Trace organic compounds (TrOCs) have been detected in drinking water supplies around the world. Since the current treatment process is originally designed for the removal of suspended solids and pathogenic bacteria, the removal efficiencies of TrOCs are typically low, which may bring concern on health risk. Thus, update the current treatment process is urgently needed. This study proposed a novel peroxomonosulfate (PMS) amended iron coagulation process and found its effectiveness in eliminating TrOCs in synthetic and natural waters. In synthetic waters containing hydroquinone (HQ) or benzoquinone (BQ), Fe(III)/PMS effectively degraded carbamazepine (CBZ), a representative of resistant TrOCs. The step of reduction of Fe(III) to form Fe(II) governed the degradation rates of CBZ as PMS activation by Fe(II) was the dominant reaction to generate sulfate radicals (Fig. 1), which was the major reactive oxidant in the system. Meanwhile, HQ was quickly transformed to BQ in the Fe(III)/PMS system and BQ acted as an electron shuttle to induce Fe(III)/Fe(II) redox cycle and accelerate PMS activation (Fig. 1). Natural organic matter (NOM) bearing phenolic and quinone moieties played similar roles as HQ and BQ and fast CBZ degradation was also observed. Finally, two surface waters spiked CBZ were subjected to bench-scale experimentation to simulate coagulation/flocculation/sedimentation processes in water treatment plants. Compared to the conventional iron coagulation process, the PMS-amended iron coagulation process increased the removal percentage of CBZ by 50% - 80%. Overall, this study demonstrates that PMS-amended iron coagulation is a promising process for the abatement of TrOCs in water treatment.

Novel peroxymonosulfate (PMS)-enhanced iron coagulation process for simultaneous removal of trace organic pollutants in water

ACS Spring Meeting 2021

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