A comparative study of Cu (II) biosorption on Ca-alginate and immobilized live and inactivated Cladosporium sp.

ABSTRACT

Spores of Cladosporium sp. were immobilized into Ca-alginate beads via entrapment. The alginate beads and both entrapped live and inactivated spores of Cladosporium sp. were used for comparison of biosorptive capacity from aqueous solutions. The factors affecting the adsorption ability on Cu (II), such as the contact time, initial pH, temperature were investigated. The results showed that the Ca-alginate beads containing live spores of Cladosporium sp. had the maximum biosorptive capacity. The biosorption equilibrium was established in about 3 h. The maximum biosorption of Cu (II) on Ca-alginate entrapping spores and no spores were obtained between pH 4.0 and 3.5. Temperature over the range of 15-45 degrees C had no significant effect on the biosorption capacity. The biosorptive capacity increased with initial concentrations in the concentration range of 30-800mg/l. The equilibrium was well described by Langmuir biosorption isotherms. The Ca-alginate beads could be regenerated using 0.1M HCl, The biosorbents were reused in three biosorption-desorption cycles with negligible decrease in biosorptive capacity.