The removal of oil from oily wastewater in thermal power plant by coal fly ash(CFA) was investigated. It contained about 2.5 g/L of mineral oil,which had to be treated efficiently before it was discharged. The experim...The removal of oil from oily wastewater in thermal power plant by coal fly ash(CFA) was investigated. It contained about 2.5 g/L of mineral oil,which had to be treated efficiently before it was discharged. The experiments were carried out as a function of different initial concentrations of oil,mass dosage,contact time and pH value to obtain the optimum conditions for the removal of oil from oily wastewater. The experimental results show that CFA presents the most suitable conditions for the removal of oil from waste-water at a dosage of CFA 2.5 g/L,15 min of contact time and a pH value of 4.8. The adsorption process is performed with almost 96% of oil removal from wastewater. The kinetic data meet the second-order kinetic model. The Langmuir and Freundlich adsorption models were applied to describing the experimental isotherms and isotherm constants. The equilibrium data fit very well with the Freundlich model.展开更多
Coal fly ashes WSRA and BQRA were ball milled for 5 h to produce their ultrafine coal fly ashes WSUA and BQUA, respectively. Batch kinetic, isotherm and pH effect on adsorption were studied to evaluate removal of Cr ...Coal fly ashes WSRA and BQRA were ball milled for 5 h to produce their ultrafine coal fly ashes WSUA and BQUA, respectively. Batch kinetic, isotherm and pH effect on adsorption were studied to evaluate removal of Cr (VI) from aqueous solutions by ultrafine coal fly ashes comparing with raw coal fly ashes. The kinetics of adsorption indicates the process to be intraparticle diffusion controlled and follows the Lagergren first-order kinetics for all coal fly ashes. The first-order rate constants (k1) of Cr (VI) adsorption onto WSRA, WSUA, BQRA and BQUA are 1.981, 1.497, 2.119 and 1.500 (×10^-2) min^-1, respectively. The adsorption capacities of WSUA and BQUA are much better than those of WSRA and BQRA. Equilibrium adsorption data of all coal fly ashes well satisfy the Langmuir isotherm. The adsorbed amounts of Cr (VI) onto WSUA and BQUA decrease from pH 2 to pH 6 and then increase up to pH 12.展开更多
基金Project(2007BAC24B02) supported by the National Science & Technology Pillar Program during the 11th Five-Year Plan Period,ChinaProject(20070420713) supported by China Postdoctoral Science FoundationProject(CSTC2007AD7036) supported by Chongqing Key Tackle Research Project,China
文摘The removal of oil from oily wastewater in thermal power plant by coal fly ash(CFA) was investigated. It contained about 2.5 g/L of mineral oil,which had to be treated efficiently before it was discharged. The experiments were carried out as a function of different initial concentrations of oil,mass dosage,contact time and pH value to obtain the optimum conditions for the removal of oil from oily wastewater. The experimental results show that CFA presents the most suitable conditions for the removal of oil from waste-water at a dosage of CFA 2.5 g/L,15 min of contact time and a pH value of 4.8. The adsorption process is performed with almost 96% of oil removal from wastewater. The kinetic data meet the second-order kinetic model. The Langmuir and Freundlich adsorption models were applied to describing the experimental isotherms and isotherm constants. The equilibrium data fit very well with the Freundlich model.
基金Funded by the China Post Doctoral Science Foundation (20070411124)the Scientific and Technological Key Project of Shaanxi Province (2006k07-G19)+1 种基金the Industrialization Project of Shaanxi Provincal Department of Education(06JC11)the Scientific and Technological Key Project of Xi’anCity(GG06074)
文摘Coal fly ashes WSRA and BQRA were ball milled for 5 h to produce their ultrafine coal fly ashes WSUA and BQUA, respectively. Batch kinetic, isotherm and pH effect on adsorption were studied to evaluate removal of Cr (VI) from aqueous solutions by ultrafine coal fly ashes comparing with raw coal fly ashes. The kinetics of adsorption indicates the process to be intraparticle diffusion controlled and follows the Lagergren first-order kinetics for all coal fly ashes. The first-order rate constants (k1) of Cr (VI) adsorption onto WSRA, WSUA, BQRA and BQUA are 1.981, 1.497, 2.119 and 1.500 (×10^-2) min^-1, respectively. The adsorption capacities of WSUA and BQUA are much better than those of WSRA and BQRA. Equilibrium adsorption data of all coal fly ashes well satisfy the Langmuir isotherm. The adsorbed amounts of Cr (VI) onto WSUA and BQUA decrease from pH 2 to pH 6 and then increase up to pH 12.