Removal of persistent organic pollutants and disinfection of pathogens from secondary treated municipal wastewater using advanced oxidation processes.

Abstract

An affordable and sustainable tertiary treatment is imperative to solve the secondary contamination issues related to wastewater reuse. To decontaminate and disinfect the actual secondary treated wastewater, various types of advanced oxidation processes (AOPs) have been studied. The optimization of the oxidant and catalyst is carried out to identify the best-performing system. Under selected experimental conditions, UV/peroxymonosulfate (PMS), O3/PMS, UV/MnO2, O3/MnO2, UV/O3/H2O2, O3/MnO2/H2O2, UV/MnO2/H2O2, and UV/O3/MnO2 has been identified as an efficient treatment option for simultaneous decontamination (>90% COD removal) and disinfection (100% inactivation of the total viable count of bacteria). The techno-economic assessment revealed that UV/MnO2 (23.5 $ kg-1 of COD) UV/O3/MnO2 (37.4 $ kg-1 of COD), UV/H2O2/MnO2 (36.4 $ kg-1 of COD), and O3/MnO2/H2O2 (32.5 $ kg-1 of COD) are comparatively low-cost treatment processes. Overall, UV/MnO2, UV/H2O2/MnO2, and O3/MnO2/H2O2 are the three best treatments. Nevertheless, further investigation on by-product and catalyst toxicity/recovery is needed. The results showed that AOPs are a technologically feasible treatment for simultaneously removing persistent organic pollutants and pathogens from secondary treated wastewater.