Electrochemically-based hybrid oxidative technologies for the treatment of micropollutants in drinking water

Simultaneous degradation of sulfadiazine, naproxen, diclofenac, ketoprofen and ibuprofen from drinking water was investigated by different technologies including photolysis, electrooxidation, photo-electrooxidation, zerovalent iron and their combinations. All oxidation technologies were very effective for the degradation of all drugs under anoxic conditions and the efficiency decreased under oxic conditions. Results also revealed that all drugs can be photochemically degraded by direct reactions, being ketoprofen and diclofenac completely degraded in only 10 min. Oxidizability with electrooxidation decreases in the sequence sulfadiazine > naproxen > diclofenac > ketoprofen > ibuprofen. Antagonistic effect was observed when photolysis was coupled to electrooxidation for all drugs under anoxic and oxic conditions, except for ibuprofen under O2 bubbling. On the other hand, synergistic effect was observed for ZVI + photolysis, ZVI + electrooxidation for ketoprofen and ibuprofen drugs and ZVI + Photo-electrooxidation for ibuprofen removal. Photo-electrooxidation coupled to ZVI under nitrogen bubbling was found to be the most efficient process.

Automated summary

Various technologies were investigated for the simultaneous degradation of multiple drugs in drinking water, with photolysis and electrooxidation showing the best performance under anoxic conditions. The oxidizability of different drugs varied, with some combinations displaying synergistic or antagonistic effects.