Simultaneous removal of carbamazepine and Cd(II) in groundwater by integration of peroxydisulfate oxidation and sulfidogenic process: The bridging role of SO.

Heat-activated PDS oxidation (HAPO) has been widely used for in-situ chemical oxidation (ISCO) of micropollutants in groundwater, whereas the aesthetic demerit of additional SO production is largely overlooked. In this study, the sulfidogenic process is used to offset the aesthetic demerit, and the production of SO is then employed to recycle heavy metals. The innovative integration technology with PDS oxidation and sulfidogenic process via the bridging role of SO was reported to remove micropollutants and heavy metals in groundwater simultaneously. HAPO could completely degrade CBZ, producing 400 mg/L SO with the addition of 0.50 g/L PDS. Sulfate-reducing bacteria (SRB) utilize SO generated from HAPO as the electron acceptor in the sulfidogenic process, removing and recycling Cd(II) via the precipitation of CdS. The SRB tolerance experiment revealed the viability of PDS oxidation coupled with the sulfidogenic process via the bridging role of SO. Overall, the integration technology is a green and promising technology for simultaneous micropollutants removal and heavy metals recycling in groundwater.