Biosorption of Cu (II) from aqueous solutions: Kinetics and characterization studies

摘要

Removal of heavy metals from industrial wastes has been an important environmental research area. In the present study a mixture of two different types of biosorbent for removal of copper from water was investigated. Three types of biosorbents were tested i.e. EG, UA and a combination of both (EG+UA). The batch scale studies were carried out to study the effect of pH, metal concentration and contact time on adsorption capacity. Maximum removal percentage of Cu (II) by EG was about 99 at pH 5 UA and EG+UA got the maximum removal of Cu of about 68, 74 at pH 8 respectively. In the metal concentration studies EG and UA adsorbed the increased concentration of Cu (II), the combination of adsorbents showed 79.8 adsorption for Cu at 100mg/L and for other concentrations of 200mg/L, 300mg/L, 400mg/L and 500mg/L it showed 68.6, 67.6, 58.8 and 57.1 respectively. The maximum Cu (II) removal exhibited by the EG+UA combination was 79.85 obtained for the optimal contact time of 120 min. EG showed Cu (II) removal was maximum up to 99 and UA showed the removal was maximum up to 84 with the contact time 120 min. The morphology characterization of the three adsorbent systems was investigated using the Scanning Electron Microscope (SEM). The Langmuir isotherm was found to be the best-fitting isotherm which indicates the experimental values match with the theoretical reported values. In the kinetic studies the higher R2 values confirm that the adsorption data are well explained by pseudo second order kinetics.