Biosorption of copper using algae

Abstract

Using algae in biosorption process is considered as a good method for removal copper because of low cost, high efficiency in low copper concentration, possibility of metal recovery. In this study, Copper absorption capacity of Nannochloropsis oculata, Isochrysis galbana in viable form, non-viable form and dry aquatic plant Ceratophyllum demersum were carried out under various experimental conditions. The effect of pH, initial copper concentration, biosorbent concentration and contact time has been investigated following by the bath absorption method. Nannochloropsis oculata and Isochrysis galbana in viable form have no capacity for copper absorption because of copper toxicity to algae cell. On the other hand, for non-viable form, the optimal condition of biosorption process for pH is 4.7 (nature pH of medium 0.5 g Cu/L) and contact time from three to four hours when copper removal yield constant. The higher copper removal yield in all treatments found in dry Ceratophyllum demersum treatment, for 1 g dry this aquatic plant can remove 0.41 g Cu reaches 41% total copper in solution, which is four times of Nannochloropsis oculata, Isochrysis galbana in same condition. The biosorption capacity increased with increase in the amount of biosorbent used for removal. These results could be useful for removing copper in solution contaminated below 1 g Cu/L. Keywords: Biosorption, copper, viable form, non-viable form, Nannochloropsis oculata, Isochrysis galbana, Ceratophyllum demersum.