The performance of urea-intercalated and delaminated kaolinites-adsorption kinetics involving copper and lead

Journal of the Brazilian Chemical Society

Universidade Estadual de Campinas, Campinas, Brazil¹  Guerra, Denis L.¹  Airoldi, Claudio¹ 

关键词: kaolinite;    adsorption;    heavy metals;    kinetics;    delamination;   

DOI  :  10.1590/S0103-50532009000100005

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

Brazilian kaolinite clay was used to study urea intercalation (KUR) and delamination (Kur/DL) processes. The intercalated sample was delaminated by ultrasonic treatment in acidic solution. The basal distance changed from 0.72 to 1.08 nm with increasing surface area from 20.3 to 90.5 m2 g-1 for KUR and KUR/DL. Suspended pristine, intercalated and delaminated clays at pH 5.0 adsorbed copper and lead cations at the solid/liquid interface. The Langmuir, Redlich-Peterson and Toth adsorption isotherm models were employed in linear and nonlinear regression processes, to give b and KL values for all kaolinites. The highest adsorption capacity of 12.8 mmol g-1 was obtained with delaminated kaolinite. The kinetic parameters analyzed by the Lagergren and Elovich models gave a good fit for a pseudo-second order reaction with k2 in the 5.0 to 11.0 and the 4.9 to13.0 mmol-1 min-1 ranges for copper and lead cations, respectively.

【 授权许可】

Unknown