The Experts below are selected from a list of 20064 Experts worldwide ranked by ideXlab platform
Ayad A H Faisal - One of the best experts on this subject based on the ideXlab platform.
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waterworks sludge filter sand permeable Reactive Barrier for removal of toxic lead ions from contaminated groundwater
Journal of water process engineering, 2020Co-Authors: Ayad A H Faisal, Saad Faik Alwakel, Hussein A Assi, Laith A Naji, Mu NaushadAbstract:Abstract This study aims to use of inexpensive and available byproduct waterworks sludge resulted in huge quantities from the activities of water supply treatment system in the remediation of groundwater contaminated with lead ions as an application of sustainability principles. Results revealed that this material can be used effectively in the permeable Reactive Barrier technology. The best operational conditions for initial pH, contact time, and sorbent dosage in the batch tests were 5, 1 h, and 0.3 g/50 mL, respectively at agitation speed of 200 rpm and initial concentration of 50 mg/L to achieve the maximum removal efficiency (97 %). Langmuir isotherm model was introduced a fair description for sorption measurements with maximum capacity of 20.41 mg/g. Also, the precipitation/co-precipitation processes were found the predominant mechanisms in the sorption process under consideration based on Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) images in combination with final pH values. The developed model for continuous tests solved by COMSOL Multiphysics 3.5a to plot the contaminant transport under the effects of initial concentration, flowrate and bed depth. It is recognized that the model predictions can be simulated the experimental values with satisfactory concurrence where the coefficient of determination (R2) ≥ 0.983. The breakthrough point in the continuous transport was appeared earlier by decreasing the bed depth, and increasing both the initial concentration as well as the flow rate.
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cement kiln dust ckd filter sand permeable Reactive Barrier for the removal of cu ii and zn ii from simulated acidic groundwater
Journal of Hazardous Materials, 2015Co-Authors: Abbas H Sulaymon, Ayad A H Faisal, Qusey M KhaliefaAbstract:Abstract The hydraulic conductivity and breakthrough curves of copper and zinc contaminants were measured in a set of continuous column experiments for 99 days using cement kiln dust (CKD)-filter sand as the permeable Reactive Barrier. The results of these experiments proved that the weight ratios of the cement kiln dust-filter sand (10:90 and 20:80) are adequate in preventing the loss of reactivity and hydraulic conductivity and, in turn, avoiding reduction in the groundwater flow. These results reveal a decrease in the hydraulic conductivity, which can be attributed to an accumulation of most of the quantity of the contaminant masses in the first sections of the column bed. Breakthrough curves for the description of the temporal contaminant transport within the Barrier were found to be more representative by the Belter–Cussler–Hu and Yan models based on the coefficient of determination and Nash–Sutcliffe efficiency. The longevity of the Barrier was simulated for the field scale, based on the laboratory column tests and the values verified that cement kiln dust can be effectively used in the future, as the Reactive material in permeable Reactive Barrier technology. These results signify that the longevity of the Barrier is directly proportional to its thickness and inversely to the percentage of the CKD used.
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performance of granular dead anaerobic sludge as permeable Reactive Barrier for containment of lead from contaminated groundwater
Desalination and Water Treatment, 2015Co-Authors: Abbas H Sulaymon, Ayad A H Faisal, Ziad Abd T AliAbstract:AbstractThis study investigates the performance of granular dead anaerobic sludge (GDAS) bio-sorbent as permeable Reactive Barrier (PRB) in removing lead from a contaminated shallow groundwater. Batch tests have been performed to characterize the equilibrium sorption properties of the GDAS and sandy soil in lead-containing aqueous solutions. A 1D advection–dispersion equation, solved by computer solutions Multiphysics 3.5a software which is based on finite element method, has been used to simulate the equilibrium transport of Pb+2 ions within groundwater. This equation has taken into account the pollutant sorption onto the GDAS and sandy soil which is performed by Langmuir equation. Numerical results proved that the PRB plays a potential role in the restriction of the contaminant plume migration. These results also show that the thicker PRB is better than the thinner ones in lead treatment and the Barrier starts to saturate with contaminant as a function of the travel time. A good agreement between the pr...
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Groundwater protection from lead contamination using granular dead anaerobic sludge biosorbent as permeable Reactive Barrier
Desalination and Water Treatment, 2014Co-Authors: Ayad A H Faisal, Ziad T. Abd AliAbstract:AbstractThis study investigated the performance of granular dead anaerobic sludge (GDAS) biosorbent as permeable Reactive Barrier (PRB) in removing lead from contaminated shallow groundwater. Batch tests were performed to characterize the equilibrium sorption properties of the GDAS and sandy soil in lead-containing aqueous solutions. Fourier transform infrared analysis proved that the carboxylic, alcohol, and alkyl halides groups were responsible for the biosorption of lead onto GDAS. A two-dimensional numerical model, solved by COMSOL Multiphysics 3.5a software, which is based on finite element method, was developed to simulate the equilibrium transport of lead within groundwater. This model considered the pollutant sorption onto the GDAS and sandy soil using Langmuir equation. Numerical and experimental results proved that the PRB plays a potential role in the restriction of the contaminant plume migration. Furthermore, the Barrier started to saturate with contaminant as a function of the travel time, a...
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groundwater protection from cadmium contamination by zeolite permeable Reactive Barrier
Desalination and Water Treatment, 2013Co-Authors: Ayad A H Faisal, Zamman A HmoodAbstract:AbstractThis work studies the performance of zeolite permeable Reactive Barrier in removing cadmium from a contaminated shallow aquifer. Batch tests have been performed to characterize the equilibrium sorption properties of the zeolite in cadmium-containing aqueous solutions. A 1D numerical finite difference model has been developed to describe pollutant transport within groundwater taking pollutant sorption on the permeable Reactive Barrier (PRB), which is performed by Langmuir equation, into account. Numerical results show that the PRB starts to saturate after a period of time (~120 h) due to reduction of the retardation factor, indicating a decrease in the percentage of zeolite functionality. However, a reasonable agreement between model predictions and experimental results of Cd+2 concentration across the soil bed in the presence of zeolite permeable Reactive Barrier was recognized.
Geoffrey W Stevens - One of the best experts on this subject based on the ideXlab platform.
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a permeable Reactive Barrier prb media sequence for the remediation of heavy metal and hydrocarbon contaminated water a field assessment at casey station antarctica
Chemosphere, 2016Co-Authors: Tom M Statham, Ian Snape, Scott C Stark, Geoffrey W Stevens, Kathryn A MumfordAbstract:Abstract A field trial was conducted at Casey Station, Antarctica to assess the suitability of a permeable Reactive Barrier (PRB) media sequence for the remediation of sites containing both hydrocarbon and heavy metal contamination. An existing PRB was modified to assess a sequence consisting of three sections: (i) Nutrient release/hydrocarbon sorption using ZeoPro™ and granular activated carbon; (ii) Phosphorus and heavy metal capture by granular iron and sand; (iii) Nutrient and excess iron capture by zeolite. The media sequence achieved a greater phosphorus removal capacity than previous Antarctic PRB configurations installed on site. Phosphorus concentrations were reduced during flow through the iron/sand section and iron concentrations were reduced within the zeolite section. However, non-ideal flow was detected during a tracer test and supported by analysis of media and liquid samples from the second summer of operation. Results indicate that the PRB media sequence trialled might be appropriate for other locations, especially less environmentally challenging contaminated sites.
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evaluation of a permeable Reactive Barrier to capture and degrade hydrocarbon contaminants
Environmental Science and Pollution Research, 2015Co-Authors: Kathryn A Mumford, Ian Snape, Shane M Powell, Greg Hince, John L Rayner, Geoffrey W StevensAbstract:A permeable Reactive Barrier (PRB) was installed during 2005/2006 to intercept, capture and degrade a fuel spill at the Main Power House, Casey Station, Antarctica. Here, evaluation of the performance of the PRB is conducted via interpretation of total petroleum hydrocarbon (TPH) concentrations, degradation indices and most probable number (MPN) counts of total heterotroph and fuel degrading microbial populations. Results indicate that locations which contained the lowest TPH concentrations also exhibited the highest levels of degradation and numbers of fuel degrading microbes, based on the degradation indices and MPN methods selected. This provides insights to the most appropriate Reactive materials for use in PRB’s in cold and nutrient-limited environments.
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hydraulic performance of a permeable Reactive Barrier at casey station antarctica
Chemosphere, 2014Co-Authors: Kathryn A Mumford, Ian Snape, John L Rayner, Geoffrey W StevensAbstract:Abstract A permeable bio-Reactive Barrier (PRB) was installed at Casey Station, Antarctica in 2005/06 to intercept, capture and degrade petroleum hydrocarbons from a decade old fuel spill. A funnel and gate configuration was selected and implemented. The Reactive gate was split into five separate cells to enable the testing of five different treatment combinations. Although different treatment materials were used in each cell, each treatment combination contained the following Reactive zones: a zone for the controlled release of nutrients to enhance degradation, a zone for hydrocarbon capture and enhanced degradation, and a zone to capture excess nutrients. The materials selected for each of these zones had other requirements, these included; not having any adverse impact on the environment, being permeable enough to capture the entire catchment flow, and having sufficient residence time to fully capture migrating hydrocarbons. Over a five year period the performance of the PRB was extensively monitored and evaluated for nutrient concentration, fuel retention and permeability. At the end of the five year test period the material located within the Reactive gate was excavated, total petroleum hydrocarbon concentrations present on the material determined and particle size analysis conducted. This work found that although maintaining media reactivity is obviously important, the most critical aspect of PRB performance is preserving the permeability of the Barrier itself, in this case by maintaining appropriate particle size distribution. This is particularly important when PRBs are installed in regions that are subject to freeze thaw processes that may result in particle disintegration over time.
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a natural zeolite permeable Reactive Barrier to treat heavy metal contaminated waters in antarctica kinetic and fixed bed studies
Process Safety and Environmental Protection, 2006Co-Authors: A.z. Woinarski, Geoffrey W Stevens, Ian SnapeAbstract:Ion exchange characteristics of Cu2+ on the natural zeolite clinoptilolite at 2 and 22°C are presented to facilitate the development of a permeable Reactive Barrier (PRB) to treat heavy-metal contaminated waters in Antarctica. A one-dimensional mass transfer transport model describing non-equilibrium sorption of Cu2+ in fixed-bed flow reveals that saturation capacities are independent of flow rate, but mass transfer coefficients increase with water velocity. Clinoptilolite capacity in fixed-beds is approximately 50% the capacity in equivalent batch systems, and mass transfer coefficients are between two and eight times batch-estimated values. Fixed-bed performance is significantly reduced at cold temperature, with breakthrough points and saturation capacities at 2°C between 60 and 65% less than operation at 22°C. The detrimental effects of cold temperature on fixed-bed performance will have significant implications for the design of a natural zeolite PRB to treat heavy-metal contaminated waters in Antarctica or other cold regions.
Robert M. Kalin - One of the best experts on this subject based on the ideXlab platform.
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performance of a field scale biological permeable Reactive Barrier for in situ remediation of nitrate contaminated groundwater
Science of The Total Environment, 2019Co-Authors: Oriol Gibert, Amer Assal, Trevor Elliot, Hayley Devlin, Robert M. KalinAbstract:We report the performance of a field-scale permeable Reactive Barrier (PRB) for the biological treatment of nitrate-contaminated groundwater. The Reactive material of the PRB consisted of a mixture of gravel and mulch as a carbon source for denitrifying bacteria. The PRB was equipped with a delivery system that allowed injecting NO3- at controlled rates from the surface directly into the up-gradient layer of the PRB. This way, NO3- concentration entering the PRB was varied (from 1 to 530 mg/L) with the purpose of evaluating the ultimate efficiency of the PRB under different NO3- loadings. The PRB was successful at removing NO3- from groundwater at inlet concentrations up to 280 mg/L (with NO3- removal percentages ≥97%). Monitoring of groundwater at different depths within the PRB provided evidence that NO3- underwent denitrification preferably at the deepest part of the PRB, where more favourable reducing conditions were achieved. Among the shortcomings of the PRB were the fluctuations of groundwater fluxes caused by intense rainfalls during the study period, although they generally did not pose concern for the denitrification capacity of the PRB. Emission fluxes of gases (CO2, CH4 and N2O) from the PRB to the atmosphere were also measured. The results are finally compared with the few others reported existing PRBs for nitrate-contaminated groundwater worldwide.
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ten year performance evaluation of a field scale zero valent iron permeable Reactive Barrier installed to remediate trichloroethene contaminated groundwater
Environmental Science & Technology, 2010Co-Authors: Debra Phillips, Thomas Van Nooten, Keith Dickson, S Plant, Jason M E Ahad, T Newton, Trevor Elliot, M I Russell, Leen Bastiaens, Robert M. KalinAbstract:The Monkstown zero-valent iron permeable Reactive Barrier (ZVI PRB), Europe’s oldest commercially-installed ZVI PRB, had been treating trichloroethene (TCE) contaminated groundwater for about 10 years on the Nortel Network site in Northern Ireland when cores from the Reactive zone were collected in December, 2006. Groundwater data from 2001−2006 indicated that TCE is still being remediated to below detection limits as the contaminated groundwater flows through the PRB. Ca and Fe carbonates, crystalline and amorphous Fe sulfides, and Fe (hydr)oxides have precipitated in the granular ZVI material in the PRB. The greatest variety of minerals is associated with a ∼1-2 cm thick, slightly cemented crust on top (up-gradient influent entrance) of the ZVI section of the PRB and also with the discontinuous cemented ZVI material (∼23 cm thick) directly below it. The greatest presence of microbial communities also occurred in the up-gradient influent portion of the PRB compared to its down-gradient effluent section, ...
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selection of organic substrates as potential Reactive materials for use in a denitrification permeable Reactive Barrier prb
Bioresource Technology, 2008Co-Authors: Oriol Gibert, Ivan Rowe, Sylwia Pomierny, Robert M. KalinAbstract:The aim of the present study was to select a suitable natural organic substrate as a potential carbon source for use in a denitrification permeable Reactive Barrier (PRB). A number of seven organic substrates were first tested in batch tests. The materials attained varying degrees of success at promoting denitrification. Some of the organic substrates performed very well, achieving complete nitrate removal (>98%), while others were considered unsuitable for a variety of reasons, including: insufficient nitrate or nitrogen removal, excessive release of leachable nitrogen from the substrate or excessive reduction of nitrate to ammonium rather than removing it as gaseous N2. The top performing substrate in terms of denitrification extent (>98%) and rate () was then selected for two bench-scale column experiments in an attempt to simulate the PRB. The inlet concentration was 50 mg dm−3 and the columns operated at two different flow rates: 0.3 cm3 min−1 (Column 1) and 1.1 cm3 min−1 (Column 2). The two columns showed different general patterns, making it clear that the flow rate was a key factor at the nitrate removal. Nitrate was completely removed (>96%) by the passage through Column 1, while only partially removed in Column 2 (66%). The results indicated that the selected organic substrate (Softwood) was applicable for further use as a filling material for a PRB.
Kathryn A Mumford - One of the best experts on this subject based on the ideXlab platform.
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a permeable Reactive Barrier prb media sequence for the remediation of heavy metal and hydrocarbon contaminated water a field assessment at casey station antarctica
Chemosphere, 2016Co-Authors: Tom M Statham, Ian Snape, Scott C Stark, Geoffrey W Stevens, Kathryn A MumfordAbstract:Abstract A field trial was conducted at Casey Station, Antarctica to assess the suitability of a permeable Reactive Barrier (PRB) media sequence for the remediation of sites containing both hydrocarbon and heavy metal contamination. An existing PRB was modified to assess a sequence consisting of three sections: (i) Nutrient release/hydrocarbon sorption using ZeoPro™ and granular activated carbon; (ii) Phosphorus and heavy metal capture by granular iron and sand; (iii) Nutrient and excess iron capture by zeolite. The media sequence achieved a greater phosphorus removal capacity than previous Antarctic PRB configurations installed on site. Phosphorus concentrations were reduced during flow through the iron/sand section and iron concentrations were reduced within the zeolite section. However, non-ideal flow was detected during a tracer test and supported by analysis of media and liquid samples from the second summer of operation. Results indicate that the PRB media sequence trialled might be appropriate for other locations, especially less environmentally challenging contaminated sites.
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evaluation of a permeable Reactive Barrier to capture and degrade hydrocarbon contaminants
Environmental Science and Pollution Research, 2015Co-Authors: Kathryn A Mumford, Ian Snape, Shane M Powell, Greg Hince, John L Rayner, Geoffrey W StevensAbstract:A permeable Reactive Barrier (PRB) was installed during 2005/2006 to intercept, capture and degrade a fuel spill at the Main Power House, Casey Station, Antarctica. Here, evaluation of the performance of the PRB is conducted via interpretation of total petroleum hydrocarbon (TPH) concentrations, degradation indices and most probable number (MPN) counts of total heterotroph and fuel degrading microbial populations. Results indicate that locations which contained the lowest TPH concentrations also exhibited the highest levels of degradation and numbers of fuel degrading microbes, based on the degradation indices and MPN methods selected. This provides insights to the most appropriate Reactive materials for use in PRB’s in cold and nutrient-limited environments.
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hydraulic performance of a permeable Reactive Barrier at casey station antarctica
Chemosphere, 2014Co-Authors: Kathryn A Mumford, Ian Snape, John L Rayner, Geoffrey W StevensAbstract:Abstract A permeable bio-Reactive Barrier (PRB) was installed at Casey Station, Antarctica in 2005/06 to intercept, capture and degrade petroleum hydrocarbons from a decade old fuel spill. A funnel and gate configuration was selected and implemented. The Reactive gate was split into five separate cells to enable the testing of five different treatment combinations. Although different treatment materials were used in each cell, each treatment combination contained the following Reactive zones: a zone for the controlled release of nutrients to enhance degradation, a zone for hydrocarbon capture and enhanced degradation, and a zone to capture excess nutrients. The materials selected for each of these zones had other requirements, these included; not having any adverse impact on the environment, being permeable enough to capture the entire catchment flow, and having sufficient residence time to fully capture migrating hydrocarbons. Over a five year period the performance of the PRB was extensively monitored and evaluated for nutrient concentration, fuel retention and permeability. At the end of the five year test period the material located within the Reactive gate was excavated, total petroleum hydrocarbon concentrations present on the material determined and particle size analysis conducted. This work found that although maintaining media reactivity is obviously important, the most critical aspect of PRB performance is preserving the permeability of the Barrier itself, in this case by maintaining appropriate particle size distribution. This is particularly important when PRBs are installed in regions that are subject to freeze thaw processes that may result in particle disintegration over time.
Oriol Gibert - One of the best experts on this subject based on the ideXlab platform.
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performance of a field scale biological permeable Reactive Barrier for in situ remediation of nitrate contaminated groundwater
Science of The Total Environment, 2019Co-Authors: Oriol Gibert, Amer Assal, Trevor Elliot, Hayley Devlin, Robert M. KalinAbstract:We report the performance of a field-scale permeable Reactive Barrier (PRB) for the biological treatment of nitrate-contaminated groundwater. The Reactive material of the PRB consisted of a mixture of gravel and mulch as a carbon source for denitrifying bacteria. The PRB was equipped with a delivery system that allowed injecting NO3- at controlled rates from the surface directly into the up-gradient layer of the PRB. This way, NO3- concentration entering the PRB was varied (from 1 to 530 mg/L) with the purpose of evaluating the ultimate efficiency of the PRB under different NO3- loadings. The PRB was successful at removing NO3- from groundwater at inlet concentrations up to 280 mg/L (with NO3- removal percentages ≥97%). Monitoring of groundwater at different depths within the PRB provided evidence that NO3- underwent denitrification preferably at the deepest part of the PRB, where more favourable reducing conditions were achieved. Among the shortcomings of the PRB were the fluctuations of groundwater fluxes caused by intense rainfalls during the study period, although they generally did not pose concern for the denitrification capacity of the PRB. Emission fluxes of gases (CO2, CH4 and N2O) from the PRB to the atmosphere were also measured. The results are finally compared with the few others reported existing PRBs for nitrate-contaminated groundwater worldwide.
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in situ remediation of acid mine drainage using a permeable Reactive Barrier in aznalcollar sw spain
Journal of Hazardous Materials, 2011Co-Authors: Oriol Gibert, Tobias S Rotting, Jos?? Luis Cortina, Joan De Pablo, Jesus Carrera, Carlos Ayora, J BolziccoAbstract:Abstract Following on the accident occurred in Aznalcollar in 1998, whereby a huge amount of acid mine drainage and heavy metal-bearing pyritic sludge was released to the Agrio river valley with the subsequent contamination of groundwater, a subsurface permeable Reactive Barrier (PRB) was installed to mitigate the long-term impacts by the spillage. The PRB material consisted of a mixture of limestone and vegetal compost. A particular characteristic of the Agrio aquifer is its high water flow velocity (0.5–1 m/d), which may pose difficulties in its remediation using PRB technology. The present study reports the 36-month performance of the PRB. Vertical differences in water velocity were observed within the PRB, with the deeper part being slower and more effective in neutralizing pH and removing heavy metals (Zn, Al, Cu). On the other hand, partial sulfate removal appeard to be restricted to the bottom of the PRB, but with no apparent influence on downgradient water quality. The results are finally compared with the other four reported existing PRBs for AMD worldwide.
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selection of organic substrates as potential Reactive materials for use in a denitrification permeable Reactive Barrier prb
Bioresource Technology, 2008Co-Authors: Oriol Gibert, Ivan Rowe, Sylwia Pomierny, Robert M. KalinAbstract:The aim of the present study was to select a suitable natural organic substrate as a potential carbon source for use in a denitrification permeable Reactive Barrier (PRB). A number of seven organic substrates were first tested in batch tests. The materials attained varying degrees of success at promoting denitrification. Some of the organic substrates performed very well, achieving complete nitrate removal (>98%), while others were considered unsuitable for a variety of reasons, including: insufficient nitrate or nitrogen removal, excessive release of leachable nitrogen from the substrate or excessive reduction of nitrate to ammonium rather than removing it as gaseous N2. The top performing substrate in terms of denitrification extent (>98%) and rate () was then selected for two bench-scale column experiments in an attempt to simulate the PRB. The inlet concentration was 50 mg dm−3 and the columns operated at two different flow rates: 0.3 cm3 min−1 (Column 1) and 1.1 cm3 min−1 (Column 2). The two columns showed different general patterns, making it clear that the flow rate was a key factor at the nitrate removal. Nitrate was completely removed (>96%) by the passage through Column 1, while only partially removed in Column 2 (66%). The results indicated that the selected organic substrate (Softwood) was applicable for further use as a filling material for a PRB.
