The Experts below are selected from a list of 16398 Experts worldwide ranked by ideXlab platform
Changsheng Peng - One of the best experts on this subject based on the ideXlab platform.
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Removal of crystal violet and methylene blue from aqueous solutions using the fly ash-based Adsorbent Material-supported zero-valent iron
Journal of Molecular Liquids, 2018Co-Authors: Jiwei Liu, Teza Mwamulima, Yongmei Wang, Shaoxian Song, Yi Fang, Changsheng PengAbstract:Abstract A novel granular Adsorbent Material containing zero-valent iron (ZVI-GAM) was prepared with fly ash as skeletal Material, bentonite as binder and Enteromorpha prolifera as pore former. ZVI was synthesized by direct reduction of iron ore tailings powder with the coke as reductant in high temperature reducing atmosphere and embedded in the fly ash-based porous Adsorbent, which could reduce the agglomeration and oxidation of ZVI. The structure of ZVI-GAM was characterized by SEM, EDX, XRD, FTIR and BET. The removal amount of crystal violet (CV) and methylene blue (MB) was evaluated at different contact time, initial dye concentration, pH values and temperature. The adsorption isotherms of CV and MB fitted well to the Langmuir model. The maximum removal capacity of ZVI-GAM for CV and MB was found to be 172.41 mg/g and 151.52 mg/g, respectively. The adsorption processes of CV and MB could be described by a pseudo-second-order kinetic model. The reduction kinetics of CV by ZVI-GAM fitted to pseudo-first-order kinetics model. The results indicated that chemisorption and reduction controlled the removal process of CV while chemisorption only controlled the removal process of MB. The thermodynamic study indicated that the adsorption processes of CV and MB were found to be endothermic and spontaneous. Therefore, ZVI-GAM was an effective, low-cost and recyclable Material for dye removal.
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Removal of Pb(II) and Cr(VI) from aqueous solutions using the fly ash-based Adsorbent Material-supported zero-valent iron
Journal of Molecular Liquids, 2017Co-Authors: Jiwei Liu, Teza Mwamulima, Yongmei Wang, Shaoxian Song, Yi Fang, Changsheng PengAbstract:Abstract In this study, a granular Adsorbent Material containing zero valent iron (ZVI-GAM) was made with fly ash as skeletal Material, bentonite as binder and Enteromorpha prolifera as pore former. Zero-valent iron was synthesized by direct reduction of iron ore tailings with the coke as reductant at 900 °C in the anoxic atmosphere. SEM/EDX, XRD, FTIR and BET analysis were used to characterize ZVI-GAM. SEM image showed that there were many different size pores in ZVI-GAM. XRD analysis indicated the presence of iron in zero-valent state. FTIR analysis revealed that the surface of ZVI-GAM owned the groups responsible for the heavy metals adsorption. The specific surface area of ZVI-GAM was 8.19 m 2 /g. ZVI-GAM was used as reaction and Adsorbent Material for the removal of Pb(II) and Cr(VI) from aqueous solutions. The factors affecting Pb(II) and Cr(VI) ions removal by ZVI-GAM in a batch model were studied including initial heavy metal concentrations, contact time, Adsorbent dosage, pH values and temperature. Maximum removal capacity for Pb(II) and Cr(VI) by ZVI-GAM was found to be 78.13 mg/g and 15.70 mg/g. ZVI-GAM had the best adsorption and reduction capacity for Cr(VI) and Pb(II) and could reduce Cr(VI) to Cr(III) and Pb(II) to Pb 0 . Therefore, ZVI-GAM was an effective, low-cost and recyclable Material and had great potential to be a promising technique for heavy metal remediation.
Jean-françois Focant - One of the best experts on this subject based on the ideXlab platform.
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Impact of the Adsorbent Material on volatile metabolites during in vitro and in vivo bio-sampling.
Talanta, 2020Co-Authors: Flavio A. Franchina, Delphine Zanella, Thibaut Dejong, Jean-françois FocantAbstract:The increased attraction of biological volatile compounds has opened the route to a wide variety of sampling techniques, amongst which trap tubes packed with Adsorbent Materials are commonly used. Many types of Adsorbent Materials are available and the choice of the Adsorbent can impact the obtained results in untargeted analysis. Therefore, a proper combination of the Adsorbent Material and the sample is necessary to increase the robustness and reproducibility of biological studies. In this study, the sampling performance of thermal desorption tubes with six common Adsorbent Material combinations, i.e., Tenax® TA, Tenax® TA/Carbopack™ B, Tenax® TA/Sulficarb, Tenax® TA/Carbograph™ 5TD, Tenax® TA/Carbograph™ 1TD/Carboxen® 1003, and Carboxen® 1016/Carbograph™ 5TD, was evaluated in two different setups: in vitro and in vivo sampling. The in vitro setup consisted of the headspace dynamic extraction of spiked serum, and a mixture of 19 standards was evaluated in terms of response and reproducibility. The in vivo setup consisted into two parts: the first one was based the evaluation of the standard mixture, which was flash-vaporised into Tedlar® bags containing exhaled breath; the second part was based on the longitudinal monitoring of breath metabolites originating from a beverage intake (i.e., brewed coffee), over a 90 min time period. The tubes were all desorbed and analysed in a comprehensive two-dimensional gas chromatography system coupled to a high-resolution time-of-flight mass spectrometer (GC × GC-HR ToF MS). In both sampling setups, the widest analytes coverage and the overall best extraction yield on the selected compounds were obtained using Tenax® TA, followed by Tenax® TA/Carbopack™ B. Tenax® TA provided the highest sampling reproducibility with 12 %RSD, 10 %RSD and
Jiwei Liu - One of the best experts on this subject based on the ideXlab platform.
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Removal of crystal violet and methylene blue from aqueous solutions using the fly ash-based Adsorbent Material-supported zero-valent iron
Journal of Molecular Liquids, 2018Co-Authors: Jiwei Liu, Teza Mwamulima, Yongmei Wang, Shaoxian Song, Yi Fang, Changsheng PengAbstract:Abstract A novel granular Adsorbent Material containing zero-valent iron (ZVI-GAM) was prepared with fly ash as skeletal Material, bentonite as binder and Enteromorpha prolifera as pore former. ZVI was synthesized by direct reduction of iron ore tailings powder with the coke as reductant in high temperature reducing atmosphere and embedded in the fly ash-based porous Adsorbent, which could reduce the agglomeration and oxidation of ZVI. The structure of ZVI-GAM was characterized by SEM, EDX, XRD, FTIR and BET. The removal amount of crystal violet (CV) and methylene blue (MB) was evaluated at different contact time, initial dye concentration, pH values and temperature. The adsorption isotherms of CV and MB fitted well to the Langmuir model. The maximum removal capacity of ZVI-GAM for CV and MB was found to be 172.41 mg/g and 151.52 mg/g, respectively. The adsorption processes of CV and MB could be described by a pseudo-second-order kinetic model. The reduction kinetics of CV by ZVI-GAM fitted to pseudo-first-order kinetics model. The results indicated that chemisorption and reduction controlled the removal process of CV while chemisorption only controlled the removal process of MB. The thermodynamic study indicated that the adsorption processes of CV and MB were found to be endothermic and spontaneous. Therefore, ZVI-GAM was an effective, low-cost and recyclable Material for dye removal.
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Removal of Pb(II) and Cr(VI) from aqueous solutions using the fly ash-based Adsorbent Material-supported zero-valent iron
Journal of Molecular Liquids, 2017Co-Authors: Jiwei Liu, Teza Mwamulima, Yongmei Wang, Shaoxian Song, Yi Fang, Changsheng PengAbstract:Abstract In this study, a granular Adsorbent Material containing zero valent iron (ZVI-GAM) was made with fly ash as skeletal Material, bentonite as binder and Enteromorpha prolifera as pore former. Zero-valent iron was synthesized by direct reduction of iron ore tailings with the coke as reductant at 900 °C in the anoxic atmosphere. SEM/EDX, XRD, FTIR and BET analysis were used to characterize ZVI-GAM. SEM image showed that there were many different size pores in ZVI-GAM. XRD analysis indicated the presence of iron in zero-valent state. FTIR analysis revealed that the surface of ZVI-GAM owned the groups responsible for the heavy metals adsorption. The specific surface area of ZVI-GAM was 8.19 m 2 /g. ZVI-GAM was used as reaction and Adsorbent Material for the removal of Pb(II) and Cr(VI) from aqueous solutions. The factors affecting Pb(II) and Cr(VI) ions removal by ZVI-GAM in a batch model were studied including initial heavy metal concentrations, contact time, Adsorbent dosage, pH values and temperature. Maximum removal capacity for Pb(II) and Cr(VI) by ZVI-GAM was found to be 78.13 mg/g and 15.70 mg/g. ZVI-GAM had the best adsorption and reduction capacity for Cr(VI) and Pb(II) and could reduce Cr(VI) to Cr(III) and Pb(II) to Pb 0 . Therefore, ZVI-GAM was an effective, low-cost and recyclable Material and had great potential to be a promising technique for heavy metal remediation.
Marina Coquery - One of the best experts on this subject based on the ideXlab platform.
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Removal of xenobiotics from effluent discharge by adsorption on zeolite and expanded clay: an alternative to activated carbon?
Environmental Science and Pollution Research, 2014Co-Authors: A. Tahar, J.m. Choubert, C. Miege, M. Esperanza, K. Le Ménach, H. Budzinski, Christelle Wisniewski, Marina CoqueryAbstract:Xenobiotics such as pesticides and pharmaceuticals are an increasingly large problem in aquatic environments. A fixed-bed adsorption filter, used as tertiary stage of sewage treatment, could be a solution to decrease xenobiotics concentrations in wastewater treatment plants (WWTPs) effluent. The adsorption efficiency of two mineral Adsorbent Materials (expanded clay (EC) and zeolite (ZE)), both seen as a possible alternative to activated carbon (AC), was evaluated in batch tests. Experiments involving secondary treated domestic wastewater spiked with a cocktail of ten xenobiotics (eight pharmaceuticals and two pesticides) known to be poorly eliminated in conventional biological process were carried out. Removal efficiencies and partitions coefficientswere calculated for two levels of initial xenobiotic concentration, i.e, concentrations lower to 10 microg/L and concentrations ranged from 100 to 1,000 microg/L. While AC was the most efficient Adsorbent Material, both alternative Adsorbent Materials showed good adsorption efficiencies for all ten xenobiotics (from 50 to 100 % depending on the xenobiotic/Adsorbent Material pair). For all the targeted xenobiotics, at lower concentrations, EC presented the best adsorption potential with higher partition coefficients, confirming the results in terms of removal efficiencies. Nevertheless, Zeolite presents virtually the same adsorption potential for both high and low xenobiotics concentrations to be treated. According to this first batch investigation, ZE and EC could be used as alternative absorbent Materials to AC in WWTP.
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Removal of xenobiotics by adsorption on two mineral Adsorbent Materials as an alternative to activated carbon: a comparative batch approach
2012Co-Authors: A. Tahar, J.m. Choubert, C. Miege, M. Esperanza, K. Le Ménach, H. Budzinski, Christelle Wisniewski, Marina CoqueryAbstract:Xenobiotics, such as some pharmaceuticals and pesticides, are poorly treated in wastewater treatment plants (WWTPs). Thus, their occurrence into the aquatic environment is more and more highlighted. Adsorption process on Materials, such as in tertiary stage of treatment, could be a solution to decrease the concentrations of xenobiotics in effluents that are discharged into the aquatic environment. We carried out an original experiment involving treated domestic wastewater spiked with a cocktail of 10 xenobiotics known as being poorly eliminated in WWTPs (8 pharmaceuticals and 2 pesticides). Two mineral Adsorbent Materials (expanded clay and zeolite), representing a possible alternative to activated carbon, were evaluated for the adsorption of the cocktail of xenobiotics. We studied the influence of the concentration level of xenobiotics on adsorption results. We focused on the concentrations near from usual effluent ranges to be representative with conditions faced in tertiary treatment stage. If activated carbon was the most efficient Adsorbent Material, both alternative Adsorbent Materials showed good adsorption efficiencies for the 10 xenobiotics (in the range of 50-100% depending on the couple Adsorbent Material / xenobiotic). Kd partition coefficients were quantified for different xenobiotics concentration ranges. At low concentration (0.1 – 10 µg/L), expanded clay showed higher Kd values than at high concentration (100 – 1000 µg/L) for a majority of xenobiotics (7 among 10). Kd values for zeolite seemed to be independent of xenobiotic concentration levels. Our results point out that mineral microporous Adsorbent are credible alternatives to activated carbon for adsorption of xenobiotics usually known to be poorly eliminated in WWTPs. The results suggest a possible use into a tertiary stage of treatment in wastewater treatment plants.
Flavio A. Franchina - One of the best experts on this subject based on the ideXlab platform.
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Impact of the Adsorbent Material on volatile metabolites during in vitro and in vivo bio-sampling.
Talanta, 2020Co-Authors: Flavio A. Franchina, Delphine Zanella, Thibaut Dejong, Jean-françois FocantAbstract:The increased attraction of biological volatile compounds has opened the route to a wide variety of sampling techniques, amongst which trap tubes packed with Adsorbent Materials are commonly used. Many types of Adsorbent Materials are available and the choice of the Adsorbent can impact the obtained results in untargeted analysis. Therefore, a proper combination of the Adsorbent Material and the sample is necessary to increase the robustness and reproducibility of biological studies. In this study, the sampling performance of thermal desorption tubes with six common Adsorbent Material combinations, i.e., Tenax® TA, Tenax® TA/Carbopack™ B, Tenax® TA/Sulficarb, Tenax® TA/Carbograph™ 5TD, Tenax® TA/Carbograph™ 1TD/Carboxen® 1003, and Carboxen® 1016/Carbograph™ 5TD, was evaluated in two different setups: in vitro and in vivo sampling. The in vitro setup consisted of the headspace dynamic extraction of spiked serum, and a mixture of 19 standards was evaluated in terms of response and reproducibility. The in vivo setup consisted into two parts: the first one was based the evaluation of the standard mixture, which was flash-vaporised into Tedlar® bags containing exhaled breath; the second part was based on the longitudinal monitoring of breath metabolites originating from a beverage intake (i.e., brewed coffee), over a 90 min time period. The tubes were all desorbed and analysed in a comprehensive two-dimensional gas chromatography system coupled to a high-resolution time-of-flight mass spectrometer (GC × GC-HR ToF MS). In both sampling setups, the widest analytes coverage and the overall best extraction yield on the selected compounds were obtained using Tenax® TA, followed by Tenax® TA/Carbopack™ B. Tenax® TA provided the highest sampling reproducibility with 12 %RSD, 10 %RSD and
