Para-nitrophenol adsorbed on bone char synthesized from cow bones has been studied.The Langmuir Freundlich and Sips models were applied to the equilibrium data to describe the adsorption process.The Langmuir model bes...Para-nitrophenol adsorbed on bone char synthesized from cow bones has been studied.The Langmuir Freundlich and Sips models were applied to the equilibrium data to describe the adsorption process.The Langmuir model best described the adsorption process with R^2=0.919;and maximum adsorption capacity,qmax of 365.76 mg/g.Batch kinetic studies conformed to pseudo-second-order indicating that several mechanisms may be involved in the process and gave a value of 2.5×10^4 g/mg/min for the rate constant for the sorption ofp-nitrophenol on bone char.The values of thermodynamic parameters,free energy≈-22.0 kJ/mol,enthalpy-20.2 kJ/mol and entropy 5.34 J/K mol for the adsorption of p-nitrophenol on bone char showed that the adsorption was spontaneous and exothermic.展开更多
Paddy soil and irrigation water are commonly contaminated with hexavalent chromium[Cr(Ⅵ)]near urban industrial areas,thereby threatening the safety of agricultural products and human health.In this study,we develop a...Paddy soil and irrigation water are commonly contaminated with hexavalent chromium[Cr(Ⅵ)]near urban industrial areas,thereby threatening the safety of agricultural products and human health.In this study,we develop a porous and high specific area bone char(BC)to support nanoscale zero-valent iron(n ZVI)and apply it to remediate Cr(Ⅵ)pollution in water and paddy soil under anaerobic conditions.The batch experiments reveal that BC/n ZVI exhibits a higher removal capacity of 516.7 mg/(g·n ZVI)for Cr(Ⅵ)than n ZVI when normalized to the actual n ZVI content,which is 2.8 times that of n ZVI;moreover,the highest n ZVI utilization is the n ZVI loading of 15%(BC/n ZVI15).The Cr(Ⅵ)removal efficiency of BC/n ZVI15 decreases with increasing p H(4–10).Coexisting ions(phosphate and carbonate)and humic acid can inhibit the removal of Cr(Ⅵ)with BC/n ZVI15.Additionally,BC exhibits a strong advantage in promoting Cr(Ⅵ)removal by n ZVI compared to the widely used biochar and activated carbon.Our results demonstrate that reduction and coprecipitation are the dominant Cr(Ⅵ)removal mechanisms.Furthermore,BC/n ZVI15 shows a significantly higher reduction and removal efficiency as well as a strong anti-interference ability for Cr(Ⅵ)in paddy soil,as compared to n ZVI.These findings provide a new effective material for remediating Cr(Ⅵ)pollution from water and soil.展开更多
文摘Para-nitrophenol adsorbed on bone char synthesized from cow bones has been studied.The Langmuir Freundlich and Sips models were applied to the equilibrium data to describe the adsorption process.The Langmuir model best described the adsorption process with R^2=0.919;and maximum adsorption capacity,qmax of 365.76 mg/g.Batch kinetic studies conformed to pseudo-second-order indicating that several mechanisms may be involved in the process and gave a value of 2.5×10^4 g/mg/min for the rate constant for the sorption ofp-nitrophenol on bone char.The values of thermodynamic parameters,free energy≈-22.0 kJ/mol,enthalpy-20.2 kJ/mol and entropy 5.34 J/K mol for the adsorption of p-nitrophenol on bone char showed that the adsorption was spontaneous and exothermic.
基金financially supported by the National Natural Science Foundation of China(Nos.21876161,42077301,41420104007)the National Key Research and Development Project of China(No.2018YFF0213403)+1 种基金the Guangdong Academy of Sciences'Project(Nos.2019GDASYL-0102006,2019GDASYL-0301002,2018GDASCX-0501)the Research Fund of China Geological Survey(DD20190703)。
文摘Paddy soil and irrigation water are commonly contaminated with hexavalent chromium[Cr(Ⅵ)]near urban industrial areas,thereby threatening the safety of agricultural products and human health.In this study,we develop a porous and high specific area bone char(BC)to support nanoscale zero-valent iron(n ZVI)and apply it to remediate Cr(Ⅵ)pollution in water and paddy soil under anaerobic conditions.The batch experiments reveal that BC/n ZVI exhibits a higher removal capacity of 516.7 mg/(g·n ZVI)for Cr(Ⅵ)than n ZVI when normalized to the actual n ZVI content,which is 2.8 times that of n ZVI;moreover,the highest n ZVI utilization is the n ZVI loading of 15%(BC/n ZVI15).The Cr(Ⅵ)removal efficiency of BC/n ZVI15 decreases with increasing p H(4–10).Coexisting ions(phosphate and carbonate)and humic acid can inhibit the removal of Cr(Ⅵ)with BC/n ZVI15.Additionally,BC exhibits a strong advantage in promoting Cr(Ⅵ)removal by n ZVI compared to the widely used biochar and activated carbon.Our results demonstrate that reduction and coprecipitation are the dominant Cr(Ⅵ)removal mechanisms.Furthermore,BC/n ZVI15 shows a significantly higher reduction and removal efficiency as well as a strong anti-interference ability for Cr(Ⅵ)in paddy soil,as compared to n ZVI.These findings provide a new effective material for remediating Cr(Ⅵ)pollution from water and soil.
