Adsorption of Cd(Ⅱ) and Pb(Ⅱ) from wastewater onto porous lignin beads
In this paper,a crosslinked porous lignin beads (PLB) as adsorbent was adopted to adsorb toxic Pb2+ and Cd2+ ions from aqueous solutions.The pore structure and surface morphology of PLB were characterized by by a variety of techniques.The influences of pH,contact time,initial metal ions concentration,temperatures were investigated.The results showed that the adsorption of both heavy metal ions increases with pH.The adsorption equilibrium data under different temperature can be successfully described by Langmuir,Freundlich and Dubinin-Radushkevich (D-R) isotherms.The Langmuir adsorption model showed the best fit to the adsorption data of Cd2+ and D-R model fits best to the adsorption data of Pb2+.The results obtained also indicated that the adsorption of Cd2+ and Pb2+ increased with increasing temperature indicating endothermic nature of the adsorption process.The kinetic study showed that Cd2+ adsorption followed pseudo-second order rate kinetics and Pb2+ adsorption followed pseudo-first order rate kinetics.Cd2+ adsorption on PLB was mainly through the chemisorption mechanism (ED-R between 12.62 kJ·mol-1 and 16.20 kJ·mo1-1) while physical and chemical absorption coexistence was observed to Pb2+ adsorption.Desorption studies revealed that the desorption rate increased with increasing hydrochloric acid concentration and could finally reach 94 % and 85.1% for Cd2+ and Pb2+,respectively,by adding 3 mol/L of HCI.
Porous lignin beads (PLB) Adsorption Desorption Cd(Ⅱ), Pb(Ⅱ)
Xianfa Li Xuegang Luo
School of Life Science and Engineering, Southwest University of Science and Technology; Engineering School of Life Science and Engineering, Southwest University of Science and Technology
国际会议
太原
英文
423-427
2012-06-23（万方平台首次上网日期，不代表论文的发表时间）