Modified photo-Fenton for degradation of emerging contaminants in municipal wastewater effluents

摘要

As normal municipal wastewater treatment plants (MWTP) are not able to entirely degrade xenobi-otic substances, this study focuses on modified solar photo-Fenton treatment (5 mg L~(-1) Fe, initial pH ≈ 7) of a municipal wastewater treatment plant (MWTP) effluent. However, effluents do not contain compounds which could form photoactive Fe~(3+) complexes. The use of ferrioxalate, humic substances (HA) and mixing the MWTP effluent with small amounts of influent could be justified to form photoactive Fe~(3+) complexes. All experiments were done in MWTP effluent spiked (5 or 100μg/L) with 15 emerging contaminants (ECs) using a pilot compound parabolic collector (CPC) solar plant designed for solar photocatalytic applications. Dissolved organic carbon and UPLC-UV (with prior solid phase extraction) were applied for evaluating the results. The oxalate-enhanced process provided satisfactory EC degradation results but low residual pH of the treated water. H A (10 mg L~(-1)) enhanced the process, balancing degradation time and residual pH. Mixing of MWTP influent and effluent delivered rather disappointing results, as EC degradation was unsuccessful in all cases tested.