Bio-adsorbent preparation based on Chinese Radix isatidis residue for Pb(II) removal

Abstract

Abstract A series of bio-adsorbents with potential for Pb(II) removal from wastewater were prepared by treating Radix isatidis residue (RIR) with integrated chemical treatment and fermentation methods. Batch experiments were used to test the adsorption and desorption performance of different bio-adsorbents. The results showed that treated RIRs had significantly enhanced adsorption capacity of 23.5 and 27.6 mg g−1 for Pb(II) within 50 minutes, in contrast to the raw RIR's 12.2 mg g−1. RIR produced by modified chemical/fermentation treatment can remove up to 31.1 mg g−1. After five adsorption/desorption cycles, about 75% of the adsorption capacities were maintained. This study is a novel approach to reusing the enormous quantity of Chinese herbal medicine residues.