Separation and preconcentration of lead from aquatic environment using Microcystis--based biosorbent

The naturally abundant Microcystis surrounded by a slime layer has been immobilized as biofilm on a polymer-modified silica gel to obtain a lead-selective robust column packing material which is recyclable for 70 times without any distinct deterioration. The biosorbent has shown quantitative sorption with a preconcentration factor of 83 for trace level lead ion (initial concentration 0.48 microg ml(-1)) in multielemental/natural water samples at pH 5.0 and flow rate 1.0 ml min(-1).