Journal articles: 'Groundwater In situ remediation. Oxidation'

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Yu, Shu Bin, Zhen Min Ma, and Hui Shen Zhang. "In Situ Remediation Technology of Groundwater Contaminated by Petroleum Contaminants." Advanced Materials Research 322 (August 2011): 213–18. http://dx.doi.org/10.4028/www.scientific.net/amr.322.213.

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The paper presents concepts of permeable reactive wall, groundwater aeration, in-situ chemical oxidation, in-situ electrokinetic remediation, bioremediation, and the progress of their researches are discussed. Situ remediation of petroleum contaminants in groundwater proposed a variety of technologies should combine to improve the repair efficiency and reduce capital investment.

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Seyedpour, S. M., I. Valizadeh, P. Kirmizakis, R. Doherty, and T. Ricken. "Optimization of the Groundwater Remediation Process Using a Coupled Genetic Algorithm-Finite Difference Method." Water 13, no. 3 (February 1, 2021): 383. http://dx.doi.org/10.3390/w13030383.

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In situ chemical oxidation using permanganate as an oxidant is a remediation technique often used to treat contaminated groundwater. In this paper, groundwater flow with a full hydraulic conductivity tensor and remediation process through in situ chemical oxidation are simulated. The numerical approach was verified with a physical sandbox experiment and analytical solution for 2D advection-diffusion with a first-order decay rate constant. The numerical results were in good agreement with the results of physical sandbox model and the analytical solution. The developed model was applied to two different studies, using multi-objective genetic algorithm to optimise remediation design. In order to reach the optimised design, three objectives considering three constraints were defined. The time to reach the desired concentration and remediation cost regarding the number of required oxidant sources in the optimised design was less than any arbitrary design.

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Xie, Tian, Zhi Dang, Jian Zhang, Qian Zhang, Rong-Hai Zhang, Chang-Jun Liao, and Gui-Ning Lu. "Decontamination of dense nonaqueous-phase liquids in groundwater using pump-and-treat and in situ chemical oxidation processes: a field test." RSC Advances 11, no. 7 (2021): 4237–46. http://dx.doi.org/10.1039/d0ra10010b.

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Maier, D., M. Maier, and M. Sörensen. "Funnel and radiation: a new technique for groundwater remediation." Water Supply 2, no. 1 (January 1, 2002): 109–12. http://dx.doi.org/10.2166/ws.2002.0014.

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For the remediation of the groundwater of the former gas plant site of the city of Karlsruhe, which is contaminated with Polycyclic Aromatic Hydrocarbons (PAHs), a funnel-and-gate system was designed. In addition to the primary contamination with PAHs from the site itself a secondary contamination with vinylchloride (VC) is present in the aquifer as a result of a plume of degraded volatile organic compounds (VOCs) transported into the contaminated area from outside. For the removal of the contaminants an advanced novel technique consisting of an in-situ-UV-radiation in combination with adsorption on activated carbon was used. In this paper the first results of the experiments of the application of pilot scale equipment for the in-situ-UV-radiation for the oxidation of PAHs and VC are presented.

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Beretta, Daghio, Espinoza Tofalos, Franzetti, Mastorgio, Saponaro, and Sezenna. "Progress Towards Bioelectrochemical Remediation of Hexavalent Chromium." Water 11, no. 11 (November 7, 2019): 2336. http://dx.doi.org/10.3390/w11112336.

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Chromium is one of the most frequently used metal contaminants. Its hexavalent form Cr(VI), which is exploited in many industrial activities, is highly toxic, is water-soluble in the full pH range, and is a major threat to groundwater resources. Alongside traditional approaches to Cr(VI) treatment based on physical-chemical methods, technologies exploiting the ability of several microorganisms to reduce toxic and mobile Cr(VI) to the less toxic and stable Cr(III) form have been developed to improve the cost-effectiveness and sustainability of remediating hexavalent chromium-contaminated groundwater. Bioelectrochemical systems (BESs), principally investigated for wastewater treatment, may represent an innovative option for groundwater remediation. By using electrodes as virtually inexhaustible electron donors and acceptors to promote microbial oxidation-reduction reactions, in in situ remediation, BESs may offer the advantage of limited energy and chemicals requirements in comparison to other bioremediation technologies, which rely on external supplies of limiting inorganic nutrients and electron acceptors or donors to ensure proper conditions for microbial activity. Electron transfer is continuously promoted/controlled in terms of current or voltage application between the electrodes, close to which electrochemically active microorganisms are located. Therefore, this enhances the options of process real-time monitoring and control, which are often limited in in situ treatment schemes. This paper reviews research with BESs for treating chromium-contaminated wastewater, by focusing on the perspectives for Cr(VI) bioelectrochemical remediation and open research issues.

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Anvarov, Adyl, Adelaida Pelaez Angel, Beatriz Felices Rando, and Jimena Lazaro Gil. "Remediation of groundwater contamination from an old, non-functional landfill in Hořkovec open cast mine, Czech Republic." Journal of Water Supply: Research and Technology-Aqua 68, no. 8 (November 28, 2019): 829–41. http://dx.doi.org/10.2166/aqua.2019.198.

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Abstract The main aim of this work was to assess different suitable strategies for the remediation of groundwater contaminated with the leachate from an old, not functional landfill located next to Hořkovec open cast mine, in the Czech Republic. The leachate consisted of mainly chlorinated aliphatic compounds and aromatic volatile compounds. The site, that had already been treated, was observed to show rebounding effects after the first remediation treatment. This article analyses the possibilities of using different types of remediation technologies that include in-situ chemical oxidation (ISCO) with different oxidants (potassium permanganate, sodium permanganate and sodium persulfate), as well as in-situ bioremediation (ISB), and the combination of both types of treatment. From the results of the analysis it was concluded that the best option for this case was to carry out a pre-treatment of the area by ISCO with sodium persulfate as the oxidant agent and then a further biological treatment.

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Schmitt, Jean-Michel, Sabine Huet-Taillanter, and Médard Thiry. "The industrial waste land of Mortagne-du-Nord (59) – II – Oxidizing alteration of the slags, hydrochemistry, geochemical modelling and remediation proposal." Bulletin de la Société Géologique de France 173, no. 4 (July 1, 2002): 383–93. http://dx.doi.org/10.2113/173.4.383.

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Abstract The slag backfills of the former sulfuric acid factory of Mortagne-du-Nord (59) are sulfide- and metal-rich (Zn, Pb, Cd). Sulfide oxidation leads to acidification of surficial groundwater and the dispersal of the metals into the environment, by flow towards the rivers which run along the site. The surficial groundwater pHs fall between 2.5 and 6.8 and the metal content is very high, reaching in places 6 000 mg/L of Zn, 2.5 mg/L of Pb and 600 mg/L of Cd. To conceive a remediation scenario, we tried beforehand to understand the phenomena that govern the oxidation of the sulfides. For this purpose, water levels and water compositions have been surveyed every 2 months during 4 years, a geochemical simulation of the alteration/oxidation has been proposed and leaching tests have been performed. The survey of the water table level and periodical chemical analyses of the groundwater have shown that the slag alteration is reactivated when the water table drops until the sulfide-bearing ≪ fresh ≫ slags are unsaturated. The analysed waters always show an unbalanced negative ionic charge. Geochemical calculations allow to propose several equilibrium models of the waters and to conclude that the presence of thiosulfates (S2O23−) in the original waters most likely explains the observed ionic disequilibrium. The geochemical modelling of the slag alteration, first by percolation in unsaturated conditions (allowing O2 supply) and then under saturated conditions (without O2 renewal), reproduces satisfactorily the chemistry of sampled groundwaters. Leaching tests of the slags have been performed in the laboratory both by percolation (unsatured environment) and by cirulation (saturated and closed environment). These tests allowed to obtain alteration solutions comparable to the waters sampled on site, with progressive ≪ aging ≫ of the material, in agreement with the decrease of the dissolved metals observed on site during the 4-year survey. Moreover, the tests confirm the importance of the oxygen supply in the reactivation of the alteration. The evolution of the groundwater chemistry, the thermodynamic modelling, as well as the leaching experiments allow to determine with some details the alteration/oxidation mechanism and show that: (1) alteration is actived or reactived after a drop of the water table within the sulfide-bearing facies, (2) the oxygen supply by diffusion in the poral air is the driving force of slag oxidation, and (3) maintaining the backfills in saturated conditions practically stops alteration. The geochemical evolution of the site is directly related to its history, with successive re-profiling of the channels which have lead to a lowering of the water table of about 2 m. The remediation should be focused on in-situ processing (water treatment aimed to lower acidity, active barriers, …) rather than on ex-situ (excavation) solutions.

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Zhang, Qihui, Shengyu Zhang, Cong Lyu, Xuejiao Yang, Wei Liu, and Xiaosi Su. "A cost-effective catalytically adsorbent for in situ remediation of manganese contaminated groundwater." Water Supply 18, no. 2 (June 28, 2017): 504–14. http://dx.doi.org/10.2166/ws.2017.104.

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Abstract Manganese oxide coated scoria (MOCS) was prepared as a cost-effective catalytically adsorbent with high permeability to remediate manganese contaminated groundwater. Scanning electron microscope visual expressed that on the relatively smooth surface of raw scoria (RS) a large amount of micro pores and dense bulk-like structures after modification and filtration appeared. The data from Fourier transform infrared showed that the intrinsic scoria structure was unchanged during modification. The X-ray diffraction and X-ray photoelectron spectroscopy instrumental studies revealed that the newborn manganese oxide layer was a mixed-valence of manganese (Mn3+ and Mn4+) which could absorb the Mn2+ and catalytically facilitate oxidation with oxygen. Subsequently, the adsorption capacity of RS and MOCS was demonstrated in adsorption experiments. The kinetics of manganese adsorption by RS and MOCS followed pseudo-second-order with the correlation coefficients of 0.983 and 0.989, respectively. The experimental data were better fitted to Langmuir isotherm than Freundlich isotherm, indicating that the monolayer adsorption process for manganese was acting on the surface of RS and MOCS. The filtration experiment showed high Mn2+ removal efficiency by MOCS in a wide range of hydraulic retention time (15–40 min) in 40 days, which demonstrated that the MOCS is a good potential application prospect for manganese removal from groundwater.

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Liang, Chenju, and Cheng-Yu Chen. "Characterization of a Sodium Persulfate Sustained Release Rod for in Situ Chemical Oxidation Groundwater Remediation." Industrial & Engineering Chemistry Research 56, no. 18 (April 28, 2017): 5271–76. http://dx.doi.org/10.1021/acs.iecr.7b00082.

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Baciocchi, Renato, Laura D'Aprile, Ivan Innocenti, Felicia Massetti, and Iason Verginelli. "Development of technical guidelines for the application of in-situ chemical oxidation to groundwater remediation." Journal of Cleaner Production 77 (August 2014): 47–55. http://dx.doi.org/10.1016/j.jclepro.2013.12.016.

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Kalogerakis, G. C., Q. Zhao, G. Grasselli, and B. E. Sleep. "In situ chemical oxidation processes: 4D quantitative visualization of byproduct formation and deposition via micro-CT imaging." Leading Edge 37, no. 6 (June 2018): 462–67. http://dx.doi.org/10.1190/tle37060462.1.

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In Canada alone, petroleum hydrocarbons have been found in groundwater and soil at approximately 1400 and 4000 sites, respectively. In situ chemical oxidation (ISCO) is a remediation technology that delivers oxidants to the subsurface to mineralize the contaminants. A typical oxidant is permanganate, which generates carbon dioxide (CO2) as gas and manganese oxides (MnO2) as precipitates. In this study, microcomputed tomography (micro-CT) imaging has been used successfully to visualize the oxidation of diesel fuel with permanganate in a 1D column packed with silica sand with respect to time (4D imaging). The byproducts of diesel fuel oxidation with permanganate have been visualized with micro-CT image analysis and subsequently qualitatively and quantitatively assessed via image processing. This is the first study to visualize the distribution of the byproducts in the pores in a noninvasive manner and to quantify both the gaseous CO2 and MnO2. Flushing water through the sample to remove the byproducts was also investigated. Imaging results showed a reduction of the gas phase by approximately 6% from water flushing, but the MnO2 deposits were not removed. CO2 and MnO2 generation from permanganate addition for contaminant remediation may result in preferential pathways, and potential permanganate bypassing of the target treatment zone may occur, reducing the efficiency of the remediation process. Using 4D micro-CT imaging offers an opportunity to further elucidate the fundamental understanding of all underlying processes and potentially help in improving the design of ISCO schemes.

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Chang, Yu-Chen, Ting-Yu Chen, Yung-Pin Tsai, and Ku-Fan Chen. "Remediation of trichloroethene (TCE)-contaminated groundwater by persulfate oxidation: a field-scale study." RSC Advances 8, no. 5 (2018): 2433–40. http://dx.doi.org/10.1039/c7ra10860e.

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Lacina, Petr, and Scott Goold. "Use of the ferrates (FeIV–VI) in combination with hydrogen peroxide for rapid and effective remediation of water – laboratory and pilot study." Water Science and Technology 72, no. 10 (August 5, 2015): 1869–78. http://dx.doi.org/10.2166/wst.2015.414.

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In recent years, particles of iron in higher oxidation states (FeIV–VI), commonly called ferrates, have been presented theoretically as very effective oxidants. They can potentially be used for elimination of a wide range of organic and inorganic contaminants. However, so far the majority of applications have been carried out only as laboratory tests using model samples in many cases. The application of ferrates in remediation programs has so far proved to be more complicated with results failing to meet expectations. Therefore there is a necessity to consider the suitability of their use or consider their possible combination with other agents in order to reach required removal efficiencies in remediation. This study is focused on laboratory experiments using industrial groundwater leading to the proposal of a pilot field application realized as an ex-situ remediation. The combination of ferrates with hydrogen peroxide was used in this study in order to enhance the removal efficiency during pilot remediation of groundwater strongly contaminated by a wide range of organic contaminants. This combination has been shown to be very effective. During the 24-hour reaction time the majority of detected contaminants were removed by approximately 60–80%. Moreover, the unpleasant odor of the water was suppressed and suspended particles were removed by the flocculation effect of ferric sludge.

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Yang, Zong-Han, Yih-Terng Sheu, Cheng-Di Dong, Chiu-Wen Chen, Shaohua Chen, and Chih-Ming Kao. "Remediation of phenol-contaminated groundwater using in situ Fenton and persulfate oxidation: performance and mechanism studies." DESALINATION AND WATER TREATMENT 175 (2020): 359–68. http://dx.doi.org/10.5004/dwt.2020.24827.

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Azadpour-Keeley, Ann, Lynn A. Wood, Tony R. Lee, and Susan C. Mravik. "Microbial responses toin situ chemical oxidation, six-phase heating, and steam injection remediation technologies in groundwater." Remediation Journal 14, no. 4 (2004): 5–17. http://dx.doi.org/10.1002/rem.20018.

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Li, Hui, Zhantao Han, Yong Qian, Xiangke Kong, and Ping Wang. "In Situ Persulfate Oxidation of 1,2,3-Trichloropropane in Groundwater of North China Plain." International Journal of Environmental Research and Public Health 16, no. 15 (August 1, 2019): 2752. http://dx.doi.org/10.3390/ijerph16152752.

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In situ injection of Fe(II)-activated persulfate was carried out to oxidize chlorinated hydrocarbons and benzene, toluene, ethylbenzene, and xylene (BTEX) in groundwater in a contaminated site in North China Plain. To confirm the degradation of contaminants, an oxidant mixture of persulfate, ferrous sulfate, and citric acid was mixed with the main contaminants including 1,2,3-trichloropropane (TCP) and benzene before field demonstration. Then the mixed oxidant solution of 6 m3 was injected into an aquifer with two different depths of 8 and 15 m to oxidize a high concentration of TCP, other kinds of chlorinated hydrocarbons, and BTEX. In laboratory tests, the removal efficiency of TCP reached 61.4% in 24 h without other contaminants but the removal rate was decreased by the presence of benzene. Organic matter also reduced the TCP degradation rate and the removal efficiency was only 8.3% in 24 h. In the field test, as the solution was injected, the oxidation reaction occurred immediately, accompanied by a sharp increase of oxidation–reduction potential (ORP) and a decrease in pH. Though the concentration of pollutants increased due to the dissolution of non-aqueous phase liquid (NAPL) at the initial stage, BTEX could still be effectively degraded in subsequent time by persulfate in both aquifers, and their removal efficiency approached 100%. However, chlorinated hydrocarbon was relatively difficult to degrade, especially TCP, which had a relatively higher initial concentration, only had a removal efficiency of 30%–45% at different aquifers and monitoring wells. These finding are important for the development of injection technology for chlorinated hydrocarbon and BTEX contaminated site remediation.

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Yue, Jun Jie, Xiao Qiao Zhu, Yu Ting Wang, Yu Qin Zhang, Li Zhao, and Zhao Hong Shi. "Oxidative Degradation and Kinetics of Trichloroethylene by Thermally Activated Persulfate." Applied Mechanics and Materials 675-677 (October 2014): 547–50. http://dx.doi.org/10.4028/www.scientific.net/amm.675-677.547.

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In situ chemical oxidation with persulfate (PS) anion (S2O82-) is a viable technique for remediation of groundwater contaminants such as trichloroethylene (TCE). This laboratory study investigated the use of the oxidant sodium PS for the chemical oxidation of TCE at different conditions to determine the influence of temperature, pH, and the PS/TCE molar ratio. Experiments revealed that higher temperatures, lower pH, and higher PS/TCE molar ratios were to the benefit of TCE oxidation by PS. By investigating the reaction kinetics, the degradations of contaminant can be described by use of pseudo-first-order reaction. At the temperatures ranging from 25°C to 40°C, the activation energy for the degradation of TCE was determined to be 85.04 KJ/mol.

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Li, Muzi, Yuanzheng Zhai, and Li Wan. "Measurement of NAPL–water interfacial areas and mass transfer rates in two-dimensional flow cell." Water Science and Technology 74, no. 9 (August 19, 2016): 2145–51. http://dx.doi.org/10.2166/wst.2016.397.

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The nonaqueous-phase liquid (NAPL)–water interfacial area and the mass transfer rate across the NAPL and water interface are often key factors in in situ groundwater pollution treatment. In this study, the NAPL–water interfacial area and residual NAPL saturation were measured using interfacial and partitioning tracer tests in a two-dimensional flow cell. The results were compared with previous column and field experiment results. In addition, the mass transfer rates at various NAPL–water interfacial areas were investigated. Fe2+-activated persulfate was used for in situ chemical oxidation remediation to remove NAPL gradually. The results showed that the reduction of NAPL–water interfacial areas as well as NAPL saturation by chemical oxidation caused a linear decrease in the interphase mass transfer rates (R2 = 0.97), revealing the relationship between mass transfer rates and interfacial areas in a two-dimensional system. The NAPL oxidation rates decreased with the reduction of interfacial areas, owing to the control of NAPL mass transfer into the aqueous phase.

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Yang, Zong-Han, Francis Verpoort, Cheng-Di Dong, Chiu-Wen Chen, Shaohua Chen, and Chih-Ming Kao. "Remediation of petroleum-hydrocarbon contaminated groundwater using optimized in situ chemical oxidation system: Batch and column studies." Process Safety and Environmental Protection 138 (June 2020): 18–26. http://dx.doi.org/10.1016/j.psep.2020.02.032.

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Zhang, Kegang, Xiaodong Wang, Xiaohui Zhang, and Shengjie Peng. "Degradation of Trichloroethylene in Groundwater Using Iron Catalyzed Calcium Peroxide Systems." E3S Web of Conferences 143 (2020): 02046. http://dx.doi.org/10.1051/e3sconf/202014302046.

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The application of calcium peroxide (CaO2) activated with ferrous ion chelate sodium citrate （TCD）to stimulate the degradation of trichloroethylene (TCE) was investigated. The experimental results show that the removal efficiency of TCE increases first and then decreases with the increase of CaO2 and Na2S2O8 dosage; the chelation ratio of Fe(II)/TCD, too much or too little, will affect the removal efficiency of TCE; when the molar ratio of CaO2/ Fe(II)/ TCD/ TCE is 18/6/6/1, the removal efficiency of TCE is the highest, reaching 97.99% within 200Min. The results demonstrated that the technique of CaO2 activated with ferrous ion is a highly promising technique in in situ chemical oxidation (ISCO) remediation in TCE contaminated sites.

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Sun, Meng, Yong Sheng Zhao, Jun Dong, and Li Li Dong. "Study on Degradation of Nitrobenzene in Groundwater by Fenton-Like Oxidation Based on Iron in Aquifer Materials." Advanced Materials Research 183-185 (January 2011): 516–21. http://dx.doi.org/10.4028/www.scientific.net/amr.183-185.516.

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Fenton and Fenton-like reactions are regarded as high efficient methods in advanced treatment of nitrobenzene wastewater but both restrained in degradation of nitrobenzene in groundwater because of the low pH condition( less than 4 ) requirement and other problems such as secondary pollution by the irons in contaminated sites. This paper reports a new Fenton-like technology combined irons extraction from aquifer materials which were found in a nitrobenzene contaminated site in China with hydrogen peroxide catalytic oxidation. The simulate experiments were conducted to investigate the oxidation of nitrobenzene in groundwater by this method under the condition of neutral pH and 8~10°C. The comparison of different extraction agent and production rule of hydroxyl radical were both studied in this research. The results indicated that extraction had hysteresis property because the highest extracting efficiency occurred after 36h. Extraction agent DCB has the highest efficiency, for Fe3+ was 62.92% and Fe2+ was 30.17%. The highest removal efficiency could reach 80.2% while the mole ratio of nitrobenzene to H2O2 was 1:200. Three stages could found in hydroxyl radical generation process, in the first stage hydroxyl radical generated rapidly in 0~30min, then decreased slowly between 30min and 120min, at last the generation tended to be steady after 120h. The results could possess a good potential for application in the treatment of nitrobenzene contaminated groundwater and provide theoretical basis on in-situ chemical remediation technology of nitrobenzene contaminated sites.

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Hrabák, Pavel, Martina Homolková, Stanisław Wacławek, and Miroslav Černík. "Chemical Degradation of PCDD/F in Contaminated Sediment." Ecological Chemistry and Engineering S 23, no. 3 (September 1, 2016): 473–82. http://dx.doi.org/10.1515/eces-2016-0034.

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Abstract Due to the extreme toxicity of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), the remediation of PCDD/F aquifer source zones is greatly needed; however, it is very difficult due to their persistence and recalcitrance. The potential degradability of PCDD/F bound to a real matrix was studied in five systems: iron in a high oxidation state (ferrate), zero-valent iron nanoparticles (nZVI), palladium nanopowder (Pd), a combination of nZVI and Pd, and persulfate (PSF). The results were expressed by comparing the total toxicity of treated and untreated samples. This was done by weighting the concentrations of congeners (determined using a standardized GC/HRMS technique) by their defined toxicity equivalent factors (TEF). The results indicated that only PSF was able to significantly degrade PCDD/F. Toxicity in the system decreased by 65% after PSF treatment. Thus, we conclude that PSF may be a potential solution for in-situ remediation of soil and groundwater at PCDD/F contaminated sites.

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Lester, Yaal, Asmaa Dabash, and Darine Eghbareya. "UV Sensitization of Nitrate and Sulfite: A Powerful Tool for Groundwater Remediation." Environments 5, no. 11 (October 31, 2018): 117. http://dx.doi.org/10.3390/environments5110117.

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Groundwater contamination by nitrate and organic chemicals (for example, 1,4-dioxane) is a growing worldwide concern. This work presents a new approach for simultaneously treating nitrate and 1,4-dioxane, which is based on the ultra-violet (UV) sensitization of nitrate and sulfite, and the production of reactive species. Specifically, water contaminated with nitrate and 1,4-dioxane is irradiated by a UV source (<250 nm) at relatively high doses, to sensitize in situ nitrate and generate OH•. This leads to the oxidation of 1,4-dioxane (and other organics) and the (undesired) production of nitrite as an intermediate. Subsequently, sulfite is added at an optimized time-point, and its UV sensitization produces hydrated electrons that react and reduces nitrite. Our results confirm the effectivity of the proposed treatment: UV irradiation of nitrate (at >5 mg N/L) efficiently degraded 1,4-dioxane, while producing nitrite at levels higher than its maximum contaminant level (MCL) of 1 mg N/L in drinking water. Adding sulfite to the process after 10 min of irradiation reduces the concentration of nitrite without affecting the degradation rate of 1,4-dioxane. The treated water contained elevated levels of sulfate; albeit at much lower concentration than its MCL. Treating water contaminated with nitrate and organic chemicals (often detected concomitantly) typically requires several expensive treatment processes. The proposed approach presents a cost-effective alternative, employing a single system for the treatment of nitrate and organic contaminants.

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Talvenmäki, Harri, Niina Lallukka, Suvi Survo, and Martin Romantschuk. "Fenton’s reaction-based chemical oxidation in suboptimal conditions can lead to mobilization of oil hydrocarbons but also contribute to the total removal of volatile compounds." Environmental Science and Pollution Research 26, no. 33 (October 26, 2019): 34670–84. http://dx.doi.org/10.1007/s11356-019-06547-3.

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Abstract Fenton’s reaction-based chemical oxidation is in principle a method that can be utilized for all organic fuel residues thus making it a potential all-purpose, multi-contaminant, in situ application for cases in which storage and distribution of different types of fuels have resulted in contamination of soil or groundwater. Since peroxide breakdown reactions are also expected to lead to a physical transport of the target compound, this secondary physical removal, or rebound concentrations related to it, is prone to be affected by the chemical properties of the target compound. Also, since soil conditions are seldom optimal for Fenton’s reaction, the balance between chemical oxidation and transport may vary. In this study, it was found that, with a high enough hydrogen peroxide concentration (5 M), methyl tert-butyl ether–spiked groundwater could be treated even under suboptimal conditions for chemical mineralization. In these cases, volatilization was not only contributing to the total removal but also leading to rebound effects similar to those associated with air sparging techniques. Likewise for diesel, temporal transport from soil to the aqueous phase was found to lead to false positives that outweighed the actual remediation effect through chemical mineralization.

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Fang, Shyang Chyuan, and Shang Lien Lo. "Persulfate Oxidation Activated by Peroxide with and without Iron for Remediation of Soil Contaminated by Heavy Fuel Oil: Laboratory and Pilot-Scale Demonstrations." Applied Mechanics and Materials 121-126 (October 2011): 2546–56. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.2546.

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The main objective of this study was to evaluate and optimize the chemical oxidation process to be implemented at a power plant in Penghu County, Taiwan through laboratory and pilot-scale experiments were used to evaluate and optimize the chemical oxidation process at a power plant in Penghu County, Taiwan. Prior to pilot test, bench-scale tests were performed in the laboratory and analytical results indicated that persulfate oxidation achieved 90% removal of fuel oil while Fenton-like oxidation achieved only 41% removal of fuel oil within three days of testing period. Persulfate oxidation coupled with Fenton-like reaction was then used in a pilot test to treat the contaminated soil onsite. The Fenton-like reaction served the first stage of oxidation which formed hydroxyl radicals to break down fuel oil. The excess heat and ferrous ions resulted from such oxidation process would then activate persulfate oxidation which, in turn, produced sulfate radicals for continual brake-down of fuel oil. Result of soil pilot test indicated that the concentration of fuel oil was reduced to below the regulated standard in less than a week. Because the treated soil was originated from the local basaltic basement rock, it is rich in heavy metals, by nature. As such, the heavy metals as nickel and chromium were detected in leachate collected from the treatment cells, at concentrations exceeding the Taiwan Contaminant Control Standard and would have posed secondary contamination to the ambient environment if in-situ soil persulfate oxidation was implemented. Therefore, the result of this case study provides an alert that implementation of in-situ persulfate oxidation for soil and groundwater treatment could pose a threat of secondary contamination of heavy metals to the ambient environment.

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KLIMKOVA, STEPANKA, MIROSLAV CERNIK, LENKA LACINOVA, and JAROSLAV NOSEK. "APPLICATION OF NANOSCALE ZERO-VALENT IRON FOR GROUNDWATER REMEDIATION: LABORATORY AND PILOT EXPERIMENTS." Nano 03, no. 04 (August 2008): 287–89. http://dx.doi.org/10.1142/s1793292008001118.

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It is known that the reductive effects of zero-valent iron ( Fe 0) and the sorptive capability of iron and its oxides can be used for both the dehalogenation of chlorinated hydrocarbons (CHC), especially of chlorinated ethenes (PCE → TCE → DCE → VC → ethene, ethane), and the removing of heavy metals from groundwater by turning them into a less-soluble form through changes of their oxidation state, or by adsorption. These consequences are being exploited in the construction of iron filling permeable reactive barriers for a longer time.1 The advantages of nanoscale zero-valent iron ( nanoFe 0) over the macroscopic one consist not only in the better reactivity implicit in their greater specific surface area but also in their mobility in rock environment.2,3 Numerous laboratory experiments, especially the batch-agitated experiments, with samples from seven various contaminated localities in Europe have been carried out with the aim to discover the measurement of the reductive effect of the nanoFe 0 on selected contaminants. It was found that the nanoFe 0 can be reliably usable as a reductive reactant for in-situ chemical decontamination of sites polluted by chlorinated ethenes (CEs), or hexa-valent chromium ( Cr VI ). The rate of reductive reaction and the optimal concentrations for the real remediation action were determined. On the basis of these laboratory experiments, the methods for pilot application of nanoFe 0 have been specified. Subsequently the pilot experiments were accomplished in surveyed localities.

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Park, Saerom, Linda S. Lee, Victor F. Medina, Aaron Zull, and Scott Waisner. "Heat-activated persulfate oxidation of PFOA, 6:2 fluorotelomer sulfonate, and PFOS under conditions suitable for in-situ groundwater remediation." Chemosphere 145 (February 2016): 376–83. http://dx.doi.org/10.1016/j.chemosphere.2015.11.097.

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Topudurti, Kirankumar, Michael Keefe, Patrick Wooliever, and Norma Lewis. "Field evaluation of perox-pure™ chemical oxidation technology." Water Science and Technology 30, no. 7 (October 1, 1994): 95–104. http://dx.doi.org/10.2166/wst.1994.0317.

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This paper presents the field evaluation results for an advanced chemical oxidation technology developed by Peroxidation Systems, Inc., of Tucson, Arizona. The technology, known as the perox-pure™ technology, was evaluated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation program at Lawrence Livermore National Laboratory (LLNL), Site 300 in Tracy, California, in September 1992. The perox-pure™ technology uses ultraviolet radiation and hydrogen peroxide to oxidize dissolved organic compounds in water. At the LLNL site, this technology was evaluated in treating groundwater contaminated with volatile organic compounds (VOC) including trichloroethene (TCE); tetrachloroethene (PCE); 1,1,1-trichloroethane (TCA); 1,1-dichloroethane (DCA); and chloroform. The perox-pure™ system generally produced an effluent that contained TCE, PCE, and DCA at levels below detection limits, and TCA and chloroform at levels slightly above detection limits. The system achieved maximum removal efficiencies of greater than 99.9, 98.7, and 95.8 percent for TCE, PCE, and DCA, respectively. The system also achieved removal efficiencies of up to 92.9 and 93.6 percent for TCA and chloroform, respectively. The treatment system effluent met California drinking water action levels and federal drinking water maximum contaminant levels for all VOCs at the 95 percent confidence level. Cost analysis indicated that the groundwater remediation cost for a 50-gallon per minute perox-pure™ system would range from $7 to $11 per 1,000 gallons, depending on contaminated groundwater characteristics. Of this total cost, the perox-pure™ system direct treatment cost would range from $3 to $5 per 1,000 gallons.

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Checa-Fernandez, Alicia, Aurora Santos, Arturo Romero, and Carmen M. Dominguez. "Application of Chelating Agents to Enhance Fenton Process in Soil Remediation: A Review." Catalysts 11, no. 6 (June 10, 2021): 722. http://dx.doi.org/10.3390/catal11060722.

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Persistent organic contaminants affecting soil and groundwater pose a significant threat to ecosystems and human health. Fenton oxidation is an efficient treatment for removing these pollutants in the aqueous phase at acidic pH. However, the in-situ application of this technology for soil remediation (where pHs around neutrality are required) presents important limitations, such as catalyst (iron) availability and oxidant (H2O2) stability. The addition of chelating agents (CAs), forming complexes with Fe and enabling Fenton reactions under these conditions, so-called chelate-modified Fenton process (MF), tries to overcome the challenges identified in conventional Fenton. Despite the growing interest in this technology, there is not yet a critical review compiling the information needed for its real application. The advantages and drawbacks of MF must be clarified, and the recent achievements should be shared with the scientific community. This review provides a general overview of the application of CAs to enhance the Fenton process for the remediation of soils polluted with the most common organic contaminants, especially for a deep understanding of the activation mechanisms and influential factors. The existing shortcomings and research needs have been highlighted. Finally, future research perspectives on the use of CAs in MF and recommendations have been provided.

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Zhang, Sai, Xuebin Hu, Li Li, Xiaoliu Huangfu, Yingzhi Xu, and Yuhang Qin. "Activation of sodium percarbonate with ferrous ions for degradation of chlorobenzene in aqueous solution: mechanism, pathway and comparison with hydrogen peroxide." Environmental Chemistry 14, no. 8 (2017): 486. http://dx.doi.org/10.1071/en17137.

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Environmental contextIt is practicable to remediate chlorobenzene-contaminated groundwater by in situ chemical oxidation. This study shows highly efficient degradation of chlorobenzene by an Fe-based process in a wide range of pH values. The technology is feasible for the removal of chlorobenzene from aqueous solutions and is appropriate for remediation of groundwater. AbstractSodium percarbonate (SPC) could be applied as a strong oxidant to degrade organic compounds activated by transition metals. In this study, the degradation performance of chlorobenzene (CB) in the Fe2+-catalysed SPC system was investigated at different Fe2+ and SPC concentrations and pH conditions. Fe2+/Fe3+ conversion was also studied, and the SPC system was compared with the H2O2 and H2O2/Na2CO3 systems. Free radicals were identified through scavenging tests and electron paramagnetic resonance (EPR) experiments, and the reaction intermediates and by-products were determined as well. The results show that CB was completely removed when the molar concentration ratio of Fe2+/SPC/CB was 8 : 8 : 1 and that the decomposition of CB increased as the initial Fe2+/SPC dosage increased. The optimal molar concentration of Fe2+/SPC/CB was 2 : 1 : 1, and the degradation rate was inhibited when increasing or decreasing Fe2+ or SPC. CB degradation was not significantly affected by variation of initial pH, and the variation of pH during the degradation process corresponded well with the degree of Fe2+ to Fe3+ conversion and the formation of •OH. It was confirmed that •OH, O2•− and 1O2 participate in the degradation process. Moreover, not all the •OH takes part in the degradation process, as some transforms into O2•− and 1O2. The same degradation efficiency was obtained when replacing SPC by equal stoichiometric amounts of H2O2, compared with inhibition with the addition of Na2CO3. Further, a likely degradation pathway for CB is proposed based on the identified products. These results show that the Fe2+/SPC system can form the basis of a promising technology for the remediation of CB-contaminated groundwater.

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Tumolo, Marina, Valeria Ancona, Domenico De Paola, Daniela Losacco, Claudia Campanale, Carmine Massarelli, and Vito Felice Uricchio. "Chromium Pollution in European Water, Sources, Health Risk, and Remediation Strategies: An Overview." International Journal of Environmental Research and Public Health 17, no. 15 (July 28, 2020): 5438. http://dx.doi.org/10.3390/ijerph17155438.

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Chromium is a potentially toxic metal occurring in water and groundwater as a result of natural and anthropogenic sources. Microbial interaction with mafic and ultramafic rocks together with geogenic processes release Cr (VI) in natural environment by chromite oxidation. Moreover, Cr (VI) pollution is largely related to several Cr (VI) industrial applications in the field of energy production, manufacturing of metals and chemicals, and subsequent waste and wastewater management. Chromium discharge in European Union (EU) waters is subjected to nationwide recommendations, which vary depending on the type of industry and receiving water body. Once in water, chromium mainly occurs in two oxidation states Cr (III) and Cr (VI) and related ion forms depending on pH values, redox potential, and presence of natural reducing agents. Public concerns with chromium are primarily related to hexavalent compounds owing to their toxic effects on humans, animals, plants, and microorganisms. Risks for human health range from skin irritation to DNA damages and cancer development, depending on dose, exposure level, and duration. Remediation strategies commonly used for Cr (VI) removal include physico-chemical and biological methods. This work critically presents their advantages and disadvantages, suggesting a site-specific and accurate evaluation for choosing the best available recovering technology.

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Lien, Po Jen, Hsiao Jung Ho, Tzu Hsin Lee, Wen Liang Lai, and Chih Ming Kao. "Effects of Aquifer Heterogeneity and Geochemical Variation on Petroleum-Hydrocarbon Biodegradation at a Gasoline Spill Site." Advanced Materials Research 1079-1080 (December 2014): 584–88. http://dx.doi.org/10.4028/www.scientific.net/amr.1079-1080.584.

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In subsurface environment, small-scale heterogeneities usually cause the reduction of the applicability of in situ remedial techniques. Biogeochemical heterogeneities and preferential groundwater flow paths create complex hydrogeologic conditions at most contaminated sites. A thorough understanding of the resulting three-dimensional distribution of contaminants is a necessity prior to determining a need for remediation. In this study, a gasoline spill site was selected to examine the effects of aquifer heterogeneities and geochemical variations on petroleum hydrocarbon biodegradation via different oxidation-reduction process. At this site, two multilevel sampling wells were installed to delineate the lateral (5 m) and vertical (0.5 m) distribution of contaminant concentrations and different biogeochemical parameters. Two 5-cm (I.D.) continuous soil cores [from 4 to 8 m below land surface (bls)] were collected within the gasoline plume to evaluate the distribution of the microbial population in soils. Results show that high microbial activities were observed in soil samples based on the following evidences: (1) high petroleum hydrocarbon degradation rate, and (2) high microbial biomass. Each soil section was used for chemical extraction, microbial enumeration, and grain size distribution. Results show that the soil sections with more permeable sediment materials corresponded with higher biomass (total anaerobes > 2 x 106cells/g) and significant contaminant degradation. However, those sections with less permeable sediments contained lower microbial population. Results indicate that the subsurface microorganisms were distributed unevenly in the aquifer, and some regions were devoid of microorganisms and biodegradation activities. Spatial distribution of microorganisms, soil materials, and biogeochemical characteristics in the subsurface soils control the extent and kinetics of contaminant biodegradation. Thus, using blended aquifer materials for measurement of in situ biodegradation rates may not achieve representative results.

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Doong, R. A., and S. C. Wu. "The Effect of Oxidation-Reduction Potential on the Biotransformations of Chlorinated Hydrocarbons." Water Science and Technology 26, no. 1-2 (July 1, 1992): 159–68. http://dx.doi.org/10.2166/wst.1992.0396.

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Two batch experiments with acetate as the primary substrate and different combinations of chlorinated hydrocarbons as the secondary substrate were carried out to evaluate the effect of the redox potential of the environment on the biotransformations of chlorinated hydrocarbons. In both single and mixed contaminant(s) systems, biotransformations of 100 µg/L of tetrachloroethylene (PCE) and carbon tetrachloride (CT) were observed, but that of 1,1,1-trichloroethane(1,1,1-TCA) was not observed within 108 days. Chlorinated hydrocarbons acted as electron traps and scavenged the electrons when they underwent reductive dechlorination. Adequate activity of free available electrons is necessary for chlorinated hydrocarbons to undergo reductive dechlorination. The environment with low redox potential has relatively strong electron activity and therefore facilitates the biotransformation of the chlorinated hydrocarbons more readily. Disappearance of 17 to 62 % and 22 to 99.9 % of the original concentration of PCE and CT were observed when the redox potentials of the microcosms were ranged from 225 to -263 mV and 188 to -263 mV, respectively. The viable count of microorganisms determined by the epifluorescence technique showed that higher concentration of primary substrate produced more biomass than lower concentration of primary substrate did, but the DNA content of the microbes was not a good biochemical indicator for the biotransformability of the chlorinated hydrocarbons. It is concluded that oxidation-reduction potential is the major factor controlling the biotransformation efficiencies of chlorinated hydrocarbons. In the case of in-situ biorestoration, proper control of redox potential of the environment will give a good result of remediation of the groundwater contaminated with chlorinated hydrocarbons.

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Ji, Yuefei, Lu Wang, Mengdi Jiang, Junhe Lu, Corinne Ferronato, and Jean-Marc Chovelon. "The role of nitrite in sulfate radical-based degradation of phenolic compounds: An unexpected nitration process relevant to groundwater remediation by in-situ chemical oxidation (ISCO)." Water Research 123 (October 2017): 249–57. http://dx.doi.org/10.1016/j.watres.2017.06.081.

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Yang, Mingxing, Zhendong Cao, Yue Zhang, and Honghan Wu. "Deciphering the biodegradation of petroleum hydrocarbons using FTIR spectroscopy: application to a contaminated site." Water Science and Technology 80, no. 7 (October 1, 2019): 1315–25. http://dx.doi.org/10.2166/wst.2019.375.

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Abstract The chemical composition of groundwater in a petroleum-contaminated site is determined by the present functional groups and these play a vital role in a feasibility remediation technique. Based on the in situ investigation of a contaminated shallow groundwater in an oilfield, Fourier transform infrared (FTIR) spectroscopy associated with chemometric treatments, principal component analysis (PCA), and simple-to-use interactive self-modeling mixture analysis (SIMPLISMA), were used to decipher the biodegradation process by analyzing the conversion of functional groups. Environmental factors that can influence microbial metabolism were also evaluated for a comprehensive explanation. FTIR spectroscopy and PCA results showed that the contamination in the study area can be divided into three parts based on FTIR spectra: (1) regular contamination plume distribution and biodegradation level to fresh oil, (2) moderate biodegradation area, and (3) intensive biodegradation area. FTIR spectra further revealed the present functional groups as aliphatic, aromatic, and polar family compounds. SIMPLISMA was used to discuss the degree of biodegradation along the flow path quantitatively and qualitatively and elucidated that the aliphatic and aromatic compounds were mainly metabolized into polar compounds with nitrogen, sulfur, and oxygen via microbes. During metabolism, microbial indices, such as the Shannon–Weaver, Simpson, and Pielou indices, indicated that microbial diversity did not greatly change; hence, hydrocarbons were constantly consumed to feed dominant microbes. Dissolved oxygen concentrations decreased from 4.58 ± 0.31 mg/L (in monitoring well Z1) to 3.21 ± 0.26 mg/L (in monitoring well Z16) and then became constant in the down-gradient area, demonstrating that aerobic biodegradation was the dominant process at the up-gradient plume. Results were in accordance with the oxidation index, which continuously increased from 0.028 ± 0.013 (in monitoring well Z1) to 0.669 ± 0.047 (in monitoring well Z10), showing that oxygen was consumed along the flow path. Similarly, concentration changes in Fe2+, Mn2+, and SO42− proved that the down-gradient area was in reduction condition.

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Dietmann, Karen Maria, Tobias Linke, Miguel del Nogal Sánchez, José Luis Pérez Pavón, and Vicente Rives. "Layered Double Hydroxides with Intercalated Permanganate and Peroxydisulphate Anions for Oxidative Removal of Chlorinated Organic Solvents Contaminated Water." Minerals 10, no. 5 (May 20, 2020): 462. http://dx.doi.org/10.3390/min10050462.

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The contamination by chlorinated organic solvents is a worldwide problem as they can deeply penetrate aquifers, accumulating in the sub-surface as lenses of highly hazardous pollutants. In recent years, so called in situ oxidation processes have been developed to remediate chlorinated organic solvents from groundwater and soil by injecting solutions of oxidising agents such as permanganate or peroxydisulphate. We here present modified layered double hydroxides (LDHs) with intercalated oxidising agents that might serve as new reactants for these remediation strategies. LDHs might serve as support and stabiliser materials for selected oxidising agents during injection, as the uncontrolled reaction and consumption might be inhibited, and guarantee that the selected oxidants persist in the subsurface after injection. In this study, LDHs with hydrotalcite- and hydrocalumite-like structures intercalated with permanganate and peroxydisulphate anions were synthesised and their efficiency was tested in batch experiments using trichloroethene or 1,1,2-trichloroethane as the target contaminants. All samples were characterised using powder X-ray diffraction, thermal analysis coupled with mass spectrometry to directly analyse evolving gases, and Fourier-transform infrared spectroscopy. Additionally, particle size distribution measurements were carried out on the synthesised materials. Results of the batch experiments confirmed the hypothesis that oxidising agents keep their properties after intercalation. Permanganate intercalated LDHs proved to be most efficient at degrading trichloroethene while peroxydisulphate intercalated Ca,Al-LDHs were the most promising studied reactants degrading 1,1,2-trichloroethane. The detection of dichloroethene as well as the transformation of the studied reactants into new LDH phases confirmed the successful degradation of the target contaminant by oxidation processes generated from the intercalated oxidising agent.

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Danzer, Jörg, and Mike Herbert. "Using surfactants for in-situ groundwater remediation." altlastenforum Baden-Württemberg e.V., Schriftenreihe 3 (August 16, 2000): 1–20. http://dx.doi.org/10.1127/altlastenforum/3/2000/1.

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Bryda, Lisa K., and Peter E. Morris. "Emerging technologies for in-situ groundwater remediation." Remediation Journal 7, no. 3 (June 1997): 109–25. http://dx.doi.org/10.1002/rem.3440070309.

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Smith, Gregory J., and Yi Wang. "Groundwater geochemistry diagnostics during in situ ERH remediation." Remediation Journal 21, no. 1 (December 2010): 97–114. http://dx.doi.org/10.1002/rem.20274.

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Boudreaux, Erin. "NASA uses new oxidation technology for groundwater remediation." Journal - American Water Works Association 100, no. 11 (November 2008): 48–49. http://dx.doi.org/10.1002/j.1551-8833.2008.tb09768.x.

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da Silva, Marcio Luis Busi, Marcos Felipe Wendt, José Carlos Silveira de Oliveira, and Marcio Roberto Schneider. "In situ source zone sediment mixing coupled to groundwater biostimulation to enhance phenol natural attenuation." Water Science and Technology 66, no. 1 (July 1, 2012): 130–37. http://dx.doi.org/10.2166/wst.2012.149.

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Phenol is an industrially key compound that has a wide range of applications and also one of the most commonly found toxic pollutants in wastewaters and groundwater. This paper demonstrates the applicability of in situ remediation at a deactivated industrial site using source zone excavation and sediment mixing associated with nutrients delivery into groundwater. Sediment excavation and mixing displaced the entrapped source zone enhancing mass transfer into groundwater and contaminant bioavailability. A nutrient solution prepared with nitrate, phosphate, sodium hydroxide and hydrogen peroxide was continuously delivered into groundwater to stimulate biodegradation and restrict plume migration. The observed correlation between phenol-dependent Enterobacteriaceae concentrations throughout the remediation time frame supported circumstantial evidence of biodegradation. Phenol concentration in groundwater (up to 1,300 mg/L) was reduced >99% after 5 months following remediation and remained under the established site specific target level (4 mg/L). Nitrate and phosphate concentrations returned to background concentrations levels at the end of the remediation. Overall, the proposed in situ remediation scheme was effective to remediate this particular aquifer contaminated with phenol for over 20 years.

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Mategaonkar, Meenal, T. I. Eldho, and Sahajanand Kamat. "In-situ bioremediation of groundwater using a meshfree model and particle swarm optimization." Journal of Hydroinformatics 20, no. 4 (February 9, 2018): 886–97. http://dx.doi.org/10.2166/hydro.2018.110.

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Abstract Groundwater contamination due to contaminants like trichloroethylene (TCE), tetrachloroethylene, dichloroethylene, phenol, etc., is an alarming concern for most of the manufacturing areas. It is important to identify the type of pollutant, concentration, location, and direction of the contaminant plume for groundwater remediation. Bioremediation has been identified as one of the important remediation techniques for these types of contaminants. Bioremediation modeling comprises solutions to biodegradation equations and fixing the time of remediation and locating the oxygen injection wells. In this study, a simulation-optimization (S/O) model based on the coupled meshfree point collocation method (MFree-PCM) and particle swarm optimization (PSO) is proposed for in-situ bioremediation design. The in-situ bioremediation process of groundwater contamination is explored using the developed PCM-BIO-PSO multi-objective model with different strategies of minimization of cost, number of wells and time of remediation. The proposed model can be effectively used for the in-situ bioremediation design of contaminated sites.

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Gavrilescu, Maria. "OVERVIEW OF IN SITU REMEDIATION TECHNOLOGIES FOR SITES AND GROUNDWATER." Environmental Engineering and Management Journal 5, no. 1 (2006): 79–114. http://dx.doi.org/10.30638/eemj.2006.009.

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Kasi, Murthy, John McEvoy, G. Padmanabhan, and Eakalak Khan. "In situ Groundwater Remediation Using Enricher Reactor – Permeable Reactive Biobarrier." Proceedings of the Water Environment Federation 2010, no. 18 (January 1, 2010): 300–317. http://dx.doi.org/10.2175/193864710798130643.

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Younger, Paul L. "Groundwater and Subsurface Remediation: Research Strategies for In-situ Technologies." Journal of Hydrology 192, no. 1-4 (May 1997): 383–86. http://dx.doi.org/10.1016/s0022-1694(96)03315-x.

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Clark, Lewis. "Groundwater and subsurface remediation: Research strategies for In-situ technologies." Environmental Pollution 94, no. 1 (1996): 101–2. http://dx.doi.org/10.1016/s0269-7491(97)88955-5.

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Zhao, Bei, Zhanxue Sun, and Yajie Liu. "An overview of in-situ remediation for nitrate in groundwater." Science of The Total Environment 804 (January 2022): 149981. http://dx.doi.org/10.1016/j.scitotenv.2021.149981.

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Peng, Shengjie, Xiaodong Wang, and Xiaohui Zhang. "Research progress of in-situ remediation of polluted soil and groundwater by electrokinetic and permeable reaction barrier." E3S Web of Conferences 143 (2020): 02043. http://dx.doi.org/10.1051/e3sconf/202014302043.

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The combination of electrokinetic remediation and permeable reactive barrier (EK-PRB combined remediation technology) is a new green technology for in-situ removal of soil and groundwater pollutants. This technology combines the advantages of electrokinetic remediation and permeable reactive barrier technology, and can deal with different types of organic and inorganic pollutants. It has the characteristics of convenient installation, simple operation, no secondary pollution, etc., and has broad development and application prospect. This paper introduces the technical principle of EK-PRB, summarizes the latest research results on the remediation of heavy metal, organic matter and nitrate contaminated soil and groundwater by the electrokinetic remediation and PRB. Finally,the technical problems of combinated remediation were pointed out, and development and application direction of this technology was noted.

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Shiba, S., S. Hino, Y. Hirata, and T. Seno. "Removal of heavy metal from soil and groundwater by in-situ electrokinetic remediation." Water Science and Technology 42, no. 7-8 (October 1, 2000): 335–43. http://dx.doi.org/10.2166/wst.2000.0586.

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The operational variables of electrokinetic remediation have not been cleared yet, because this method is relatively new and is an innovative technique in the aquifer remediation. In order to investigate the operational variables of the electrokinetic remediation, a mathematical model has been constructed based on the physico chemical mass transport process of heavy metals in pore water of contaminated aquifer. The transport of the heavy metals is driven not only by the hydraulic flow due to the injection of the purge water but also by the electromigration due to the application of the electric potential gradient. The electric potential between anode and cathode is the important operational variable for the electrokinetic remediation. From the numerical simulations with use of this model it is confirmed that the remediation starts from the up stream anode and gradually the heavy metal is transported to the down stream cathode and drawn out through the purge water.

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He, Qianfeng, Shihui Si, Jun Yang, and Xiaoyu Tu. "Application of permeable reactive barrier in groundwater remediation." E3S Web of Conferences 136 (2019): 06021. http://dx.doi.org/10.1051/e3sconf/201913606021.

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As a new in-situ remediation of groundwater, compared with the traditional “pump and treat” technology, the permeable reactive barrier (PRB) has the advantages of low cost, no external power, the small disturbance to groundwater, small secondary pollution and long-term operation, this paper introduces the basic concept of PRB, technical principle, structure type, the principle of active materials selection and mechanisms of remediation, design and installation factors, it provides ideas for further research and application of PRB technology in groundwater remediation projects in China.

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Journal articles on the topic 'Groundwater In situ remediation. Oxidation'

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