Recent Papers in Groundwater Remediation
Content Table
- Applying Dynamic Surrogate Models in Noisy Genetic Algorithms to Optimize Groundwater Remediation Designs
- Column study of Cr(VI) removal by cationic hydrogel for in-situ remediation of contaminated groundwater and soil
- In situ oxidation of petroleum-hydrocarbon contaminated groundwater using passive ISCO system
- Hydraulic performance of a proposed in situ photocatalytic reactor for degradation of MTBE in water
- Heavy metals removal and hydraulic performance in zero-valent iron/pumice permeable reactive barriers
- Managing groundwater as a common-pool resource: an Australian case study
- Performance of electron beam irradiation for treatment of groundwater contaminated with acetone
- Performance of tetramethoxyphenyl porphyrin cobalt(II) (CoTMPP) based stainless steel cathode in the electricigenic permeable reactive barrier for groundwater organic contamination remediation
- Wells are not always water follies: sustainable groundwater policies for the American West
- Improving groundwater level forecasting with a feedforward neural network and linearly regressed projected precipitation
- Bioremediation of trichloroethylene contaminated groundwater using anaerobic process
- Removal of arsenic from groundwater by arsenite-oxidizing bacteria
- Remediation of chlorophenol- and phenol-contaminated groundwater by a sequencing batch biofilm reactor
Applying Dynamic Surrogate Models in Noisy Genetic Algorithms to Optimize Groundwater Remediation Designs
Journal of Water Resources Planning and Management article in press © ASCE 2010 doi:10.1061/(ASCE)WR.1943-5452.0000106
Shengquan Yan and Barbara Minsker
Department of Civil and Environmental Engineering, University of Illinois, Urbana
Abstract
Computational cost is a critical issue for large‐scale water resource optimization under uncertainty, since time‐intensive Monte Carlo simulations are often required to evaluate over multiple parameter realizations. This paper presents an efficient approach for replacing most Monte Carlo simulations with efficient surrogate models within a noisy genetic algorithm (GA). The surrogates are trained to predict the posterior expectations online based on stochastic decision theory, using Monte Carlo simulation results created during the GA run. The surrogates, which in this application are neural networks, are adaptively updated to improve their prediction performance as the search progresses. Latin Hypercube sampling method is used to efficiently sample parameters for the Monte Carlo simulation and the sampling results are archived so that the estimate of posterior expectation can be iteratively improved in an efficient manner. In addition, the GA is modified to incorporate hypothesis tests in its selection operator to account for sampling noise. The method is applied to a field‐scale groundwater remediation design case study, where the primary source of uncertainty stems from hydraulic conductivity values in the aquifers. The results show that the method identified more reliable and cost‐effective solutions with 86–90% less computational effort than the purely physically‐based Noisy‐GA approach.
Column study of Cr(VI) removal by cationic hydrogel for in-situ remediation of contaminated groundwater and soil
Journal of Contaminant Hydrology article in press © Elsevier 2011 doi:10.1016/j.jconhyd.2011.04.005
Samuel C.N. Tang, Ke Yin1, Irene M.C. Lo1
1Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
Abstract
Column experiments were conducted for examining the effectiveness of the cationic hydrogel on Cr(VI) removal from groundwater and soil. For in-situ groundwater remediation, the effects of background anions, humic acid (HA) and pH were studied. Cr(VI) has a higher preference for being adsorbed onto the cationic hydrogel than sulphate, bicarbonate ions and HA. However, the adsorbed HA reduced the Cr(VI) removal capacity of the cationic hydrogel, especially after regeneration of the adsorbents, probably due to the blockage of adsorption sites. The Cr(VI) removal was slightly influenced by the groundwater pH that could be attributed to Cr(VI) speciation. The 6-cycle regeneration and reusability study shows that the effectiveness of the cationic hydrogel remained almost unchanged. On average, 93% of the adsorbed Cr(VI) was recovered in each cycle and concentrated Cr(VI) solution was obtained after regeneration. For in-situ soil remediation, the flushing water pH had an insignificant effect on the release of Cr(VI) from the soils. Multiple-pulse flushing increased the removal of Cr(VI) from the soils. In contrast, more flushing water and longer operation may be required to achieve the same removal level by continuous flushing.
In situ oxidation of petroleum-hydrocarbon contaminated groundwater using passive ISCO system
Water Research Vol 45 Issue 8 pp 2496-2506 © IWA Publishing 2011 doi:10.1016/j.watres.2011.02.005
S.H. Lianga, C.M. Kaoa, Y.C. Kuoa, K.F. Chenb, B.M. Yanga
aInstitute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
bDepartment of Civil Engineering, National Chi-Nan University, Nanto County, Taiwan
Abstract
Groundwater contamination by gasoline spill is a worldwide environmental problem. Gasoline contains methyl tertiary-butyl ether (MTBE) (a fuel oxygenates) and benzene, which are the chemicals of concerns among the gasoline components. In this study, an in situ chemical oxidation (ISCO) barrier system was developed to evaluate the feasibility of applying this passive system on the control of MTBE and benzene plume in aquifer. The developed ISCO barrier contained oxidant-releasing materials, which could release oxidants (e.g., persulfate) when contact with water for the contaminants’ oxidation in groundwater. In this study, laboratory-scale fill-and-draw experiments were conducted to determine the component ratios of the oxidant-releasing materials and evaluate the persulfate release rates. Results indicate that the average persulfate-releasing rate of 7.26 mg S2O82−/d/g was obtained when the mass ratio of sodium persulfate/cement/sand/water was 1/1.4/0.24/0.7. The column study was conducted to evaluate the efficiency of in situ application of the developed ISCO barrier system on MTBE and benzene oxidation. Results from the column study indicate that approximately 86–92% of MTBE and 95–99% of benzene could be removed during the early persulfate-releasing stage (before 48 pore volumes of groundwater pumping). The removal efficiencies for MTBE and benzene dropped to approximately 40–56% and 85–93%, respectively, during the latter part of the releasing period due to the decreased persulfate-releasing rate. Results reveal that acetone, byproduct of MTBE, was observed and then further oxidized completely. Results suggest that the addition of ferrous ion would activate the persulfate oxidation. However, excess ferrous ion would compete with organic contaminants for persulfate, and thus, cause the decrease in contaminant oxidation rates. The proposed treatment scheme would be expected to provide a more cost-effective alternative to remediate MTBE, benzene, and other petroleum-hydrocarbon contaminated aquifers. Results from this study will be useful in designing a scale-up system for field application.
Hydraulic performance of a proposed in situ photocatalytic reactor for degradation of MTBE in water
Chemosphere Vol 82 Issue 4 pp 613-620 © Elsevier 2010 doi:10.1016/j.jenvman.2010.06.01Link to Summary Page
Leonard Lik Pueh Lima and Rod Lyncha
aDepartment of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, United Kingdom
Abstract
Methyl tert-butyl ether (MTBE) groundwater remediation projects often require a combination of technologies resulting in increasing the project costs. A cost-effective in situ photocatalytic reactor design, Honeycomb II, is proposed and tested for its efficiency in MTBE degradation at various flows. This study is an intermediate phase of the research in developing an in situ photocatalytic reactor for groundwater remediation. It examines the effect of the operating variables: air and water flow and double passages through Honeycomb II, on the MTBE removal. MTBE vaporisation is affected by not only temperature, Henry’s law constant and air flow to volume ratio but also reactor geometry. The column reactor achieved more than 84% MTBE removal after 8 h at flows equivalent to horizontal groundwater velocities slower than 21.2 cm d−1. Despite the contrasting properties between a photocatalytic indicator methylene blue and MTBE, the reactor efficiency in degrading both compounds showed similar responses towards flow (equivalent groundwater velocity and hydraulic residence time (HRT)). The critical HRT for both compounds was approximately 1 d, which corresponded to a velocity of 21.2 cm d−1. A double pass through both new and used catalysts achieved more than 95% MTBE removal after two passes in 48 h. It also verified that the removal efficiency can be estimated via the sequential order of the removal efficiency of one pass obtained in the laboratory. This study reinforces the potential of this reactor design for in situ groundwater remediation.
Heavy metals removal and hydraulic performance in zero-valent iron/pumice permeable reactive barriers
Journal of Environmental Management Vol 91 Issue 11 pp 2336-2341 © Elsevier 2010 doi:10.1016/j.jenvman.2010.06.019
Nicola Moracia and Paolo S. Calabròa
aMechanic and Materials Department, Mediterranean University of Reggio Calabria, Faculty of Engineering, Via Graziella, loc. Feo di Vito, 89122 Reggio Calabria (RC), Italy
Abstract
Long-term behaviour is a major issue related to the use of zero-valent iron (ZVI) in permeable reactive barriers for groundwater remediation; in fact, in several published cases the hydraulic conductivity and removal efficiency were progressively reduced during operation, potentially compromising the functionality of the barrier. To solve this problem, the use of granular mixtures of ZVI and natural pumice has recently been proposed. This paper reports the results of column tests using aqueous nickel and copper solutions of various concentrations. Three configurations of reactive material (ZVI only, granular mixture of ZVI and pumice, and pumice and ZVI in series) are discussed. The results clearly demonstrate that iron-pumice granular mixtures perform well both in terms of contaminant removal and in maintaining the long-term hydraulic conductivity. Comparison with previous reports concerning copper removal by ZVI/sand mixtures reveals higher performance in the case of ZVI/pumice.
Keywords: Contaminated groundwater; Heavy metals; Hydraulic conductivity; Permeable reactive barrier; Pumice; Zero-valent iron
Managing groundwater as a common-pool resource: an Australian case study
Water Policy Vol 11 No 5 pp 598–614 © IWA Publishing 2009 doi:10.2166/wp.2009.076
Ashutosh Sarkera, Claudia Baldwinb and Helen Rossa
aSchool of Integrative Systems, The University of Queensland, Gatton Campus, Gatton Qld 4343, Australia.
bUniversity of the Sunshine Coast, Maroochydore, Qld 4558, Australia
Abstract
Over-appropriation and degradation of groundwater can result from lack of recognition of, and inappropriate arrangements for, managing groundwater as a common-pool resource. An irrigators group in the Lockyer Valley, South-East Queensland, Australia and the Queensland government are currently working together to address over-exploitation of groundwater through a co-management model designed to be nested within the state and national water reform framework. This paper applies Ostrom's design principles for common-pool resource governance to this proposed co-management framework to strengthen the approach.
Performance of electron beam irradiation for treatment of groundwater contaminated with acetone
Water Science & Technology—WST Vol 59 No 12 pp 2475–2483 © IWA Publishing 2009 doi:10.2166/wst.2009.234
Y. J. Yoon, Y. J. Jung, B. S. Han and J. W. Kang
Department of Environmental Engineering, Yonsei University, 234, Maeji-ri, Heungup-myeon, Wonju-si, Gangwon-do 220-710, Republic of Korea E-mail: jwk@yonsei.ac.kr
EB-TECH Co. Limited, 103-6 Munji, Yusung, Daejeon 305-380, Republic of Korea
Abstract
The purposes of this study were to evaluate the efficiency of acetone removal by electron beam irradiation in groundwater and the effect of various conditions. According to the results, the removal kinetics of acetone were pseudo first-order, and the removal efficiencies were expressed to the (%) removal and G-values. By adding sulfite, it was confirmed that acetone was mainly degraded by the reaction with the hydrated electrons. The presence of nitrate caused the removal of acetone to decrease. But there was no significant effect of alkalinity on the removal of acetone. The effect of the initial pH values (pH 5 to 9) on the acetone removal efficiency was negligible, but the pH value decreases due to the formation of acidic compounds after irradiation. Consequently, the radiation-induced removal reactions of acetone followed the pseudo-first-order kinetic model; in addition to the initial concentration of acetone, nitrate and the absorbed dose were important factors in removing acetone from an aqueous solution using electron beam irradiation. The effects of general pH and alkalinity on the degrading acetone were negligible.
Performance of tetramethoxyphenyl porphyrin cobalt(II) (CoTMPP) based stainless steel cathode in the electricigenic permeable reactive barrier for groundwater organic contamination remediation
Water Science & Technology—WST Vol 59 No 5 pp 979–985 © IWA Publishing 2009 doi:10.2166/wst.2009.077
Shi-Kun Zhu, Bin Fan, Jie-Wei Wu, Yuan-Yuan Feng and Yun Zhang
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, PR China E-mail: fanbin@rcees.ac.cn
Abstract
An electricigenic permeable reactive barrier (EPRB) technology was brought forward for remediation of organic-contaminated groundwater, with a benefit that it overcame the limitations of electron acceptor addition in other groundwater remediation methods. To investigate performances of constructions and materials used in EPRB system, several kinds of reactors were designed and prepared in laboratory. Stainless steel wires, a kind of nontoxic, inexpensive and conductive material, were used as basic material of electrode. In order to improve cathodic oxygen reduction capability, a cathode based on tetramethoxyphenyl porphyrin cobalt (II) (CoTMPP) was prepared and studied in this paper. Results showed that a high catalytic activity for oxygen reduction was exhibited by the CoTMPP based cathode, with an electricity generation 3 times as high as that of the naked stainless steel cathode. Some evidence indicated that by loading on the surface of stainless steel wires and heat-treated under anaerobic conditions, epoxy resin, with its curing agents, might have got a catalytic capability for oxygen reduction.
Wells are not always water follies: sustainable groundwater policies for the American West
Water Policy Vol 10 No 2 pp 145–164 © IWA Publishing 2008 doi:10.2166/wp.2008.037
Aparna Rajagopal-Durbin and Timothy Joslin Durbin
Timothy J. Durbin Incorporated, 5330 Primrose Drive, Suite 228, Fair Oaks, CA 95628, USA. E-mail: aparnarajagopal@hotmail.com
Abstract
In his top-ten bestseller, Water Follies, Robert Jerome Glennon catalogues humanity's crimes against the Western American landscape by discussing the host of environmental impacts caused by groundwater pumping. Robert Glennon's solution to increased environmental damage due to groundwater pumping is to stop growth and development. Although development is the primary force behind environmental degradation of the American West, removing people wholesale from the ecological equation is a logistical impossibility. Furthermore, you cannot realistically introducing human beings into the West without causing some environmental impact unless people stop using water. By the same token, just because environmental degradation is unavoidable does not mean that it cannot be mitigated to some extent. This paper provides a critique on Robert Glennon's solution to the environmental damage caused by groundwater pumping and proposes a more realistic groundwater policy that entails establishing a tree of environmental values and directing the damage to the least valuable environmental resource. This proposal is made against the backdrop of the unique hydrology of the American West, the history of American groundwater policy, and projections for future growth and development of the American West. Ultimately, a system of trade-offs between environmental values embraces the reality of population growth, but at the same time empowers societies to make wise decisions about which resources to protective and preserve.
Improving groundwater level forecasting with a feedforward neural network and linearly regressed projected precipitation
Journal of Hydroinformatics Vol 10 No 4 pp 317–330 © IWA Publishing 2008 doi:10.2166/hydro.2008.006
Ioannis K. Tsanis, Paulin Coulibaly and Ioannis N. Daliakopoulos
Department of Civil Engineering, McMaster University, Hamilton, Ontario, Canada E-mail: tsanis@mcmaster.ca
Department of Environmental Engineering, Technical University of Crete, Chania, Greece
Abstract
A module that uses neural networks was developed for forecasting the groundwater changes in an aquifer. A modified standard Feedforward Neural Network (FNN), trained with the Levenberg–Marquardt (LM) algorithm with five input variables (precipitation, temperature, runoff, groundwater level and specific yield) with a deterministic component, is used. The deterministic component links precipitation with the seasonal recharge of the aquifer and projects the seasonal average precipitations. A new algorithm is applied to forecast the groundwater level changes in Messara Valley, Crete, Greece, where groundwater level has been steadily decreasing due to overexploitation during the last 20 years. Results from the new algorithm show that the introduction of specific yield improved the groundwater level forecasting marginally but the linearly projected precipitation component drastically increased the window of forecasting up to 30 months, equivalent to five biannual time-steps.
Bioremediation of trichloroethylene contaminated groundwater using anaerobic process
Water Science & Technology—WST Vol 58 No 11 pp 2127–2132 © IWA Publishing 2008 doi:10.2166/wst.2008.830
Cheema Chomsurin, Juthathip Kajorntraidej and Kongrit Luangmuang
Department of Environmental Engineering, Kasetsart University, Bangkok, 10900, Thailand E-mail: cheema.c@ku.ac.th
Abstract
Anaerobic remediation of trichloroethylene (TCE) contaminated soil and groundwater was studied in laboratory setups. In this process fermentation of polymeric organic materials (POMS) produced volatile fatty acids (VFAs) that were electron donors in reductive dechlorination of TCE. Shredded peanut shell was selected as low cost POM and the experiments were set up in 500 ml Erlenmeyer flasks. In the setups, approximately 25 mg of leachate contaminated soil was used as the main source of microorganisms and about 5 g of shredded peanut shell (0.5–2.36 mm) was added to produce VFAs for dechlorination of TCE. In the first set of experiments, fermentation of soil and shredded peanut shell was studied and it was found that VFAs were produced continuously with increasing concentration (5.63 mM as CH3COOH from the first day to 17.17 in the 10th day of the experiment). During the fermentation, concentration of ammonia-nitrogen was 22–50 mg/L, the ratio of VFA to NH3 was 15.29–23.44 and pH was 5.24–6.00. These results show that the system was appropriate for microorganism activities. In the second set of experiments, TCE (~48 mg/L) was added to the fermentation system and remediation of TCE by reductive dechlorination was studied. It was found that 0.04(±0.01) mg TCE adsorbed to a gram of soil and peanut shells at the beginning of the experiment and based on mass balance of the system, TCE concentration in water was linearly reduced at the rate of 0.0098 mg/hr.
Removal of arsenic from groundwater by arsenite-oxidizing bacteria
Water Science & Technology—WST Vol 58 No 5 pp 1095–1100 © IWA Publishing 2008 doi:10.2166/wst.2008.462
M. Ike, T. Miyazaki, N. Yamamoto, K. Sei and S. Soda
Division of Sustainable Energy and Environmental Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan E-mail: ike@see.eng.osaka-u,.ac.jp
Abstract
The presence of arsenic in groundwater has been of great public concern because of its high toxicity. For purification of arsenic-contaminated groundwater, bacterial oxidation of arsenite, As(III), with a chemical adsorption process was examined in this study. After As(III) oxidation to arsenate, As(V), arsenic is easily removable from contaminated groundwater because As(V) is more adsorptive to absorbents than As(III). By acclimation to As(III) of high concentrations, a mixed culture of heterotrophic bacteria with high As(III)-oxidizing activity was obtained from a soil sample that was free from contamination. With initial concentration up to 1,500 mg l-1 As(III), the mixed culture showed high As(III)-oxidizing activity at pH values of 7–10 and at temperatures of 25–35°C. The mixed culture contained several genera of heterotrophic As(III)-oxidizing and arsenic-tolerant bacteria: Haemophilus, Micrococcus, and Bacillus. Activated alumina was added to the basal salt medium containing 75 mg l-1 As(III) before and after bacterial oxidation. Arsenic removal by activated alumina was greatly enhanced by bacterial oxidation of As(III) to As(V). The isotherms of As(III) and As(V) onto activated alumina verified that bacterial As(III) oxidation is a helpful pretreatment process for the conventional adsorption process for arsenic removal.
Remediation of chlorophenol- and phenol-contaminated groundwater by a sequencing batch biofilm reactor
Water Science & Technology—WST Vol 58 No 2 pp 295–301 © IWA Publishing 2008 doi:10.2166/wst.2008.398
G. Farabegoli, A. Chiavola and E. Rolle
Department of Hydraulics, Transportation and Roads, Faculty of Engineering, Sapienza University of Rome, Via Eudossiana, 18, 00184, Rome, Italy E-mail: geneve.farabegoli@polimi.it; agostina.chiavola@uniroma1.it; enrico.rolle@uniroma1.it
Abstract
The paper describes the results of an investigation aimed at evaluating suitability of a lab-scale Sequencing Batch Biofilm Reactor (SBBR) for the remediation of groundwater contaminated by phenol (P) and 2-chlorophenol (2-CP). Kinetics of compound degradation was determined along the bed height in the absence and in presence of effluent recirculation, and with different influent composition (compounds fed separately or in combination in the same stream). SBBR performances with and without recirculation were very satisfactory for all the influent compositions: the system showed 99% removal efficiencies for both phenol and 2-CP and their complete removal was always achieved far before the end of react. In the presence of recirculation, the concentration gradient established during fill was rapidly eliminated and an even biomass distribution along the bed height was formed. Consequently, an acceleration of the elimination process was observed, particularly for phenol that was mostly removed in the first hour of the cycle. When the compounds were fed simultaneously, 2-CP removal kinetics improved probably due to cometabolism. The adsorption phenomena of the toxic compounds on the packing material were studied also, showing about 50% COD removal after 7 hours contact time.
