsorption/desorption reactions. The ability to predict acid-base behavior and associated geochemical effects is thus critical to evaluate remediation performance of pH manipulation strategies. This study was undertaken to develop a practical but generally applicable geochemical model to predict aqueous and solid-phase speciation during soil and groundwater titration. To model titration in the presence of aquifer solids, an approach proposed by Spalding and Spalding (2001) was utilized, which treats aquifer solids as a polyprotic acid. Previous studies have shown that Fe and Al-oxyhydroxides strongly sorb dissolved Ni, U and Tc species. In this study, since the total Fe concentration is much smaller than that of Al, only ion exchange reactions associated with Al hydroxides are considered. An equilibrium reaction model that includes aqueous complexation, precipitation, ion exchange, and soil buffering reactions was developed and implemented in the code HydroGeoChem 5.0 (HGC5). Comparison of model results with experimental titration curves for contaminated groundwater alone and for soil- water systems indicated close agreement. This study is expected to facilitate field-scale modeling of geochemical processes under conditions with highly variable pH to develop practical methods to control contaminant mobility at geochemically complex sites.

Analysis and determination of age of oil spills in soil and groundwater

International Nuclear Information System (INIS)

Hoedl, P.; Schindlbauer, H.

1995-01-01

The extensive searching for hydrocarbon-based spills in soil and groundwater during the last few years rises the question of whom caused these contaminations. The answer to this very specific question is not easy and often requires the exact determination of age of the contamination. Therefore, the sampling of all imaginable data around the spilled material is necessary. Beginning at the precise check-up of the geological surrounding, including the definition of the condition and construction of the soil as well as the determination of the flow-direction of the groundwater, the chemical analysis should describe the containing substances and/or the products in the best possible way. Summing all these data and taking into consideration of the well-known microbiological pathways of decomposition for one- and/or a group of substances, it should be possible to determine the age of a contamination. (orig.) [de

Soil and geologic controls on recharge and groundwater flow response to climate perturbation: A case study of the Yakima River Basin

Science.gov (United States)

Nguyen, T. T.; Pham, H. V.; Bachmann, M.; Tague, C.; Adam, J. C.

2017-12-01

The Yakima River Basin (YRB) is one of the most important agricultural basins in Washington State with annual revenues in excess of $3.2 billion. This intensively irrigated basin is, however, one of the state's most climatically sensitive water resources system as it heavily relies on winter snowpack and limited reservoir storage. Water shortages and drought are expected to be more frequent with climate change, population growth and increasing agricultural demand. This could result in significant impacts on the groundwater system and subsequently the Yakima River. The goal of this study is to assess how soil and geologic characteristics affect catchment recharge and groundwater flow across three catchments within the YRB using a coupled framework including a physically based hydro-ecological model, the Regional Hydro-Ecologic Simulation System (RHESSys) and a groundwater model, MODFLOW. Soil and geologic-related parameters were randomly sampled to use within the Distributed Evaluation of Local Sensitivity Analysis (DELSA) framework to explore their roles in governing catchment recharge and groundwater flow to climate perturbation. Preliminarily results show that catchment recharge is most sensitive to variation in soil transmissivity in two catchments. However, in the other catchment, recharge is more influenced by soil field capacity and bypass recharge. Recharge is also more sensitive to geologic related parameters in catchments where a portion of its flow comes from deep groundwater. When including the effect of climate perturbations, the sensitivity of recharge responses to soil and geologic characteristics varies with temperature and precipitation change. On the other hand, horizontal hydraulic conductivity is the dominant factor that controls groundwater flow responses in catchments with low permeability soil; alternatively, specific storage (and, to some extent, vertical anisotropy) are important in catchments with more conductive soil. The modeling

Three-dimensional modeling of nitrate-N transport in vadose zone: Roles of soil heterogeneity and groundwater flux

Science.gov (United States)

Akbariyeh, Simin; Bartelt-Hunt, Shannon; Snow, Daniel; Li, Xu; Tang, Zhenghong; Li, Yusong

2018-04-01

Contamination of groundwater from nitrogen fertilizers in agricultural lands is an important environmental and water quality management issue. It is well recognized that in agriculturally intensive areas, fertilizers and pesticides may leach through the vadose zone and eventually reach groundwater. While numerical models are commonly used to simulate fate and transport of agricultural contaminants, few models have considered a controlled field work to investigate the influence of soil heterogeneity and groundwater flow on nitrate-N distribution in both root zone and deep vadose zone. In this work, a numerical model was developed to simulate nitrate-N transport and transformation beneath a center pivot-irrigated corn field on Nebraska Management System Evaluation area over a three-year period. The model was based on a realistic three-dimensional sediment lithology, as well as carefully controlled irrigation and fertilizer application plans. In parallel, a homogeneous soil domain, containing the major sediment type of the site (i.e. sandy loam), was developed to conduct the same water flow and nitrate-N leaching simulations. Simulated nitrate-N concentrations were compared with the monitored nitrate-N concentrations in 10 multi-level sampling wells over a three-year period. Although soil heterogeneity was mainly observed from top soil to 3 m below the surface, heterogeneity controlled the spatial distribution of nitrate-N concentration. Soil heterogeneity, however, has minimal impact on the total mass of nitrate-N in the domain. In the deeper saturated zone, short-term variations of nitrate-N concentration correlated with the groundwater level fluctuations.

Inorganic soil and groundwater chemistry near Paducah Gaseous Diffusion Plant, Paducah, Kentucky

Energy Technology Data Exchange (ETDEWEB)

Moore, G.K. [Tennessee Univ., Knoxville, TN (United States)

1995-03-01

Near-surface soils, boreholes, and sediments near the Paducah Gaseous Diffusion Plant (PGDP) were sampled in 1989-91 as were monitoring wells, TVA wells, and privately-owned wells. Most wells were sampled two or three times. The resulting chemical analyses have been published in previous reports and have been previously described (CH2M HILL 1991, 1992; Clausen et al. 1992). The two reports by CH2M HILL are controversial, however, because, the concentrations of some constituents were reported to exceed background levels or drinking water standards and because both on-site (within the perimeter fence at PGDP) and off-site pollution was reported to have occurred. The groundwater samples upon which these interpretations were based may not be representative, however. The CH2M HILL findings are discussed in the report. The purpose of this report is to characterize the inorganic chemistry of groundwater and soils near PGDP, using data from the CH2M HILL reports (1991, 1992), and to determine whether or not any contamination has occurred. The scope is limited to analysis and interpretation of data in the CH2M HILL reports because previous interpretations of these data may not be valid, because samples were collected in a relatively short period of time at several hundred locations, and because the chemical analyses are nearly complete. Recent water samples from the same wells were not considered because the characterization of inorganic chemistry for groundwater and soil requirements only one representative sample and an accurate analysis from each location.

Inorganic soil and groundwater chemistry near Paducah Gaseous Diffusion Plant, Paducah, Kentucky

International Nuclear Information System (INIS)

Moore, G.K.

1995-03-01

Near-surface soils, boreholes, and sediments near the Paducah Gaseous Diffusion Plant (PGDP) were sampled in 1989-91 as were monitoring wells, TVA wells, and privately-owned wells. Most wells were sampled two or three times. The resulting chemical analyses have been published in previous reports and have been previously described (CH2M HILL 1991, 1992; Clausen et al. 1992). The two reports by CH2M HILL are controversial, however, because, the concentrations of some constituents were reported to exceed background levels or drinking water standards and because both on-site (within the perimeter fence at PGDP) and off-site pollution was reported to have occurred. The groundwater samples upon which these interpretations were based may not be representative, however. The CH2M HILL findings are discussed in the report. The purpose of this report is to characterize the inorganic chemistry of groundwater and soils near PGDP, using data from the CH2M HILL reports (1991, 1992), and to determine whether or not any contamination has occurred. The scope is limited to analysis and interpretation of data in the CH2M HILL reports because previous interpretations of these data may not be valid, because samples were collected in a relatively short period of time at several hundred locations, and because the chemical analyses are nearly complete. Recent water samples from the same wells were not considered because the characterization of inorganic chemistry for groundwater and soil requirements only one representative sample and an accurate analysis from each location

APPLICATION STRATEGIES AND DESIGN CRITERIA FOR IN SITU BIOREMEDIATION OF SOIL AND GROUNDWATER IMPACTED BY PAHS

Science.gov (United States)

Biotreatability studies conducted in our laboratory used soils from two former wood-treatment facilities to evaluate the use of in situ bioventing and biosparging applications for their potential ability to remediate soil and groundwater containing creosote. The combination of ph...

Soil and groundwater cleanup: benefits and limits of emerging technologies

Energy Technology Data Exchange (ETDEWEB)

Caliman, Florentina Anca; Robu, Brindusa Mihaela; Smaranda, Camelia; Pavel, Vasile Lucian; Gavrilescu, Maria [Technical University of Iasi, Department of Environmental Engineering and Management, Faculty of Chemical Engineering and Environmental Protection, Iasi (Romania)

2011-04-15

Contaminated soil and groundwater have been the subject of study and research, so that the field of remediation has grown and evolved, continually developing and adopting new technologies in attempts to improve the decontamination. The cleanup of environmental pollution involves a variety of techniques, ranging from simple biological processes to advanced engineering technologies. Cleanup activities may also address a wide range of contaminants. This article is a short analysis of the technologies for cleaning up groundwater and soil, highlighting knowledge and information gaps. Challenges and strategies for cleaning up different types of contaminants, mainly heavy metals and persistent organic compounds are described. Included are technologies that treat ground water contaminants in place in the subsurface and soil technologies that treat the soil either in place or on site in a treatment unit. Emerging technologies such as those based on oxidation-reduction, bioremediation, and nanotechnologies are covered. It is evident that for a good efficiency of remediation, techniques or even whole new technologies may be incorporated into an existing technology as a treatment train, improving its performance or overcome limitations. Several economic and decision-making elements are developed in the final part, based on the analysis carried out throughout the article. The work highlights the fact that excellence in research and technology progress could be attained by the development of technologies to deal more effectively and economically with certain toxic contaminants such as heavy metals, volatile organic compounds, and persistent organic pollutants, associated with optimization of technologies under field remediation conditions and requirements, improving capacity and yields, and reducing costs. Moreover, increasing knowledge of the scope and problem of equipment development could improve the benefits. (orig.)

Case study: Free product recovery and site remediation using horizontal trenching, soil vapor treatment and groundwater extraction

International Nuclear Information System (INIS)

Sanderson, E.P.; Johnston, H.S. Jr.; Farrell, M.; Twedell, D.B.

1993-01-01

Sites with soil and groundwater impacted by petroleum hydrocarbons have been remediated using a variety of traditional techniques. However, when the site impacted lies within a very confined downtown area of an expanding metropolitan city, a more complex array of technologies must be considered. The Law Enforcement Center site is the City of Charlotte's worst known underground storage tank (UST) release to date. A cost effective free product recovery, soil vapor and groundwater extraction system is being piloted here using new horizontal trenching technology and state of the art equipment. On-site low permeability soil required that an alternative to standard recovery wells be developed for groundwater recovery and vapor extraction. Operation and maintenance (O and M) of the large number of recovery wells required would have been extremely costly over the expected lifetime of the project. Although horizontal trenching was the best solution to the O and M costs, many problems were encountered during their installation

Rapid nutrient leaching to groundwater and surface water in clay soil areas

NARCIS (Netherlands)

Bronswijk, J.J.B.; Hamminga, W.; Oostindie, K.

1995-01-01

The mechanism and magnitude of nitrate leaching from grassland on a heavy clay soil were investigated by measuring nitrogen input, and nitrate concentrations in groundwater and drain discharge for two years. A bromide tracer was applied to study solute transport mechanisms. Nitrate transport in the

Experimental and numerical investigations of soil water balance at the hinterland of the Badain Jaran Desert for groundwater recharge estimation

Science.gov (United States)

Hou, Lizhu; Wang, Xu-Sheng; Hu, Bill X.; Shang, Jie; Wan, Li

2016-09-01

Quantification of groundwater recharge from precipitation in the huge sand dunes is an issue in accounting for regional water balance in the Badain Jaran Desert (BJD) where about 100 lakes exist between dunes. In this study, field observations were conducted on a sand dune near a large saline lake in the BJD to investigate soil water movement through a thick vadose zone for groundwater estimation. The hydraulic properties of the soils at the site were determined using in situ experiments and laboratory measurements. A HYDRUS-1D model was built up for simulating the coupling processes of vertical water-vapor movement and heat transport in the desert soil. The model was well calibrated and validated using the site measurements of the soil water and temperature at various depths. Then, the model was applied to simulate the vertical flow across a 3-m-depth soil during a 53-year period under variable climate conditions. The simulated flow rate at the depth is an approximate estimation of groundwater recharge from the precipitation in the desert. It was found that the annual groundwater recharge would be 11-30 mm during 1983-2012, while the annual precipitation varied from 68 to 172 mm in the same period. The recharge rates are significantly higher than those estimated from the previous studies using chemical information. The modeling results highlight the role of the local precipitation as an essential source of groundwater in the BJD.

IMPACTS OF ROAD DE-ICING SALTS ON MANGANESE TRANSPORT TO GROUNDWATER IN ROADSIDE SOILS

OpenAIRE

Wen, Yingrong

2012-01-01

Manganese (Mn) is an important element in soil, it occur natural in minerals and precipitated as Mn-oxides. Several factors could decide the solubility and mobility of Mn in soil water. In this study, the impact of road de-icing salts (NaCl) on manganese mobilization and transport to groundwater in roadside soils has been investigated by leaching tests. Generally, in the salt solution leachates, the water-soluble concentrations of Mn tended to increase with elevated salt concentrations, sugge...

The resistivity imaging application in groundwater exploration: resistivity value and soil type

International Nuclear Information System (INIS)

Mohd Khardzir Husain

2006-01-01

Malaysia is rich in water resources. Water development has fueled socio-economic development of the country during the past decades. Dams and thousands of kilometers of pipes and canals divert water from the rivers to sustain domestic, industrial and agricultural needs. Lately, the water situation for the country has changed from one of relative abundance to one of relative scarcity. The population growth and the expansion in urbanization, industrialization and irrigated agriculture are imposing rapidly growing demands and pressure on the water resources, besides contributing to the rising water pollution. Surface water resource, the traditional source of water supply in the past, has become inadequate in some areas. The problem becomes more acute in areas where surface water is affected by the increasing pollution from industrial and agricultural waste and where changes in land have adversely affected the quantity and quality of surface water supply. The development of groundwater as a source of water supply or as an alternative source is therefore a timely outlook. Lack in groundwater development will becoming disasters to country. Electrical resistivity had been used in groundwater exploration to get an accuracy result in a short time. This method measures the apparent resistivity of the subsurface, including effects of any or all of the following: soil type, bedrock fractures, contaminants and ground water. Variations in electrical resistivity may indicate changes in composition, layer thickness or contaminant levels. The resistivity values obtained from various groundwater exploration and experimental sites shows that the value differs also in related to the soil type. (Author)

Thermal Removal of Tritium from Concrete and Soil to Reduce Groundwater Impacts - 13197

Energy Technology Data Exchange (ETDEWEB)

Jackson, Dennis G. [Savannah River National Laboratory, Building 773-42A, Aiken, South Carolina 29808 (United States); Blount, Gerald C. [Savannah River Nuclear Solutions (United States); Wells, Leslie H.; Cardoso, Joao E.; Kmetz, Thomas F.; Reed, Misty L. [U.S Department of Energy-Savannah River Site (United States)

2013-07-01

Legacy heavy-water moderator operations at the Savannah River Site (SRS) have resulted in the contamination of equipment pads, building slabs, and surrounding soil with tritium. At the time of discovery the tritium had impacted the shallow (< 3-m) groundwater at the facility. While tritium was present in the groundwater, characterization efforts determined that a significant source remained in a concrete slab at the surface and within the associated vadose zone soils. To prevent continued long-term impacts to the shallow groundwater a CERCLA non-time critical removal action for these source materials was conducted to reduce the leaching of tritium from the vadose zone soils and concrete slabs. In order to minimize transportation and disposal costs, an on-site thermal treatment process was designed, tested, and implemented. The on-site treatment consisted of thermal detritiation of the concrete rubble and soil. During this process concrete rubble was heated to a temperature of 815 deg. C (1,500 deg. F) resulting in the dehydration and removal of water bound tritium. During heating, tritium contaminated soil was used to provide thermal insulation during which it's temperature exceeded 100 deg. C (212 deg. F), causing drying and removal of tritium. The thermal treatment process volatiles the water bound tritium and releases it to the atmosphere. The released tritium was considered insignificant based upon Clean Air Act Compliance Package (CAP88) analysis and did not exceed exposure thresholds. A treatability study evaluated the effectiveness of this thermal configuration and viability as a decontamination method for tritium in concrete and soil materials. Post treatment sampling confirmed the effectiveness at reducing tritium to acceptable waste site specific levels. With American Recovery and Reinvestment Act (ARRA) funding three additional treatment cells were assembled utilizing commercial heating equipment and common construction materials. This provided a

The Role of Frozen Soil in Groundwater Discharge Predictions for Warming Alpine Watersheds

Science.gov (United States)

Evans, Sarah G.; Ge, Shemin; Voss, Clifford I.; Molotch, Noah P.

2018-03-01

Climate warming may alter the quantity and timing of groundwater discharge to streams in high alpine watersheds due to changes in the timing of the duration of seasonal freezing in the subsurface and snowmelt recharge. It is imperative to understand the effects of seasonal freezing and recharge on groundwater discharge to streams in warming alpine watersheds as streamflow originating from these watersheds is a critical water resource for downstream users. This study evaluates how climate warming may alter groundwater discharge due to changes in seasonally frozen ground and snowmelt using a 2-D coupled flow and heat transport model with freeze and thaw capabilities for variably saturated media. The model is applied to a representative snowmelt-dominated watershed in the Rocky Mountains of central Colorado, USA, with snowmelt time series reconstructed from a 12 year data set of hydrometeorological records and satellite-derived snow covered area. Model analyses indicate that the duration of seasonal freezing in the subsurface controls groundwater discharge to streams, while snowmelt timing controls groundwater discharge to hillslope faces. Climate warming causes changes to subsurface ice content and duration, rerouting groundwater flow paths but not altering the total magnitude of future groundwater discharge outside of the bounds of hydrologic parameter uncertainties. These findings suggest that frozen soil routines play an important role for predicting the future location of groundwater discharge in watersheds underlain by seasonally frozen ground.

The role of frozen soil in groundwater discharge predictions for warming alpine watersheds

Science.gov (United States)

Evans, Sarah G.; Ge, Shemin; Voss, Clifford I.; Molotch, Noah P.

2018-01-01

Climate warming may alter the quantity and timing of groundwater discharge to streams in high alpine watersheds due to changes in the timing of the duration of seasonal freezing in the subsurface and snowmelt recharge. It is imperative to understand the effects of seasonal freezing and recharge on groundwater discharge to streams in warming alpine watersheds as streamflow originating from these watersheds is a critical water resource for downstream users. This study evaluates how climate warming may alter groundwater discharge due to changes in seasonally frozen ground and snowmelt using a 2‐D coupled flow and heat transport model with freeze and thaw capabilities for variably saturated media. The model is applied to a representative snowmelt‐dominated watershed in the Rocky Mountains of central Colorado, USA, with snowmelt time series reconstructed from a 12 year data set of hydrometeorological records and satellite‐derived snow covered area. Model analyses indicate that the duration of seasonal freezing in the subsurface controls groundwater discharge to streams, while snowmelt timing controls groundwater discharge to hillslope faces. Climate warming causes changes to subsurface ice content and duration, rerouting groundwater flow paths but not altering the total magnitude of future groundwater discharge outside of the bounds of hydrologic parameter uncertainties. These findings suggest that frozen soil routines play an important role for predicting the future location of groundwater discharge in watersheds underlain by seasonally frozen ground.

Impacts of Sampling and Handling Procedures on DNA- and RNA-based Microbial Characterization and Quantification of Groundwater and Saturated Soil

Science.gov (United States)

2012-07-01

Interference of soil extracts and of the matrix itself (e.g., sand, clay, compost , activated carbon) to the derived DNA quantity and quality is often...phase. Both cultures were washed twice in sodium phosphate buffer, combined and inoculated to 100 g of homogenized soil at a moisture content

Evidence of terrestrial discharge of deep groundwater on the Canadian Shield from helium in soil gases

International Nuclear Information System (INIS)

Gascoyne, M.; Sheppard, M.I.

1993-01-01

Assessment of the impact of deep geological disposal of nuclear fuel wastes at a site in the Canadian Shield requires knowledge of the location and size of areas of discharge of deep groundwater from the vicinity of the underground disposal vault. A strong He anomaly has been detected in soil gases in a 10 X 10 m area of wetland on the banks of Boggy Creek, near Lac du Bonnet, Manitoba. The area has He concentrations in near-surface soils as high as 360 nL·L -1 and is assumed to indicate discharge of He-rich groundwater through a permeable subsurface bedrock fracture. Elevated Cl - concentrations in groundwater and its use as a open-quotes deer lickclose quotes support this interpretation. A He flux density of ∼ 2.1 L·m -2 ·a -1 is determined from a depth profile of He concentrations at one location in the site. A total He flux of 270 L·a -1 is determined for the entire site, which corresponds to a deep groundwater discharge of about 26 000 L·a -1 . This estimate is comparable with He fluxes and calculated groundwater discharges for two other lake-bottom locations on the Canadian Shield. 26 refs., 6 figs., 1 tab

Effect of harsh or mild extraction of soil on pesticide leaching to groundwater

NARCIS (Netherlands)

Boesten, Jos J.T.I.

2016-01-01

Assessment of leaching to groundwater is an important aspect of pesticide risk assessment. The first leaching tier usually consists of simulations with leaching scenarios based on pesticide- soil properties derived from laboratory studies. Because the extractability of pesticide residues in such

Water, Sanitation and Hygiene (WASH) and environmental risk factors for soil-transmitted helminth intensity of infection in Timor-Leste, using real time PCR.

Science.gov (United States)

Campbell, Suzy J; Nery, Susana V; Wardell, Rebecca; D'Este, Catherine A; Gray, Darren J; McCarthy, James S; Traub, Rebecca J; Andrews, Ross M; Llewellyn, Stacey; Vallely, Andrew J; Williams, Gail M; Clements, Archie C A

2017-03-01

No investigations have been undertaken of risk factors for intensity of soil-transmitted helminth (STH) infection in Timor-Leste. This study provides the first analysis of risk factors for intensity of STH infection, as determined by quantitative PCR (qPCR), examining a broad range of water, sanitation and hygiene (WASH) and environmental factors, among communities in Manufahi District, Timor-Leste. A baseline cross-sectional survey of 18 communities was undertaken as part of a cluster randomised controlled trial, with additional identically-collected data from six other communities. qPCR was used to assess STH infection from stool samples, and questionnaires administered to collect WASH, demographic, and socioeconomic data. Environmental information was obtained from open-access sources and linked to infection outcomes. Mixed-effects multinomial logistic regression was undertaken to assess risk factors for intensity of Necator americanus and Ascaris infection. 2152 participants provided stool and questionnaire information for this analysis. In adjusted models incorporating WASH, demographic and environmental variables, environmental variables were generally associated with infection intensity for both N. americanus and Ascaris spp. Precipitation (in centimetres) was associated with increased risk of moderate-intensity (adjusted relative risk [ARR] 6.1; 95% confidence interval [CI] 1.9-19.3) and heavy-intensity (ARR 6.6; 95% CI 3.1-14.1) N. americanus infection, as was sandy-loam soil around households (moderate-intensity ARR 2.1; 95% CI 1.0-4.3; heavy-intensity ARR 2.7; 95% CI 1.6-4.5; compared to no infection). For Ascaris, alkaline soil around the household was associated with reduced risk of moderate-intensity infection (ARR 0.21; 95% CI 0.09-0.51), and heavy-intensity infection (ARR 0.04; 95% CI 0.01-0.25). Few WASH risk factors were significant. In this high-prevalence setting, strong risk associations with environmental factors indicate that anthelmintic

Glyphosate and AMPA in U.S. streams, groundwater, precipitation and soils

Science.gov (United States)

Battaglin, William A.; Meyer, Michael T.; Kuivila, Kathryn; Dietze, Julie E.

2014-01-01

Herbicides containing glyphosate are used in more than 130 countries on more than 100 crops. In the United States (U.S.), agricultural use of glyphosate [N-(phosphonomethyl)glycine] has increased from less than 10,000 metric tons per year (active ingredient) in 1993 to more than 70,000 metric tons per year in 2006. In 2006, glyphosate accounted for about 20 percent of all herbicide use (by weight of active ingredient). Glyphosate formulations such as Roundup® are used in homes and in agriculture. Part of the reason for the popularity of glyphosate is the perception that it is an “environmentally benign” herbicide that has low toxicity and little mobility or persistence in the environment. The U.S. Geological Survey developed an analytical method using liquid chromatography/tandem mass spectrometry that can detect small amounts of glyphosate and its primary degradation product aminomethylphosphonic acid (AMPA) in water and sediment. Results from more than 2,000 samples collected from locations distributed across the U.S. indicate that glyphosate is more mobile and occurs more widely in the environment than was previously thought. Glyphosate and AMPA were detected (reporting limits between 0.1 and 0.02 micrograms per liter) in samples collected from surface water, groundwater, rainfall, soil water, and soil, at concentrations from less than 0.1 to more than 100 micrograms per liter. Glyphosate was detected more frequently in rain (86%), ditches and drains (71%), and soil (63%); and less frequently in groundwater (3%) and large rivers (18%). AMPA was detected more frequently in rain (86%), soil (82%), and large rivers (78%); and less frequently in groundwater (8%) and wetlands or vernal pools (37%). Most observed concentrations of glyphosate were well below levels of concern for humans or wildlife, and none exceeded the U.S. Environmental Protection Agency’s Maximum Contaminant Level of 700 micrograms per liter. However, the ecosystem effects of chronic low

U-ages in soils and groundwater evidencing wet periods 400-600 kyr ago in southeast Brazil

International Nuclear Information System (INIS)

Bonotto, D.M.; Jimenez-Rueda, J.R.

2007-01-01

238 U and its radiogenic daughter 234 U have been utilized for dating soil formation and groundwater residence time during the last 1.5 million years, in this case based on the U-dissolution/precipitation occurring during modifications of the oxidation-reduction conditions. In this paper, we report a 400-600 kyr proxy of wet periods from sediments occurring in a soil profile developed over rocks outcropping at the Parana sedimentary basin in Brazil, and from groundwater exploited of Guarani aquifer at the same basin. The approaches indicated successful use of the U-modeled ages for suggesting wet periods exceeding the past 116-210 kyr from previous studies

Characterization of contaminated soil and groundwater surrounding an illegal landfill (S. Giuliano, Venice, Italy) by principal component analysis and kriging

International Nuclear Information System (INIS)

Critto, Andrea; Carlon, Claudio; Marcomini, Antonio

2003-01-01

Information on soil and groundwater contamination was used to develop a site conceptual model and to identify exposure scenarios. - The characterization of a hydrologically complex contaminated site bordering the lagoon of Venice (Italy) was undertaken by investigating soils and groundwaters affected by the chemical contaminants originated by the wastes dumped into an illegal landfill. Statistical tools such as principal components analysis and geostatistical techniques were applied to obtain the spatial distribution of chemical contaminants. Dissolved organic carbon (DOC), SO 4 2- and Cl - were used to trace the migration of the contaminants from the top soil to the underlying groundwaters. The chemical and hydrogeological available information was assembled to obtain the schematic of the conceptual model of the contaminated site capable to support the formulation of major exposure scenarios, which are also provided

Successive use of vacuum-enhanced extraction, in situ chemical oxidation, bioaugmentation and mathematical modeling for the restoration of impacted soil and groundwater

Energy Technology Data Exchange (ETDEWEB)

Morin, A.; Lauzon, J.M. [TechnoRem Inc., Laval, PQ (Canada)

2007-07-01

A leak from an active gasoline service station in northern Quebec was discussed. Leaking petroleum from an underground storage tank (UST) in June 2005 resulted in a 4,000 m{sup 2} light non-aqueous phase liquid (LNAPL) plume causing both soil and groundwater contamination. This presentation described the site, environmental issues, selected remedial technologies, worked performed and results. TechnoRem conducted laboratory and bench-scale testing to determine the optimal treatment products and conditions for mitigation. The LNAPL was recovered using vacuum-enhanced extraction (VEE). Chemical oxidation (CO) and bioaugmentation (BA) was also used to restore the site. The soil and groundwater targets for various parameters were tabulated for total petroleum hydrocarbons and BTEX (benzene, toluene, ethylbenzene and xylenes). It was noted that groundwater was flowing south towards a lake 100 metres downgradient. Schematics of the VEE, CO and BA equipment were presented along with several images of the design, installation, commission and operation of the systems. A total of 128 pumping/injection wells were used to sample soil, groundwater and LNAPL. In November 2006, soil analyses indicated that the total petroleum hydrocarbons and BTEX met the applicable criteria. The contaminated groundwater plume is now minor and in regression. Groundwater monitoring and supply of nutrients and oxygen will be performed for the coming years to allow for enhanced natural attenuation to mitigate the residual contaminants. tabs., figs.

Assessment of groundwater, soil-gas, and soil contamination at the Vietnam Armor Training Facility, 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 groundwater, soil gas, and soil for contaminants at the Vietnam Armor Training Facility (VATF) at Fort Gordon, from October 2009 to September 2010. The assessment included the detection of organic compounds in the groundwater and soil gas, and inorganic compounds in the soil. In addition, organic contaminant assessment included organic compounds classified as explosives and chemical agents in selected areas. 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. Four passive samplers were deployed in groundwater wells at the VATF in Fort Gordon. Total petroleum hydrocarbons were detected above the method detection level at all four wells. The only other volatile organic compounds detected above their method detection level were undecane and pentadecane, which were detected in two of the four wells sampled. Soil-gas samplers were deployed at 72 locations in a grid pattern across the VATF. Total petroleum hydrocarbons were detected in 71 of the 72 samplers (one sampler was destroyed in the field and not analyzed) at levels above the method detection level, and the combined mass of benzene, toluene, ethylbenzene, and total xylene was detected above the detection level in 31 of the 71 samplers that were analyzed. Other volatile organic compounds detected above their respective method detection levels were naphthalene, 2-methyl-naphthalene, tridecane, 1,2,4-trimethylbenzene, and perchloroethene. Subsequent to the soil-gas survey, four areas determined to have elevated contaminant mass were selected and sampled for explosives and chemical agents. No detections of explosives or chemical agents above their

Validation of regression models for nitrate concentrations in the upper groundwater in sandy soils

International Nuclear Information System (INIS)

Sonneveld, M.P.W.; Brus, D.J.; Roelsma, J.

2010-01-01

For Dutch sandy regions, linear regression models have been developed that predict nitrate concentrations in the upper groundwater on the basis of residual nitrate contents in the soil in autumn. The objective of our study was to validate these regression models for one particular sandy region dominated by dairy farming. No data from this area were used for calibrating the regression models. The model was validated by additional probability sampling. This sample was used to estimate errors in 1) the predicted areal fractions where the EU standard of 50 mg l -1 is exceeded for farms with low N surpluses (ALT) and farms with higher N surpluses (REF); 2) predicted cumulative frequency distributions of nitrate concentration for both groups of farms. Both the errors in the predicted areal fractions as well as the errors in the predicted cumulative frequency distributions indicate that the regression models are invalid for the sandy soils of this study area. - This study indicates that linear regression models that predict nitrate concentrations in the upper groundwater using residual soil N contents should be applied with care.

Soil and groundwater remediation through the program of energy research and development at Environment Canada

International Nuclear Information System (INIS)

Bacchus, P.

2005-01-01

Research and development in groundwater and soil remediation within the federal Program of Energy Research and Development (PERD) are conducted in the context of activities related to the oil and gas industry. Contamination of groundwater and soil by the oil and gas sector affects the health of ecosystems and the economic viability of impacted lands. This paper presented an outline of remediation research and development activities associated with PERD, as well as an overview of PERD's development of improved generic remediation technologies and approaches for use by industries. In addition, issues concerning the development of key guidelines, methods and protocols for use by regulators were discussed. Science and technology efforts within PERD contribute to the development of national standards and guidelines concerning public safety and environmental needs

Uncertainty in 14C model ages of groundwater: The influence of soil gas in terranes dominated by C3 plants

Science.gov (United States)

Nelson, S.; Hart, R.; Eggett, D.

2009-12-01

Groundwater is the largest source of fresh water readily available to humanity and aquifers with long residence times are particularly susceptible to overuse. Thus, it is important to have quantitative estimates of the residence time of water in such aquifers. Many models used to calculate 14C ages of groundwater depend on an estimate of the δ13C value of carbon dioxide in soil at the time of recharge, a value that must be estimated. Other work has suggested that for terranes dominated by C3 plants, -23‰ is an appropriate value, and sensitivity calculations show that the apparent age of a groundwater is strongly dependent on the choice of this parameter. This is especially true where the measured values of δ13C of dissolved inorganic carbon (DIC) are used to estimate the contribution of “dead” carbon to the DIC load via the dissolution of calcite in the aquifer and soil zones. To better understand the temporal and spatial isotopic and abundance variability of soil carbon dioxide, we established soil gas sampling sites that encompassed a wide variety of settings in terms of season, elevation, climate, and plant community that were sampled monthly throughout regions of the state of Utah where C3 flora dominate. Direct measurements of soil gas suggest a value of -21.8 ± 1.4‰ (1σ) is a good input variable as long as: a) C3 vegetation dominates, and b) extreme aridity does not prevail such that plant densities and soil microbial activities are minimized. If recharge is envisaged to occur during spring and early summer in highly vegetated uplands, a value of -24.0 ± 0.6‰ may be more appropriate as statistical analysis reveals that seasonality and plant density are most clearly correlated to the carbon isotope composition of carbon dioxide in soil gas. Although the two values and ranges cited above values do not diverge strongly from other published estimates, they place fairly narrow limits on the uncertainty of ±500 and ±200 yr., respectively, in

Limiting nitrogen and veterinary pharmaceutical input into groundwater: combining hydrogeophysics and soil science

Science.gov (United States)

Noell, Ursula; Stadler, Susanne

2017-04-01

The EU Interreg project TOPSOIL investigates opportunities to improve surface and groundwater quality as well as water management strategies under the consideration of climate adaptation challenges. Within the framework of the project, we investigate the transport behavior of percolation water in the unsaturated zone, the migration of nitrogen and veterinary pharmaceuticals in soils, and - together with different stakeholders (e.g. farmers, water supply companies) - develop common strategies to minimize the migration of these substances into the groundwater. In our study we focus on distinguishing preferential and diffuse flow using soil scientific and geophysical methods. During the first investigation campaign, we combined soil sampling with radiometry and electrical conductivity overview measurements on the typical sandy soil of the studied area south of Oldenburg, Germany. We used the CMD explorer for the electromagnetic mapping (horizontal and vertical dipoles, intercoil spacing of 1.48/2.82/4.49 m, investigations depths of appr. 0 - 6 m) and the radiometry detector comprised five sodium-iodide crystals each with a volume of 4 litres. The spectral data are evaluated for potassium (1.37 - 1.57 MeV), uranium (Bi-214) (1.66 - 1.86MeV) and thorium (T-208) (2.41 - 2.81MeV) and total counts (0.41-2.81MeV). A total of 292 soil samples were taken from 46 ram coring profiles (depth range: 0 to 3 m) and analyzed for soil chemical parameters and water content. The first evaluation showed a good correlation between conductivity and radiometry measurements. While the uranium and thorium values are generally low, the potassium values possibly reflect higher clay contents as do the higher conductivity values. The geophysical overview measurements were used to select the locations for soil sampling and we specifically targeted presumably clay-rich as well as clay-poor areas for sampling.

Potential groundwater recharge for the State of Minnesota using the Soil-Water-Balance model, 1996-2010

Science.gov (United States)

Smith, Erik A.; Westenbroek, Stephen M.

2015-01-01

Groundwater recharge is one of the most difficult components of a water budget to ascertain, yet is an important boundary condition necessary for the quantification of water resources. In Minnesota, improved estimates of recharge are necessary because approximately 75 percent of drinking water and 90 percent of agricultural irrigation water in Minnesota are supplied from groundwater. The water that is withdrawn must be supplied by some combination of (1) increased recharge, (2) decreased discharge to streams, lakes, and other surface-water bodies, and (3) removal of water that was stored in the system. Recent pressure on groundwater resources has highlighted the need to provide more accurate recharge estimates for various tools that can assess the sustainability of long-term water use. As part of this effort, the U.S. Geological Survey, in cooperation with the Minnesota Pollution Control Agency, used the Soil-Water-Balance model to calculate gridded estimates of potential groundwater recharge across Minnesota for 1996‒2010 at a 1-kilometer (0.621-mile) resolution. The potential groundwater recharge estimates calculated for Minnesota from the Soil-Water Balance model included gridded values (1-kilometer resolution) of annual mean estimates (that is, the means for individual years from 1996 through 2010) and mean annual estimates (that is, the mean for the 15-year period 1996−2010).

Interaction of Peat Soil and Sulphidic Material Substratum: Role of Peat Layer and Groundwater Level Fluctuations on Phosphorus Concentration

Directory of Open Access Journals (Sweden)

Benito Heru Purwanto

2014-09-01

Full Text Available Phosphorus (P often becomes limiting factor for plants growth. Phosphorus geochemistry in peatland soil is associated with the presence of peat layer and groundwater level fluctuations. The research was conducted to study the role of peat layer and groundwater level fluctuations on P concentration in peatland. The research was conducted on deep, moderate and shallow peat with sulphidic material as substratum, peaty acid sulphate soil, and potential acid sulphate soil. While P concentration was observed in wet season, in transition from wet to dry season, and in dry season. Soil samples were collected by using peat borer according to interlayer and soil horizon. The results showed that peat layer might act as the main source of P in peatland with sulphidic material substratum. The upper peat layer on sulphidic material caused by groundwater level fluctuations had no directly effect on P concentration in the peat layers. Increased of P concentration in the lowest sulphidic layer might relate to redox reaction of iron in the sulphidic layer and precipitation process. Phosphorus concentration in peatland with sulphidic material as substratum was not influenced by peat thickness. However, depletion or disappearance of peat layer decreased P concentration in soil solution. Disappearance of peat layer means loss of a natural source of P for peatland with sulphidic material as substratum, therefore peat layer must be kept in order to maintain of peatlands.

Fracture detection and groundwater flow characterization in poorly exposed ground using helium and radon in soil gases

International Nuclear Information System (INIS)

Gascoyne, M.; Wuschke, D.M.

1991-05-01

Radon and helium in soil gases have been used to identify locations of groundwater discharge and the presence of fractures outcropping beneath overburden in two areas near the Underground Research Laboratory (URL), Lac du Bonnet, Manitoba, Canada. In particular, groundwater discharge from a known, inclined fracture zone at the URL was clearly identified by a helium excess in overlying soil gases. A model was developed to describe gas phase flow in bedrock and overburden at this location, from gas injection in an adjacent borehole. Predictions were made of gas transport pathway and breakthrough time at the surface, in preparation for a gas injection test

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...

Tannic acid for remediation of historically arsenic-contaminated soils.

Science.gov (United States)

Gusiatin, Zygmunt Mariusz; Klik, Barbara; Kulikowska, Dorota

2017-12-22

Soil washing effectively and permanently decreases soil pollution. Thus, it can be considered for the removal of the most toxic elements, for example arsenic (As). In this study, historically As-contaminated soils (2041-4294 mg/kg) were remediated with tannic acid (TA) as the washing agent. The scope of this study included optimization of the operational conditions of As removal, determination of As distribution in soil before and after double soil washing, and measurement of TA loss during washing. The optimum conditions for As removal were 4% TA, pH 4 and 24 h washing time. The average As removal after single and double washings was 38% and 63%, respectively. TA decreased As content in amorphous and poorly crystalline oxides by >90%. Although TA increased the amount of As in the easily mobilizable As fraction, the stability of As in washed soils increased, with reduced partition indexes of 0.52-0.66 after washing. The maximum capacity of the soils to adsorb TA (q max ) was 50.2-70.4 g C/kg. TA sorption was higher at alkaline than at acidic conditions. Only TA removes As from soils effectively if the proportion of As in amorphous and poorly crystalline oxides is high. Thus, it can be considered for remediation of historically contaminated soils.

Assessment of washing procedure for determination some of ...

African Journals Online (AJOL)

This study was proposed to assess the suitability of washing technique to distinguish between airborne and soil borne several metal contaminants. For this reason, six plant species which grew under Mobarakeh Steel Company emissions were selected. Aluminum, iron, nickel, manganese, zinc, copper and lead ...

Effect of washing on pesticide residues in olives.

Science.gov (United States)

Guardia-Rubio, M; Ayora-Cañada, M J; Ruiz-Medina, A

2007-03-01

The present work aims at contributing to the knowledge of the fate of 5 pesticides in olives in order to evaluate how washing may affect the presence of these residues in this fruit (and consequently in olive oil). For this purpose, olives were sprayed with commercial formulations containing the active ingredients and a series of analyses were performed for 64 d by using gas chromatography with mass spectrometric detection. Selected pesticides, ranked by their importance, were diuron, terbuthylazine, simazine, alpha-endosulfan, and beta-endosulfan. The pesticide fraction, which was not removable from olives by washing, increased with time after treatment until their degradation started at week 6. Washing performed 1 d after treatment was the most effective in reducing residues, especially for simazine. Consequently, the washing step performed in olive mills could be effective in removing those herbicide residues present in olives as a consequence of contact with contaminated soil for a short time. This happens when olives are dropped and harvested off the ground by means of brushes or suction equipment.

Evaluation of available data on the geohydrology, soil chemistry, and groundwater chemistry of Gas Works Park and surrounding region, Seattle, Washington

Energy Technology Data Exchange (ETDEWEB)

Sabol, M.A.; Turney, G.L.; Ryals, G.N.

1988-01-01

Gas Works Park, in Seattle, Washington, is located at the site of an abandon gasification plant on Lake Union. Soil contaminants include polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls, pesticides volatile organic compounds, cyanide, and metals PAHs and metals have been detected in Lake Union sediments. Maximum total PAH concentrations exceeded 100 million micrograms/kilogram in some places in the soils of the park at 6-inch depths and in some lake sediments. Other contaminants present are much lower in concentrations. The park is on glacial drift overlain by gasification waste materials and clean fill. Waste materials include sand and gravels, mixed with lampblack, oil, bricks, and other industrial wastes. Groundwater flows through the soils and waste toward Lake Union. Vertical groundwater movement is uncertain, but is assumed to be upward near Lake Union. Concentrations of most soil contaminants are probably low in the groundwater and in Lake Union due to the low solubilities and high sorptive, characteristics of these contaminants. However, no water quality data are available to confirm this premise. 14 refs., 18 figs., 5 tabs.

Watershed wash-off of atmospherically deposited radionuclides: a review of normalized entrainment coefficients

International Nuclear Information System (INIS)

Garcia-Sanchez, L.; Konoplev, A.V.

2009-01-01

Radionuclide wash-off is the transport of activity by flowing water over the soil surface (runoff). To complete existing reviews on long-term removal rates, this paper focuses on short-term wash-off fluxes, quantified in the literature by soil-runoff transfer factors called normalized liquid and solid entrainment coefficients (noted K l *, K s *). Compiled data concerned essentially 137 Cs and 90 Sr wash-off measured under simulated rainfalls on small experimental plots after Chernobyl fallout in the exclusion zone. K l * and K s * values span approximately one order of magnitude. Their validity is limited to a season, and their representativeness is limited by restricted studied situations, notably dominant unsoluble forms in fallout, light soils and intense rainfalls. Formulas based on a simplified representation of the soil-runoff system were proposed to generalize the existing values for other conditions. However, their implementation requires a more systematic compilation of the available information, including decisive influence factors such as the fraction of exchangeable form, distribution coefficient, suspended matter enrichment ratio. Entrainment coefficients K l * and K s * were mathematically related to the transfer function approach. The proposed relationships proved their complementarity in terms of time support and captured fluctuations. Both approaches should be used in assessments to estimate average fluxes and their variability.

Investigation of different ethylenediamine-N,N'-disuccinic acid-enhanced washing configurations for remediation of a Cu-contaminated soil: process kinetics and efficiency comparison between single-stage and multi-stage configurations.

Science.gov (United States)

Ferraro, Alberto; Fabbricino, Massimiliano; van Hullebusch, Eric D; Esposito, Giovanni

2017-09-01

A comparison of Cu extraction yields for three different ethylenediamine-N,N'-disuccinic acid (EDDS)-enhanced washing configurations was performed on a Cu-contaminated soil. Batch experiments were used to simulate a single-stage continuous stirred tank reactor (CSTR) and a multi-stage (side feeding and counter-current) reactor. Single-stage CSTR conditions were simulated for various EDDS:(Cu + Cd + Pb + Co + Ni + Zn) molar ratio (EDDS:M ratio) (from 1 to 30) and liquid to soil (L/S) ratio (from 15 to 45). The highest Cu extraction yield (≃56%) was achieved with EDDS:M = 30. In contrast, a Cu extraction yield decrease was observed with increasing L/S ratio with highest extracted Cu achievement (≃48%) for L/S = 15. Side feeding configuration was tested in four experimental conditions through different fractionation mode of EDDS dose and treatment time at each washing step. Results from the four tests showed all enhanced Cu extraction (maximum values from ≃43 to ≃51%) achieved at lower treatment time and lower EDDS:M molar ratio compared to CSTR configuration with L/S = 25 and EDDS:M = 10. The counter-current washing was carried out through two washing flows achieving a process performance enhancement with 27% increase of extracted Cu compared to single-stage CSTR configuration. Higher Cu extraction percentage (36.8%) was observed in the first washing phase than in the second one (24.7%).

Assessment of groundwater, soil-gas, and soil contamination at the Vietnam Armor Training Facility, Fort Gordon, Georgia, 2009-2011

Science.gov (United States)

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

2012-01-01

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 groundwater, soil gas, and soil for contaminants at the Vietnam Armor Training Facility (VATF) at Fort Gordon, from October 2009 to September 2011. The assessment included the detection of organic compounds in the groundwater and soil gas, and inorganic compounds in the soil. In addition, organic contaminant assessment included organic compounds classified as explosives and chemical agents in selected areas. 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. This report is a revision of "Assessment of soil-gas, surface-water, and soil contamination at the Vietnam Armor Training Facility, Fort Gordon, Georgia, 2009-2010," Open-File Report 2011-1200, and supersedes that report to include results of additional samples collected in July 2011. Four passive samplers were deployed in groundwater wells at the VATF in Fort Gordon. Total petroleum hydrocarbons and benzene and octane were detected above the method detection level at all four wells. The only other volatile organic compounds detected above their method detection level were undecane and pentadecane, which were detected in two of the four wells. Soil-gas samplers were deployed at 72 locations in a grid pattern across the VATF on June 3, 2010, and then later retrieved on June 9, 2010. Total petroleum hydrocarbons were detected in 71 of the 72 samplers (one sampler was destroyed in the field and not analyzed) at levels above the method detection level, and the combined mass of benzene, toluene, ethylbenzene, and total xylene (BTEX) was detected above the detection level in 31 of the 71 samplers that were analyzed. Other volatile organic compounds

NTS groundwater recharge study, FY 1992

International Nuclear Information System (INIS)

Lyles, B.F.; Mihevc, T.M.

1992-10-01

Groundwater recharge from precipitation is thought by many scientists to be extremely low in Southem Nevada; however, no direct measurements of recharge have been made to substantiate this hypothesis. Three geomorphic regions have been identified as potential areas of groundwater recharge at the Nevada Test Site (NTS): mesas, washes, and lowlands. Eight recharge monitoring stations have been installed to monitor each of these regions; four of the stations are on Pahute/Rainier Mesa, two stations are in Fortymile Wash, one station is in a transition area between the mesas and the lowlands (Whiterock Spring), and one station is located in Yucca Flat at the bottom of the U-3fd crater. An additional station is proposed for Frenchman Flat near the Area 5 mixed waste facility; however, the instrumentation of that site has been delayed due to the complex permitting process associated with instrument installation near the mixed waste facility. Digital data were collected from eight sites during FY 1992

Advanced remediation of uranium-contaminated soil.

Science.gov (United States)

Kim, S S; Han, G S; Kim, G N; Koo, D S; Kim, I G; Choi, J W

2016-11-01

The existing decontamination method using electrokinetic equipment after acidic washing for uranium-contaminated soil requires a long decontamination time and a significant amount of electric power. However, after soil washing, with a sulfuric acid solution and an oxidant at 65 °C, the removal of the muddy solution using a 100 mesh sieve can decrease the radioactivity of the remaining coarse soil to the clearance level. Therefore, only a small amount of fine soil collected from the muddy solution requires the electrokinetic process for its decontamination. Furthermore, it is found that the selective removal of uranium from the sulfuric washing solution is not obtained using an anion exchanger but rather using a cation exchanger, unexpectedly. More than 90% of the uranium in the soil washing solutions is adsorbed on the S-950 resin, and 87% of the uranium adsorbed on S-950 is desorbed by washing with a 0.5 M Na 2 CO 3 solution at 60 °C. Copyright © 2016 Elsevier Ltd. All rights reserved.

Full-scale testing and early production results from horizontal air sparging and soil vapor extraction wells remediating jet fuel in soil and groundwater at JFK International Airport, New York

International Nuclear Information System (INIS)

Roth, R.J.; Bianco, P.; Pressly, N.C.

1996-01-01

Jet fuel contaminated soil and groundwater contaminated at the International Arrivals Building (IAB) of the JFK International Airport in Jamaica, New York, are being remediated using soil vapor extraction (SVE) and air sparging (AS). The areal extent of the contaminated soil is estimated to be 70 acres and the volume of contaminated groundwater is estimated to be 2.3 million gallons. The remediation uses approximately 13,000 feet of horizontal SVE (HSVE) wells and 7,000 feet of horizontal AS (HAS) wells. The design of the HSVE and HAS wells was based on a pilot study followed by a full-scale test. In addition to the horizontal wells, 28 vertical AS wells and 15 vertical SVE wells are used. Three areas are being remediated, thus, three separate treatment systems have been installed. The SVE and AS wells are operated continuously while groundwater will be intermittently extracted at each HAS well, treated by liquid phase activated carbon and discharged into stormwater collection sewerage. Vapors extracted by the SVE wells are treated by vapor phase activated carbon and discharged into ambient air. The duration of the remediation is anticipated to be between two and three years before soil and groundwater are remediated to New York State cleanup criteria for the site. Based on the monitoring data for the first two months of operation, approximately 14,600 lbs. of vapor phase VOCs have been extracted. Analyses show that the majority of the VOCs are branched alkanes, branched alkenes, cyclohexane and methylated cyclohexanes

On the use of the GRACE normal equation of inter-satellite tracking data for estimation of soil moisture and groundwater in Australia

Directory of Open Access Journals (Sweden)

N. Tangdamrongsub

2018-03-01

Full Text Available An accurate estimation of soil moisture and groundwater is essential for monitoring the availability of water supply in domestic and agricultural sectors. In order to improve the water storage estimates, previous studies assimilated terrestrial water storage variation (ΔTWS derived from the Gravity Recovery and Climate Experiment (GRACE into land surface models (LSMs. However, the GRACE-derived ΔTWS was generally computed from the high-level products (e.g. time-variable gravity fields, i.e. level 2, and land grid from the level 3 product. The gridded data products are subjected to several drawbacks such as signal attenuation and/or distortion caused by a posteriori filters and a lack of error covariance information. The post-processing of GRACE data might lead to the undesired alteration of the signal and its statistical property. This study uses the GRACE least-squares normal equation data to exploit the GRACE information rigorously and negate these limitations. Our approach combines GRACE's least-squares normal equation (obtained from ITSG-Grace2016 product with the results from the Community Atmosphere Biosphere Land Exchange (CABLE model to improve soil moisture and groundwater estimates. This study demonstrates, for the first time, an importance of using the GRACE raw data. The GRACE-combined (GC approach is developed for optimal least-squares combination and the approach is applied to estimate the soil moisture and groundwater over 10 Australian river basins. The results are validated against the satellite soil moisture observation and the in situ groundwater data. Comparing to CABLE, we demonstrate the GC approach delivers evident improvement of water storage estimates, consistently from all basins, yielding better agreement on seasonal and inter-annual timescales. Significant improvement is found in groundwater storage while marginal improvement is observed in surface soil moisture estimates.

On the use of the GRACE normal equation of inter-satellite tracking data for estimation of soil moisture and groundwater in Australia

Science.gov (United States)

Tangdamrongsub, Natthachet; Han, Shin-Chan; Decker, Mark; Yeo, In-Young; Kim, Hyungjun

2018-03-01

An accurate estimation of soil moisture and groundwater is essential for monitoring the availability of water supply in domestic and agricultural sectors. In order to improve the water storage estimates, previous studies assimilated terrestrial water storage variation (ΔTWS) derived from the Gravity Recovery and Climate Experiment (GRACE) into land surface models (LSMs). However, the GRACE-derived ΔTWS was generally computed from the high-level products (e.g. time-variable gravity fields, i.e. level 2, and land grid from the level 3 product). The gridded data products are subjected to several drawbacks such as signal attenuation and/or distortion caused by a posteriori filters and a lack of error covariance information. The post-processing of GRACE data might lead to the undesired alteration of the signal and its statistical property. This study uses the GRACE least-squares normal equation data to exploit the GRACE information rigorously and negate these limitations. Our approach combines GRACE's least-squares normal equation (obtained from ITSG-Grace2016 product) with the results from the Community Atmosphere Biosphere Land Exchange (CABLE) model to improve soil moisture and groundwater estimates. This study demonstrates, for the first time, an importance of using the GRACE raw data. The GRACE-combined (GC) approach is developed for optimal least-squares combination and the approach is applied to estimate the soil moisture and groundwater over 10 Australian river basins. The results are validated against the satellite soil moisture observation and the in situ groundwater data. Comparing to CABLE, we demonstrate the GC approach delivers evident improvement of water storage estimates, consistently from all basins, yielding better agreement on seasonal and inter-annual timescales. Significant improvement is found in groundwater storage while marginal improvement is observed in surface soil moisture estimates.

Organizing groundwater regimes and response thresholds by soils: A framework for understanding runoff generation in a headwater catchment

Science.gov (United States)

John P. Gannon; Scott W. Bailey; Kevin J. McGuire

2014-01-01

A network of shallow groundwater wells in a headwater catchment at the Hubbard Brook Experimental Forest in New Hampshire, U.S. was used to investigate the hydrologic behavior of five distinct soil morphological units. The soil morphological units were hypothesized to be indicative of distinct water table regimes. Water table fluctuations in the wells were...

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-02-15

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

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Screening Approach to the Activation of Soil and Contamination of Groundwater at Linear Proton Accelerator Sites

CERN Document Server

Otto, Thomas

The activation of soil and the contamination of groundwater at proton accelerator sites with the radionuclides 3H and 22Na are estimated with a Monte-Carlo calculation and a conservative soil- and ground water model. The obtained radionuclide concentrations show that the underground environment of future accelerators must be adequately protected against a migration of activation products. This study is of particular importance for the proton driver accelerator in the planned EURISOL facility.

SLiM : an improved soil moisture balance method to simulate runoff and potential groundwater recharge processes using spatio-temporal weather and catchment characteristics

OpenAIRE

Wang, Lei; Barkwith, Andrew; Jackson, Christopher; Ellis, Michael

2012-01-01

The numerical modelling of runoff and groundwater recharge plays an important role in water resource management. The methodologies developed for these simulations should represent the key physical processes, and be applicable in a wide variety of climates for routine simulations using readily available field information. This paper describes the development of a Soil and Landuse based rainfall-runoff and recharge Model (SLiM) based on Rushton’s method – a single soil layer groundwater recharg...

Carbon mineralization and pyrite oxidation in groundwater: Importance for silicate weathering in boreal forest soils and stream base-flow chemistry

International Nuclear Information System (INIS)

Klaminder, J.; Grip, H.; Moerth, C.-M.; Laudon, H.

2011-01-01

Research highlights: → Organic compounds is mineralized during later transport in deep groundwater aquifers. → Carbonic acid generated by this process stimulates dissolution of silicate minerals. → Protons derived from pyrite oxidation also affects weathering in deep groundwater. → The identified weathering mechanisms affect base-flow chemistry in boreal streams. - Abstract: What role does mineralized organic C and sulfide oxidation play in weathering of silicate minerals in deep groundwater aquifers? In this study, how H 2 CO 3 , produced as a result of mineralization of organic matter during groundwater transport, affects silicate weathering in the saturated zone of the mineral soil along a 70 m-long boreal hillslope is demonstrated. Stream water measurements of base cations and δ 18 O are included to determine the importance of the deep groundwater system for downstream surface water. The results suggest that H 2 CO 3 generated from organic compounds being mineralized during the lateral transport stimulates weathering at depths between 0.5 and 3 m in the soil. This finding is indicated by progressively increasing concentrations of base cations-, silica- and inorganic C (IC) in the groundwater along the hillslope that co-occur with decreasing organic C (OC) concentrations. Protons derived from sulfide oxidation appear to be an additional driver of the weathering process as indicated by a build-up of SO 4 2- in the groundwater during lateral transport and a δ 34 S per mille value of +0.26-3.76 per mille in the deep groundwater indicating S inputs from pyrite. The two identified active acids in the deep groundwater are likely to control the base-flow chemistry of streams draining larger catchments (>1 km 2 ) as evident by δ 18 O signatures and base cation concentrations that overlap with that of the groundwater.

Carbon mineralization and pyrite oxidation in groundwater: Importance for silicate weathering in boreal forest soils and stream base-flow chemistry

Energy Technology Data Exchange (ETDEWEB)

Klaminder, J., E-mail: jonatan.klaminder@emg.umu.se [Department of Forest Ecology and Management, SLU, SE-901 83 Umea (Sweden)] [Department of Ecology and Environmental Science, Umea University, SE-901 87 (Sweden); Grip, H. [Department of Forest Ecology and Management, SLU, SE-901 83 Umea (Sweden); Moerth, C.-M. [Department of Geological Sciences, Stockholm University, 106 91 Stockholm (Sweden); Laudon, H. [Department of Forest Ecology and Management, SLU, SE-901 83 Umea (Sweden)

2011-03-15

Research highlights: {yields} Organic compounds is mineralized during later transport in deep groundwater aquifers. {yields} Carbonic acid generated by this process stimulates dissolution of silicate minerals. {yields} Protons derived from pyrite oxidation also affects weathering in deep groundwater. {yields} The identified weathering mechanisms affect base-flow chemistry in boreal streams. - Abstract: What role does mineralized organic C and sulfide oxidation play in weathering of silicate minerals in deep groundwater aquifers? In this study, how H{sub 2}CO{sub 3}, produced as a result of mineralization of organic matter during groundwater transport, affects silicate weathering in the saturated zone of the mineral soil along a 70 m-long boreal hillslope is demonstrated. Stream water measurements of base cations and {delta}{sup 18}O are included to determine the importance of the deep groundwater system for downstream surface water. The results suggest that H{sub 2}CO{sub 3} generated from organic compounds being mineralized during the lateral transport stimulates weathering at depths between 0.5 and 3 m in the soil. This finding is indicated by progressively increasing concentrations of base cations-, silica- and inorganic C (IC) in the groundwater along the hillslope that co-occur with decreasing organic C (OC) concentrations. Protons derived from sulfide oxidation appear to be an additional driver of the weathering process as indicated by a build-up of SO{sub 4}{sup 2-} in the groundwater during lateral transport and a {delta}{sup 34}S per mille value of +0.26-3.76 per mille in the deep groundwater indicating S inputs from pyrite. The two identified active acids in the deep groundwater are likely to control the base-flow chemistry of streams draining larger catchments (>1 km{sup 2}) as evident by {delta}{sup 18}O signatures and base cation concentrations that overlap with that of the groundwater.

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

DEFF Research Database (Denmark)

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

2009-01-01

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

Groundwater contamination by chlorinated hydrocarbons in the soil vapour phase - risk assessment at a former dry cleaner site

Energy Technology Data Exchange (ETDEWEB)

Danzer, J. [Boden-und-Grundwasser GbR, Sonthofen (Germany)

2002-07-01

Chlorinated hydrocarbons, e.g. Perchloroethene (PCE) were commonly used for dry cleaning purposes among other ones. Since they have a significant toxic potential they impose a serious risk to groundwater quality. Due to their physico-chemical properties - particularly high volatility and medium to high water solubility - and their low biodegradation potential they are highly mobile within the unsaturated soil (vapour phase) as well as within the groundwater. This poster (paper) presents data and calculations of a consultant's ''virtual every day'' work in order to assess the risk of groundwater contamination at a former dry cleaner site. (orig.)

Overview of soil and groundwater research activities of the American Petroleum Institute (API)

International Nuclear Information System (INIS)

Bauman, B.

1992-01-01

The American Petroleum Institute (API) is a trade association for the domestic petroleum industry in the USA, with over 2000 corporate and 5000 individual members. Subsurface research activities are managed by the API soil/groundwater technical task force, a committee made up of over 25 member company engineers, hydrologists, soil scientists, and chemists representing both the research and operations sectors of the petroleum industry. The research areas of the group have been divided into five principle areas: biodegradation processes, fate and transport, remediation, decision making tools for remediation, and detection/analytical methods. A summary of each of the current projects in these subject areas is presented

Technology evaluation report: Biotrol Soil Washing System for treatment of a wood-preserving site. Volume 2, Part B

International Nuclear Information System (INIS)

Skovronek, H.S.; Ellis, W.; Evans, J.; Kitaplioglu, O.; McPherson, J.

1991-12-01

The SITE Program demonstration of one configuration of the BioTrol Soil Washing System (BSWS) was conducted to obtain reliable performance and cost data that can be used to evaluate the potential applicability of the technology as a remediation alternative for sites contaminated with hazardous wastes. The BSWS treatment train used in the study consists of three technologies: a soil washer; an aqueous treatment system; and a slurry bio-reactor. The demonstration was carried out at the MacGillis and Gibbs Superfund site in New Brighton, MN. The report analyzes the results from the SITE demonstration. It includes discussion of the operation of the three separate treatment technologies (SW, SBR, and BATS) evaluated in the test and provides flow diagrams, a summary of the sampling and analytical programs, an economic analysis, and a quality assurance/quality control evaluation of the data. Conclusions were reached concerning the technology's suitability for use in remediations involving both similar and different materials at other sites

Radiological impact of a municipal solid waste landfill on soil and groundwater using 2-D resistivity tomography and gamma ray spectroscopy

International Nuclear Information System (INIS)

Ehirim, C.N.; Itota, G.O.

2011-01-01

The radiological impacts of a municipal solid waste landfill on soil and groundwater in Port Harcourt municipality was investigated by integrating 2-D resistivity imaging and gamma-ray spectroscopy. The objective of the study is to determine the lateral and vertical limits of leachate contamination, and to estimate the radioactivity concentrations in soil and groundwater. Results show that the soil and ground water have been contaminated by landfill emissions and radioactive materials throughout the landfill area. The distribution of the contamination is uneven and spotty, both horizontally and vertically, and has penetrated to depths exceeding 31m into the ground water aquifer. The primary contaminants found in the site were leachate, landfill gases, and 40 K, 226 Ra, and 228 Ra radionuclides. The mean absorbed dose rates of 31.98nGy/hr, 10.51nGy/hr and 6.98nGy/hr, and mean dose rate equivalents of 0.28mSv/yr, 0.09mSv/yr and 0.06mSv/yr were obtained for the soil, leachate and water samples, respectively. The mean absorbed and equivalent dose rates in the soil and water samples are greater than their controls, suggesting that the landfill area is contaminated. These results are comparable to those reported for other waste sites in the area and lower than the maximum permitted limits for the general public of 1mSv/yr and 0.1mSv/yr for soil and water, respectively. These therefore, have no immediate radiological health burden on the inhabitants who depend on the soil and groundwater for their crops and potable water supply, except for the effects of disease causing micro-organism and non-methane volatile organic compounds (VOCs) from the leachate. However, with continuous consumption of crop products and intake of groundwater, increase in the activity concentration and dose rates of these radionuclides may occur over time, with adverse effects on humans.

Evaluation of available data on the geohydrology, soil chemistry, and ground-water chemistry of Gas Works Park and surrounding region, Seattle, Washington

Science.gov (United States)

Sabol, M.A.; Turney, G.L.; Ryals, G.N.

1988-01-01

Gas Works Park, in Seattle, Washington, is located at the site of an abandon gasification plant on Lake Union. Wastes deposited during 50 years of plant operations (1906-1956) have extended the shore line 100 ft and left the park soil contaminated with a number of hazardous material. Soil contaminants include polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls, pesticides, volatile organic compounds, cyanide, and metals. PAHs and metals have been detected in Lake Union sediments. Maximum total PAH concentrations exceeded 100 million micrograms/kilogram in some places in the soils of the park at 6-inch depths and in some lake sediments. Other contaminants present are much lower in concentrations. The park is on glacial drift overlain by gasification waste materials and clean fill. Waste materials include sand and gravels, mixed with lampblack, oil, bricks, and other industrial wastes. Groundwater flows through the soils and waste toward Lake Union. Vertical groundwater movement is uncertain, but is assumed to be upward near Lake Union. Concentrations of most soil contaminants are probably low in the groundwater and in Lake Union due to the low solubilities and high sorptive characteristics of these contaminants. However, no water quality data are available to confirm this premise. (USGS)

Geothermal energy plants. Technologies and risk of soil and groundwater pollution; Jordvarmeanlaeg. Teknologier og risiko for jord- og grundvandsforurening

Energy Technology Data Exchange (ETDEWEB)

Villumsen, B. (COWI A/S, Kgs. Lyngby (Denmark))

2008-07-01

Ground source heat systems utilise the natural heat in the ground to heat houses and domestic hot water. The technology is energy-saving and can therefore contribute to the targets of reducing Denmark's CO{sub 2} emissions. All else being equal, a ground source heat system containing chemicals poses a potential contamination risk to soil and groundwater. Therefore a permit is required when installing a ground source heat system, and the general regulations for implementing the system etc. combined with the municipality's administrative procedures for the area must ensure sufficient protection of the groundwater. This project only deals with the heat exchanging system, which is the part of the ground source heat system which involves risk of soil and groundwater contamination. The aim of the project is to procure an overall updated knowledge base about the different types of ground source heat systems and the contamination risk associated with them. The project also reviews how disadvantages can be managed or minimized. (au)

Adsorptive properties of alluvial soil for arsenic(V) and its potential for protection of the shallow groundwater among Changsha, Zhuzhou, and Xiangtan cities, China.

Science.gov (United States)

Chen, Hongwei; Mei, Jinhua; Luo, Yueping; Qiu, Anni; Wang, Huan

2017-02-01

The study area is among Changsha, Zhuzhou, and Xiangtan cities, which was under agricultural use and natural conditions about 10 years ago and now is becoming part of the metropolis because of the urban expansion. This study aims to investigate the mechanisms and capabilities of the local alluvial soil layer for protecting the local shallow groundwater from arsenic pollution by field surveys and batch experiments. The field surveys showed that there was an acidic tendency of the groundwater, and phosphate, nitrate, and arsenic in the groundwater significantly increased comparing to their reference values. It indicates that the disturbance of the former agricultural land due to the change of land use may be responsible for these changes. From the experimental results, the maximum adsorption capacity of the soil for As(V) was as low as 0.334 mg/g, and lower As(V) adsorption capacities were obtained at higher As(V) concentration, higher pH, and lower temperature. The presence of H 2 PO 4 - and SiO 3 2- posed negative, while HCO 3 - slight positive, and SO 4 2- , NO 3 - and Cl - negligible influences on the As(V) adsorption. The surface-derived organic matter played a negative role in the adsorption process, and low specific surface area influenced adsorption capacity of the soil. The study reveals that the local soil layer shows poor potential for protection of the local shallow groundwater from As(V) pollution, and the change trends of the groundwater environments due to more intensive anthropogenic activities will further weaken this potential and increase the risk of the groundwater contamination.

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

Denitrification as an adaptive trait in soil and groundwater bacteria

Energy Technology Data Exchange (ETDEWEB)

Bergwall, C

1997-09-01

The focus of this thesis is on selection and adaptation processes in bacteria with emphasis on denitrifying bacteria in groundwater. Other nitrogen transformation processes such as dissimilatory nitrate reduction to ammonium (nitrate ammonification) and nitrification of forest soil bacteria are briefly discussed. Microcosms with sterile sediment and groundwater were inoculated with single denitrifying strains isolated from three groundwater aquifers, two of which are agricultural aquifers (in situ NO{sub 3}{sup -}-N was 24.1 and 35.2 mg1{sup -1}) and the third which is a pristine lake water infiltration aquifer (in situ NO{sub 3}{sup -}-N was 6.3 mg1{sup -1}). The average denitrification activity for strains from the nitrate contaminated sites were twice as high as the activity of the strains from the pristine site. Denitrification were carbon limited and glucose amendment increased the denitrification activity about a 2-fold for all strains. The strain specific differences in denitrification rates increased to a 2.5-fold after carbon addition indicating that the differences in reduction rates cannot be explained by different carbon utilisation rates but rather reflect innate differences in the reductases of the strains. A preliminary identification of the molecular target for adaptation was performed with artificial electron donors and electron acceptors for all enzymatic steps in the denitrification pathway. Nitrous oxide reductase activity was significantly higher in denitrifiers from the nitrate contaminated sites. This suggests that nos genes may be the molecular target, possibly by mutation or gene duplication for adaptation to high nitrate concentrations. Two anaerobic denitrifiers from each of the contaminated sites were capable of aerobic denitrification indicating that high nitrate concentrations may select for strains that denitrifies in the presence of both oxygen and nitrate. Microcosm experiments with fertilized coniferous forest soil showed that the

Soil, a sponge for pollutants

International Nuclear Information System (INIS)

Lichtfouse, E.

1997-01-01

Soil has been regarded for a long time as an inert and closed medium where it was possible to dump any kind of hazardous wastes without implications on living organisms. But all pollutants entering the soil system can be stocked, transformed (often into more hazardous compounds) and transferred towards the atmosphere, groundwater and rivers. Obviously, the building up of toxic wastes into the soil system is a risk for all living beings. Pollution sources are numerous and diverse. They are given here into details. To follow the path of pollutants into the soil puzzle, with emphasis on the determination of bound residues, analytical experiments using labelled elements are by far the most efficient. But as a matter of fact, real toxicity can only be measured with biological tests, where living organisms such as light-emitting bacteria or plants are grown in contact with the toxic media. In order to minimize the diffusion of pollutants toward other natural media, a wide panel of remediation techniques are under development. Incineration and thermal desorption, for instance, are fast. Alternatively, the spreading of detergents onto the soil surface solubilizes pollutants that are later water-washed toward other media. Nonetheless, it is rarely complete and favors the migration of the pollutants toward groundwater, rivers and other ecosystems. On the other hand, mild, low-cost and efficient biological methods are now developing rapidly. Their principle lies on the natural ability of living organisms to extract and degrade toxic molecules. Lastly, plants may be used to remedy polluted soils, a process called ''phyto-remediation''. Its principles lies on two main phenomena. Firstly, some plant species are able to selectively extract large amounts of heavy metals from the ground then store them. Secondly, plants activate strongly the microbial biomass by injection of exudate enriched in organic nutriments in the root zone called ''rhizosphere''. Thus, the microbes, well

Landscape structure, groundwater dynamics, and soil water content influence soil respiration across riparian-hillslope transitions in the Tenderfoot Creek Experimental Forest, Montana

Science.gov (United States)

Vincent J. Pacific; Brian L. McGlynn; Diego A. Riveros-Iregui; Daniel L. Welsch; Howard E. Epstein

2011-01-01

Variability in soil respiration at various spatial and temporal scales has been the focus of much research over the last decade aimed to improve our understanding and parameterization of physical and environmental controls on this flux. However, few studies have assessed the control of landscape position and groundwater table dynamics on the spatiotemporal variability...

Management of Nitrate m Groundwater: A Simulation Study

Directory of Open Access Journals (Sweden)

M. Ahmed

2001-01-01

Full Text Available Agriculture may cause nitrate and other chemicals to enter into groundwater systems. Nitrate in drinking water is considered a health hazard. A study was conducted to assess the extent of nitrate pollution of groundwater caused by agriculture and to evaluate the possibility of using the LEACHN model to manage nitrate entry into groundwater of agricultural areas of Al-Batinah, which is the most important agricultural region of Oman. Groundwater samples were collected and analyzed to assess the problem and to detect possible trends. Soil sampling and analyses were done to demonstrate the difference in the nitrate concentration in agricultural and non-agricultural soils. A questionnaire survey was conducted to gather information on agricultural practices, fertilizer input, and other possible sources of nitrate pollution. Results from the study show that 23% of groundwater samples have a concentration of nitrate-N concentration of 10 mg/l and 34% samples exceed 8 mg/l. Agricultural soils have higher levels of nitrate compared to non- agricultural soils. Results also demonstrate that nitrate levels in groundwater in Al-Batinah are rising. Application of the ‘LEACHN’ model demonstrated its suitability for use as a management tool to reduce nitrate leaching to groundwater by controlling fertilizer and water input.

Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: a potential source of geogenic Cr(VI) to groundwater

Science.gov (United States)

Mills, Christopher T.; Morrison, Jean M.; Goldhaber, Martin B.; Ellefsen, Karl J.

2011-01-01

Concentrations of geogenic Cr(VI) in groundwater that exceed the World Health Organization’s maximum contaminant level for drinking water (50 μg L−1) occur in several locations globally. The major mechanism for mobilization of this Cr(VI) at these sites is the weathering of Cr(III) from ultramafic rocks and its subsequent oxidation on Mn oxides. This process may be occurring in the southern Sacramento Valley of California where Cr(VI) concentrations in groundwater can approach or exceed 50 μg L−1. To characterize Cr geochemistry in the area, samples from several soil auger cores (approximately 4 m deep) and drill cores (approximately 25 m deep) were analyzed for total concentrations of 44 major, minor and trace elements, Cr associated with labile Mn and Fe oxides, and Cr(VI). Total concentrations of Cr in these samples ranged from 140 to 2220 mg per kg soil. Between 9 and 70 mg per kg soil was released by selective extractions that target Fe oxides, but essentially no Cr was associated with the abundant reactive Mn oxides (up to ~1000 mg hydroxylamine-reducible Mn per kg soil was present). Both borehole magnetic susceptibility surveys performed at some of the drill core sites and relative differences between Cr released in a 4-acid digestion versus total Cr (lithium metaborate fusion digestion) suggest that the majority of total Cr in the samples is present in refractory chromite minerals transported from ultramafic exposures in the Coast Range Mountains. Chromium(VI) in the samples studied ranged from 0 to 42 μg kg−1, representing a minute fraction of total Cr. Chromium(VI) content was typically below detection in surface soils (top 10 cm) where soil organic matter was high, and increased with increasing depth in the soil auger cores as organic matter decreased. Maximum concentrations of Cr(VI) were up to 3 times greater in the deeper drill core samples than the shallow auger cores. Although Cr(VI) in these vadose zone soils and sediments was only a

Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: A potential source of geogenic Cr(VI) to groundwater

International Nuclear Information System (INIS)

Mills, Christopher T.; Morrison, Jean M.; Goldhaber, Martin B.; Ellefsen, Karl J.

2011-01-01

Highlights: → Southern Sacramento Valley soil and sediment has abundant naturally-occurring Cr(III). → Cr(III) resides mainly in chromite but some is associated with clays and Fe oxides. → Cr(VI) is mostly absent in surface soil but ubiquitous in deeper soil and sediment. → Cr(VI) increased linearly with time during lab soil incubations with no additions. → Cation exchange processes resulted in greater Cr(VI) generation rates. - Abstract: Concentrations of geogenic Cr(VI) in groundwater that exceed the World Health Organization's maximum contaminant level for drinking water (50 μg L -1 ) occur in several locations globally. The major mechanism for mobilization of this Cr(VI) at these sites is the weathering of Cr(III) from ultramafic rocks and its subsequent oxidation on Mn oxides. This process may be occurring in the southern Sacramento Valley of California where Cr(VI) concentrations in groundwater can approach or exceed 50 μg L -1 . To characterize Cr geochemistry in the area, samples from several soil auger cores (approximately 4 m deep) and drill cores (approximately 25 m deep) were analyzed for total concentrations of 44 major, minor and trace elements, Cr associated with labile Mn and Fe oxides, and Cr(VI). Total concentrations of Cr in these samples ranged from 140 to 2220 mg per kg soil. Between 9 and 70 mg per kg soil was released by selective extractions that target Fe oxides, but essentially no Cr was associated with the abundant reactive Mn oxides (up to ∼1000 mg hydroxylamine-reducible Mn per kg soil was present). Both borehole magnetic susceptibility surveys performed at some of the drill core sites and relative differences between Cr released in a 4-acid digestion versus total Cr (lithium metaborate fusion digestion) suggest that the majority of total Cr in the samples is present in refractory chromite minerals transported from ultramafic exposures in the Coast Range Mountains. Chromium(VI) in the samples studied ranged from 0 to 42 �

Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: A potential source of geogenic Cr(VI) to groundwater

Energy Technology Data Exchange (ETDEWEB)

Mills, Christopher T., E-mail: cmills@usgs.gov [United States Geological Survey, Crustal Geophysics and Geochemistry Science Center, Denver Federal Center, MS 964D, Denver, CO 80225 (United States); Morrison, Jean M.; Goldhaber, Martin B.; Ellefsen, Karl J. [United States Geological Survey, Crustal Geophysics and Geochemistry Science Center, Denver Federal Center, MS 964D, Denver, CO 80225 (United States)

2011-08-15

Highlights: > Southern Sacramento Valley soil and sediment has abundant naturally-occurring Cr(III). > Cr(III) resides mainly in chromite but some is associated with clays and Fe oxides. > Cr(VI) is mostly absent in surface soil but ubiquitous in deeper soil and sediment. > Cr(VI) increased linearly with time during lab soil incubations with no additions. > Cation exchange processes resulted in greater Cr(VI) generation rates. - Abstract: Concentrations of geogenic Cr(VI) in groundwater that exceed the World Health Organization's maximum contaminant level for drinking water (50 {mu}g L{sup -1}) occur in several locations globally. The major mechanism for mobilization of this Cr(VI) at these sites is the weathering of Cr(III) from ultramafic rocks and its subsequent oxidation on Mn oxides. This process may be occurring in the southern Sacramento Valley of California where Cr(VI) concentrations in groundwater can approach or exceed 50 {mu}g L{sup -1}. To characterize Cr geochemistry in the area, samples from several soil auger cores (approximately 4 m deep) and drill cores (approximately 25 m deep) were analyzed for total concentrations of 44 major, minor and trace elements, Cr associated with labile Mn and Fe oxides, and Cr(VI). Total concentrations of Cr in these samples ranged from 140 to 2220 mg per kg soil. Between 9 and 70 mg per kg soil was released by selective extractions that target Fe oxides, but essentially no Cr was associated with the abundant reactive Mn oxides (up to {approx}1000 mg hydroxylamine-reducible Mn per kg soil was present). Both borehole magnetic susceptibility surveys performed at some of the drill core sites and relative differences between Cr released in a 4-acid digestion versus total Cr (lithium metaborate fusion digestion) suggest that the majority of total Cr in the samples is present in refractory chromite minerals transported from ultramafic exposures in the Coast Range Mountains. Chromium(VI) in the samples studied ranged

Evaluation and comparison of closed-loop wash-water system

International Nuclear Information System (INIS)

Whitney, P.M.; Greer, C.R.

1991-01-01

Effluent from vehicle and equipment cleaning is known to contain a variety of potential pollutants, the most common being hydrocarbons and suspended solids. Proper treatment and discharge of this effluent is a growing concern as environmental awareness increases. In the United States, discharge of this effluent to municipal sewage treatment systems requires a permit from local authorities, discharge to surface waters requires a federal permit and, in most cases, discharge to the ground in prohibited. Furthermore, discharge to ground and surface waters can cause soil or groundwater contamination resulting in property devaluation, adverse impact on human health, fines from regulatory agencies, expensive cleanup and negative publicity. Effluent from vehicle washing typically does not meet the minimum pollutant levels allowed by regulatory agencies for discharge to surface waters or sewage treatment plants. Because of the liability associated with discharge to ground and surface waters and the difficulty in meeting municipal sewer discharge permit requirements, closed-loop wastewater treatment is an attractive alternative to discharge. Evaluation and comparison of systems from each category constitute the basis of this paper. Factors involved in selecting a system and available water-treatment technologies are discussed. The conclusion summarizes the results of the system comparison and makes recommendations for selecting and installing closed-loop water treatment systems for vehicle and equipment cleaning

Late Washing efficiency

International Nuclear Information System (INIS)

Morrissey, M.F.

1992-01-01

Interim Waste Technology has demonstrated the Late Washing concept on the Experimental Laboratory Filter (ELF) at TNX. In two tests, washing reduced the [NO 2 - ] from 0.08 M to approximately 0.01 M on slurries with 2 year equivalent radiation exposures and 9.5 wt. % solids. For both washes, the [NO 2 - ] decreased at rates near theoretical for a constant volume stirred vessel, indicating approximately l00% washing efficiency. Permeate flux was greater than 0.05 gpm/ft 2 for both washes at a transmembrane pressure of 50 psi and flow velocity of 9 ft/sec

Phase 1 remediation of jet fuel contaminated soil and groundwater at JFK International Airport using dual phase extraction and bioventing

International Nuclear Information System (INIS)

Roth, R.; Bianco, P. Rizzo, M.

1995-01-01

Soil and groundwater contaminated with jet fuel at Terminal One of the JFK International Airport in New York have been remediated using dual phase extraction (DPE) and bioventing. Two areas were remediated using 51 DPE wells and 20 air sparging/air injection wells. The total area remediated by the DPE wells is estimated to be 4.8 acres. Groundwater was extracted to recover nonaqueous phase and aqueous phase jet fuel from the shallow aquifer and treated above ground by the following processes; oil/water separation, iron-oxidation, flocculation, sedimentation, filtration, air stripping and liquid-phase granular activated carbon (LPGAC) adsorption. The extracted vapors were treated by vapor-phase granular activated carbon (VPGAC) adsorption in one area, and catalytic oxidation and VPGAC adsorption in another area. After 6 months of remediation, approximately 5,490 lbs. of volatile organic compounds (VOCs) were removed by soil vapor extraction (SVE), 109,650 lbs. of petroleum hydrocarbons were removed from the extracted groundwater, and 60,550 lbs. of petroleum hydrocarbons were biologically oxidized by subsurface microorganisms. Of these three mechanisms, the rate of petroleum hydrocarbon removal was the highest for biological oxidation in one area and by groundwater extraction in another area

Combined mild soil washing and compost-assisted phytoremediation in treatment of silt loams contaminated with copper, nickel, and chromium.

Science.gov (United States)

Sung, Menghau; Lee, Chi-Yi; Lee, Suen-Zone

2011-06-15

A new soil remediation option, combining the soil washing process using pure water followed by the compost-assisted phytoextraction, is evaluated using silt loams contaminated with plating wastewater containing Cu, Ni, and Cr. Plants utilized in this study are the rapeseeds, sunflowers, tomatoes, and soapworts. Phytoextraction operation was carried out in pot experiments over a period of 4 months. Metal concentrations in roots and shoots of plants were analyzed upon completion of each pot experiment. Hypothesis testing was employed in assessing the significance of difference in the experimental data. Results indicated that the rapeseed, a hyperaccumulator, is most effective in extracting metals from the compost-amended silt loams. The fast-growing sunflowers and tomatoes are comparable to rapeseeds in accumulating metals despite their relatively low metal concentrations in tissues. Bioaccumulation coefficients obtained for all plants are less than one, indicating that phytostabilization rather than phytoextraction is the dominant mechanism at this simulated final-phase condition. Copyright © 2011 Elsevier B.V. All rights reserved.

Nasal Wash Treatment

Science.gov (United States)

... Medications Alternative Therapies Nasal Wash Treatment Nasal Wash Treatment Make an Appointment Ask a Question Refer Patient The Centers for Disease Control (CDC) guidelines for preparing water used in a nasal wash are listed below. Many ...

Sustainable decontamination of an actual-site aged PCB-polluted soil through a biosurfactant-based washing followed by a photocatalytic treatment.

Science.gov (United States)

Occulti, Fabio; Roda, Giovanni Camera; Berselli, Sara; Fava, Fabio

2008-04-15

A two phases process consisting of a soya lecithin (SL)-based soil washing process followed by the photocatalytic treatment of resulting effluents was developed and applied at the laboratory scale in the remediation of an actual-site soil historically contaminated by 0.65 g/kg of polychlorinated biphenyls (PCBs). Triton X-100 (TX) was employed in the same process as a control surfactant. SL and TX, both applied as 2.25 g/L aqueous solutions, displayed a comparable ability to remove PCBs from the soil. However, SL solution displayed a lower ecotoxicity, a lower ability to mobilize soil constituents and a higher soil detoxification capacity with respect to the TX one. The photocatalytic treatment resulted in marked depletions (from 50% to 70%) of total organic carbon (TOC) and PCBs initially occurring in the SL and TX contaminated effluents. Despite the ability of SL to adversely affect the rate of TOC and PCB photodegradation, higher PCB depletion and dechlorination yields along with lower increases of ecotoxicity were observed in SL-containing effluents with respect to the TX ones at the end of 15 days of treatment. The two phases process developed and tested for the first time in this study seems to have the required features to become, after a proper optimization and scale up, a challenging procedure for the sustainable remediation of actual site, poorly biotreatable PCB-contaminated soils. Copyright 2007 Wiley Periodicals, Inc.

Mobility of fertiliser-derived uranium in arable soils and its contribution to uranium concentrations in groundwater and tap water

International Nuclear Information System (INIS)

Smidt, Geerd Ahlrich

2011-01-01

Phosphorus (P) mineral fertilisers are found to contain high concentrations of uranium (U) (up to 206 mg U kg -1 ) and other trace elements (TE), such as Cd, Pb, Ni, Cu, Zn, Th, Nb, Sr, V, and rare earth elements. The content of U and other trace elements is depended on the sedimentary of igneous origin of the rock phosphate. In this study, the production of P fertilisers has been shown to contaminate top soil horizons with U and other trace elements in the close vicinity of a factory located in Southern Brazil. In contrast to this point source, agricultural P fertilisation leads to a diffuse contamination of the agro-ecosystem with U and other fertiliser-derived trace elements on a large scale. Top soil horizons of arable land accumulate fertiliser-derived U. According to the geochemical behaviour of U(VI) species under oxidising conditions, the mobilisation capacity for U in top soil horizons is considered to be high, contrary to other fertiliser-derived heavy metals (e.g. Cd). Hence, it is assumed that U can be leached to shallow groundwater and can reach fresh water resources potentially used for drinking water supply. The aims of this study were to investigate the concentration of U and other contaminants in P fertilisers, to identify geochemical processes of fertiliser-derived U mobility and mobilisation from arable top soil horizons to the groundwater, and to evaluate the origin of U in German groundwater and tap water. This study presents the broadest recent data set on regional distribution of U concentrations in German tap water to which 76 % of the German population has access. The mean U concentration was 0.68 μg L -1 , the median 0.50 μg L -1 . 1.3 % or 1 million of the 80.6 million inhabitants in Germany are exposed to U concentrations in tap water which are higher than the German drinking water threshold limit of 10 μg L -1 . The regional distribution of U concentrations largely agrees with the geological setting reported for mineral waters

Mobility of fertiliser-derived uranium in arable soils and its contribution to uranium concentrations in groundwater and tap water

Energy Technology Data Exchange (ETDEWEB)

Smidt, Geerd Ahlrich

2011-12-20

Phosphorus (P) mineral fertilisers are found to contain high concentrations of uranium (U) (up to 206 mg U kg{sup -1}) and other trace elements (TE), such as Cd, Pb, Ni, Cu, Zn, Th, Nb, Sr, V, and rare earth elements. The content of U and other trace elements is depended on the sedimentary of igneous origin of the rock phosphate. In this study, the production of P fertilisers has been shown to contaminate top soil horizons with U and other trace elements in the close vicinity of a factory located in Southern Brazil. In contrast to this point source, agricultural P fertilisation leads to a diffuse contamination of the agro-ecosystem with U and other fertiliser-derived trace elements on a large scale. Top soil horizons of arable land accumulate fertiliser-derived U. According to the geochemical behaviour of U(VI) species under oxidising conditions, the mobilisation capacity for U in top soil horizons is considered to be high, contrary to other fertiliser-derived heavy metals (e.g. Cd). Hence, it is assumed that U can be leached to shallow groundwater and can reach fresh water resources potentially used for drinking water supply. The aims of this study were to investigate the concentration of U and other contaminants in P fertilisers, to identify geochemical processes of fertiliser-derived U mobility and mobilisation from arable top soil horizons to the groundwater, and to evaluate the origin of U in German groundwater and tap water. This study presents the broadest recent data set on regional distribution of U concentrations in German tap water to which 76 % of the German population has access. The mean U concentration was 0.68 μg L{sup -1}, the median 0.50 μg L{sup -1}. 1.3 % or 1 million of the 80.6 million inhabitants in Germany are exposed to U concentrations in tap water which are higher than the German drinking water threshold limit of 10 μg L{sup -1}. The regional distribution of U concentrations largely agrees with the geological setting reported for

Instrumenting an upland research catchment in Canterbury, New Zealand to study controls on variability of soil moisture, shallow groundwater and streamflow

Science.gov (United States)

McMillan, Hilary; Srinivasan, Ms

2015-04-01

Hydrologists recognise the importance of vertical drainage and deep flow paths in runoff generation, even in headwater catchments. Both soil and groundwater stores are highly variable over multiple scales, and the distribution of water has a strong control on flow rates and timing. In this study, we instrumented an upland headwater catchment in New Zealand to measure the temporal and spatial variation in unsaturated and saturated-zone responses. In NZ, upland catchments are the source of much of the water used in lowland agriculture, but the hydrology of such catchments and their role in water partitioning, storage and transport is poorly understood. The study area is the Langs Gully catchment in the North Branch of the Waipara River, Canterbury: this catchment was chosen to be representative of the foothills environment, with lightly managed dryland pasture and native Matagouri shrub vegetation cover. Over a period of 16 months we measured continuous soil moisture at 32 locations and near-surface water table (versus hillslope locations, and convergent versus divergent hillslopes. We found that temporal variability is strongly controlled by the climatic seasonal cycle, for both soil moisture and water table, and for both the mean and extremes of their distributions. Groundwater is a larger water storage component than soil moisture, and the difference increases with catchment wetness. The spatial standard deviation of both soil moisture and groundwater is larger in winter than in summer. It peaks during rainfall events due to partial saturation of the catchment, and also rises in spring as different locations dry out at different rates. The most important controls on spatial variability are aspect and distance from stream. South-facing and near-stream locations have higher water tables and more, larger soil moisture wetting events. Typical hydrological models do not explicitly account for aspect, but our results suggest that it is an important factor in hillslope

Long-Term Groundwater Monitoring Optimization, Clare Water Supply Superfund Site, Permeable Reactive Barrier and Soil Remedy Areas, Clare, Michigan

Science.gov (United States)

This report contains a review of the long-term groundwater monitoring network for the Permeable Reactive Barrier (PRB) and Soil Remedy Areas at the Clare Water Supply Superfund Site in Clare, Michigan.

Air sparging of organic compounds in groundwater

International Nuclear Information System (INIS)

Hicks, P.M.

1994-01-01

Soils and aquifers containing organic compounds have been traditionally treated by excavation and disposal of the soil and/or pumping and treating the groundwater. These remedial options are often not practical or cost effective solutions. A more favorable alternative for removal of the adsorbed/dissolved organic compounds would be an in situ technology. Air sparging will remove volatile organic compounds from both the adsorbed and dissolved phases in the saturated zone. This technology effectively creates a crude air stripper below the aquifer where the soil acts as the ''packing''. The air stream that contacts dissolved/adsorbed phase organics in the aquifer induces volatilization. A case history illustrates the effectiveness of air sparging as a remedial technology for addressing organic compounds in soil and groundwater. The site is an operating heavy equipment manufacturing facility in central Florida. The soil and groundwater below a large building at the facility was found to contain primarily diesel type petroleum hydrocarbons during removal of underground storage tanks. The organic compounds identified in the groundwater were Benzene, Xylenes, Ethylbenzene and Toluenes (BTEX), Methyl tert-Butyl Ether (MTBE) and naphthalenes in concentrations related to diesel fuel

Scientific Opportunity to Reduce Risk in Groundwater and Soil Remediation

Energy Technology Data Exchange (ETDEWEB)

Pierce, Eric M.; Freshley, Mark D.; Hubbard, Susan S.; Looney, Brian B.; Zachara, John M.; Liang, Liyuan; Lesmes, D.; Chamberlain, G. M.; Skubal, Karen L.; Adams, V.; Denham, Miles E.; Wellman, Dawn M.

2009-08-25

In this report, we start by examining previous efforts at linking science and DOE EM research with cleanup activities. Many of these efforts were initiated by creating science and technology roadmaps. A recurring feature of successfully implementing these roadmaps into EM applied research efforts and successful cleanup is the focus on integration. Such integration takes many forms, ranging from combining information generated by various scientific disciplines, to providing technical expertise to facilitate successful application of novel technology, to bringing the resources and creativity of many to address the common goal of moving EM cleanup forward. Successful projects identify and focus research efforts on addressing the problems and challenges that are causing “failure” in actual cleanup activities. In this way, basic and applied science resources are used strategically to address the particular unknowns that are barriers to cleanup. The brief descriptions of the Office of Science basic (Environmental Remediation Science Program [ERSP]) and EM’s applied (Groundwater and Soil Remediation Program) research programs in subsurface science provide context to the five “crosscutting” themes that have been developed in this strategic planning effort. To address these challenges and opportunities, a tiered systematic approach is proposed that leverages basic science investments with new applied research investments from the DOE Office of Engineering and Technology within the framework of the identified basic science and applied research crosscutting themes. These themes are evident in the initial portfolio of initiatives in the EM groundwater and soil cleanup multi-year program plan. As stated in a companion document for tank waste processing (Bredt et al. 2008), in addition to achieving its mission, DOE EM is experiencing a fundamental shift in philosophy from driving to closure to enabling the long-term needs of DOE and the nation.

Impact of Climate Change on Soil and Groundwater Chemistry Subject to Process Waste Land Application

Science.gov (United States)

McNab, W. W.

2013-12-01

Nonhazardous aqueous process waste streams from food and beverage industry operations are often discharged via managed land application in a manner designed to minimize impacts to underlying groundwater. Process waste streams are typically characterized by elevated concentrations of solutes such as ammonium, organic nitrogen, potassium, sodium, and organic acids. Land application involves the mixing of process waste streams with irrigation water which is subsequently applied to crops. The combination of evapotranspiration and crop salt uptake reduces the downward mass fluxes of percolation water and salts. By carefully managing application schedules in the context of annual climatological cycles, growing seasons, and process requirements, potential adverse environmental impacts to groundwater can be mitigated. However, climate change poses challenges to future process waste land application efforts because the key factors that determine loading rates - temperature, evapotranspiration, seasonal changes in the quality and quantity of applied water, and various crop factors - are all likely to deviate from current averages. To assess the potential impact of future climate change on the practice of land application, coupled process modeling entailing transient unsaturated fluid flow, evapotranspiration, crop salt uptake, and multispecies reactive chemical transport was used to predict changes in salt loading if current practices are maintained in a warmer, drier setting. As a first step, a coupled process model (Hydrus-1D, combined with PHREEQC) was calibrated to existing data sets which summarize land application loading rates, soil water chemistry, and crop salt uptake for land disposal of process wastes from a food industry facility in the northern San Joaquin Valley of California. Model results quantify, for example, the impacts of evapotranspiration on both fluid flow and soil water chemistry at shallow depths, with secondary effects including carbonate mineral

Validation on groundwater flow model including sea level change. Modeling on groundwater flow in coastal granite area

International Nuclear Information System (INIS)

Hasegawa, Takuma; Miyakawa, Kimio

2009-01-01

It is important to verify the groundwater flow model that reproduces pressure head, water chemistry, and groundwater age. However, water chemistry and groundwater age are considered to be influenced by historical events. In this study, sea level change during glacial-interglacial cycle was taken into account for simulating salinity and groundwater age at coastal granite area. As a result of simulation, salinity movement could not catch up with sea level changes, and mixing zone was formed below the fresh-water zone. This mixing zone was observed in the field measurement, and the observed salinities were agreed with simulated results including sea level change. The simulated residence time including sea level change is one-tenth of steady state. The reason is that the saline water was washed out during regression and modern sea-water was infiltrated during transgression. As mentioned before, considering sea level change are important to reproduce salinity and helium age at coastal area. (author)

Quantifying Potential Groundwater Recharge In South Texas

Science.gov (United States)

Basant, S.; Zhou, Y.; Leite, P. A.; Wilcox, B. P.

2015-12-01

Groundwater in South Texas is heavily relied on for human consumption and irrigation for food crops. Like most of the south west US, woody encroachment has altered the grassland ecosystems here too. While brush removal has been widely implemented in Texas with the objective of increasing groundwater recharge, the linkage between vegetation and groundwater recharge in South Texas is still unclear. Studies have been conducted to understand plant-root-water dynamics at the scale of plants. However, little work has been done to quantify the changes in soil water and deep percolation at the landscape scale. Modeling water flow through soil profiles can provide an estimate of the total water flowing into deep percolation. These models are especially powerful with parameterized and calibrated with long term soil water data. In this study we parameterize the HYDRUS soil water model using long term soil water data collected in Jim Wells County in South Texas. Soil water was measured at every 20 cm intervals up to a depth of 200 cm. The parameterized model will be used to simulate soil water dynamics under a variety of precipitation regimes ranging from well above normal to severe drought conditions. The results from the model will be compared with the changes in soil moisture profile observed in response to vegetation cover and treatments from a study in a similar. Comparative studies like this can be used to build new and strengthen existing hypotheses regarding deep percolation and the role of soil texture and vegetation in groundwater recharge.

Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion

Science.gov (United States)

Xiaobo Zhou; Matthew J. Helmers; Heidi Asbjornsen; Randy Kolka; Mark D. Tomer

2010-01-01

Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to...

Comparison of soil solution sampling techniques to assess metal fluxes from contaminated soil to groundwater.

Science.gov (United States)

Coutelot, F; Sappin-Didier, V; Keller, C; Atteia, O

2014-12-01

The unsaturated zone plays a major role in elemental fluxes in terrestrial ecosystems. A representative chemical analysis of soil pore water is required for the interpretation of soil chemical phenomena and particularly to assess Trace Elements (TEs) mobility. This requires an optimal sampling system to avoid modification of the extracted soil water chemistry and allow for an accurate estimation of solute fluxes. In this paper, the chemical composition of soil solutions sampled by Rhizon® samplers connected to a standard syringe was compared to two other types of suction probes (Rhizon® + vacuum tube and Rhizon® + diverted flow system). We investigated the effects of different vacuum application procedures on concentrations of spiked elements (Cr, As, Zn) mixed as powder into the first 20 cm of 100-cm columns and non-spiked elements (Ca, Na, Mg) concentrations in two types of columns (SiO2 sand and a mixture of kaolinite + SiO2 sand substrates). Rhizon® was installed at different depths. The metals concentrations showed that (i) in sand, peak concentrations cannot be correctly sampled, thus the flux cannot be estimated, and the errors can easily reach a factor 2; (ii) in sand + clay columns, peak concentrations were larger, indicating that they could be sampled but, due to sorption on clay, it was not possible to compare fluxes at different depths. The different samplers tested were not able to reflect the elemental flux to groundwater and, although the Rhizon® + syringe device was more accurate, the best solution remains to be the use of a lysimeter, whose bottom is kept continuously at a suction close to the one existing in the soil.

In situ formation of magnetite reactive barriers in soil for waste stabilization

Science.gov (United States)

Moore, Robert C.

2003-01-01

Reactive barriers containing magnetite and methods for making magnetite reactive barriers in situ in soil for sequestering soil contaminants including actinides and heavy metals, organic materials, iodine and technetium are disclosed. According to one embodiment, a two-step reagent introduction into soil takes place. In the first step, free oxygen is removed from the soil by separately injecting into the soil aqueous solutions of iron (II) salt, for example FeCl.sub.2, and base, for example NaOH or NH.sub.3 in about a 1:1 volume ratio. Then, in the second step, similar reagents are injected a second time (however, according to about a 1:2 volume ratio, iron to salt) to form magnetite. The magnetite formation is facilitated, in part, due to slow intrusion of oxygen into the soil from the surface. The invention techniques are suited to injection of reagents into soil in proximity to a contamination plume or source allowing in situ formation of the reactive barrier at the location of waste or hazardous material. Mixing of reagents to form. precipitate is mediated and enhanced through movement of reagents in soil as a result of phenomena including capillary action, movement of groundwater, soil washing and reagent injection pressure.

Estimating Natural Recharge in a Desert Environment Facing Increasing Ground-Water Demands

Science.gov (United States)

Nishikawa, T.; Izbicki, J. A.; Hevesi, J. A.; Martin, P.

2004-12-01

Ground water historically has been the sole source of water supply for the community of Joshua Tree in the Joshua Tree ground-water subbasin of the Morongo ground-water basin in the southern Mojave Desert. Joshua Basin Water District (JBWD) supplies water to the community from the underlying Joshua Tree ground-water subbasin, and ground-water withdrawals averaging about 960 acre-ft/yr have resulted in as much as 35 ft of drawdown. As growth continues in the desert, ground-water resources may need to be supplemented using imported water. To help meet future demands, JBWD plans to construct production wells in the adjacent Copper Mountain ground-water subbasin. To manage the ground-water resources and to identify future mitigating measures, a thorough understanding of the ground-water system is needed. To this end, field and numerical techniques were applied to determine the distribution and quantity of natural recharge. Field techniques included the installation of instrumented boreholes in selected washes and at a nearby control site. Numerical techniques included the use of a distributed-parameter watershed model and a ground-water flow model. The results from the field techniques indicated that as much as 70 acre-ft/yr of water infiltrated downward through the two principal washes during the study period (2001-3). The results from the watershed model indicated that the average annual recharge in the ground-water subbasins is about 160 acre-ft/yr. The results from the calibrated ground-water flow model indicated that the average annual recharge for the same area is about 125 acre-ft/yr. Although the field and numerical techniques were applied to different scales (local vs. large), all indicate that natural recharge in the Joshua Tree area is very limited; therefore, careful management of the limited ground-water resources is needed. Moreover, the calibrated model can now be used to estimate the effects of different water-management strategies on the ground-water

Record of Decision for Tank Farm Soil and INTEC Groundwater, Operable Unit 3-14

Energy Technology Data Exchange (ETDEWEB)

L. S. Cahn

2007-05-16

This decision document presents the selected remedy for Operable Unit (OU) 3-14 tank farm soil and groundwater at the Idaho Nuclear Technology and Engineering Center (INTEC), which is located on the Idaho National Laboratory (INL) Site. The tank farm was initially evaluated in the OU 3-13 Record of Decision (ROD), and it was determined that additional information was needed to make a final decision. Additional information has been obtained on the nature and extent of contamination in the tank farm and on the impact to groundwater. The selected remedy was chosen in accordance with the Comprehensive Environmental Response, Liability and Compensation Act of 1980 (CERCLA) (42 USC 9601 et seq.), as amended by the Superfund Amendments and Reauthorization Act of 1986 (Public Law 99-499) and the National Oil and Hazardous Substances Pollution Contingency Plan (40 CFR 300). The selected remedy is intended to be the final action for tank farm soil and groundwater at INTEC. The response action selected in this ROD is necessary to protect the public health, welfare, or the environment from actual or threatened releases of hazardous substances into the environment. Such a release or threat of release may present an imminent and substantial endangerment to public health, welfare, or the environment. The remedial actions selected in this ROD are designed to reduce the potential threats to human health and the environment to acceptable levels. In addition, DOE-ID, EPA, and DEQ (the Agencies) have determined that no action is necessary under CERCLA to protect public health, welfare, or the environment at 16 sites located outside the tank farm boundary. The purposes of the selected remedy are to (1) contain contaminated soil as the radionuclides decay in place, (2) isolate current and future workers and biological receptors from contact with contaminated soil, and (3) restore the portion of Snake River Plain Aquifer contaminated by INTEC releases to Idaho Ground Water Quality

Acid sulphate soil disturbance and metals in groundwater: Implications for human exposure through home grown produce

International Nuclear Information System (INIS)

Hinwood, Andrea Lee; Horwitz, Pierre; Appleyard, Steve; Barton, Caroline; Wajrak, Magda

2006-01-01

A significant emerging environmental problem is the disturbance and oxidation of soils with high levels of iron sulphide minerals resulting in acidification and causing the mobilization of metals into groundwater. This process is occurring in many parts of the world. In Western Australia, impacted groundwater is extracted by residents for domestic use. We sought to establish domestic use patterns of bore water and the concentration of metals. Sixty-seven domestic bore water samples clearly indicated oxidation of sulphidic materials with heavy metal concentrations ranging for aluminium (< DL-37.0 mg/L), arsenic (< DL-6.6 mg/L), iron (< DL-1200 mg/L), cadmium (< DL-0.021 mg/L), lead (< DL-0.040 mg/L), selenium (< DL-0.006 mg/L). A high proportion of residents used bore water on home grown produce. The study suggests that there is potential for human exposure to heavy metals via the consumption of home grown produce. This warrants further investigation in light of increasing acid sulphate soil disturbance in many locations. - Acidified bore water may introduce metals into produce for home consumption

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

Efficiency of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from contaminated soil.

Science.gov (United States)

Singh, Anil Kumar; Cameotra, Swaranjit Singh

2013-10-01

This study describes the potential application of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from the soil samples collected from industrial dumping site. High concentrations of heavy metals (like iron, lead, nickel, cadmium, copper, cobalt and zinc) and petroleum hydrocarbons were present in the contaminated soil samples. Lipopeptide biosurfactant, consisting of surfactin and fengycin was obtained from Bacillus subtilis A21. Soil washing with biosurfactant solution removed significant amount of petroleum hydrocarbon (64.5 %) and metals namely cadmium (44.2 %), cobalt (35.4 %), lead (40.3 %), nickel (32.2 %), copper (26.2 %) and zinc (32.07 %). Parameters like surfactant concentration, temperature, agitation condition and pH of the washing solution influenced the pollutant removing ability of biosurfactant mixture. Biosurfactant exhibited substantial hydrocarbon solubility above its critical micelle concentration. During washing, 50 % of biosurfactant was sorbed to the soil particles decreasing effective concentration during washing process. Biosurfactant washed soil exhibited 100 % mustard seed germination contradictory to water washed soil where no germination was observed. The results indicate that the soil washing with mixture of lipopeptide biosurfactants at concentrations above its critical micelle concentration can be an efficient and environment friendly approach for removing pollutants (petroleum hydrocarbon and heavy metals) from contaminated soil.

Functioning of metal contaminated garden soil after remediation

International Nuclear Information System (INIS)

Jelusic, Masa; Grcman, Helena; Vodnik, Dominik; Suhadolc, Metka; Lestan, Domen

2013-01-01

The effect of remediation using three EDTA doses (10, 30, 60 mmol kg −1 ) on soil functioning was assessed using column experiment and Brassica rapa. Soil washing removed up to 77, 29 and 72% of metals from soil contaminated with 1378, 578 and 8.5 mg kg −1 of Pb, Zn and Cd, respectively. Sequential extraction indicated removal from the carbonate soil fraction. Metal oral-accessibility from the stomach phase was reduced by up to 75 and from the small intestine by up to 79% (Pb). Part of metals (up to 0.8% Cd) was lost due to leaching from columns. Remediation reduced toxic metal soil-root transfer by up to 61% but did not prevent metal accumulation in leaves. The fitness of plants grown on EDTA washed soils (gas exchange, fluorescence) was not compromised. Remediation initially reduced the soil DNA content (up to 29%, 30 mmol kg −1 EDTA) and changed the structure of microbial population. -- Highlights: ► Toxic metals contaminated garden soil was remediated in a pilot-scale. ► EDTA washing reduced soil Pb, Zn and Cd content and bioavailability. ► Remediated soil preserved the function of plant and microbial substrate. ► Remediation didn't prevent the accumulation of toxic metals in the test plant. -- EDTA soil washing effectively removed toxic metals and reduced their transfer from the soil to plant roots but did not prevent their accumulation in leaves

Extraction of Pentachlorophenol from Soils using Environmentally Benign Lactic Acid Solutions

Science.gov (United States)

Soil contamination with pentachlorophenol (PCP) is widespread across the globe. Soil washing/extraction is a common technique to remove this compound. Several soil washing/extraction solutions have been used but a majority of them have the problem of persistence in the environmen...

Emulation of recharge and evapotranspiration processes in shallow groundwater systems

Science.gov (United States)

Doble, Rebecca C.; Pickett, Trevor; Crosbie, Russell S.; Morgan, Leanne K.; Turnadge, Chris; Davies, Phil J.

2017-12-01

In shallow groundwater systems, recharge and evapotranspiration are highly sensitive to changes in the depth to water table. To effectively model these fluxes, complex functions that include soil and vegetation properties are often required. Model emulation (surrogate modelling or meta-modelling) can provide a means of incorporating detailed conceptualisation of recharge and evapotranspiration processes, while maintaining the numerical tractability and computational performance required for regional scale groundwater models and uncertainty analysis. A method for emulating recharge and evapotranspiration processes in groundwater flow models was developed, and applied to the South East region of South Australia and western Victoria, which is characterised by shallow groundwater, wetlands and coastal lakes. The soil-vegetation-atmosphere transfer (SVAT) model WAVES was used to generate relationships between net recharge (diffuse recharge minus evapotranspiration from groundwater) and depth to water table for different combinations of climate, soil and land cover types. These relationships, which mimicked previously described soil, vegetation and groundwater behaviour, were combined into a net recharge lookup table. The segmented evapotranspiration package in MODFLOW was adapted to select values of net recharge from the lookup table depending on groundwater depth, and the climate, soil and land use characteristics of each cell. The model was found to be numerically robust in steady state testing, had no major increase in run time, and would be more efficient than tightly-coupled modelling approaches. It made reasonable predictions of net recharge and groundwater head compared with remotely sensed estimates of net recharge and a standard MODFLOW comparison model. In particular, the method was better able to predict net recharge and groundwater head in areas with steep hydraulic gradients.

Improving groundwater storage and soil moisture estimates by assimilating GRACE, SMOS, and SMAP data into CABLE using ensemble Kalman batch smoother and particle batch smoother frameworks

Science.gov (United States)

Han, S. C.; Tangdamrongsub, N.; Yeo, I. Y.; Dong, J.

2017-12-01

Soil moisture and groundwater storage are important information for comprehensive understanding of the climate system and accurate assessment of the regional/global water resources. It is possible to derive the water storage from land surface models but the outputs are commonly biased by inaccurate forcing data, inefficacious model physics, and improper model parameter calibration. To mitigate the model uncertainty, the observation (e.g., from remote sensing as well as ground in-situ data) are often integrated into the models via data assimilation (DA). This study aims to improve the estimation of soil moisture and groundwater storage by simultaneously assimilating satellite observations from the Gravity Recovery And Climate Experiment (GRACE), the Soil Moisture Ocean Salinity (SMOS), and the Soil Moisture Active Passive (SMAP) into the Community Atmosphere Biosphere Land Exchange (CABLE) land surface model using the ensemble Kalman batch smoother (EnBS) and particle batch smoother (PBS) frameworks. The uncertainty of GRACE observation is obtained rigorously from the full error variance-covariance matrix of the GRACE data product. This method demonstrates the use of a realistic representative of GRACE uncertainty, which is spatially correlated in nature, leads to a higher accuracy of water storage computation. Additionally, the comparison between EnBS and PBS results is discussed to understand the filter's performance, limitation, and suitability. The joint DA is demonstrated in the Goulburn catchment, South-East Australia, where diverse ground observations (surface soil moisture, root-zone soil moisture, and groundwater level) are available for evaluation of our DA results. Preliminary results show that both smoothers provide significant improvement of surface soil moisture and groundwater storage estimates. Importantly, our developed DA scheme disaggregates the catchment-scale GRACE information into finer vertical and spatial scales ( 25 km). We present an

Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion.

Science.gov (United States)

Zhou, Xiaobo; Helmers, Matthew J; Asbjornsen, Heidi; Kolka, Randy; Tomer, Mark D

2010-01-01

Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to assess the potential for perennial filter strips (PFS) to mitigate increases in NO3-N levels. The study, conducted at the Neal Smith National Wildlife Refuge (NSNWR) in central Iowa, consisted of a balanced incomplete block design with 12 watersheds and four watershed-scale treatments having different proportions and topographic positions of PFS planted in native prairie grasses: 100% rowcrop, 10% PFS (toeslope position), 10% PFS (distributed on toe and as contour strips), and 20 PFS (distributed on toe and as contour strips). All treatments were established in fall 2006 on watersheds that were under bromegrass (Bromus L.) cover for at least 10 yr. Nonperennial areas were maintained under a no-till 2-yr corn (Zea mays L.)--soybean [Glycine max. (L.) Merr.] rotation since spring 2007. Suction lysimeter and shallow groundwater wells located at upslope and toeslope positions were sampled monthly during the growing season to determine NO3-N concentration from 2005 to 2008. The results indicated significant increases in NO3-N concentration in soil and groundwater following grassland-to-cropland conversion. Nitrate-nitrogen levels in the vadose zone and groundwater under PFS were lower compared with 100% cropland, with the most significant differences occurring at the toeslope position. During the years following conversion, PFS mitigated increases in subsurface nitrate, but long-term monitoring is needed to observe and understand the full response to land-use conversion.

GASReP/DESRT: Proceedings [of the] 2nd annual symposium on groundwater and soil remediation. Comptes rendus [de la] 2e symposium annuel sur la restauration des eaux souterraines et des sois contamines

Energy Technology Data Exchange (ETDEWEB)

1992-01-01

A conference was held to discuss ground water and soil remediation with emphasis on the Canadian national Groundwater and Soil Remediation Program (GASReP) and the Development and Demonstration of Site Remediation Technology (DESRT) program. Papers were presented on the subjects of groundwater and soil remediation research projects, bioremediation, excavation and treatment, pumping and treatment/soil venting, and industry and government initiatives. Separate abstracts have been prepared for 15 papers from the conference.

Jet grouting for a groundwater cutoff wall in difficult glacial soil deposits

International Nuclear Information System (INIS)

Flanagan, R.F.; Pepe, F. Jr.

1997-01-01

Jet grouting is being used as part of a groundwater cutoff wall system in a major New York City subway construction project to limit drawdowns in an adjacent PCB contamination plume. A circular test shaft of jet grout columns was conducted during the design phase to obtain wall installation parameters. The test program also included shaft wall mapping, and measurements of; inflows, piezometric levels, ground heave and temperature, and jet grout hydraulic conductivity. An axisymmetric finite element method groundwater model was established to back calculate the in-situ hydraulic conductivities of both the surrounding glacial soils and the jet grout walls by matching observed inflows and piezometric levels. The model also verified the use of packer permeability test as a tool in the field to evaluate the hydraulic conductivities of jet grout columns. Both the test program and analytic studies indicated that adjustments to the construction procedures would be required to obtain lower hydraulic conductivities of the jet grout walls for construction. A comparison is made with the conductivities estimated from the test program/analytic studies with those from the present construction

Enhancement of surfactant efficacy during the cleanup of engine oil contaminated soil using salt and multi-walled carbon nanotubes.

Science.gov (United States)

Bonal, Niteesh Singh; Paramkusam, Bala Ramudu; Basudhar, Prabir Kumar

2018-06-05

The study aims to enhance the efficacy of surfactants using salt and multi-walled carbon nanotubes (MWCNT) for washing used engine oil (UEO) contaminated soil and compare the geotechnical properties of contaminated soil before and after washing (batch washing and soil washing). From batch washing of the contaminated soil the efficacy of the cleaning process is established. Contamination of soil with hydrocarbons present in UEO significantly affects its' engineering properties manifesting in no plasticity and low specific gravity; the corresponding optimum moisture content value is 6.42% while maximum dry density is 1.770 g/cc, which are considerably lower than those of the uncontaminated soil. The result also showed decrease in the values of cohesion intercept and increase in the friction angle values. The adopted soil washing technique resulted increase in specific gravity from 1.85 to 2.13 and cohesion from 0.443 to 1.04 kg/cm 2 and substantial decrease in the friction angle from 31.16° to 17.14° when washed with most efficient combination of SDS surfactant along with sodium meta-silicate (salt) and MWCNT. Effectiveness of the washing of contaminated soil by batch processing and soil washing techniques has been established qualitatively. The efficiency of surfactant treatment has been observed to be increased significantly by the addition of salt and MWCNT. Copyright © 2018 Elsevier B.V. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-05-15

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

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

International Nuclear Information System (INIS)

Lestan, Domen; Luo Chunling; Li Xiangdong

2008-01-01

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

Quantifying phosphorus levels in soils, plants, surface water, and shallow groundwater associated with bahiagrass-based pastures.

Science.gov (United States)

Sigua, Gilbert C; Hubbard, Robert K; Coleman, Samuel W

2010-01-01

Recent assessments of water quality status have identified eutrophication as one of the major causes of water quality 'impairment' not only in the USA but also around the world. In most cases, eutrophication has accelerated by increased inputs of phosphorus due to intensification of crop and animal production systems since the early 1990 s. Despite substantial measurements using both laboratory and field techniques, little is known about the spatial and temporal variability of phosphorus dynamics across landscapes, especially in agricultural landscapes with cow-calf operations. Critical to determining environmental balance and accountability is an understanding of phosphorus excreted by animals, phosphorus removal by plants, acceptable losses of phosphorus within the manure management and crop production systems into soil and waters, and export of phosphorus off-farm. Further research effort on optimizing forage-based cow-calf operations to improve pasture sustainability and protect water quality is therefore warranted. We hypothesized that properly managed cow-calf operations in subtropical agroecosystem would not be major contributors to excess loads of phosphorus in surface and ground water. To verify our hypothesis, we examined the comparative concentrations of total phosphorus among soils, forage, surface water, and groundwater beneath bahiagrass-based pastures with cow-calf operations in central Florida, USA. Soil samples were collected at 0-20; 20-40, 40-60, and 60-100 cm across the landscape (top slope, middle slope, and bottom slope) of 8 ha pasture in the fall and spring of 2004 to 2006. Forage availability and phosphorus uptake of bahiagrass were also measured from the top slope, middle slope, and bottom slope. Bi-weekly (2004-2006) groundwater and surface water samples were taken from wells located at top slope, middle slope, and bottom slope, and from the runoff/seepage area. Concentrations of phosphorus in soils, forage, surface water, and shallow

Salt composition of groundwater and reclaimed solonetzes in the Baraba Lowland

Science.gov (United States)

Semendyaeva, N. V.; Elizarov, N. V.

2017-10-01

Solonetzes of experimental trials established in 1981 and 1986 in the Baraba Lowland were examined. It was found that gypsum-based ameliorants improve the soil and lead to a decrease in the content of soluble salts in the soil profile. Exchange processes between cations of the soil adsorption complex and calcium of gypsum were particularly intensive in the first years after gypsum application. This resulted in a sharp rise in the content of soluble salts that migrated down the soil profile to the groundwater. In the following years, the reclaimed solonetzes were desalinized under the conditions of relatively stable groundwater level. On the 30th year after single gypsum application, the groundwater level sharply rose (to 50 cm), and the soil was subjected to the secondary salinization; the contents of bicarbonates, carbonates, and sodium in the soils increased. Spring leaching caused some desalinization, but the content of soluble salts in the upper soil meter increased again in the fall. A close correlation between the salt compositions of the groundwater and the reclaimed solonetzes was revealed.

High 36Cl/Cl ratios in Chernobyl groundwater

International Nuclear Information System (INIS)

Roux, Céline; Le Gal La Salle, Corinne; Simonucci, Caroline; Van Meir, Nathalie; Fifield, L. Keith; Diez, Olivier; Bassot, Sylvain

2014-01-01

After the explosion of the Chernobyl Nuclear Power Plant in April 1986, contaminated material was buried in shallow trenches within the exclusion zone. A 90 Sr plume was evidenced downgradient of one of these trenches, trench T22. Due to its conservative properties, 36 Cl is investigated here as a potential tracer to determine the maximal extent of the contamination plume from the trench in groundwater. 36 Cl/Cl ratios measured in groundwater, trench soil water and leaf leachates are 1–5 orders of magnitude higher than the theoretical natural 36 Cl/Cl ratio. This contamination occurred after the Chernobyl explosion and currently persists. Trench T22 acts as an obvious modern point source of 36 Cl, however other sources have to be involved to explain such contamination. 36 Cl contamination of groundwater can be explained by dilution of trench soil water by uncontaminated water (rainwater or deep groundwater). With a plume extending further than that of 90 Sr, radionuclide which is impacted by retention and decay processes, 36 Cl can be considered as a suitable tracer of contamination from the trench in groundwater provided that modern release processes of 36 Cl from trench soil are better characterized. - Highlights: • High 36 Cl/Cl ratios measured in the Chernobyl Pilot Site groundwater. • Trench T22 acts as a modern source of groundwater contamination by 36 Cl but other sources are involved. • Contamination results from dilution of a contaminated “T22” soil water with rainwater. • Processes involved in the modern release need to be investigated

Geomorphic Characterization of the FortyMile Wash Alluvial Fan, Nye County, Nevada, In Support of the Yucca Mountain Project

International Nuclear Information System (INIS)

Cline; De Long; Pelletier; Harrington

2005-01-01

In the event of an unlikely volcanic eruption through the proposed high-level radioactive waste repository at Yucca Mountain, contaminated ash would be deposited in portions of the Fortymile Wash drainage basin and would subsequently be redistributed to the Fortymile Wash alluvial fan by fluvial processes. As part of an effort to quantify the transport of contaminated ash throughout the fluvial system, characterization of the Fortymile Wash alluvial fan is required, especially the spatial distribution of fluvial activity over time scales of repository operation, and the rates of radionuclide migration into different soils on the fan. The Fortymile Wash alluvial fan consists of extremely low relief terraces as old as 70 ka. By conducting soils-geomorphic mapping and correlating relative surface ages with available geochronology from the Fortymile Wash fan and adjacent piedmonts, we identified 4 distinct surfaces on the fan. Surface ages are used to predict the relative stability of different areas of the fan to fluvial activity. Pleistocene-aged surfaces are assumed to be fluvially inactive over the 10 kyr time scale, for example. Our mapping and correlation provides a map of the depozone for contaminated ash that takes into account long-term channel migration the time scales of repository operation, and it provides a geomorphic framework for predicting radionuclide dispersion rates into different soils across the fan. The standard model for vertical migration of radionuclides in soil is diffusion; therefore we used diffusion profiles derived from 137 Cs fallout to determine infiltration rates on the various geomorphic surfaces. The results show a strong inverse correlation of the geomorphic surface age and diffusivity values inferred from the 137 Cs profiles collected on the different surfaces of the fan

In Situ Evaluation of Crop Productivity and Bioaccumulation of Heavy Metals in Paddy Soils after Remediation of Metal-Contaminated Soils.

Science.gov (United States)

Kim, Shin Woong; Chae, Yooeun; Moon, Jongmin; Kim, Dokyung; Cui, Rongxue; An, Gyeonghyeon; Jeong, Seung-Woo; An, Youn-Joo

2017-02-15

Soils contaminated with heavy metals have been reused for agricultural, building, and industrial uses following remediation. This study assesses plant growth and bioaccumulation of heavy metals following remediation of industrially contaminated soil. The soil was collected from a field site near a nonferrous smelter and was subjected to laboratory- and field-scale studies. Soil from the contaminated site was remediated by washing with acid or mixed with soil taken from a distant uncontaminated site. The activities of various soil exoenzymes, the rate of plant growth, and the bioaccumulations of six heavy metals were measured to assess the efficacy of these bioremediation techniques. Growth of rice (Oryza sativa) was unaffected in acid-washed soil or the amended soil compared to untreated soil from the contaminated site. The levels of heavy metals in the rice kernels remained within safe limits in treated and untreated soils. Rice, sorghum (Sorghum bicolor), and wheat (Triticum aestivum) cultivated in the same soils in the laboratory showed similar growth rates. Soil exoenzyme activities and crop productivity were not affected by soil treatment in field experiments. In conclusion, treatment of industrially contaminated soil by acid washing or amendment did not adversely affect plant productivity or lead to increased bioaccumulation of heavy metals in rice.

Cadmium geochemistry in soil and groundwater at the F and H Seepage Basins

International Nuclear Information System (INIS)

Serkiz, S.M.; Johnson, W.H.

1994-10-01

For 33 years, low activity liquid wastes from the chemical separation areas at the US Department of Energy's Savannah River Site were disposed of in unlined seepage basins. This disposal practice was discontinued in 1988. At that time, the basins were drained and a low permeability cover system was placed over the basins. In the summer of 1993, soil and associated pore water samples of widely varying groundwater chemistries and contaminant concentrations were collected from the region downgradient of these basins using cone penetrometer technology. Analysis of these samples using inductively coupled plasma - mass spectrometry has allowed the investigation of cadmium partitioning between the aqueous phase and soil surfaces at this site. The distribution of cadmium was examined with respect to the solution and soil chemistry and aqueous-phase chemical speciation modeling. Cadmium was detected in 35 of 53 aqueous samples from the F- and H-Area Seepage Basins (FHSB). Porewater concentration were found to vary from 0.48 to 23.5 μg 1 -1 , with a mean concentration of 3.1 ± 4.3 μg 1 -1 . Based on the 43 of 86 soil samples for which cadmium was detected, the concentration in the soil ranged 88.5 to 1090 μg kg -1 . The mean soil concentration was 214 ± 168 μg kg -1 . This concentration is not significantly different from the concentrations observed in two upgradient soil samples collected from the same lithologic unit. The concentrations from these samples were 293 ± 214 and 431 ± 293 μg kg -1

Characterizing Normal Groundwater Chemistry in Hawaii

Science.gov (United States)

Tachera, D.; Lautze, N. C.; Thomas, D. M.; Whittier, R. B.; Frazer, L. N.

2017-12-01

Hawaii is dependent on groundwater resources, yet how water moves through the subsurface is not well understood in many locations across the state. As marine air moves across the islands water evaporates from the ocean, along with trace amounts of sea-salt ions, and interacts with the anthropogenic and volcanic aerosols (e.g. sulfuric acid, ammonium sulfate, HCl), creating a slightly more acidic rain. When this rain falls, it has a chemical signature distinctive of past processes. As this precipitation infiltrates through soil it may pick up another distinctive chemical signature associated with land use and degree of soil development, and as it flows through the underlying geology, its chemistry is influenced by the host rock. We are currently conducting an investigation of groundwater chemistry in selected aquifer areas of Hawaii, having diverse land use, land cover, and soil development conditions, in an effort to investigate and document what may be considered a "normal" water chemistry for an area. Through this effort, we believe we better assess anomalies due to contamination events, hydrothermal alteration, and other processes; and we can use this information to better understand groundwater flow direction. The project has compiled a large amount of precipitation, soil, and groundwater chemistry data in the three focus areas distributed across in the State of Hawaii. Statistical analyses of these data sets will be performed in an effort to determine what is "normal" and what is anomalous chemistry for a given area. Where possible, results will be used to trace groundwater flow paths. Methods and preliminary results will be presented.

Soil water storage and groundwater behaviour in a catenary sequence beneath forest in central Amazonia: I. Comparisons between plateau, slope and valley floor

Directory of Open Access Journals (Sweden)

M. G. Hodnett

1997-01-01

Full Text Available Soil water storage was monitored in three landscape elements in the forest (plateau, slope and valley floor over a 3 year period to identify differences in sub-surface hydrological response. Under the plateau and slope, the changes of storage were very similar and there was no indication of surface runoff on the slope. The mean maximum seasonal storage change was 156 mm in the 2 m profile but it was clear that, in the dry season, the forest was able to take up water from below 3.6 m. Soil water availability was low. Soil water storage changes in the valley were dominated by the behaviour of a shallow water table which, in normal years, varied between 0.1 m below the surface at the end of the wet season and 0.8 m at the end of the dry season. Soil water storage changes were small because root uptake was largely replenished by groundwater flow towards the stream. The groundwater behaviour is controlled mainly by the deep drainage from beneath the plateau and slope areas. The groundwater gradient beneath the slope indicated that recharge beneath the plateau and slope commences only after the soil water deficits from the previous dry season have been replenished. Following a wet season with little recharge, the water table fell, ceasing to influence the valley soil water storage, and the stream dried up. The plateau and slope, a zone of very high porosity between 0.4 and 1.1 m, underlain by a less conductive layer, is a probable route for interflow during, and for a few hours after, heavy and prolonged rainfall.

Assessment of arsenic content in soil, rice grains and groundwater and associated health risks in human population from Ropar wetland, India, and its vicinity.

Science.gov (United States)

Sharma, Sakshi; Kaur, Inderpreet; Nagpal, Avinash Kaur

2017-08-01

In the present study, potential health risks posed to human population from Ropar wetland and its vicinity, by consumption of inorganic arsenic (i-As) via arsenic contaminated rice grains and groundwater, were assessed. Total arsenic (t-As) in soil and rice grains were found in the range of 0.06-0.11 mg/kg and 0.03-0.33 mg/kg, respectively, on dry weight basis. Total arsenic in groundwater was in the range of 2.31-15.91 μg/L. i-As was calculated from t-As using relevant conversion factors. Rice plants were found to be arsenic accumulators as bioconcentration factor (BCF) was observed to be >1 in 75% of rice grain samples. Further, correlation analysis revealed that arsenic accumulation in rice grains decreased with increase in the electrical conductivity of soil. One-way ANOVA, cluster analysis and principal component analysis indicated that both geogenic and anthropogenic sources affected t-As in soil and groundwater. Hazard index and total cancer risk estimated for individuals from the study area were above the USEPA limits of 1.00 and 1.00 × 10 -6 , respectively. Kruskal-Wallis H test indicated that groundwater intake posed significantly higher health risk than rice grain consumption (χ 2 (1) = 17.280, p = 0.00003).

Cl/Br ratios and chlorine isotope evidences for groundwater salinization and its impact on groundwater arsenic, fluoride and iodine enrichment in the Datong basin, China.

Science.gov (United States)

Li, Junxia; Wang, Yanxin; Xie, Xianjun

2016-02-15

In order to identify the salinization processes and its impact on arsenic, fluoride and iodine enrichment in groundwater, hydrogeochemical and environmental isotope studies have been conducted on groundwater from the Datong basin, China. The total dissolved solid (TDS) concentrations in groundwater ranged from 451 to 8250 mg/L, and 41% of all samples were identified as moderately saline groundwater with TDS of 3000-10,000 mg/L. The results of groundwater Cl concentrations, Cl/Br molar ratio and Cl isotope composition suggest that three processes including water-rock interaction, surface saline soil flushing, and evapotranspiration result in the groundwater salinization in the study area. The relatively higher Cl/Br molar ratio in groundwater from multiple screening wells indicates the contribution of halite dissolution from saline soil flushed by vertical infiltration to the groundwater salinization. However, the results of groundwater Cl/Br molar ratio model indicate that the effect of saline soil flushing practice is limited to account for the observed salinity variation in groundwater. The plots of groundwater Cl vs. Cl/Br molar ratio, and Cl vs δ(37)Cl perform the dominant effects of evapotranspiration on groundwater salinization. Inverse geochemical modeling results show that evapotranspiration may cause approximately 66% loss of shallow groundwater to account for the observed hydrochemical pattern. Due to the redox condition fluctuation induced by irrigation activities and evapotranspiration, groundwater salinization processes have negative effects on groundwater arsenic enrichment. For groundwater iodine and fluoride enrichment, evapotranspiration partly accounts for their elevation in slightly saline water. However, too strong evapotranspiration would restrict groundwater fluoride concentration due to the limitation of fluorite solubility. Copyright © 2015. Published by Elsevier B.V.

IMPACT OF LEATHER PROCESSING INDUSTRIES ON CHROMIUM CONCENTRATION IN GROUNDWATER SOUTH OF CHENNAI CITY, INDIA

Science.gov (United States)

Elango, L.; Brindha, K.; G. Rajesh, V.

2009-12-01

The groundwater quality is under threat due to disposal of effluents from a number of industries. Poor practice of treatment of wastes from tanning industries or leather processing industries lead to pollution of groundwater. This study was carried out with the objective of assessing the impact of tanneries on groundwater quality in Chromepet area which is a part of the metropolitan area of Chennai, Tamil Nadu, India. This area serves as the home town for a number of small and large scale tanning industries. People in certain parts of this area depend on the groundwater for their domestic needs as there is no piped drinking water supply system. Topographically this region is generally flat with gentle slope towards east and north east. The charnockite rocks occur as basement at the depth of about 15m from the surface of this area. Weathered charnockite rock occurs at the depth from 7m to 15m from the ground surface. The upper layer consists of loamy soil. Groundwater occurs in the unconfined condition at a depth from 0.5m to 5m. Thirty six groundwater samples were collected during March 2008 and the groundwater samples were analysed for their heavy metal (chromium) content using atomic absorption spectrophotometer. Bureau of Indian Standards (BIS) recommended the maximum permissible limit of chromium in drinking water as 0.05 mg/l. Considering this, it was found that 86% of the groundwater samples possessed concentration of chromium above the maximum permissible limit recommended by BIS. The tanneries use chrome sulphate to strengthen the leather and make it water repellent. The excess of chromium gets washed off and remains in the wastewater. This wastewater is disposed into open uncovered drains either untreated or after partial treatment. Thus the chromium leaches through the soil and reaches the groundwater table. Apart from this, there is also huge quantity of solid waste resulting from the hides and skins which are dumped off without suitable treatment. The

Concentrations of inorganic arsenic in groundwater, agricultural soils and subsurface sediments from the middle Gangetic plain of Bihar, India.

Science.gov (United States)

Kumar, Manoj; Ramanathan, A L; Rahman, Mohammad Mahmudur; Naidu, Ravi

2016-12-15

Concentrations of inorganic forms [arsenite, As(III) and arsenate, As(V) of arsenic (As) present in groundwater, agricultural soils and subsurface sediments located in the middle Gangetic plain of Bihar, India were determined. Approximately 73% of the groundwater samples (n=19) show As(III) as the dominant species while 27% reveals As(V) was the dominant species. The concentration of As(III) in agricultural soil samples varies from not detectable to 40μg/kg and As(V) was observed as the major species (ranging from 1050 to 6835μg/kg) while the total As concentration varied from 3528 to 14,690μg/kg. Total extracted concentration of As was higher in the subsurface sediments (range 9119-20,056μg/kg in Methrapur and 4788-19,681μg/kg in Harail Chapar) than the agricultural soil, indicating the subsurface sediment as a source of As. Results of X-ray diffraction (XRD) and environmental scanning electron microscope (ESEM) revealed the presence of hematite and goethite throughout the vertical section below while magnetite was observed only in the upper oxidized layer at Methrapur and Harail Chapar. Alteration of Fe-oxides and presence of fibrous goethite indicating presence of diagenetic sediment. Siderite plays a crucial role as sinks to the As in subsurface sediments. The study also concluded that decomposition of organic matter present in dark and grey sections promote the redox conditions and trigger mobilization of As into groundwater. Copyright © 2016 Elsevier B.V. All rights reserved.

An investigation of groundwater organics, soil minerals, and activated carbon on the complexation, adsorption, and separation of technetium-99

International Nuclear Information System (INIS)

Gu, B.

1996-01-01

This report summarizes studies on the interactions of technetium-99 (Tc) with different organic compounds and soil minerals under both oxidizing and reducing conditions. The report is divided into four parts and includes (1) effect of natural organic matter (NOM) on the complexation and solubility of Tc, (2) complexation between Tc and trichloroethylene (TCE) in aqueous solutions, (3) adsorption of Tc on soil samples from Paducah Gaseous Diffusion Plant (PGDP), and (4) adsorption and separation of Tc on activated carbon. Various experimental techniques were applied to characterize and identify Tc complexation with organic compounds and TCE, including liquid-liquid extraction, membrane filtration, size exclusion, and gel chromatography. Results indicate, within the experimental error, Tc (as pertechnetate, TcO 4 ) did not appear to form complexes with groundwater or natural organic matter under both atmospheric and reducing conditions. However, Tc can form complexes with certain organic compounds or specific functional groups such as salicylate. Tc did not appear to form complexes with TCE in aqueous solution.Both liquid-liquid extraction and high performance liquid chromatography (HPLC) gave no indication Tc was complexed with TCE. The correlations between Tc and TCE concentrations in monitoring wells at PGDP may be a coincidence because TCE was commonly used as a decontamination reagent. Once TCE and Tc entered the groundwater, they behaved similarly because both TcO 4 - and TCE are poorly adsorbed by soils. An effective remediation technique to remove TcO 4 - from PGDP contaminated groundwater is needed. One possibility is the use of an activated carbon adsorption technique developed in this study

Physico-Chemical Analysis of Groundwater and Agriculture Soil of Gambat, Khairpur District, Pakistan

International Nuclear Information System (INIS)

Pirzada, T.; Talpur, M.M.A.; Qazi, Y.F.; Naseem, S.

2013-01-01

This study was conducted to estimate the ground water as well as agriculture soil quality, nutrient status and physico-chemical characteristics of Gambat, District Khairpur, Pakistan. Assorted parameters like temperature, pH, EC, TDS, Cl-, SO/sub 4/sup 2-/, HCO/sub 3/ /sup -/, sodium, potassium, calcium, magnesium, SAR values as well as the Piper and Stiff diagrams were determined to confer a clear picture of quality parameters in ground water and agriculture soil of the area. The present investigations conclude that the maximum parameters are not at the level of pollution except major metal ions Na/sup +/ and Ca/sup 2+/. The higher concentration of Ca/sup 2+/ and Na/sup +/ could be due to the deposits of the salts of these elements into soil, which may had leached into ground water. The Piper diagram suggest that composition of water is (Na+/sup +/K/sup +/)-(Ca/sup 2+/+Mg/sup 2+/)-HCO/sub 3/ /sup -/ - (Cl/sup -/+SO/sub 4//sup 2-/)-type. The areal distribution of stiff diagram constructed for groundwater samples showed ionic balances, indicating the major ion analyses are of good quality. Therefore, both ground water and soil samples observed are satisfactory for their utilization in various purposes such as domestic, agricultural, industrial, etc. (author)

Electrochemical EDTA recycling with sacrificial Al anode for remediation of Pb contaminated soil

International Nuclear Information System (INIS)

Pociecha, Maja; Lestan, Domen

2010-01-01

Recycling chelant is a precondition for cost-effective EDTA-based soil remediation. Extraction with EDTA removed 67.5% of Pb from the contaminated soil and yielded washing solution with 1535 mg L -1 Pb and 33.4 mM EDTA. Electrochemical treatment of the washing solution using Al anode, current density 96 mA cm -2 and pH 10 removed 90% of Pb from the solution (by electrodeposition on the stainless steel cathode) while the concentration of EDTA in the treated solution remained the same. The obtained data indicate that the Pb in the EDTA complex was replaced by electro-corroded Al after electro-reduction of the EDTA and subsequently removed from the solution. Additional soil extraction with the treated washing solution resulted in total removal of 87% of Pb from the contaminated soil. The recycled EDTA retained the Pb extraction potential through several steps of soil extraction and washing solution treatment, although part of the EDTA was lost by soil absorption. - Aluminium anode at alkaline pH in conventional electrolytic cell enables efficient recycling of EDTA as a part of soil washing remediation technology.

Comparison of the laboratory standard washing using CIPAC washing agent and the domestic washing on three recommended types of long-lasting insecticidal mosquito nets.

Science.gov (United States)

Ouattara, Jean Pierre Nabléni; Louwagie, Johanna; Pigeon, Olivier; Spanoghe, Pieter

2013-01-01

One of the best ways to prevent malaria is the use of insecticide-treated bed nets. Manufacturers pursue easier, safer and more efficient nets. Hence, many studies on the efficacy and wash resistance using World Health Organization standards have been reported. The commonly used detergent is "Savon de Marseille", because it closely resembles actually used soaps. At the 54(th) Collaborative International Pesticides Analytical Council (CIPAC) Technical Meeting in 2010, it was suggested to replace it by a standardized "CIPAC washing agent". The aim of this study was to investigate the difference between a laboratory hand washing simulation using the CIPAC washing agent (method-1) and a domestic washing (method-2) on different bed nets, as well as the effect of the drying process on the release of active ingredient. Interceptor®, Permanet®2.0 and Netprotect® nets were used in three treatments, each repeated 20 times. The first treatment included method-1 washing and indoor drying. The second treatment included method-2 washing and indoor drying. The third treatment used method-2 washing and UV-drying. The residual insecticide contents were determined using gas chromatography. The washing procedure and the number of washes have a significant effect on the release of active ingredient. Statistically, the two washing methods have the same effect on removing the active ingredient from the Interceptor® and Permanet®2.0 net, but a significantly different influence on the Netprotect® nets. The drying process has no significant effect on the insecticide. Both washing procedures affected the amount of insecticide remaining on nets independently of the impregnation technology. The active ingredient decreases with the number of washing cycles following an exponential or logarithmic model for coated nets. The laboratory hand washing simulation had more impact on the decrease of active ingredient content of the Netprotect® nets. All net types seemed to be effectively

Comparison of the laboratory standard washing using CIPAC washing agent and the domestic washing on three recommended types of long-lasting insecticidal mosquito nets.

Directory of Open Access Journals (Sweden)

Jean Pierre Nabléni Ouattara

Full Text Available One of the best ways to prevent malaria is the use of insecticide-treated bed nets. Manufacturers pursue easier, safer and more efficient nets. Hence, many studies on the efficacy and wash resistance using World Health Organization standards have been reported. The commonly used detergent is "Savon de Marseille", because it closely resembles actually used soaps. At the 54(th Collaborative International Pesticides Analytical Council (CIPAC Technical Meeting in 2010, it was suggested to replace it by a standardized "CIPAC washing agent". The aim of this study was to investigate the difference between a laboratory hand washing simulation using the CIPAC washing agent (method-1 and a domestic washing (method-2 on different bed nets, as well as the effect of the drying process on the release of active ingredient.Interceptor®, Permanet®2.0 and Netprotect® nets were used in three treatments, each repeated 20 times. The first treatment included method-1 washing and indoor drying. The second treatment included method-2 washing and indoor drying. The third treatment used method-2 washing and UV-drying. The residual insecticide contents were determined using gas chromatography.The washing procedure and the number of washes have a significant effect on the release of active ingredient. Statistically, the two washing methods have the same effect on removing the active ingredient from the Interceptor® and Permanet®2.0 net, but a significantly different influence on the Netprotect® nets. The drying process has no significant effect on the insecticide.Both washing procedures affected the amount of insecticide remaining on nets independently of the impregnation technology. The active ingredient decreases with the number of washing cycles following an exponential or logarithmic model for coated nets. The laboratory hand washing simulation had more impact on the decrease of active ingredient content of the Netprotect® nets. All net types seemed to be

The influence of sodium-polyacrilic macromolecular chain length to the powder detergents secondary washing performances

Directory of Open Access Journals (Sweden)

Milojević Vladimir S.

2013-01-01

Full Text Available In order to investigate the influence of sodium-polyacrylate polymer as a co-builder in addition to the carbonate/zeolite builders in detergent builder system, secondary washing performances of powder laundry detergent containing equal percentage of sodium polyacrylate with the different weight average molar mass, Mw, have been examined. The value of the degree of whiteness, elongation at break, and total residue content are the most important secondary washing performances that significantly depend on sodium polyacrylates efficiency used as crystal inhibitors, stabilizers for suspended soil, and agents for soil redisposition prevention on fabric surface. The values of the whiteness and elongation at break for cotton fabrics increase with the increase of average weight molecular mass, Mw, up to the value of 70000 g/mol, while in the case of further increase of weight average molar mass up to the 250000 g/mol value of these characteristics begin to decline. The values of the total residue content after combustion indicate an increase in its content with the increase of weight average molar mass of 3000 to 70000 g/mol, while the highest value has been reached in the sample of detergent containing sodiumpolyacrilic with the weight average molar mass of 250000 g/mol. All detergent samples show no significant dependence of the secondary washing characteristics on the number of washing cycles.

Impact of Drought on Groundwater and Soil Moisture - A Geospatial Tool for Water Resource Management

Science.gov (United States)

Ziolkowska, J. R.; Reyes, R.

2016-12-01

For many decades, recurring droughts in different regions in the US have been negatively impacting ecosystems and economic sectors. Oklahoma and Texas have been suffering from exceptional and extreme droughts in 2011-2014, with almost 95% of the state areas being affected (Drought Monitor, 2015). Accordingly, in 2011 alone, around 1.6 billion were lost in the agricultural sector alone as a result of drought in Oklahoma (Stotts 2011), and 7.6 billion in Texas agriculture (Fannin 2012). While surface water is among the instant indicators of drought conditions, it does not translate directly to groundwater resources that are the main source of irrigation water. Both surface water and groundwater are susceptible to drought, while groundwater depletion is a long-term process and might not show immediately. However, understanding groundwater availability is crucial for designing water management strategies and sustainable water use in the agricultural sector and other economic sectors. This paper presents an interactive geospatially weighted evaluation model and a tool at the same time to analyze groundwater resources that can be used for decision support in water management. The tool combines both groundwater and soil moisture changes in Oklahoma and Texas in 2003-2014, thus representing the most important indicators of agricultural and hydrological drought. The model allows for analyzing temporal and geospatial long-term drought at the county level. It can be expanded to other regions in the US and the world. The model has been validated with the Palmer Drought Index Severity Index to account for other indicators of meteorological drought. It can serve as a basis for an upcoming socio-economic and environmental analysis of drought events in the short and long-term in different geographic regions.

Laboratory evaluation of the in situ chemical treatment approach to soil and groundwater remediation

International Nuclear Information System (INIS)

Thorton, E.C.; Trader, D.E.

1993-10-01

Results of initial proof of principle laboratory testing activities successfully demonstrated the viability of the in situ chemical treatment approach for remediation of soil and groundwater contaminated by hexavalent chromium. Testing activities currently in progress further indicate that soils contaminated with hexavalent chromium and uranium at concentrations of several hundred parts per million can be successfully treated with 100 ppM hydrogen sulfide gas mixtures. Greater than 90% immobilization of hexavalent chromium and 50% immobilization of uranium have been achieved in these tests after a treatment period of one day. Activities associated with further development and implementation of the in situ chemical treatment approach include conducting additional bench scale tests with contaminated geomedia, and undertaking scale-up laboratory tests and a field demonstration. This report discusses the testing and further development of this process

Method for in situ or ex situ bioremediation of hexavalent chromium contaminated soils and/or groundwater

Science.gov (United States)

Turick, Charles E.; Apel, William W.

1997-10-28

A method of reducing the concentration of Cr(VI) in a liquid aqueous residue comprises the steps of providing anaerobic Cr(VI) reducing bacteria, mixing the liquid aqueous residue with a nutrient medium to form a mixture, and contacting the mixture with the anaerobic Cr(VI) reducing bacteria such that Cr(VI) is reduced to Cr(III). The anaerobic Cr(VI) reducing bacteria appear to be ubiquitous in soil and can be selected by collecting a soil sample, diluting the soil sample with a sterile diluent to form a diluted sample, mixing the diluted sample with an effective amount of a nutrient medium and an effective amount of Cr(VI) to form a mixture, and incubating the mixture in the substantial absence of oxygen such that growth of Cr(VI) sensitive microorganisms is inhibited and growth of the anaerobic Cr(VI) reducing bacteria is stimulated. A method of in situ bioremediation of Cr(VI) contaminated soil and/or groundwater is also disclosed.

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

Science.gov (United States)

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

2017-02-15

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

Dirt in cane removal influenced by soil characteristics

International Nuclear Information System (INIS)

Fernandes, E.A.N.

1997-01-01

Dirt level in sugar cane consignments delivered to the factory is dependent on soil type, in association with harvesting system and weather conditions. Efforts for reducing soil in harvested cane have been made by sugar cane millers, especially improving the washing system installed before crushing. Instrumental neutron activation analysis has shown its potential for assessing dirt reductions in the washed material. Knowledge of elemental concentrations in the different soil fractions highlights the reliability of such measurements especially when taking into account the soil characteristics. (author)

Water Balance Study of a Groundwater-dependent Oak Forest

Directory of Open Access Journals (Sweden)

MÓRICZ, Norbert

2010-01-01

Full Text Available The objectives of this study were (1 to estimate the water balance components of an oak standby calibrating a Hydrus 1-D model, (2 to determine the groundwater consumption by the water tablefluctuation method and (3 to compare the results of the modelling with a remote-sensing based estimation.Model simulation described the observed soil moisture and groundwater level relatively well, theroot mean square errors varied between 12.0 and 14.9% for the soil moisture measurements and 5.0%for the groundwater level. Groundwater consumption was estimated also by the water table fluctuationmethod, which provided slightly different groundwater consumption rates than estimated by theHydrus model simulation. The simulated evapotranspiration was compared with results of a remotesensingbased estimation using the surface temperature database of MODIS.According to the Hydrus model, the estimated evapotranspiration resulted from transpiration(73%, interception loss (23% and soil surface evaporation (4% in the two-year study period. Theproportion of groundwater consumption was 58% of the total transpiration. During the dry growingseason of 2007 the groundwater consumption was significant with 66% of the total transpiration.Water supply from groundwater was found to be less important in the wet growing season of 2008with 50%. The remote-sensing based estimation of evapotranspiration was about 4% lower than themodel based results of nearby comparable sites.

Chelant extraction of heavy metals from contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Peters, R.W. [Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

1999-04-23

The current state of the art regarding the use of chelating agents to extract heavy metal contaminants has been addressed. Results are presented for treatability studies conducted as worst-case and representative soils from Aberdeen Proving Ground's J-Field for extraction of copper (Cu), lead (Pb), and zinc (Zn). The particle size distribution characteristics of the soils determined from hydrometer tests are approximately 60% sand, 30% silt, and 10% clay. Sequential extractions were performed on the 'as-received' soils (worst case and representative) to determine the speciation of the metal forms. The technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound, and residual forms. The results indicated that most of the metals are in forms that are amenable to soil washing (i.e. exchangeable+carbonate+reducible oxides). The metals Cu, Pb, Zn, and Cr have greater than 70% of their distribution in forms amenable to soil washing techniques, while Cd, Mn, and Fe are somewhat less amenable to soil washing using chelant extraction. However, the concentrations of Cd and Mn are low in the contaminated soil. From the batch chelant extraction studies, ethylenediaminetetraacetic acid (EDTA), citric acid, and nitrilotriacetic acid (NTA) were all effective in removing copper, lead, and zinc from the J-Field soils. Due to NTA being a Class II carcinogen, it is not recommended for use in remediating contaminated soils. EDTA and citric acid appear to offer the greatest potential as chelating agents to use in soil washing the Aberdeen Proving Ground soils. The other chelating agents studied (gluconate, oxalate, Citranox, ammonium acetate, and phosphoric acid, along with pH-adjusted water) were generally ineffective in mobilizing the heavy metals from the soils. The chelant solution removes the heavy metals (Cd, Cu, Pb, Zn, Fe, Cr, As, and Hg) simultaneously. Using a multiple

Chelant extraction of heavy metals from contaminated soils

International Nuclear Information System (INIS)

Peters, R.W.

1999-01-01

The current state of the art regarding the use of chelating agents to extract heavy metal contaminants has been addressed. Results are presented for treatability studies conducted as worst-case and representative soils from Aberdeen Proving Ground's J-Field for extraction of copper (Cu), lead (Pb), and zinc (Zn). The particle size distribution characteristics of the soils determined from hydrometer tests are approximately 60% sand, 30% silt, and 10% clay. Sequential extractions were performed on the 'as-received' soils (worst case and representative) to determine the speciation of the metal forms. The technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound, and residual forms. The results indicated that most of the metals are in forms that are amenable to soil washing (i.e. exchangeable+carbonate+reducible oxides). The metals Cu, Pb, Zn, and Cr have greater than 70% of their distribution in forms amenable to soil washing techniques, while Cd, Mn, and Fe are somewhat less amenable to soil washing using chelant extraction. However, the concentrations of Cd and Mn are low in the contaminated soil. From the batch chelant extraction studies, ethylenediaminetetraacetic acid (EDTA), citric acid, and nitrilotriacetic acid (NTA) were all effective in removing copper, lead, and zinc from the J-Field soils. Due to NTA being a Class II carcinogen, it is not recommended for use in remediating contaminated soils. EDTA and citric acid appear to offer the greatest potential as chelating agents to use in soil washing the Aberdeen Proving Ground soils. The other chelating agents studied (gluconate, oxalate, Citranox, ammonium acetate, and phosphoric acid, along with pH-adjusted water) were generally ineffective in mobilizing the heavy metals from the soils. The chelant solution removes the heavy metals (Cd, Cu, Pb, Zn, Fe, Cr, As, and Hg) simultaneously. Using a multiple-stage batch extraction

Reuse of Ablution Water to Improve Peat Soil Characteristics for Ornamental Landscape Plants Cultivation

Directory of Open Access Journals (Sweden)

Radin Mohamed Radin Maya Saphira

2017-01-01

Full Text Available The present study aimed to reuse of ablution water for washing peat soil in order to reduce the concentrations of heavy metals in these soils which might effect negatively on the plant growth. The washing process design was similar to horizontal subsurface flow constructed wetlands (HSSFCW consist of layers of peat and sand soil and surrounded by gravel on both sides. Strelitzia sp. was used to detect the presence negative effect of the washing process on the morphological characteristics of the plants. The physical and chemical characteristics of ablution water was examined before and after the washing process by using Inductively Couple Plasma- Mass Spectrometer (ICP-MS Atomic Absorption Spectrometer (AAS. The characteristics of peat soil before and after the washing process were examined by using X-Ray Fluorescence (XRF. The results revealed that the percentage of FeO3in peat soil reduced from 45.80 to 1.01%. The percentage of SiO2 in sand soil dropped from 87.7 to 67.10%. Parameters of ablution water resulted from the washing process which including Biological Oxygen Demand (BOD5 and heavy metals have increased but still within the standard limits for the disposal of ablution water into the environment. No atrophy was observed in Strelitzia sp. leaves, indicating the ability of plant to grow normally. It can be concluded that the utilization of ablution water in the washing of peat soil has improve the characteristics of the soil without effect on their organic constitutes.

Texas market profile: soil and groundwater decontamination sector

International Nuclear Information System (INIS)

1998-12-01

The soil and groundwater decontamination market in Texas generated $7 billion in earnings in 1997 and should reach almost $9 billion in 2002. While Texas has introduced voluntary clean-up programs, decontamination is required at more than 200,000 sites. Pollution has arisen from such industrial sectors as chemicals, crude oil and natural gas. In Texas, government agency decontamination activities provide major business opportunities. As in the base of the environmental sector as a whole, economic factors are gradually taking over from regulation as the prime demand drivers. Cost and risk are major concerns for clients. Because the incentive to reduce costs and the trend toward contracting out and privatization are becoming stronger, companies with specialized technologies have opportunities in this market. The government is the main client for environmental restoration services, but the private sector is accounting for an increased share of the market. Aspects of market access discussed include: implications of NAFTA and 'Buy America', ATA carnets, the Environmental Technology Verification Program, centralized database, federal government contracting announcements, partnerships, and payment conditions

Hydrologic impacts of climate change and urbanization in Las Vegas Wash Watershed, Nevada

Science.gov (United States)

In this study, a cell-based model for the Las Vegas Wash (LVW) Watershed in Clark County, Nevada, was developed by combining the traditional hydrologic modeling methods (Thornthwaite’s water balance model and the Soil Conservation Survey’s Curve Number method) with the pixel-base...

Soil-water partition coefficients for uranium and thorium: a systematic study of Tummalapalle mining site, India

International Nuclear Information System (INIS)

Dalvi, Aditi; Verma, Rakesh; Kumar, Sangita D.; Reddy, A.V.R.

2012-01-01

The simplest and most common parameter for modeling radionuclide mobility in soils is the partition coefficient (K d ). The soil-water partition coefficient for radionuclide is affected by numerous geochemical parameters like pH, sorption to clays, presence of organic matter, iron oxides, other soil constituents and the chemical forms of the radionuclide as well as oxidation/reduction conditions and major ion chemistry. In these studies radionuclides uranium and thorium were systematically assessed for their behaviour in the soils from Tummalapalle mining site. Physico-chemical characteristics such as chemical composition, pH, CaCO 3 content and organic carbon were determined for soils and synthetic groundwater samples. Oven dried soil samples (1g) were taken in polycarbonate tube and washed with synthetic ground water till the pH of the supernatant solution remained unchanged. The soil sample was then equilibrated with 30 mL of synthetic ground water spiked with an element of interest. The pH was adjusted to its initial value by addition of small increments of dilute NaOH/HNO 3 . The tubes containing samples were gently shaken for 72 h at room temperature. On completion of the experiment, it was centrifuged using high-speed centrifugation for 30 min and the aqueous phase was separated and analysed. The blank was processed in the same manner without adding soil. Determination of U and Th in the supernatant was carried out using ICPMS. The K d of thorium was found to be two-three order of magnitude higher than that of uranium for both the soil samples assessed in this study. The presence of carbonates and organic carbon in the groundwater has a significant effect on the K d of uranium. The K d values for uranium were found to be hundred fold lower in the presence of carbonates. (author)

Cl/Br ratios and chlorine isotope evidences for groundwater salinization and its impact on groundwater arsenic, fluoride and iodine enrichment in the Datong basin, China

Energy Technology Data Exchange (ETDEWEB)

Li, Junxia; Wang, Yanxin, E-mail: yx.wang@cug.edu.cn; Xie, Xianjun

2016-02-15

In order to identify the salinization processes and its impact on arsenic, fluoride and iodine enrichment in groundwater, hydrogeochemical and environmental isotope studies have been conducted on groundwater from the Datong basin, China. The total dissolved solid (TDS) concentrations in groundwater ranged from 451 to 8250 mg/L, and 41% of all samples were identified as moderately saline groundwater with TDS of 3000–10,000 mg/L. The results of groundwater Cl concentrations, Cl/Br molar ratio and Cl isotope composition suggest that three processes including water-rock interaction, surface saline soil flushing, and evapotranspiration result in the groundwater salinization in the study area. The relatively higher Cl/Br molar ratio in groundwater from multiple screening wells indicates the contribution of halite dissolution from saline soil flushed by vertical infiltration to the groundwater salinization. However, the results of groundwater Cl/Br molar ratio model indicate that the effect of saline soil flushing practice is limited to account for the observed salinity variation in groundwater. The plots of groundwater Cl vs. Cl/Br molar ratio, and Cl vs δ{sup 37}Cl perform the dominant effects of evapotranspiration on groundwater salinization. Inverse geochemical modeling results show that evapotranspiration may cause approximately 66% loss of shallow groundwater to account for the observed hydrochemical pattern. Due to the redox condition fluctuation induced by irrigation activities and evapotranspiration, groundwater salinization processes have negative effects on groundwater arsenic enrichment. For groundwater iodine and fluoride enrichment, evapotranspiration partly accounts for their elevation in slightly saline water. However, too strong evapotranspiration would restrict groundwater fluoride concentration due to the limitation of fluorite solubility. - Highlights: • Natural high arsenic, fluoride and iodine groundwater co-occur with saline water. �

Cl/Br ratios and chlorine isotope evidences for groundwater salinization and its impact on groundwater arsenic, fluoride and iodine enrichment in the Datong basin, China

International Nuclear Information System (INIS)

Li, Junxia; Wang, Yanxin; Xie, Xianjun

2016-01-01

In order to identify the salinization processes and its impact on arsenic, fluoride and iodine enrichment in groundwater, hydrogeochemical and environmental isotope studies have been conducted on groundwater from the Datong basin, China. The total dissolved solid (TDS) concentrations in groundwater ranged from 451 to 8250 mg/L, and 41% of all samples were identified as moderately saline groundwater with TDS of 3000–10,000 mg/L. The results of groundwater Cl concentrations, Cl/Br molar ratio and Cl isotope composition suggest that three processes including water-rock interaction, surface saline soil flushing, and evapotranspiration result in the groundwater salinization in the study area. The relatively higher Cl/Br molar ratio in groundwater from multiple screening wells indicates the contribution of halite dissolution from saline soil flushed by vertical infiltration to the groundwater salinization. However, the results of groundwater Cl/Br molar ratio model indicate that the effect of saline soil flushing practice is limited to account for the observed salinity variation in groundwater. The plots of groundwater Cl vs. Cl/Br molar ratio, and Cl vs δ"3"7Cl perform the dominant effects of evapotranspiration on groundwater salinization. Inverse geochemical modeling results show that evapotranspiration may cause approximately 66% loss of shallow groundwater to account for the observed hydrochemical pattern. Due to the redox condition fluctuation induced by irrigation activities and evapotranspiration, groundwater salinization processes have negative effects on groundwater arsenic enrichment. For groundwater iodine and fluoride enrichment, evapotranspiration partly accounts for their elevation in slightly saline water. However, too strong evapotranspiration would restrict groundwater fluoride concentration due to the limitation of fluorite solubility. - Highlights: • Natural high arsenic, fluoride and iodine groundwater co-occur with saline water. • Groundwater

HANFORD GROUNDWATER REMEDIATION

Energy Technology Data Exchange (ETDEWEB)

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

2006-02-01

By 1990 nearly 50 years of producing plutonium put approximately 1.70E + 12 liters (450 billion gallons) of liquid wastes into the soil of the 1,518-square kilometer (586-square mile) Hanford Site in southeast Washington State. The liquid releases consisted of chemicals used in laboratory experiments, manufacturing and rinsing uranium fuel, dissolving that fuel after irradiation in Hanford's nuclear reactors, and in liquefying plutonium scraps needed to feed other plutonium-processing operations. Chemicals were also added to the water used to cool Hanford's reactors to prevent corrosion in the reactor tubes. In addition, water and acid rinses were used to clean plutonium deposits from piping in Hanford's large radiochemical facilities. All of these chemicals became contaminated with radionuclides. As Hanford raced to help win World War II, and then raced to produce materials for the Cold War, these radioactive liquid wastes were released to the Site's sandy soils. Early scientific experiments seemed to show that the most highly radioactive components of these liquids would bind to the soil just below the surface of the land, thus posing no threat to groundwater. Other experiments predicted that the water containing most radionuclides would take hundreds of years to seep into groundwater, decaying (or losing) most of its radioactivity before reaching the groundwater or subsequently flowing into the Columbia River, although it was known that some contaminants like tritium would move quickly. Evidence today, however, shows that many contaminants have reached the Site's groundwater and the Columbia River, with more on its way. Over 259 square kilometers (100 square miles) of groundwater at Hanford have contaminant levels above drinking-water standards. Also key to successfully cleaning up the Site is providing information resources and public-involvement opportunities to Hanford's stakeholders. This large, passionate, diverse, and

Suitability of Groundwater Quality for Irrigation with Reference to ...

African Journals Online (AJOL)

Further, the Sodium Adsorption Ratio (SAR) for the both the groundwater and soil samples and Exchangeable Sodium Percentage (ESP) for the soil samples were also computed. Out of the analyzed 20 groundwater samples, 8 show EC values below 0.7 and the remaining between 0.71 and 1.12 dS/m, and pH values from ...

Proceedings of emerging technologies for hazardous waste management

International Nuclear Information System (INIS)

Tedder, D.W.

1992-01-01

This paper contains the proceedings of emergin technologies for hazardous waste management. Topics covered include: advanced transuranic waste managements; remediation of soil/water systems contaminated with nonaqueous pollutants; advances in molten salt oxidation; air treatment and protection; advanced waste minimization strategies; removal of hazardous materials from soils or groundwater; bioremediation of soils and sediment; innovation, monitoring, and asbestos; high-level liquid waste chemistry in the Hanford tanks; biological contributions to soil and groundwater remediation; soil treatment technologies; pollution prevention; incineration and vitrification; current technology; systematic design approaches to hazardous waste management; waste management and environmental restoration at Savannah River; soil washing and flushing for remediation of hazardous wastes

Semianalytical model predicting transfer of volatile pollutants from groundwater to the soil surface.

Science.gov (United States)

Atteia, Olivier; Höhener, Patrick

2010-08-15

Volatilization of toxic organic contaminants from groundwater to the soil surface is often considered an important pathway in risk analysis. Most of the risk models use simplified linear solutions that may overpredict the volatile flux. Although complex numerical models have been developed, their use is restricted to experienced users and for sites where field data are known in great detail. We present here a novel semianalytical model running on a spreadsheet that simulates the volatilization flux and vertical concentration profile in a soil based on the Van Genuchten functions. These widely used functions describe precisely the gas and water saturations and movement in the capillary fringe. The analytical model shows a good accuracy over several orders of magnitude when compared to a numerical model and laboratory data. The effect of barometric pumping is also included in the semianalytical formulation, although the model predicts that barometric pumping is often negligible. A sensitivity study predicts significant fluxes in sandy vadose zones and much smaller fluxes in other soils. Fluxes are linked to the dimensionless Henry's law constant H for H < 0.2 and increase by approximately 20% when temperature increases from 5 to 25 degrees C.

Rice Field Geochemistry and Hydrology: An Explanation for Why Groundwater Irrigated Fields in Bangladesh are Net Sinks of Arsenic from Groundwater

Science.gov (United States)

Neumann, Rebecca B.; St. Vincent, Allison P.; Roberts, Linda C.; Badruzzaman, A. Borhan M.; Ali, M. Ashraf; Harvey, Charles F.

2011-01-01

Irrigation of rice fields in Bangladesh with arsenic-contaminated groundwater transfers tens of cubic kilometers of water and thousands of tons of arsenic from aquifers to rice fields each year. Here we combine observations of infiltration patterns with measurements of porewater chemical composition from our field site in Munshiganj Bangladesh to characterize the mobility of arsenic in soils beneath rice fields. We find that very little arsenic delivered by irrigation returns to the aquifer, and that recharging water mobilizes little, if any, arsenic from rice field subsoils. Arsenic from irrigation water is deposited on surface soils and sequestered along flow paths that pass through bunds, the raised soil boundaries around fields. Additionally, timing of flow into bunds limits the transport of biologically available organic carbon from rice fields into the subsurface where it could stimulate reduction processes that mobilize arsenic from soils and sediments. Together, these results explain why groundwater irrigated rice fields act as net sinks of arsenic from groundwater. PMID:21332196

Ultrasonic process for detoxification of groundwater

International Nuclear Information System (INIS)

Wu, Jiann M.; Huang, H.S.; Livengood, C.D.

1991-01-01

In this paper, we present the results of an investigation of the ultrasonic irradiation of carbon tetrachloride at various pH values, temperatures, and power intensities. Kinetic data and selected chemical mechanism are discussed and proposed. To study oxidant efficiency, chemical oxidants, such as hydrogen peroxide, are also considered. This work is part of a project entitled ''Ultrasonic Process for Detoxification of Groundwater and Soil,'' sponsored by the US Department of Energy, Office of Technology Development, to develop an innovative process for the effective destruction of chlorinated organics in soil and groundwater

Groundwater response to heavy precipitation

International Nuclear Information System (INIS)

Waring, C.; Bradd, J.; Hankin, S.

2003-05-01

An investigation of the groundwater response to heavy rainfall at Lucas Heights Science and Technology Centre (LHSTC) is required under the conditions of Facility Licence F0001 for the ANSTO's Replacement Research Reactor. Groundwater continuous hydrograph monitoring has been used for this purpose. Hydrograph data from four boreholes are presented showing the rainfall recorded during the same period for comparison. The drought conditions have provided only limited cases where groundwater responded to a rainfall event. The characteristic response was local, caused by saturated soil contributing water directly to the borehole and the falling head as the water was redistributed into he aquifer in a few hours. Hydrograph data from borehole near the head of a gully showed that groundwater flow from the plateau to the gully produced a peak a fe days after the rainfall event and that the water level returned to its original level after about 10 days. The hydrograph data are consistent with an imperfect multi-layer groundwater flow regime, developed from earlier seismic and geophysical data, with decreasing rate of flow in each layer due to decreasing hydraulic conductivity with depth. The contrast in hydraulic conductivity between the thin permeable soil layer and the low permeable sandstone forms an effective barrier to vertical flow

Does plant uptake or low soil mineral-N production limit mineral-N losses to surface waters and groundwater from soils under grass in summer?

International Nuclear Information System (INIS)

Bhatti, Ambreen; McClean, Colin J.; Cresser, Malcolm S.

2013-01-01

Summer minima and autumn/winter maxima in nitrate concentrations in rivers are reputedly due to high plant uptake of nitrate from soils in summer. A novel alternative hypothesis is tested here for soils under grass. By summer, residual readily mineralizable plant litter from the previous autumn/winter is negligible and fresh litter input low. Consequently little mineral-N is produced in the soil. Water-soluble and KCl-extractable mineral N in fresh soils and soils incubated outdoors for 7 days have been monitored over 12 months for soil transects at two permanent grassland sites near York, UK, using 6 replicates throughout. Vegetation-free soil is shown to produce very limited mineral-N in summer, despite the warm, moist conditions. Litter accumulates in autumn/winter and initially its high C:N ratio favours N accumulation in the soil. It is also shown that mineral-N generated monthly in situ in soil substantially exceeds the monthly mineral-N inputs via wet deposition at the sites. -- Highlights: •Soil mineral-N has been measured over a year at two grassland sites in the UK. •Rates of mineral-N production have also been measured in vegetation-free soils. •In summer, though soils were warm and moist, rate of mineral-N production was low. •The effect is attributed to low litter inputs in summer when grass is growing well. •Low mineral-N production in summer must be limiting N losses to fresh waters. -- Low mineral-N production in soils under grass limits summer N losses to surface- and ground-waters