Crayfish Shell Waste As a Safe Biosorbent for The Removal of Cu2+ and Pb2+ from Synthetic Wastewater
- Accepted Date: 2020-07-02
Abstract: Crayfish shell is an abundant natural waste meanwhile a potential biosorbent for pollutants if the release of heavy metals can be ignored. In this study, the safety of crayfish shell as a biosorbent was first accessed by the release experiments involving primary heavy metal ions, such as Cu2+, Zn2+, and Cr3+, in aqueous solution under environmental conditions. Although the release concentrations of heavy metals were dependent on pH, ionic strength, and humic acid, the concentrations were still lower than the national standard. The removal of Cu2+ and Pb2+ by crayfish shell in synthetic wastewater was investigated. The results indicated that crayfish shell is an excellent biosorbent for the removal of Cu2+ and Pb2+, and the removal process involved biosorption, precipitation, and complexation. Particularly, the precipitation step is calcium species-, pH- and temperature-dependent. The maximum removal capacity of Pb2+ and Cu2+ reached 676.20 and 119.98 mg g-1, respectively. The related precipitation and complex products include Cu2CO3(OH)2, Ca2CuO3, CuCO3, Pb2CO3(OH)2, CaPb3O4, and PbCO3. This study evaluated a recyclable pathway of crayfish shell waste and provides a new explanation for the biosorption of heavy metals by crayfish shell.
|Citation:||ShuoChen. Crayfish Shell Waste As a Safe Biosorbent for The Removal of Cu2+ and Pb2+ from Synthetic Wastewater[J]. Chinese Journal of Chemical Physics .|