Biosorption of Zn+2 on non living biomass of Spirulina platensis immobilized on polyurethane foam cubes: Column studies

In the present study, the non living biomass of cyanobacteria Spirulina platensis was used for biosorption of Zn+2 in column mode. Polyurethane foam (PUF) cubes were used for immobilizing the biosorbent. A maximum biomass loading of 0.2 g dry S. platensis /(g of PUF cubes) could be achieved. The effect of parameters (such as pH of feed solution, flow rate of feed solution to column, bed height and initial concentration of metal ion in feed solution )on uptake capacity of biosorbent was studied. A maximum uptake capacity of 87.3 mg Zn+2/(g S. platensis) was observed under optimum conditions. The column was regenerated using 0.1 M HCl and sorption-desorption studies were carried out for four cycles. Both  % removal of Zn+2 and uptake capacity of biosorbent were found to progressively decrease with increase in the number of cycles. The biomass was characterized by Fourier transform infrared Spectroscopy (FTIR) and Scanning Electronic Microscopic (SEM) images before and after biosorption.