Efficiency removal and mechanism of xanthate from flotation tailings wastewater via simulated acid mine drainage (AMD) activate H2O2 oxidization

This work investigates the efficiency removal and mechanism of xanthate from flotation tailings wastewater through a coagulation-Fenton oxidation process by introducing Fe 2+ and Mn 2+ to activate H 2 O 2 . Under the conditions of initial 60 mg/L SBX concentration, 50 mg/L H 2 O 2 concentration, 25 mg/L Fe 2+ concentration, 25 mg/L Mn 2+ concentration, 3.5 initial pH, and 60 min reaction time, the degradation rate of xanthate was more than 98 %. The H 2 O 2  + Fe 2+ +Mn 2+ system exhibits markedly superior degradation efficiency for SBX. The results demonstrate that the Fe 2+ +Mn 2+ bimetallic system in simulated AMD facilitates the activation of H 2 O 2 to generate a greater abundance of hydroxyl radicals (•OH). Through characterization of degradation products and analysis of intermediates, two potential degradation pathways of SBX are proposed. In the first pathway, SBX initially undergoes conversion to BPX, which subsequently degrades into small molecular compounds including CO 2 , H 2 O, and SO 4 2− under sustained •OH radical attack. The secondary pathway involves the formation of precipitates composed of xanthates metal (Fe/Mn), iron oxides, and manganese oxides. This work presents a new strategy for efficiently degrading xanthate contaminants in mineral flotation wastewater. It also valorizes AMD by exploiting its intrinsic properties, thereby mitigating AMD's environmental hazards at the source.