Biosorption of heavy metals by marine algae Ulva rigida, Cystoseira barbata and C. crinita

Abstract

Adsorption properties of three different marine algae (Ulva rigida (green algae); Cystoseira barbata (brown algae) and Cystoseira crinita (brown algae)) were investigated. They were collected from the Black Sea coastal area in Varna region, Bulgaria. Kinetics were studied to evaluate the ability of the three algae to sequester Cu (II), Zn (II), Pb (II), Ni (II), Cd (II) from aqueous solution. The maximum biosorption capacity obtained was 2.84 mgeq Ni2+/g for Cystoseira crinita and 2.28 mgeq Cu2+/g for Cystoseira barbata at a solution pH of 5 ± 0.5. The influence of pH of the solution and algae mass on the heavy metal sorption was investigated either. Desorption using 0.05 M HNO3 was carried out and was determined that regeneration of biomass for use in multiple cycles of Cd (II) biosorption –desorption should be feasible.