Mining regions are high-risk zones for co-contamination by heavy metals and organic compounds. Xanthates, as principal organic reagents, are widely employed in froth flotation processes to optimize the recovery of sulfide and oxide minerals. The extensive use of xanthates leads to significant environmental discharge, with China alone generating over 1.2 billion cubic meters of flotation wastewater annually, particularly in the mining regions of southwestern and southern China. Due to their high solubility, the residual xanthates in effluents can readily migrate via seepage from tailings facilities into adjacent soil and groundwater, creating significant pollution and health challenges.

The environmental conditions in real-world mining areas are highly complex, characterized by the coexistence of multiple heavy metals and organic reagents, leading to coupled transport processes dominated by metal-metal and metal-reagent interactions. To accurately predict the environmental fate of heavy metals in these special areas, building on the previous work (Luo et al., 2024), researchers from our school have developed a multisurface speciation reactive model and systematically investigated the coupled reactive transport processes and retention mechanisms under coexisting multimetal-xanthate conditions in porous media. The study significantly expanded the applicability of multisurface speciation models and provided a more robust theoretical tool for scientifically assessing the migration risks of pollutants in complex mining environments.

The research findings have been published in the Nature Index journal Water Research, in a paper titled "Reactive Transport and Retention of Cd, Pb, and Zn under Coexisting Multimetal-Xanthate Conditions in Porous Media." The first author of the paper is Luo Bowen, a graduate student at our school, and the corresponding author is Associate Professor Chen Kouping. Co-authors include Professor Wu Jichun from Nanjing University and Professor Li Ping from the Institute of Geochemistry, Chinese Academy of Sciences. The research was funded by the National Key Research and Development Program [Grant No.2020YFC1807601] and the National Natural Science Foundation of China (Grant No. 42177043).

Figure 1 Schematic diagram of coupled transport and retention under the scenario of coexisting multimetals and xanthate.

Figure 2. The coupled transport process under the scenario of coexisting multimetals and xanthate.

Figure 3. Retention mechanisms under the scenario of coexisting multimetals and xanthate.

Source: https://doi.org/10.1016/j.watres.2025.124713