High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(M...High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(MSWI) fly ash for Cu(Ⅱ) adsorption to achieve the purpose of “treating waste by waste.” The effects of p H, adsorption time, initial concentration, and temperature on the modified MSWI fly ash’s adsorption efficiency were systematically studied in this article. The adsorption performance of the modified MSWI fly ash can be enhanced by the ultrasonic modification. At pH = 2, 3 and 4, the adsorption capacity of the modified MSWI fly ash for Cu(Ⅱ) increased by 2.7, 1.9 and 1.2 times, respectively. Furthermore, it was suggested that the adsorption process of the modified MSWI fly ash can be better simulated by the pseudo-second-order kinetic model, with a maximum adsorption capacity calculated by the Langmuir model of 24.196 mg.g-1. Additionally, the adsorption process is spontaneous,endothermic, and chemisorption-dominated from the thermodynamic studies(ΔH and ΔS > 0, ΔG < 0).Finally, the enhanced adsorption performance of the modified MSWI fly ash for Cu(Ⅱ) may be attributed to electrostatic interaction and chelation effects.展开更多
Sewage sludge ash (SSA), the waste generated in sewage sludge incineration, was obtained from Wuhan Sewage Treatment Plant and used as a low-cost sorbent for removing Cu(Ⅱ) from wastewaters. The sorbent was first mod...Sewage sludge ash (SSA), the waste generated in sewage sludge incineration, was obtained from Wuhan Sewage Treatment Plant and used as a low-cost sorbent for removing Cu(Ⅱ) from wastewaters. The sorbent was first modified with 5 % sulfuric acid to increase its sorption capacity. The specific surface area, porosity, cation-exchange capacity (CEC) and pH ZPC of the sorbent were measured. Batch experiments were made to study the effect of contact time, solution pH value and temperature on sorption. Both Langmuir and Freundlich models well described the Cu(Ⅱ) sorption process, with correlation coefficient (R 2) values of 0.993 4 and 0.989 9 respectively. And the sorption process follows the Lagergren first order kinetic model. The equilibrium sorption capacity of acidified SSA to Cu(Ⅱ) is estimated to be 7.78 mg/g under optimal conditions.展开更多
Coal fly ash(CFA)is composed of minerals containing some oxides in crystalline phase(i.e.,quartz and mullite),as well as unburned carbon as mesoporous material,thus enabling CFA to act as a dual-sites adsorbent with u...Coal fly ash(CFA)is composed of minerals containing some oxides in crystalline phase(i.e.,quartz and mullite),as well as unburned carbon as mesoporous material,thus enabling CFA to act as a dual-sites adsorbent with unique properties.This work focused on the adsorption of Pb(Ⅱ)and Zn(Ⅱ)from binary system,a mixture containing two metal ion solutions present simultaneously,onto NaOH-modified CFA(MCFA).Several adsorption tests were conducted to evaluate the effect of several parameters,including pH and contact times.The experiment results indicated that chemical treatment of CFA with NaOH increased pore volume from 0.021 to 0.223 cm^3·g^(-1).In addition,it could also enhance the availability of functional groups on both minerals and unburned carbon,resulting in almost 100%Pb(Ⅱ)and 97%Zn(Ⅱ)adsorbed.The optimum pH for adsorption system was pH=3 and quasi-equilibrium occurred in 240 minutes.Equilibrium data from the experimental results were analyzed using Modified Extended Langmuir(MEL)and Competitive Adsorption Langmuir-Langmuir(CALL)isotherm models.The analysis results showed that the CALL isotherm model could better describe the Pb(Ⅱ)and Zn(Ⅱ)adsorption process onto MCFA in binary system compared with MEL isotherm model.展开更多
基金supported by the key program of the National Natural Science Foundation of China(52236008).
文摘High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(MSWI) fly ash for Cu(Ⅱ) adsorption to achieve the purpose of “treating waste by waste.” The effects of p H, adsorption time, initial concentration, and temperature on the modified MSWI fly ash’s adsorption efficiency were systematically studied in this article. The adsorption performance of the modified MSWI fly ash can be enhanced by the ultrasonic modification. At pH = 2, 3 and 4, the adsorption capacity of the modified MSWI fly ash for Cu(Ⅱ) increased by 2.7, 1.9 and 1.2 times, respectively. Furthermore, it was suggested that the adsorption process of the modified MSWI fly ash can be better simulated by the pseudo-second-order kinetic model, with a maximum adsorption capacity calculated by the Langmuir model of 24.196 mg.g-1. Additionally, the adsorption process is spontaneous,endothermic, and chemisorption-dominated from the thermodynamic studies(ΔH and ΔS > 0, ΔG < 0).Finally, the enhanced adsorption performance of the modified MSWI fly ash for Cu(Ⅱ) may be attributed to electrostatic interaction and chelation effects.
文摘Sewage sludge ash (SSA), the waste generated in sewage sludge incineration, was obtained from Wuhan Sewage Treatment Plant and used as a low-cost sorbent for removing Cu(Ⅱ) from wastewaters. The sorbent was first modified with 5 % sulfuric acid to increase its sorption capacity. The specific surface area, porosity, cation-exchange capacity (CEC) and pH ZPC of the sorbent were measured. Batch experiments were made to study the effect of contact time, solution pH value and temperature on sorption. Both Langmuir and Freundlich models well described the Cu(Ⅱ) sorption process, with correlation coefficient (R 2) values of 0.993 4 and 0.989 9 respectively. And the sorption process follows the Lagergren first order kinetic model. The equilibrium sorption capacity of acidified SSA to Cu(Ⅱ) is estimated to be 7.78 mg/g under optimal conditions.
基金Deanship of Scientific Research(DSR)at King Saud University(KSU),Saudi Arabia for financially supporting this research project(No.RG-1435-078)。
文摘Coal fly ash(CFA)is composed of minerals containing some oxides in crystalline phase(i.e.,quartz and mullite),as well as unburned carbon as mesoporous material,thus enabling CFA to act as a dual-sites adsorbent with unique properties.This work focused on the adsorption of Pb(Ⅱ)and Zn(Ⅱ)from binary system,a mixture containing two metal ion solutions present simultaneously,onto NaOH-modified CFA(MCFA).Several adsorption tests were conducted to evaluate the effect of several parameters,including pH and contact times.The experiment results indicated that chemical treatment of CFA with NaOH increased pore volume from 0.021 to 0.223 cm^3·g^(-1).In addition,it could also enhance the availability of functional groups on both minerals and unburned carbon,resulting in almost 100%Pb(Ⅱ)and 97%Zn(Ⅱ)adsorbed.The optimum pH for adsorption system was pH=3 and quasi-equilibrium occurred in 240 minutes.Equilibrium data from the experimental results were analyzed using Modified Extended Langmuir(MEL)and Competitive Adsorption Langmuir-Langmuir(CALL)isotherm models.The analysis results showed that the CALL isotherm model could better describe the Pb(Ⅱ)and Zn(Ⅱ)adsorption process onto MCFA in binary system compared with MEL isotherm model.
