Removal of lead in wastewater by immobilized inactivated cells of Rhizopus oligosporus

A novel technology for lead removal with nonliving Rhizopus oligosporus immobilized in calcium alginate was studied. The results show that the main influencing factors include pH value and interfering cations. pH value has different effects on biosorption of various heavy metals and lead adsorption can be proceeded by controlling pH value in a range of 2–5; interfering cations especially Cu(II) can make the adsorption amount of Pb(II) decrease by immobilized Rhizopus oligosporus. Desorption efficiency of different eluants and kinetics were investigated. Citrate acid with concentration of 0.3 mol · L⁻¹ is the best for the elution of Pb(II) and desorption rate is over 98% when the reaction equilibrium reaches 3 h. Immobilized biomass keeps high lead biosorption capacity after five cycles of regeneration. Foundation item: Project (2001-39) supported by Excellent Young Teachers Program of Ministry of Education of China