Electrochemical removal of pharmaceutical micropollutants from groundwater

This study is focused on the evaluation of the performance of electrochemical advanced oxidation processes in the treatment of a mixture of five pharmaceuticals contained in low concentration (1 ppm) in two different actual groundwater matrices with very different ionic conductivities. The five drugs selected were sulfadiazine, naproxen, diclofenac, ketoprofen and ibuprofen. Three types of technologies were compared: photolysis, electrolysis and photo-electrolysis. Results pointed out very important differences between the oxidazability of the five drugs with the three technologies. Also, a strong influence of the water matrix on the efficiency of the process. Although the resulting cell voltages were larger during the electrochemical treatments of the low conductivity groundwater, the removal of drugs was found to be faster and more efficient than that obtained when drugs are contained in the high-conductivity groundwaters. The most recalcitrant drug studied was ibuprofen for all processes evaluated, while diclofenac and ketoprofen were found to be the easiest drugs for being degraded. Differences observed are discussed at the light of the mechanisms proposed in the literature.

Automated summary

This study evaluates the performance of electrochemical advanced oxidation processes in treating low-concentration mixtures of five pharmaceuticals in groundwater matrices with different ionic conductivities. Three technologies, photolysis, electrolysis, and photo-electrolysis, were compared. The results show significant differences in the oxidizability of the drugs with the three technologies and a strong influence of the water matrix on the process efficiency.