Biosorption of lead from municipal wastewater by alginate beads, free and alginate-immobilized Chlorella vulgaris.

In this study freely suspended, Ca-alginate immobilized Chlorella vulgaris cells and blank alginate beads were used for removal of Pb(II) from municipal wastewater. Experimental data showed that biosorption capacity of algal cells dependent on the operational condition such as pH, dosages, contact time and temperature. The maximum biosorption of Pb(II) was achieved with Ca-alginate immobilized algal cells at an optimum pH of 5, algal dosage of 3 g/L and contact time of 30 min at room temperature. Results revealed that biosorption rate initially increased rapidly, the optimal removal efficiency was reached within about 30 min. Increasing initial pH resulted in an increase in ions uptake. These results showed that immobilized algal cells in alginate beads could potentially enhance the biosorption of considered metal ions than freely suspended cells. Moreover, the biosorbent has significantly removed lead ions from municipal wastewater at the optimized condition. Immobilized algae in alginate beads were more effective than free cells. Consistently high ions removal was achieved. [ABSTRACT FROM AUTHOR]