Advanced tertiary treatment of municipal effluents in order to reuse them as water for irrigation

Abstract

Our research is an attempt to treat the municipal treatment plants influents in a three-step (anoxic, anaerobic and aerobic) pilot installation and photoinduced oxidation processes for xenobiotics removal. The advanced treated effluents could be reused as irrigation water (STAS 9450/88). Degradation of chlorobenzenes using various photoinduced oxidation processes such as UV/H2O2, UV/O3 and UV/H2O2/O3 was investigated. Comparative analyses of removal efficiency for trichlorobenzene (TCB) and hexachlorobenzene (HCB) taking into account tested operating parameters were performed. The operating parameters with significant infuence upon the removal efficiency of chlorobenzenes in homogeneous advanced oxidation processes (AOPs) are as following: micropollutants concentrations, reaction/irradiation time and oxidants doses (H2O2, O3). The selected variant, based on laboratory experiments could be used as tertiary treatment step for the municipal wastewater treatment plant, after verification of microbiological indicators, and the final effluent could be used in agricultural purposes – irrigation.