Rapid Treatment and Reaction Mechanism of Complexation Plating Effluents by Molybdenum Disulfide/Copper Sulfide plus Peroxosulfate Process

摘要

The removal of complexed heavy metals in complexation plating effluents is always a problem. Here molybdenum disulfide/copper sulfide (MoS2/CuS) composite was synthesized to activate peroxosulfate (PMS) to treat complexation nickel simulated plating effluents. MoS2/CuS showed excellent PMS activation effect. The removal efficiency of 50 ppm Ni-EDTA by MoS2/CuS+PMS process and Ni-citrate by MoS2/CuS process reached 99.7 and 100 for 20 min treatment, respectively. The excellent performance of MoS2/CuS+PMS process for heavy metal complexes removal is attributed to two ways: oxidative degradation and catalytic decomplexation. Oxidative degradation is to degrade complexing agent into small molecules through (SO4-)-S-. produced by PMS activated directly by the synergy between MoS2, CuS and Ni-EDTA. Catalytic decomplexation is to replace Ni2+ in Ni-EDTA by the metal active sites of MoS2/CuS to release Ni2+ and remove it. These two degradation pathways make the MoS2/CuS+PMS process has excellent removal efficiency. In addition, the MoS2/CuS+PMS process eliminates the dependence of the Fenton reaction on iron-based reagents and avoids the production of iron sludge precipitation. These findings provide new insights for the development of metal sulfide activating PMS to treat complexation plating effluents.