Дисертації з теми "Permeable reactive barrier p"
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Kirby, Daniel. "Hydrogeological study of a sequenced permeable reactive barrier." Thesis, Kirby, Daniel (2015) Hydrogeological study of a sequenced permeable reactive barrier. Other thesis, Murdoch University, 2015. https://researchrepository.murdoch.edu.au/id/eprint/28263/.
Повний текст джерелаAbunada, Ziyad. "Innovative soil mix technology constructed permeable reactive barrier for groundwater remediation." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709154.
Повний текст джерелаPainter, Brett Duncan Murray. "Optimisation of permeable reactive barrier systems for the remediation of contaminated groundwater." Phd thesis, Lincoln University. Environment, Society and Design Division, 2005. http://theses.lincoln.ac.nz/public/adt-NZLIU20061220.151030/.
Повний текст джерелаPainter, Brett D. M. "Optimisation of permeable reactive barrier systems for the remediation of contaminated groundwater." Diss., Lincoln University, 2005. http://hdl.handle.net/10182/12.
Повний текст джерелаBulley, Jonathan A. "Improving performance of a permeable reactive barrier in the degradation of trichloroethylene using ultrasound." FIU Digital Commons, 2004. http://digitalcommons.fiu.edu/etd/1820.
Повний текст джерелаShukla, Pradeep. "Combined adsorption and oxidation technique for waste water treatment: potential application in permeable reactive barrier." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/212.
Повний текст джерелаUlsamer, Signe Martha. "A Model to Characterize the Kinetics of Dechlorination of Tetrachloroethylene and trichloroethylene By a Zero Valent Iron Permeable Reactive Barrier." Digital WPI, 2011. https://digitalcommons.wpi.edu/etd-theses/979.
Повний текст джерелаLuo, Ping. "Quantification of morphological changes in zero valent iron (ZVI) : effect on permeable reactive barrier (PRB) longevity." Thesis, University of Nottingham, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503921.
Повний текст джерелаDoherty, R. D. "Modelling of a permeable reactive barrier (PRB) in a manufactured gas plant site, Portadown, Northern Ireland." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269086.
Повний текст джерелаMcGeough, K. L. "Kinetics of contaminant removal : a comparative study of site specific treatability studies for permeable reactive barrier design." Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426659.
Повний текст джерелаLai, Chun Kit. "Laboratory and full-scale studies of a permeable reactive barrier on the dechlorination of chlorinated aliphatic hydrocarbons /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20LAI.
Повний текст джерелаIncludes bibliographical references (leaves 203-227). Also available in electronic version. Access restricted to campus users.
Uyusur, Burcu. "Laboratory Investigation Of The Treatment Of Chromium Contaminated Groundwater With Iron-based Permeable Reactive Barriers." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607550/index.pdf.
Повний текст джерелаcalcium and significant amount of iron-oxides or -hydroxides was also detected on the iron surfaces. When the same experiments were conducted at higher fluxes, an increase was observed in the treatment efficiency in the column containing 50% iron. This suggested that the precipitates may not be accumulating at higher fluxes which, in turn, create available surface area for reduction. Extraction experiments were also performed to determine the fraction of chromium that adsorbed to ironhydroxides. The analysis showed that chromium was not removed by adsorption to oxyhydroxides and that reduction is the only removal mechanism in the laboratory experiments. The observed rate of Cr(VI) removal was calculated for each reactive mixture which ranged from 48.86 hour-1 to 3804.13 hour-1. These rate constants and complete removal efficiency values were thought to be important design parameters in the field scale permeable reactive barrier applications.
Madaffari, Maria Grazia. "New mixtures to be used in permeable reactive barrier for heavy-metals contaminated groundwater remediation : long-term removal efficiency and hydraulic behavior." Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2015. http://www.theses.fr/2015ECAP0025/document.
Повний текст джерелаGroundwater remediation is currently one of the major environmental challenges, considering the number of contaminated sites and the risk posed to human health and to the environment by exposure to groundwater contamination. Permeable reactive barrier (PRB) is a passive in situ technology for the remediation of contaminated groundwater. It consists of a barrier placed perpendicularly to the contaminant flow and made of reactive material that treats contaminant plume flowing through it under the natural hydraulic gradient. It is the most cost-effective groundwater remediation technology; it allows the use of surface land and reduces the exposure of workers to contaminants. The most used reactive material is Zero Valent Iron (ZVI), which is able to remediate groundwater contaminated by a large range of contaminants by means of different chemical and physical mechanisms. The main issue of granular ZVI use regards the reduction of the porous medium porosity, because of the expansive nature of corrosion products, precipitates and gas formation. To overcome this problem, mixtures of ZVI and granular materials were tested to investigate their long-term removal efficiency and hydraulic behavior. The use of volcanic Lapillus to be mixed with ZVI to remediate heavy-metals contaminated groundwater is proposed in this work. Tests on Lapillus showed a not negligible heavy metal removal efficiency of the volcanic material, while the hydraulic monitoring of column tests performed using mixtures showed a not high reduction of hydraulic conductivity over time.Modelling batch and column tests as a tool for understanding the mechanisms involved in the reactive porous media has been set up. The analysis of the sensitivity of the models response with respect to the input parameters has also been explored
Callahan, Thomas Patrick. "Non-Newtonian fluid injection into granular media." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39618.
Повний текст джерелаAudí, Miró Carme. "Compound Specific Isotope Analysis ((13)C, (37)Cl,( 2)H) to trace induced attenuation of chlorinated organic contaminants in groundwater." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/145921.
Повний текст джерелаEl chloroform (CF), el tetracloroetè (PCE) i el tricloretè (TCE) són hidrocarburs clor-alifàtics densos usats extensament com a solvents industrials. Aquests compostos s’han alliberat al medi degut a un tractament inadequat dels seus residus. En aquesta tesi, l’efecte d’una barrera permeable reactiva de ferro zero valent (BPR-FZV) instal•lada en un emplaçament contaminat majoritàriament amb PCE, TCE i cis-dicloretè (cis-DCE, subproducte de TCE) ha estat avaluada. A més a més, s’ha proposat i desenvolupat una nova estratègia per a degradar el CF, el qual és un compost recalcitrant, consistent en la inducció de la hidròlisi alcalina del CF mitjançant residus de construcció basats en formigó. L’ànàlisi isotòpic de compost específic (AICE) és una eina valuosa per al monitoreig d’un sistema de tractament medi ambiental, basant-se en el fraccionament isotòpic d’un element durant les reaccions de transformació. L’objectiu general d’aquesta tesi és l’ús de l’anàlisi isotòpic de compost específic de 13C, 37Cl i 2H com una eina per a controlar els dos processos d’atenuació 1) la degradació dels eten-clorats mitjançant una BPR-FZV instal•lada en el camp; i, 2) la nova tècnica de remediació de CF proposada basada en l’ús de residus reciclats de la construcció per tal d’induir la hidròlisi alcalina del CF. En general, mitjançant la combinació dels isòtops de C, Cl i H, aquesta tesi aporta noves eines per discriminar la degradació dels compostos organoclorats d’estudi mitjançant FZV, respecte la biodegradació en el camp, així com també per a identificar fonts de contaminació d’origen industrial o de productes formats, entre d’altres aportacions. A més a més, el nou mètode proposat per a degradar el CF basat en la seva hidròlisi alcalina mitjançant l’ús de residus de construcció reciclats ha demostrat ser eficient en la degradació d’aquest contaminant, així com també, mitjançant l’ús de isòtops de carboni, ha demostrat funcionar en experiments pilot monitorejats a escala de camp.
Pandey, Pratiksha. "Hybrid multiobjective optimization approach for optimal design of in-situ permeable reactive barrier." Thesis, 2017. http://localhost:8080/iit/handle/2074/7357.
Повний текст джерелаHsu, Chia-Ping, and 徐嘉彬. "Groundwater Nitrate Removal by Zero-Valent Iron Permeable Reactive Barrier." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/59266737515942053622.
Повний текст джерела國立臺北科技大學
環境規劃與管理研究所
92
Laboratory scale column tests were conducted to obtain the field design parameters and possible operation problems after field installation. For the nitrate contaminant water made in the laboratory, nitrate reduction by zero-valent iron was found affected by the coating or metal oxide on the ZVI surface. Without pretreatment of ZVI, nitrate removal rate was only 30%. Surface coating can be removed by strong reduction agent (NaBH4) or acid washing, but acid washing was shown better efficiency in this study. In the column tests, 1 mg ZVI can only remove 2.14 mg nitrate and the used ZVI was only 3.42% according to the stoichiometric ratio, and which is an evidence of surface reaction for the ZVI. The reduction of ZVI becomes iron oxides coating on the ZVI surface. In the column test, iron color was grayish in the beginning (pure ZVI) and became deep black after the ZVI was used. Effluent soluble iron concentration was below 1 mg/L. ESCA analysis was conducted for the surface species of the ZVI and Fe2O3 was found on the coated surface. Effluent pH was directly related to the initial nitrate concentration and removal rate and effluent ORP was decreased during the experiment. Therefore, pH is suggested as an indicator for nitrate removal efficiency for field operation. Increasing flux leads to increasing nitrate removal percentage. For the same flux, hydraulic resident time (HRT) and removal rate had no relationship, but higher HRT would increase operation time. The problem for field operation (using actual groundwater) was the clogging in the column. The reason for clogging was due to mineral precipitates after the increased pH and gas production. The mineral precipitates include Fe2O3, FeCO3, CaCO3. ZVI mixed with sand in the column can solve the clogging, but operation time was decreased. Transfer zone in the column were proportionately related to flow rate and flux. For pretreated ZVI by acid wash (5 r.pm with 157 cm3/cm2day), transfer zone were from1.85 to 3.03 cm and real hydraulic retention time were from 10 to 16 minutes. For determination of reaction constants, Thomas Equation was applicable, where R square was above 0.8 and reaction constants were between 0.0240 and 0.0553 (L/mg-day). Column tests were scaled up using two methods including Kinetic Approach and Scale-Up Approach. The differences were small comparing the calculated to the actual breakthrough volume and time using Kinetic Approach. For calculation of PRB installation, W/A (mass of zero-valent iron/cross-sectional plume) was below 1 kg/m2, and iron well was below 16 cm. It was low comparing to the literature value and it was due to that the ZVI used in this study was pretreated.
Mieles, John Michael. "Semi-Analytical Solutions of One-Dimensional Multispecies Reactive Transport in a Permeable Reactive Barrier-Aquifer System." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9167.
Повний текст джерелаMcLean, Neil Ross. "Use of Drains for Passive Control of Flow Through a Permeable Reactive Barrier." Thesis, 2007. http://hdl.handle.net/10012/3375.
Повний текст джерелаLai, Ranee Wan Man. "The use of clinoptilolite as permeable reactive barrier substrate for acid rock drainage." Thesis, 2005. http://hdl.handle.net/2429/17004.
Повний текст джерелаApplied Science, Faculty of
Civil Engineering, Department of
Graduate
FANG, YEH JU, and 葉如芳. "Microbial Community Dynamics in a Permeable Reactive Barrier using Real-time PCR Technique." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/22789166291578300902.
Повний текст джерела大葉大學
環境工程學系碩士班
96
This study was conducted with the application of denaturing gradient gel electrophoresis (DGGE), and real-time quantitative polymerase chain reaction (real-time PCR) molecular biotechnology for monitoring the permeable reactive barrier (PRB) in the relation with BTEX decomposition efficiency and the distribution of microbial community. Various amounts of nitrogen nutrients and BTEX were added to examine the treatment efficiencies. It was shown that the high sodium nitrate amount had improved the BTEX removal, which was an evidence of effects on BTEX treatment. The results of benzene and toluene removal efficiencies revealed that it was completely degraded for both two compounds at the concentrations of 20, 40 and 80 ppm. Increasing the concentrations of these two compounds to 120, 160, 240 and 320 ppm resulted in the decreasing in treatment efficiencies, and the concentrations remained 40, 60, 65, 90 and 100 % for benzene, and 10, 40, 55, 90 % for Toluene, respectively. Furthermore, the microbial variations at various concentrations were consistent via optical density (OD), DGGE analysis and real-time PCR results. Each column test was conducted for 20 days to investigate the effectiveness of oxygen releasing compound (ORC). It was indicated that the highest dissolved oxygen was achieved, which was 5.08 mg/L (equal to 0.25 mg O2/day/g-ORC) at 40 % of CaO2. The results of long-term stability tests of oxygen releasing from PRB system showed that: (1) Oxygen released from ORC was sufficient for the demand of bacteria. (2) In shock-loading of BTEX tests, the removal efficiencies were reduced by 21%, 19%, 17% and 10 % for benzene, toluene, ethylbenzene and xylene, respectively. (3) Removal efficiencies were then recovered in the ascending order of as follow: xylene> ethylbenzene> benzene> toluene. (4) ORC can be used for 40 days. (5) DGGE analysis showed the changing in the microbial community structure before (13 groups) and after shock-loading (reduced to 9 groups), that implied the shock-loading was harmful to bacteria. (6) The results from real-time PCR in the study of catechol 2,3-dioxygenase gene revealed that the quantification of this gene has been declined after shock-loading, but it was latter well again at the 79th day.
Lin, Ming-Hei, and 林明憙. "Electrolysis-Enhanced Permeable Reactive Barrier Packed with Nano-Pd/Fe Bimetallic Particles of Perchloroethylene." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/52050176023193793112.
Повний текст джерела國立屏東科技大學
環境工程與科學系所
100
The aim of this study is to investigate the degradation efficiency of target pollutant, perchloroethylene (PCE), by nano-palladium/iron (Pd/Fe) bimetallic metal particles enhanced by electrolysis. The experiments were divided into four stages. The first stage was to characterize the properties of quartz sand and nano-Pd/Fe particles. The second stage was to conduct the batch tests under various pH values (pH 8-9) on the effects of PCE degradation with nano-Pd/Fe. The third stage was to observe the transport behaviors of solutes through the porous media in a bench-scale sand box. And the fourth stage was to identify the variations of nano-Pd/Fe before and after the reaction with PCE by SEM-EDS and FTIR analysis. The average size and specific surface area of lab-synthesized nano-Pd/Fe particles were 111.1 nm and 56.05 m2 g-1, respectively. The absorption peaks of nano-Pd/Fe analyzed by the X-ray diffraction detector (XRD) only identified Fe. That may be due to the trace amount of Pd on bimetallic metals. For the tests of various pH values (pH 8-9) on PCE degradation with nano-Pd/Fe, the efficiency decreased with higher pH values. The concentration of Cl- released from PCE degradation was close to the theoretical values. The PCE degradation levels were positive correlated with the release amounts of Cl-. In this study, the by-products of PCE degradation such as trichlorethylene (TCE), cis-1,2-dichloroethylene (cis-1,2-DCE), trans-1,2-dichloroethylene (trans-1,2-DCE), 1,1-dichloroethylene (1,1-DCE), and vinyl chloride (VC) were not detected. Via the tracer tests, the average residence time was about 1.7 times higher than the theoretical value. For the test of permeable reactive barrier (PRB) packed with nano-Pd/Fe on PCE degradation, the duration of reactivity of nano-Pd/Fe could be maintained about 28 hr which was around 2 to 4 times higher than that of nano zero valent iron. During the tests, ORP values were steadily maintained below -300 mV in the PRB showing a reduction state was kept in the system. Dechlorination of PCE with nano-Pd/Fe particles were identified by the significant increase of Cl- concentration. The test of nano-Pd/Fe PRB enhanced by electrolysis on PCE degradation, H+ released near the anode was able to acid-washed the surface of Pd/Fe particles to increase their reactivity. The results showed that PCE was not completely degraded by the nano-Pd/Fe particles. The reactivity of Pd/Fe was observed to maintain about 16 to 20 hr. Therefore, more researches on the aspects of current, potential, and electrolyte to the performance of electrolysis enhanced PRB packed with nano-Pd/Fe technology are needs to facilitate its application to in-situ remediation of groundwater contaminated by chlorinated solvents. From the images observed by SEM-EDS, the surface morphology of nano-Pd/Fe particles displayed chain-like structure and irregular flakes pre-reacted and post-reacted with PCE, respectively. The spectrum of fresh nano-Pd/Fe particles analyzed by FTIR showed that a strong and broad absorption signal ranged from 3200 to 3500 cm-1 was identified to be O-H and at 1539, 1385, 967 cm-1 to be the nitro compounds (NO2), alkane (CH3), and alkene (C = CH), respectively. Finally, a signal ranged from 600 to 800 cm-1 was C-Cl. Keywords: perchloroethylene, nano-palladium/iron, tracer, permeable reactive barrier, electrolysis
Hoppe, Jutta. "Geochemical Characterization and Longevity Estimates of a Permeable Reactive Barrier System Remediating a 90Sr plume." Thesis, 2012. http://hdl.handle.net/10012/7293.
Повний текст джерелаDam, Quoc-Khanh, and 譚國卿. "Integration of Permeable Reactive Barrier Technology and Immobilization for MTBE and BTEX Contaminated Groundwater Treatment." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/16976578381407097320.
Повний текст джерела大葉大學
環境工程學系碩士班
97
The purpose of this study was integration of permeable reactive barriers (PRB) technology and immobilization for MTBE and BTEX contaminated groundwater treatment. This study was first investigated to make the immobilized bead highly strong stability. After conducting batch and column tests, it was integrated with PRB system. PRB was run at various concentrations of substrate and removal efficiency was monitored. Results revealed that (1) Bead was formed with high stability with 2.46 hours and 6 hours immersed in solution of (5% H3BO3, 2.5% CaCl2) and 5% KH2PO4. (2) Bead has pore structure for bacteria occupancy, allowing oxygen and substrates transfer. (3) Results from batch experiments showed that: (3a) For toluene-degrading Pseudomonas sp. YATO411 strain, the most suitable value of initial biomass concentration for immobilizing was 26.7 mg/L; (3b) Rate of toluene removal was highest with 12.4 mg/L.h; (3c) When exposing at high concentration of toluene, immobilized cells were more effective than suspended cells; (3d) Pseudomonas sp. YATO411 was not only degrading toluene, but also used benzene and ethylbenzene as the source of carbon and energy; (3e) Methylibium petroleiphilum PM1 can be used for immobilization when bead was immersed in (H3BO3, CaCl2) for 0.5 hours, and KH2PO4 for 2.5 hours. (4) Results from column test showed that toluene removal increased along with increasing amount of bead. (5) Results from long term PRB monitoring showed that: (5a) MTBE removal has only shown significant increasing to 42.4% when Methylibium petroleiphilum PM1 was introduced to PRB system; (5b) When BTEX was shock loading to 80 ppm, integration PRB with immobilization of Pseudomonas sp. YATO411 has increased removal efficiency of B, T, and E to 99.4, 98.2, and 97.5 (%) comparing to 49.2, 48.6, and 62.9 (%), respectively, incase of non-integration.
Wu, Shih-Kai, and 吳士愷. "Analytical model for multispecies transport in a permeable reactive barrier- aquifer system subject to nonequilibrium." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/26xht7.
Повний текст джерела國立中央大學
應用地質研究所
106
The transport behavior of contaminants in a permeable reactive barrier (PRB)- aquifer system is complicated because of the differences in the physical and chemical properties of the PRB and the aquifer. However, dual-domain contaminant transport models are efficient tools for predicting and describing the movement of contaminants in a PRB–aquifer system. Multispecies transport models should have the ability to account for mass accumulation of the parent species while simultaneously considering the distinct transport and reactive properties of both the parent and daughter species during the transport of a degradable contaminant such as a dissolved chlorinated solvent. For mathematical simplicity, the current multispecies dual-domain transport analytical models are derived assuming equilibrium sorption. However, experimental and theoretical studies have indicated that this assumption may not be adequate and that nonequilibrium sorption could have a profound effect upon solute transport in the subsurface environment. This study presents an analytical model for multispecies transport in a PRB-aquifer system subject to nonequilibrium sorption in which the first-order reversible kinetic sorption reaction equation systems are incorporated into two sets of simultaneous advection-dispersion equations coupled together by a sequential first-order decay reaction that describes multispecies nonequilibrium transport in both the PRB and the aquifer. The analytical solutions to the complicated governing equation systems are derived with the aid of the Laplace transform and verified by comparing the computational results against those obtained using a numerical model in which the same governing systems are solved using the advanced Laplace transform finite difference method. Finally, the derived analytical model is used to investigate how the sorption reaction rate influences the performance of a PRB-aquifer system.
Pan, Chi-liang, and 潘祈良. "The Application of Biological Permeable Reactive Barrier with Immobilized Cell Technique for Diesel-Contaminated Groundwater Remediation." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/89255219361384725452.
Повний текст джерела國立成功大學
環境工程學系碩博士班
97
Soil and groundwater petroleum contamination is becoming more and more serious in recent years due to oil-leaking from storage tanks. Among current remediation technologies, bioremediation is getting more and more popular for its effectiveness, lower operational cost and milder environmental impacts. In this study, diesel degrading bacteria were utilized to treat the contaminated groundwater. However, the bacteria may be washed out from the contaminated zone by the groundwater flow and lowered the removal efficiency. Therefore in this study, we used the entrapment technique to immobilize the bacteria cell in alginate gel (AG) beads and developed a biological permeable reactive barrier (B-PRB) with the AG beads as monomers. This makes in-situ bioremediation of groundwater possible. There were two main parts in this study. First, repeated batch tests using AG beads were conducted to evaluate the diesel degradation efficiency and duration of the beads. Three different types of bacteria mixing techniques were used. Initial diesel concentration was about 500 ppm TPH-d. Also, the carbon to nitrogen ratio (C/N ratio) was changed during the repeated batches. The repeated batches were conducted for about one year. Results showed that the diesel degradation efficiency achieved more than 80% for all three batches at C/N=100:2. However, when C/N ratio changed to 100:0.5, the diesel degradation efficiency decreased to about 45%. This shows that appropriate C/N ratio is an important factor for groundwater diesel degradation. When we supplied sufficient nitrogen source (C/N=100:2) after this decrease, the diesel degradation efficiency recovered to above 80%. This indicates that the beads can mitigate the impact due to the change of the environment. In the last few runs, synthetic groundwater (C/N=100:1) was used and the diesel degradation efficiency was about 90%. From the results, we can conclude that the AG beads remained active for diesel degradation after a long period of operation. Also the structure of the beads remained. This shows that the AG beads can applied to continuous flow B-PRB. In the second part of this study, a lab-scale continuous flow B-PRB column was developed to study the possibility of in-situ groundwater remediation with B-PRB. Synthetic groundwater with saturated diesel (11±0.5 ppm TPH-d) was used as influent. Results showed that the diesel degradation efficiency was about 70% during the whole operational period (200 days). This shows that the B-PRB retained good removal efficiency after a long period of operation.
Wang, Dong-Yi, and 王東毅. "Treatment of Trichloroethylene in Groundwater Using Permeable Nano-Scale Iron Reactive Barrier Coupled with Persulfate - Sand Box Experiments." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/57574939524067079118.
Повний текст джерела國立屏東科技大學
環境工程與科學系所
96
Organic chlorinated solvents are widely used in industrial processes, such as trichloroethylene (TCE) and perchloroethylene (PCE). If those chlorinated solvents are not properly handled, they may possibly leak into soil and further pollute the aquifer. The objective of this study is to investigate the treatment efficiency of aqueous trichloroethylene by permeable reactive barrier (PRB) filled with nano-sacle iron and coupled with persulfate (Na2S2O8). The experiments were designed to simulate the solutes transporting through the porous media and the remediation of TCE contaminated aquifer. The results from preliminary study showed that the average particle size and BET specific surface area of lab synthesized nano-scale iron were 525.6 nm and 125.1 m2/g, respectively. The iron component of particles was detected through X-ray powder diffraction(XRD) examination at 2θ=44.960. The results from transport experiments through porous media showed that the breakthrough time of persulfate transport was slightly quicker than that of water flow owing to the influence of advection and dispersion. From the results of TCE transport experiments, TCE concentration reduced with the increase of distance from 128 mg/L to 47 mg/L between sampling Point A and Point D, which were 20 cm and 80 cm away from the injection well, respectively. Sampling Point A、B、C、D away from the injection well 20、40、60、80 cm, respectively. With addition of 0.75 g, i.e. 1500 mg/L, sodium persulfate (Na2S2O8), TCE concentration at sampling point A decreased from 365 mg/L to 225 mg/L. But TCE concentration gradually increased with test time implicated that TCE was not effective degraded by Na2S2O8. Degradation of TCE by Na2S2O8 was observed between point A and point C which were 20 and 40 cm away from the injection well. Addition of 45.15 g nano-scale iron into PRB with thickness of 1 cm, TCE concentration at sampling point C reduced from 230 mg/L to 30 mg/L during 40~50 hours and further reduced to 17 mg/L at sampling point D at the 62nd hour. Conductivity and concentration of chloride and ferrous increased with test time. The transport distance of ferrous ions (Fe2+) was about 10 cm in the design sandbox. TCE removal efficiencies at sampling points C and D of 5-cm thickness of PRB filled with 98.45 g nano-scale iron were worse than those of 1-cm thickness of PRB and transport distance of ferrous ions was restricted. Addition of 200 mL and 1500 mg/L Na2S2O8 from injection well at 64th hour, short-term TCE concentration at sampling point D decreased at 68th hour. Under the influence of aqueous pH and dissolved oxygen (DO), ferrous ions were easily oxidized to ferric ions (Fe3+) and formed ferric hydroxide precipitation due to high pH resulting in the clogging of PRB. The transport distance of ferrous ions were restricted by the precipitation of ferric hydroxide that caused Na2S2O8 not activated by ferrous ions. Thus that reduced the removal efficiency of TCE. This study shows TCE in aquifer can be effectively degraded by PRB filled with nano-sacle iron. The parameters concerned for activation of sodium persulfate by ferrous ions includes the transport distance of ferrous ions, dissolved oxygen and pH. The proposed technique combined the advantages of redox reaction of nano-scale iron and persulfate can be applied to effectively degrade TCE in aquifer. This study can be referred as an alternative for in-situ remediation of organic chlorinated solvents in aquifer.
Chi, Hao-Jan, and 季皓然. "Effect of polarity reversal on electrokinetic remediation of Bisphenol A contaminated soil: with or without permeable reactive barrier and sodium persulfate." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107NCHU5087011%22.&searchmode=basic.
Повний текст джерела國立中興大學
環境工程學系所
107
Bisphenol A (BPA) is an artificial industrial raw material and is widely used in the manufacture of various products. However, BPA is also a type of endocrine disrupting chemical (EDCs) which may affect human endocrine, reproductive, and nervous systems. Electrokinetic (EK) soil remediation is a remarkable technology, which especially recommended for the in-situ treatment of low permeability soils with low hydraulic conductivity values. In addition, EK remediation could combine with other soil remediation technologies to improve the efficiency. Sodium persulfate (SPS) is a common reagent for in-situ chemical oxidation. It is highly soluble, and it will not cause the secondary pollution after the reaction. Nevertheless, the reaction rate of SPS is so slow that we have to activate it by using electricity, heat, transition metal, alkali or other methods in order to generate sulfate radicals. Permeable reactive barriers (PRB) filled with reactive materials such as granular activated carbon (GAC) could intercept contaminants. The more contact of the contaminants with the PRB, the better efficiency of the process would be. Besides, periodic reversion in the polarity does not only improve the efficiency but it also helps to regulate the pH and to avoid the depletion of ionic species in the soil. The study includes three parts. In the first part, EK remediation would combine with PRB or SPS. In the next part, we have replaced EK with REK remediation. In the last part, REK remediation combined with SPS and PRB simultaneously. In part I (test 1~3), the removal rates were 27.01 %, 52.00 %, and 34.97%. The results revealed that electroosmosis flow was higher for test 3 (EK+SPS), and the distribution of residual BPA concentrations were similar for test 1 and 3. Electroosmosis flow was lower for test 2 (EK+PRB), but PRB successfully intercepted contaminants from left part of the soil. In part II (test 4~6), electrodes were reversed periodically, and the removal rates were 44.38 %, 78.52 %, and 47.50%. The removal rate of test 5 was the highest in this study, because that the polarity reversal let PRB intercept contaminants from both sides of the soil. Also, test 4’s and 6’s removal rates were higher than part I, and the residual BPA concentrated in the middle of all the soils. According to the results, periodic reversion in the polarity did improve the transport efficiency and degradation efficiency. For the last part (test 7 and 8), the removal rates were 61.45 % and 51.93 %. Base on the batch experiments results, the surface of GAC exhibited significant changes after contacting with SPS, which reduced adsorption capacity of GAC. Therefore removal rates for this part weren’t higher than test 5.
Guo, Qiang. "Some Aspects of Arsenic and Antimony Geochemistry in High Temperature Granitic Melt – Aqueous Fluid System and in Low Temperature Permeable Reactive Barrier – Groundwater System." Thesis, 2008. http://hdl.handle.net/10012/3579.
Повний текст джерелаHart, Jeffrey L. (Jeffrey Le). "Evaluating the rates of nitrate removal for a nitrate containing, low organic carbon wastewater interacting with carbon-containing solid substrates." Thesis, 2012. http://hdl.handle.net/1957/28584.
Повний текст джерелаGraduation date: 2012