Abstract:After the relocation project of a municipal WWTP in Shandong Province, its total treatment scale is 25×104 m3/d. the step-influent multi-stage AO is adopted in the secondary treatment of design. The combination of "high-efficiency clarifier + V-type filter + ozone catalytic oxidation" is adopted in the advanced treatment. The designed effluent standard is Class IV surface water standard, in which TN<15 mg/L. In Working Scheme of "Two Zero Clearings and One Standard Upgrading" for Urban Drainage in Shandong Province issued in 2022, the effluent standard of urban WWTP is required to reach Class IV surface water, in which TN is controlled at 10 mg/L. The engineering reconstruction is not implemented in the project, that is, the new discharge standard is realized.