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C M Kao - One of the best experts on this subject based on the ideXlab platform.
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treatment of petroleum hydrocarbon polluted groundwater with innovative in situ sulfate releasing Biobarrier
Journal of Cleaner Production, 2021Co-Authors: K F Hsia, C C Chen, Y T Sheu, C M KaoAbstract:Abstract Petroleum hydrocarbons are commonly found pollutants in groundwater at industrial and gas station sites. Enhanced bioremediation is a cost-effective approach to cleanup petroleum hydrocarbon-polluted groundwater. The applicability of using sulfate-reducing Biobarrier on the containment and control of petroleum-hydrocarbon plumes were assessed by batch and column studies. The innovative in situ Biobarrier contained sulfate-releasing materials (SRMs) for a long-term sulfate release to enhance anaerobic petroleum hydrocarbons biodegradation with sulfate reduction mechanisms. SRMs were developed by blending rice husk powder (or starch) (used as permeability increment materials), magnesium sulfate (used as a source of sulfate), and polylactic acid (PLA) (used as a binder) together using a kneader. The mixed components were smelted to form pasty liquid at 190 °C, and it was transferred to a cylinder container to form SRMs. A column study was used to investigate the effectiveness of developed SRMs on the treatment of a methyl tert-butyl ether (MTBE) and toluene contaminated groundwater. The optimal sulfate release rate was achieved when the mass ratio of sulfate/starch/PLA was 0.5/0.5/2 [sulfate release rate (mg.d−1.g−1) = −0.009 × release period (d) + 3.4 (mg). Approximately 70% of MTBE and 92% of toluene could be remediated via sulfate reduction processes because the released sulfate from SRMs were served as electron acceptors, which promoted the growth of sulfate reducers. The next generation sequencing data suggest that bacterial strains with sulfate reduction and petroleum hydrocarbon biodegradation functions were detected after SRM supplement. Evidences of sulfate reduction of toluene and MTBE included (1) increased concentrations of sulfate and sulfide, (2) decreased concentrations of toluene and MTBE, (3) production of tert-butyl alcohol (degradation byproduct of MTBE), and (4) increased sulfate-reducing and petroleum-hydrocarbon bacteria. The Biobarrier system containing the SRMs can be developed into a pragmatic technology for in situ remediation of petroleum-hydrocarbon plumes.
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emulsified polycolloid substrate Biobarrier for benzene and petroleum hydrocarbon plume containment and migration control a field scale study
Science of The Total Environment, 2019Co-Authors: T H Lee, Daniel C W Tsang, Yihterng Sheu, Wenzhi Cao, K F Shia, C M KaoAbstract:Abstract The objective of this field-scale study was to assess the effectiveness of applying an emulsified polycolloid substrate (EPS; containing cane molasses, soybean oil, and surfactants) Biobarrier in the control and remediation of a petroleum-hydrocarbon plume in natural waters. An abandoned petrochemical manufacturing facility site was contaminated by benzene and other petroleum products due to a leakage from a storage tank. Because benzene is a petroleum hydrocarbon with a high migration ability, it was used as the target compound in the field-scale study. Batch partition and sorption experiment results indicated that the EPS to water partition coefficient for benzene was 232 mg/mg at 25 °C. This suggests that benzene had a higher sorption affinity to EPS, which decreased the benzene concentrations in groundwater. The EPS solution was pressure-injected into three remediation wells (RWs; 150 L EPS in 800 L groundwater). Groundwater samples were collected from an upgradient background well, two downgradient monitor wells (MWs), and the three RWs for analyses. EPS injection increased total organic carbon (TOC) concentrations (up to 786 mg/L) in groundwater, which also resulted in the formation of anaerobic conditions. An abrupt drop in benzene concentration (from 6.9 to below 0.04 mg/L) was observed after EPS supplementation in the RWs due to both sorption and biodegradation mechanisms. Results show that the EPS supplement increased total viable bacteria and enhanced bioremediation efficiency, which accounted for the observed decrease in benzene concentration. The first-order decay rate in RW1 increased from 0.003 to 0.023 d−1 after EPS application. Injection of EPS resulted in significant growth of indigenous bacteria, and 23 petroleum-hydrocarbon-degrading bacterial species were detected, which enhanced the in situ benzene biodegradation efficiency. Results demonstrate that the EPS Biobarrier can effectively contain a petroleum-hydrocarbon plume and prevent its migration to downgradient areas, which reduces the immediate risk presented to downgradient receptors.
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application of an emulsified polycolloid substrate Biobarrier to remediate petroleum hydrocarbon contaminated groundwater
Chemosphere, 2019Co-Authors: T H Lee, Daniel C W Tsang, Weihsiang Chen, Francis Verpoort, Yihterng Sheu, C M KaoAbstract:Abstract Emulsified polycolloid substrate (EPS) was developed and applied in situ to form a Biobarrier for the containment and enhanced bioremediation of a petroleum-hydrocarbon plume. EPS had a negative zeta potential (−35.7 mv), which promoted its even distribution after injection. Batch and column experiments were performed to evaluate the effectiveness of EPS on toluene containment and biodegradation. The EPS-to-water partition coefficient for toluene (target compound) was 943. Thus, toluene had a significant sorption affinity to EPS, which caused reduced toluene concentration in water phase in the EPS/water system. Groundwater containing toluene (18 mg/L) was pumped into the three-column system at a flow rate of 0.28 mL/min, while EPS was injected into the second column to form a Biobarrier. A significant reduction of toluene concentration to 0.1 mg/L was observed immediately after EPS injection. This indicates that EPS could effectively contain toluene plume and prevent its further migration to farther downgradient zone. Approximately 99% of toluene was removed after 296 PVs of operation via sorption, natural attenuation, and EPS-enhanced biodegradation. Increase in total organic carbon and bacteria were also observed after EPS supplement. Supplement of EPS resulted in a growth of petroleum-hydrocarbon degrading bacteria, which enhanced the toluene biodegradation.
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control of trichloroethylene plume migration using a Biobarrier system a field scale study
Water Science and Technology, 2014Co-Authors: Y. C. Kuo, S. Y. Wang, Shaohua Chen, Yumin Chang, C M KaoAbstract:The objective of this field-scale study was to evaluate the effectiveness of controlling trichloroethylene (TCE) plume migration using the polycolloid substrate (PS) Biobarrier. The developed PS (containing soybean oil, lactate and surfactants) could release substrate to enhance the TCE dechlorination. In this study, a Biobarrier comprising PS injection wells was installed. Injection wells were installed at 5-m intervals, and approximately 15 L of PS was injected into each well. Results show that TCE concentrations in the injection wells dropped from an average of 87 μg/L to below 1 μg/L after 35 days of PS injection. The total organic carbon concentrations in the injection wells increased from an average of 2.1–543 mg/L after 30 days of PS injection. The dissolved oxygen (DO) concentrations and oxidation-reduction potential (ORP) values dropped from an average of 1.6 mg/L to below 0.1 mg/L and from 124 mv to −14 mv after 20 days of injection, respectively. The DO and ORP remained in anaerobic conditions during the remaining 100 days of the operational period. TCE degradation by-products were observed in groundwater samples during the operational period. This reveals that the addition of PS could effectively enhance the reductive dechlorinating of TCE.
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enhanced pce dechlorination by Biobarrier systems under different redox conditions
Water Research, 2003Co-Authors: C M Kao, Yalei Chen, Ssuching Chen, T Y YehAbstract:Abstract The industrial solvent tetrachloroethylene (PCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to evaluate the (1) feasibility of enhancing PCE biodegradation using cane molasses and sludge cakes as the primary substrates under methanogenic and iron reducing conditions, and (2) potential of installation a sludge cake/cane molasses Biobarrier to clean up PCE-contaminated aquifers. The biodegradability of sludge cake (from secondary wastewater treatment system) and cane molasses was tested using bioavailability experiments. Results show that biodegradable materials were released from sludge cake/cane molasses and utilized by microbial consortia. Based on the chemical oxygen demand (COD) tests, approximately 28 and 248 mg of biodegradable COD can be released from 1 g of sludge cake and 1 g of cane molasses under anaerobic conditions, which have the potential to convert 70 and 620 mg of PCE to ethylene (ETH), respectively. Reductive dechlorination was evaluated using microcosms containing primary substrates (sludge cake/cane molasses) and inocula (aquifer sediments). Results indicate that sludge cake and cane molasses can serve as the diffusion sources of primary substrates, and enhance the reductive dechlorination of PCE under methanogenic processes. However, results from this study were not sufficient enough to show that reductive dechlorination of PCE would occur under iron-reducing conditions. This indicates that more studies need to be performed to further evaluate the role of iron reduction on the PCE dechlorination. Results reveal that it is feasible and applicable to install a sludge cake or cane molasses Biobarrier to clean up PCE contaminated aquifers. From an engineering point of view, the sludge cake/cane molasses Biobarrier has the potential to become an environmentally and economically acceptable technology for PCE bioremediation.
Hristo V. Kojouharov - One of the best experts on this subject based on the ideXlab platform.
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POROUS MEDIA FOR DIFFERENT KINETICS
2014Co-Authors: Benito M. Chen-charpentier, Hristo V. Kojouharov, Dobromir T. DimitrovAbstract:Abstract. There are bacteria that can form strong biofilms in porous media. These biofilms can be used as Biobarriers to restrict the flow of pollutants. For certain contaminants, a second species of bacteria that can actually react with the contaminants can be added to the Biobarrier to actually degrade the pollutants. We propose some mathematical models for the formation of these reacting Biobarriers under different hypotheses, and numerically solve the resulting equations for the flow, transport and reactions. Qualitative comparisons with some experimental results are also given. 1
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References
2013Co-Authors: Benito M. Kojouharov, B. M. Chen, Hristo V. KojouharovAbstract:Numerical simulation of dual-species biofilms in porous media. (English summary) Applied and computational mathematics (Córdoba, 2002). Appl. Numer. Math. 47 (2003), no. 3-4, 377–389. Summary: “There are bacteria that can form strong biofilms in porous media. The biofilms can be used as Biobarriers to restrict the flow of pollutants. If a second species of bacteria that can actually react with the contaminants is added to the Biobarrier, the result is a much more effective way of controlling the pollutants. We propose a mathematical model for the formation of these Biobarriers and numerically solve the resulting equations for the flow, transport and reactions. Qualitative comparisons with some experimental results are also given.
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Modeling Of Subsurface Biobarrier Formation
2007Co-Authors: Benito Chen-charpentier And, Benito M. Chen-charpentier, Hristo V. KojouharovAbstract:Key words: Biobarriers, models, biofilms, simulations Copyright 2001 Kansas State University In this article, we use new methods that are reliable, accurate, and efficient for the model describing subsurface Biobarrier formation (Kojouharov and Chen, 1999). Without these methods, results of numerical simulations are of unstable nature. We compare the results obtained from using our numerical simulator with some of the experimental results for short cores presented in Cunningham et al. (1991). The results compare well, which is a good validation of the model. The simulator can now be used as a predictive tool to determine values of parameters that are difficult or impossible to measure, and to help design experiments, field studies, and actual Biobarriers. The outline of the paper is as follows. In the next section, the governing system of differential equations is formulated for a three-phase, four-species mixture. In Section 3, the non-standard numerical method for solving the reactive solute transport problem in porous media is given. To demonstrate the performance of the proposed method of solution for the model and the effectiveness of Biobarriers for reducing the hydraulic conductivity, numerical results and comparisons with experiments are presented in Section 4. In the last section, a summary of results is presented
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Numerical simulation of biofilm-forming bacteria and other microbes in porous media
Computational Methods in Water Resources Proceedings of the XIVth International Conference on Computational Methods in Water Resources (CMWR XIV), 2002Co-Authors: Benito M. Chen-charpentier, Hristo V. KojouharovAbstract:Biobarriers created by biofilm-forming bacteria are a new technology being used to control pollution in porous media. Nutrients are fed to the bacteria so it will grow and plug the porous medium forming a barrier to the pollutant. There are other microbes that will actually destroy some pollutants. Here we propose a model and numerically solve the equations modeling the interaction of biofilm-forming bacteria and some of these microbes in porous media. Also, some numerical results are presented.
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modeling of subsurface Biobarrier formation
Journal of Hazardous Substance Research, 2001Co-Authors: Benito M Chencharpentier, Hristo V. KojouharovAbstract:Biofilm-forming microbes can form Biobarriers to inhibit contaminant migration in groundwater. Also subsurface biofilms have the potential for biotransformation of organic contaminants to less harmful forms, thereby providing an in situ method for treatment of contaminated groundwater supplies. We present a mathematical and numerical model to describe the population distribution and growth of bacteria in porous media. The model is based on the convection-dispersion equation with nonlinear reaction terms. Accurate numerical simulations are crucial to the development of contaminant remediation strategies. We use the nonstandard numerical approach that is based on nonlocal treatment of nonlinear reactions and modified characteristic derivatives. It leads to significant, qualitative improvements in the behavior of the numerical solution. Numerical results for a simple Biobarrier formation model are presented to demonstrate the performance of the proposed new method. We show comparisons with experimental results obtained from Montana State’s Center for Biofilm Engineering.
Younguk Kim - One of the best experts on this subject based on the ideXlab platform.
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subsurface Biobarrier formation by microorganism injection for contaminant plume control
Journal of Bioscience and Bioengineering, 2006Co-Authors: Geonha Kim, Seungbong Lee, Younguk KimAbstract:The concept of an in situ mixture of residual soil and aerobic microorganisms as a Biobarrier for controlling contaminant plume was evaluated in this study. Azotobacter chroococcum was innoculated into soil with oxygen as the electron acceptor and appropriate substrate to induce biofilm clog soil pores. The hydraulic conductivity of soil decreased by 1/8000 while substrate and oxygen were provided to the injected microorganism, and increased by 400% when no substrate was provided. A series of column experiments were carried out to measure the hydraulic conductivity of soil specimens. The results showed that the highest hydraulic conductivity reduction occurred when the substrate and electron acceptors were first introduced, and this reduction increased toward the outlet of the column. The substrate was consumed mostly at the inlet and was distributed with time. The analysis of volatile substances after the test showed that the inlet had a high organic content and the outlet had a low organic content.
Pablo Cañizares - One of the best experts on this subject based on the ideXlab platform.
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influence of electric field on the remediation of polluted soil using a Biobarrier assisted electro bioremediation process
Electrochimica Acta, 2016Co-Authors: Esperanza Mena, Pablo Cañizares, J Villasenor, Manuel A RodrigoAbstract:Abstract In this work, it was carried out the study of the electro-bioremediation of soil polluted with diesel by means of combined electrokinetic soil flushing and Biobarriers, using bench scale setups and fourteen days-long tests. Two different Biobarriers were evaluated: one of them was developed in the laboratory, with a culture of diesel-degrading microorganisms supported on gravel particles (BB1); the other was obtained by mixing directly clay soil with activated sludge obtained in a municipal wastewater treatment plant (BB2). Biobarriers were placed in a central point of the soil section to be treated, to prevent the negative consequences of pH fronts on microorganisms viability. Potential difference of 0.5 and 1.0 V cm −1 were applied. For the promotion in the transport of the diesel to the Biobarrier, a surfactant solution was used as electrolyte (flushing fluid). Results confirm that negative influence of the extreme pH fronts on the microbial viability can be prevented using this electro-bioremediation approach. In the same way, uniform diesel removal was obtained all over the soil by using the surfactant solution. After fourteen days of treatment, in the experiments using the BB1, 19.36% and 27.36% of the total amount of diesel present in the soil were removed applying 0.5 and 1.0 V cm −1 , respectively. In the experiments using BB2, 23.33% and 29.10% referred to the total amount of diesel were removed after the fourteen days tests at 0.5 and 1.0 V cm −1 , respectively, indicating that the non-specific barrier is slightly more efficient despite not containing an acclimated culture.
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combination of bioremediation and electrokinetics for the in situ treatment of diesel polluted soil a comparison of strategies
Science of The Total Environment, 2015Co-Authors: Esperanza Mena Ramirez, Manuel A Rodrigo, Jose Villasenor Camacho, Pablo CañizaresAbstract:Abstract The aim of this work is to compare different strategies based on electrokinetic soil flushing and bioremediation for the remediation of diesel-polluted soil. Four options were tested at the laboratory scale: single bioremediation (Bio), performed as a control test; a direct combination of electrokinetic soil flushing and biological technologies (EKSF-Bio); EKSF-Bio with daily polarity reversal of the electric field (PR-EKSF-Bio); and a combination of electrokinetic soil flushing and a permeable reactive biological barrier (EKSF-BioPRB). Four batch experiments of 14 days duration were carried out for comparing technologies at room temperature with an electric field of 1.0 V cm − 1 (in EKSF). A diesel degrading microbial consortium was used. The experimental procedure and some specific details, such as the flushing fluids used, varied depending on the strategy. When using the EKSF-Bio option, a high buffer concentration was required to control the pH, causing soil heating, which negatively affected the biological growth and thus the diesel removal. The PR-EKSF-Bio and the EKSF-BioPRB options attained suitable operating conditions and improved the transport processes for biological growth. Polarity reversal was an efficient option for pH, moisture and temperature control. Homogeneous microbial growth was observed, and approximately 20% of the diesel was removed. The BioPRB option was not as efficient as PR-EKSF-Bio in controlling the operating conditions, but the central Biobarrier protected the biological activity. Microbial growth was observed not only in the Biobarrier but also in a large portion of the soil, and 29% of the diesel was removed in the short remediation test.
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feasibility of coupling permeable bio barriers and electrokinetics for the treatment of diesel hydrocarbons polluted soils
Electrochimica Acta, 2015Co-Authors: Esperanza Mena Ramirez, Manuel A Rodrigo, Jose Villasenor Camacho, Cristina Saez Jimenez, Pablo CañizaresAbstract:Abstract In this study, the remediation of a diesel hydrocarbon-polluted clay soil using an electrochemical-biological combined technology is assessed. The polluted soil was subjected to an electrokinetic (EK) treatment with a biological permeable reactive barrier. A lab-scale electrochemical cell for soil treatment was used. The biological barrier placed in the soil was a biofilm reactor previously adapted for diesel degradation. A batch experiment of 336 h was conducted in a synthetic clay soil spiked with 10 g·kg −1 of diesel and a constant voltage gradient of 1.0 V cm −1 . Sodium dodecyl sulphate was used as an anionic surfactant in the cathodic well to allow for hydrocarbon emulsification during the treatment. At the end of the experiment, extreme pH values were observed near the electrodes. However, the pH remained constant at approximately 7.7 in the central Biobarrier zone, which allowed for biological processes. Biological growth was observed in the Biobarrier, and a part of the biofilm was detached and transported through the soil in both directions. Furthermore, the surfactant was transported across the soil due to electromigration and electroosmosis, which resulted in diesel emulsification. The combination of biological and EK phenomena finally resulted in a homogenous hydrocarbon removal of approximately 27% in the polluted soil, which indicated a 39% removal of the diesel biodegradable fraction. Due to the electroosmotic flow and the biological degradation, some of the water, surfactant and inorganic nutrients were removed from the soil and should be continuously replaced if a long-time experiment is conducted.
Paul B Hatzinger - One of the best experts on this subject based on the ideXlab platform.
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passive in situ Biobarrier for treatment of comingled nitramine explosives and perchlorate in groundwater on an active range
Journal of Hazardous Materials, 2019Co-Authors: Mark E Fuller, Paul C Hedman, David R Lippincott, Paul B HatzingerAbstract:Abstract Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and perchlorate (ClO4−) are common, and often co-mingled, contaminants at military ranges worldwide. This project investigated the feasibility of using a passive emulsified oil Biobarrier plus a slow release pH buffering reagent to remediate RDX, HMX, and ClO4− in a low pH aquifer at an active range. A 33 m Biobarrier was emplaced perpendicular to the contaminant plumes, and dissolved explosives, perchlorate, and other relevant parameters were monitored. The pH increased and the DO and ORP decreased after emulsified oil injection, leading to >90% reductions in perchlorate, RDX, and HMX compared to upgradient groundwater. Some nitroso breakdown products were observed immediately downstream of the barrier, but generally decreased to below detection limits farther downgradient. First-order rate constants of approximately 0.1/d were obtained for all three contaminants. Dissolved metals (including As) also increased in the wells immediately adjacent to the barrier, but attenuated as the plume re-aerated in downgradient areas. Biobarrier installation and sampling were performed during scheduled range downtime and had no impacts to ongoing range activities. The field trial suggests that an emulsified oil Biobarrier with pH buffering can be a viable alternative to remove explosives and perchlorate from shallow groundwater on active ranges.
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passive Biobarrier for treating co mingled perchlorate and rdx in groundwater at an active range
2016Co-Authors: Paul B Hatzinger, Mark E FullerAbstract:Abstract : A subsurface Biobarrier consisting of emulsified vegetable oil and a buffering agent was tested to enhance bioremediation and reduce the migration of co-mingled RDX, HMX, and perchlorate in a shallow, acidic groundwater aquifer at an operational military range in Dahlgren, VA. Despite heterogeneous subsurface lithology and low hydraulic conductivity in the test site aquifer, RDX, HMX, and perchlorate were reduced by 92% in a centerline of monitoring wells extending 40 ft downgradient of the Biobarrier when adequate total organic carbon (TOC) was present from the added oil. The accumulation of toxic nitroso- degradation products MNX, DNX, and TNX from RDX was minimal. Moreover, the passive Biobarrier resulted in no significant impacts to ongoing range activities. This field trial suggests that and emulsified oil Biobarrier is a viable alternative to reduce the migration of co-mingled perchlorate and explosives in groundwater at this and similar ranges. Ideal range locations include open OB/OD areas, target areas, fast cookoff sites, EOD training areas, and other locations where high munition constituent concentrations are possible.