The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform
Paul K.s. Lam - One of the best experts on this subject based on the ideXlab platform.
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Solar-Driven Synchronous Photoelectrochemical Sulfur Recovery and Pollutant Degradation
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Chang-bin Chen, Dan-dan Wang, Feng Zhang, Di Min, Paul K.s. LamAbstract:Hydrogen sulfide (H2S) is a Hazardous Contaminant in many industrial gases and wastewaters and a potential source of sulfur to be recovered, but effective and sustainable recovery technologies are ...
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Solar-Driven Synchronous Photoelectrochemical Sulfur Recovery and Pollutant Degradation
2018Co-Authors: Chang-bin Chen, Dan-dan Wang, Feng Zhang, Di Min, Paul K.s. LamAbstract:Hydrogen sulfide (H2S) is a Hazardous Contaminant in many industrial gases and wastewaters and a potential source of sulfur to be recovered, but effective and sustainable recovery technologies are still lacking. Here, we report a novel photoelectrochemical process for synchronous sulfur recovery and removal of organic pollutant, which typically coexist in waste streams, by using solar-simulating light as the sole driving force. In this system, sulfide was selectively converted into high-purity elemental sulfur (S0) particles at the photoanode, whereas efficient electrochemical oxidation of carbamazepine occurred at the cathode through Fe2+/Fe3+-mediated peroxymonosulfate activation. The formed sulfur particles with initial sizes of below one micrometer gradually grew into larger particles. Iodine ions were used as anodic redox mediator to favor a selective S0 production in the solution over the formation of sulfite/sulfate at the electrode surface. The practical feasibility of this system was demonstrated by using carbamazepine-spiked lake water samples. Our work suggests a great opportunity for sustainable recovery of sulfur resource with concomitant benefits of pollutant control by using the inexhaustible solar energy
Douglas E Barker - One of the best experts on this subject based on the ideXlab platform.
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evaluating emergency ventilation strategies under different Contaminant source locations and evacuation modes by efficiency factor of Contaminant source efcs
Building and Environment, 2010Co-Authors: Weiding Long, Xianting Li, Douglas E BarkerAbstract:Emergency ventilation plays an important role in protecting occupants when a Hazardous Contaminant is released indoors. A number of studies have been conducted to better understand how to protect indoor occupants with effective ventilation strategies. However, little attention has been paid to the impact of the non-uniform and time-dependent distribution of occupants during evacuation. A new concept, Efficiency Factor of Contaminant Source (EFCS), has recently been proposed to evaluate the performance of emergency ventilation by comprehensively considering the spatial and temporal distributions of both the Contaminant and occupants. This paper aims to: (1) propose and demonstrate a procedure for determining an optimal ventilation strategy by using EFCS; (2) examine the effects of source locations, ventilation modes, and evacuation modes on the performance of emergency ventilation. One hundred cases with ten ventilation modes, two evacuation modes, and five source locations were investigated numerically. The results show that the EFCS concept can provide a reasonable way to evaluate the performance of emergency ventilation. The threats of different source locations may vary over a large range, and certain measures should be taken to monitor and prevent the releases at high threat locations. A system equipped with multiple ventilation modes is necessary since no universal ventilation mode can successfully mitigate all Hazardous situations. The effects of an evacuation mode may be more significant than that of a ventilation mode under certain situations.
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evaluating emergency ventilation strategies under different Contaminant source locations and evacuation modes by efficiency factor of Contaminant source efcs
Building and Environment, 2010Co-Authors: Weiding Long, Xianting Li, Douglas E BarkerAbstract:Emergency ventilation plays an important role in protecting occupants when a Hazardous Contaminant is released indoors. A number of studies have been conducted to better understand how to protect indoor occupants with effective ventilation strategies. However, little attention has been paid to the impact of the non-uniform and time-dependent distribution of occupants during evacuation. A new concept, Efficiency Factor of Contaminant Source (EFCS), has recently been proposed to evaluate the performance of emergency ventilation by comprehensively considering the spatial and temporal distributions of both the Contaminant and occupants. This paper aims to: (1) propose and demonstrate a procedure for determining an optimal ventilation strategy by using EFCS; (2) examine the effects of source locations, ventilation modes, and evacuation modes on the performance of emergency ventilation. One hundred cases with ten ventilation modes, two evacuation modes, and five source locations were investigated numerically. The results show that the EFCS concept can provide a reasonable way to evaluate the performance of emergency ventilation. The threats of different source locations may vary over a large range, and certain measures should be taken to monitor and prevent the releases at high threat locations. A system equipped with multiple ventilation modes is necessary since no universal ventilation mode can successfully mitigate all Hazardous situations. The effects of an evacuation mode may be more significant than that of a ventilation mode under certain situations.
Chang-bin Chen - One of the best experts on this subject based on the ideXlab platform.
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Solar-Driven Synchronous Photoelectrochemical Sulfur Recovery and Pollutant Degradation
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Chang-bin Chen, Dan-dan Wang, Feng Zhang, Di Min, Paul K.s. LamAbstract:Hydrogen sulfide (H2S) is a Hazardous Contaminant in many industrial gases and wastewaters and a potential source of sulfur to be recovered, but effective and sustainable recovery technologies are ...
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Solar-Driven Synchronous Photoelectrochemical Sulfur Recovery and Pollutant Degradation
2018Co-Authors: Chang-bin Chen, Dan-dan Wang, Feng Zhang, Di Min, Paul K.s. LamAbstract:Hydrogen sulfide (H2S) is a Hazardous Contaminant in many industrial gases and wastewaters and a potential source of sulfur to be recovered, but effective and sustainable recovery technologies are still lacking. Here, we report a novel photoelectrochemical process for synchronous sulfur recovery and removal of organic pollutant, which typically coexist in waste streams, by using solar-simulating light as the sole driving force. In this system, sulfide was selectively converted into high-purity elemental sulfur (S0) particles at the photoanode, whereas efficient electrochemical oxidation of carbamazepine occurred at the cathode through Fe2+/Fe3+-mediated peroxymonosulfate activation. The formed sulfur particles with initial sizes of below one micrometer gradually grew into larger particles. Iodine ions were used as anodic redox mediator to favor a selective S0 production in the solution over the formation of sulfite/sulfate at the electrode surface. The practical feasibility of this system was demonstrated by using carbamazepine-spiked lake water samples. Our work suggests a great opportunity for sustainable recovery of sulfur resource with concomitant benefits of pollutant control by using the inexhaustible solar energy
Janusz Dominik - One of the best experts on this subject based on the ideXlab platform.
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historical record of mercury contamination in sediments from the babeni reservoir in the olt river romania
Environmental Science and Pollution Research, 2009Co-Authors: Andrea G Bravo, Jeanluc Loizeau, Lydie Ancey, Viorel Gheorghe Ungureanu, Janusz DominikAbstract:Background, aim and scope Mercury (Hg) is a ubiquitous and Hazardous Contaminant in the aquatic environment showing a strong biomagnification effect along the food chain. The most common transfer path of Hg to humans is contaminated fish consumption. In severely exposed humans, Hg poisoning may lead to damage in the central nervous system. Thus, it is important to examine current and past contamination levels of Hg in aquatic milieu. The Olt River is the largest Romanian tributary of the Danube River. The use of Hg as an electrode in a chlor-alkali plant contributed to the contamination of the aquatic environment in the Rm Valcea region. The purpose of this study was to compare the current state of Hg contamination with the past contamination using a historical record obtained from a dated sediment core from one of the Olt River reservoirs (Babeni) located downstream from the chlor-alkali plant. To our knowledge, no published data on Hg contamination in this region are available. The Babeni Reservoir was selected for this study because it is situated downstream from the chlor-alkali plant, whilst the other reservoirs only retain the pollutants coming from the upstream part of the watershed. Preliminary analyses (unpublished) showed high Hg concentrations in the surface sediment of the Babeni Reservoir. One core was taken in the upstream Valcea Reservoir to provide a local background level of Hg concentrations in sediments.
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Historical record of mercury contamination in sediments from the Babeni Reservoir in the Olt River, Romania
Environmental Science and Pollution Research, 2009Co-Authors: Andrea G Bravo, Jeanluc Loizeau, Lydie Ancey, Viorel Gheorghe Ungureanu, Janusz DominikAbstract:Background, aim and scope Mercury (Hg) is a ubiquitous and Hazardous Contaminant in the aquatic environment showing a strong biomagnification effect along the food chain. The most common transfer path of Hg to humans is contaminated fish consumption. In severely exposed humans, Hg poisoning may lead to damage in the central nervous system. Thus, it is important to examine current and past contamination levels of Hg in aquatic milieu. The Olt River is the largest Romanian tributary of the Danube River. The use of Hg as an electrode in a chlor-alkali plant contributed to the contamination of the aquatic environment in the Rm Valcea region. The purpose of this study was to compare the current state of Hg contamination with the past contamination using a historical record obtained from a dated sediment core from one of the Olt River reservoirs (Babeni) located downstream from the chlor-alkali plant. To our knowledge, no published data on Hg contamination in this region are available. The Babeni Reservoir was selected for this study because it is situated downstream from the chlor-alkali plant, whilst the other reservoirs only retain the pollutants coming from the upstream part of the watershed. Preliminary analyses (unpublished) showed high Hg concentrations in the surface sediment of the Babeni Reservoir. One core was taken in the upstream Valcea Reservoir to provide a local background level of Hg concentrations in sediments. Results and discussion Sediment texture was uniform in the cores from both reservoirs. Laminated sediment structure, without any obvious discontinuities, was observed. Hg concentrations in the sediment core from the Valcea Reservoir were low and constant (0.01–0.08 mg/kg). In Babeni Reservoir sediments, Hg concentrations were very high in the deeper core section (up to 45 mg/kg in the longest core) and decreased to lower concentrations toward the top of the cores (1.3–2.4 mg/kg). This decrease probably reflects technological progress in control of emissions from the Hg-cell-based chlor-alkali industry. Two strong peaks could be distinguished in older sediments. The mean rate of sedimentation (5.9 cm/year) was calculated from the depth of the ^137Cs Chernobyl peak. This was in good agreement with the sedimentation rate estimated at this site from a bathymetric study. Assuming a constant sedimentation rate, the two Hg peaks would reflect two contamination events in 1987 and 1991, respectively. However, it is also possible that the two peaks belong to the same contamination event in 1987 but were separated by a sediment layer richer in sand and silt. This layer had a low Hg concentration, which can be interpreted as a mass deposition event related to a major flood bringing Hg-free sediments. Conclusions Whilst the chlor-alkali plant partly switched to a cleaner technology in 1999, no obvious decrease of Hg concentrations was observed in recent decade. Results from the sediment core reflected the historical trend of Hg release from the chlor-alkali plant, revealed important contamination episodes and confirmed a legacy of contamination of Hg in recent sediments even if the concentrations of Hg decreased toward the surface due to a more efficient emission control. Recommendations and perspectives Although the Hg concentrations in Babeni Reservoir sediments were extremely high in the late eighties and they remain one order of magnitude higher in the surface sediments than in sediments from the upstream reservoir, little is known about the transfer of Hg to the biota and human population. Our initial measurements indicate the presence of monomethyl-Hg (MMHg) in pore water, but further studies are necessary to evaluate fluxes of MMHg at the sediment–water interface. Samples of fish and hair from various groups of the local population were recently collected to evaluate the potential hazard of Hg contamination to human health in the Rm Valcea region.
Weiding Long - One of the best experts on this subject based on the ideXlab platform.
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evaluating emergency ventilation strategies under different Contaminant source locations and evacuation modes by efficiency factor of Contaminant source efcs
Building and Environment, 2010Co-Authors: Weiding Long, Xianting Li, Douglas E BarkerAbstract:Emergency ventilation plays an important role in protecting occupants when a Hazardous Contaminant is released indoors. A number of studies have been conducted to better understand how to protect indoor occupants with effective ventilation strategies. However, little attention has been paid to the impact of the non-uniform and time-dependent distribution of occupants during evacuation. A new concept, Efficiency Factor of Contaminant Source (EFCS), has recently been proposed to evaluate the performance of emergency ventilation by comprehensively considering the spatial and temporal distributions of both the Contaminant and occupants. This paper aims to: (1) propose and demonstrate a procedure for determining an optimal ventilation strategy by using EFCS; (2) examine the effects of source locations, ventilation modes, and evacuation modes on the performance of emergency ventilation. One hundred cases with ten ventilation modes, two evacuation modes, and five source locations were investigated numerically. The results show that the EFCS concept can provide a reasonable way to evaluate the performance of emergency ventilation. The threats of different source locations may vary over a large range, and certain measures should be taken to monitor and prevent the releases at high threat locations. A system equipped with multiple ventilation modes is necessary since no universal ventilation mode can successfully mitigate all Hazardous situations. The effects of an evacuation mode may be more significant than that of a ventilation mode under certain situations.
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evaluating emergency ventilation strategies under different Contaminant source locations and evacuation modes by efficiency factor of Contaminant source efcs
Building and Environment, 2010Co-Authors: Weiding Long, Xianting Li, Douglas E BarkerAbstract:Emergency ventilation plays an important role in protecting occupants when a Hazardous Contaminant is released indoors. A number of studies have been conducted to better understand how to protect indoor occupants with effective ventilation strategies. However, little attention has been paid to the impact of the non-uniform and time-dependent distribution of occupants during evacuation. A new concept, Efficiency Factor of Contaminant Source (EFCS), has recently been proposed to evaluate the performance of emergency ventilation by comprehensively considering the spatial and temporal distributions of both the Contaminant and occupants. This paper aims to: (1) propose and demonstrate a procedure for determining an optimal ventilation strategy by using EFCS; (2) examine the effects of source locations, ventilation modes, and evacuation modes on the performance of emergency ventilation. One hundred cases with ten ventilation modes, two evacuation modes, and five source locations were investigated numerically. The results show that the EFCS concept can provide a reasonable way to evaluate the performance of emergency ventilation. The threats of different source locations may vary over a large range, and certain measures should be taken to monitor and prevent the releases at high threat locations. A system equipped with multiple ventilation modes is necessary since no universal ventilation mode can successfully mitigate all Hazardous situations. The effects of an evacuation mode may be more significant than that of a ventilation mode under certain situations.
