Heavy metal treatment by chemical reduction

Increasing demand for the toxic metal control has led to search of more effective methods for heavy metal treatment. Chemical reduction is among the methods recently developed. In this study applicability of chemical reduction is experimentally evaluated using NaBH₄ as reducer and nickel solution to assess the performance of the chemical reduction for wastewaters of complexed metal category. EDTA and acetic acid are used as organic ligands. Results indicated that reduction of Ni²⁺ to elemental nickel (Ni⁰) state can be carried out above pH 12 without being affected from the existence of organic ligands. Lower pH experiments is shown that Ni₂B is not precipitated at lower pH. Effect of reducing agent on regular hydroxide precipitation is also experimentally evaluated and no significant effect has been observed.