Abstract

In this study, ozonator combined with flotator (OCF) have been applied to treat the mineral processing wastewater. The process efficiency has been evaluated in the bench scale. Removing xanthate from aqueous solution was conducted by OCF. In all cases, the butyl xanthate concentration in the treated water was found to be negligible (<0.42 mg L⁻¹). The experiments were preceded under different reaction conditions to study the ozonation time and pH on the oxidation of butyl xanthate. The concentration of butyl xanthate and sulfide are analyzed at special time intervals to elucidate the decomposition of butyl xanthate. In addition, oxidation reduction potential and pH are continuously measured in the course of experiments. Chemical oxygen demand is chosen as a mineralization index of the ozonation of butyl xanthate. The degradation mechanism between butyl xanthate and ozone has been discussed. The OCF technology showed to be an efficient process, which requires ozone and flotator, and the treated water ended up with a very low residual concentration of xanthate and COD. It can be inferred from ultraviolet spectrum, HPLC-MS and COD measurement that SO₄²⁻is produced. The COD of butyl xanthate solution declined dramatically, the removal rate of COD reached 72.21% when ozonation time is 60 min. And the biodegradability (BOD/COD) of butyl xanthate solution increased markedly and shifted from 0.251 to 0.361. It is believed that this ozonation–flotation technique, here named OCF, using ozonator and flotator has a high potential as a alternative method for pollutants removal (flotation reagents, such as butyl xanthate) form waste mining effluents.