Copper(II) and lead(II) sorption from aqueous solution by non-living Spirogyra neglecta

Dried biomass of Spirogyra neglecta rapidly sorbed the test metals and the process became saturated in 10–20 min. Maximum sorption of Pb(II) [116.1 mg g−1] and Cu(II) [115.3 mg g−1] occurred at 0.1 g l−1 biomass and 100 mg l−1 metal concentration in the solution. Sorption of Cu(II) and Pb(II) occurred optimally at pH 4.5 and 5.0, respectively. Lead(II) and Cu(II) sorption were lesser from binary metal solution than from single metal solution. Lead(II) more severely inhibited Cu(II) sorption than vice versa thus reflecting greater affinity of Pb(II) for the biomass. NaOH pretreatment slightly enhanced the metal removal ability of the biomass. During repeated sorption/desorption cycles, Pb(II) and Cu(II) sorption decreased by 11% and 27%, respectively, at the end of the fifth cycle due inter alia to 10–15% loss of biomass. Nevertheless, Spirogyra appears to be a good sorbent for removing metals Cu(II) and Pb(II) from wastewaters.