Nowadays, special attention has been paid to remediate contaminated media through low-cost and high-efficiency biosorbents. In this research, the sorption of zinc (Zn2+) and copper (Cu2+) by cattle manure vermicompost (VC) and VC- amended soil and the effect of common ions on sorption was studied. The VC was characterized by using FT-IR spectra, SEM, BET analyses. Isotherm experi- ments were carried out with different concentrations of Zn2+ and Cu2+ (0– 100 mg L−1) in the presence of 10 mM of background electrolytes (Ca2+, Mg2+, SO42-, and Cl−) as the binary system and the absence of other ions (single system). Data of Zn2+ and Cu2+ adsorption onto VC were fitted to the Langmuir equation. The maximum adsorption capacity (Qmax) of Zn2+ and Cu2+ onto VC in the single system was 7.27 and 17.73 mg g−1, respectively, which decreased in the following order Ca2+ > Mg2+ > SO42– > Cl – in the binary system. The effect of electrolytes on Zn2+ adsorption was more significant than Cu2+ and the Qmax of Zn2+ and Cu2+ decreased on average 20.4 and 10.8%, respectively. The VC addition increased adsorption in soil. Results indicate that VC had potential for the removal of Zn2+ and Cu2+ from single and binary systems.
