2023 Volume 79 Issue 25 Article ID: 23-25004
Semibatch ozonation treatment and its post soil batch experiment for secondary effluent of sewage treatment were conducted to comprehend the reduction characteristics of trihalomethane formation potential (THMFP) and haloacetic acids formation potential(HAAFP). The target effluents were Membrane bioreactor (A2O-MBR) and Conventional activated sludge (CAS) ones. Before the ozonation, the THMFP and HAAFP in the effluents were 90~120 μg/L and 90~100 μg/L, respectively, whereas the THMFP and HAAFP were reduced by the ozonation with approximately 0.5 mgO3/mgC0 ozone consumption. The HAAFP in A2O-MBR and CAS at the ozone consumption were 40~65 μg/L and 55~92 μg/L, respectively. Comparing to CAS effuluent, the higher reduction was obtained in A2O-MBR effuluent. The fractions of HoN, HoA and HiN contributed to the THMFP and HAAFP in both effluents, and HoN & HoA reduction occurred by the ozonation due to the decrease of these fractions. In the soil batch experiment, the reduction of the THMFP and HAAFP was observed regardless of ozonation in both effluents. Most reduction of the THMFP was found in the samples of A2O-MBR effuluent with 1.65 mgO3/mgC0 ozone consumption for 7 days SAT treatment(from 80 μg/L to 25 μg/L). This result indicated the ozonation promoted the reduction of THMFP in soil aquifer treatment.
