Pilot-Scale Evaluation of New Secondary Effluent Reclamation System Consisting of Membrane Filtration, Ozonation, H2O2/O3 Treatment and BAC Filtration

The advanced treatment system for water reclamation consisting of membrane filtration, ozonation, ozone-hydrogen peroxide-based AOP (advanced oxidation process) and BAC (biological activated carbon) process has been investigated through two-year-long pilot-scale experiments (72m3·d-1). Experimental results showed that the amount of TOC (total organic carbon) removed was increased by the combination of conventional ozonation treatment and ozone-hydrogen peroxide treatment; the optimum ozone dose for ozone-hydrogen peroxide treatment was 50-70%. The optimum operating conditions of this treatment system to achieve our target TOC concentration of 3mg·l-1 were also determined experimentally: total ozone dose of 30mg·l-1, dose ratio of hydrogen peroxide to ozone of 0.2-0.5g·g-1 and ΔO3/ΔTOC of 17g-O3·g-TOC-1. Moreover, various evaluation methods for water quality, such as chemical analyses using Japanese drinking water criteria, genotoxicity test and biological regrowth test, revealed that this advanced treatment system is suitable for water reclamation.