Abstract：The objective of this work was to investigate the effectiveness of ozonation on the removal of organic residues and pathogenic microorganism from the municipal secondary effluent. The DOC, UV254, chroma, di-n-butyl phthalate (DBP),di-2-ethylhexyl phthalate (DEHP) and organic pollutants of three-dimensional fluorescence removals of ozonation were 15.49%, 36.36%, 73.61%, 37.29%, 14.6% and above 80% at a dose of 6mg/L, respectively. And the ozonated secondary effluent concentration of DBP and DEHP was 2.64mg/L and 1.4mg/L, respectively, which meets the standard of the Reuse of Urban Recycling Water Quality Standard for Groundwater Recharge (GB/T 19772-2005). The fecal coliforms were close to 103CFU/L and 10CFU/L by ozonation (at a ozone dose of 10mg/L) and chlorination (at a available chlorine dose of 5mg/L), respectively. However, the combination of ozonation (at a ozone dose of 6mg/L) and chlorination (at a available chlorine dose of 5mg/L) led to an increased removal of fecal coliforms of 3CFU/L, which meets the standard of the Reuse of Urban Recycling Water-Water Quality Standard for Scenic Environment Use (GB/T 18921-2002). The generation of trihalomethanes (THMs) increased with the increase of available chlorine dosage, while it was reduced by 78.08% by using the combination of ozonation and chlorination.
