Equilibrium and kinetic studies of Pb(II), Cd(II) and Zn(II) sorption by Lagenaria vulgaris shell

Chemical Industry and Chemical Engineering Quarterly

卷:18

关键词: Sorption;    Lagenaria vulgaris;    heavy metals;    kinetics;    isotherms;   

DOI  :  10.2298/CICEQ111117032M

来源: DOAJ

【 摘 要 】

The sorption of lead, cadmium and zinc ions from aqueous solution byLagenaria vulgaris shell biosorbent (LVB) in batch system was investigated.The effect of relevant parameters such as contact time, biosorbent dosage andinitial metal ions concentration was evaluated. The Pb(II), Cd(II) and Zn(II)sorption equilibrium (when 98% of initial metal ions were sorbed) wasattained within 15, 20 and 25 min, respectively. The pseudo first,pseudo-second order, Chrastil’s and intra-particle diffusion models were usedto describe the kinetic data. The experimental data fitted the pseudo-secondorder kinetic model and intra-particle diffusion model. Removal efficiency oflead(II), cadmium(II) and zinc(II) ions rapidly increased with increasingbiosorbent dose from 0.5 to 8.0 g dm-3. Optimal biosorbent dose was set to4.0 g dm-3. An increase in the initial metal concentration increases thesorption capacity. The sorption data of investigated metal ions are fitted toLangmuir, Freundlich and Temkin isotherm models. Langmuir model best fittedthe equilibrium data (r2 > 0.99). Maximal sorption capacities of LVB forPb(II), Cd(II) and Zn(II) at 25.0±0.5°C were 0.130, 0.103 and 0.098 mM g-1,respectively. The desorption experiments showed that the LVB could be reusedfor six cycles with a minimum loss of the initial sorption capacity.

【 授权许可】

Unknown