Merit evaluation of disinfection, mineralization, and decolorization of municipal wastewater by the H2O2/UV process for reuse

This study evaluated the efficiency of disinfection, mineralization and decolorization of municipal wastewater by the H2O2/UV process for landscape irrigation reuse. The reaction constant, electrical energy consumption (E-EO), and operation costs were investigated. The results showed that the treated water met the reuse criteria of 200 CFU/100 mL under the conditions of either an H2O2 dose of 50 mg L-1 with an oxidation time of 40 min or an H2O2 dose of 100 mg L-1 with an oxidation time of 20 min for a UV exposure of 36 W. Moreover, the reaction constants of color and TOC could be deduced by linear regression. For disinfection, piecewise linear regressions with the first time interval of 0t 30 min and a second interval of 30t 60 min were performed to determine the reaction constants. For the first time interval, the reaction constants of disinfection (k(N)), mineralization (k(T)) and decolorization (k(C)) in descending order were k(N) > k(C) > k(T). Moreover, the electrical energy consumption was E-EO,E-TOC > E-EO,(coliform) > E-EO,(color). The operation costs of decolorization, disinfection and mineralization were 0.17, 0.22 and 0.33 US$ m(3), respectively; i.e., the operation costs for reuse were TOC > total coliform > color.