Research On Advanced Treatment Of Secondary Effluent From Wastewater Treatment Plant In Industrial Park By O₃/UV-BAF Process

Secondary effluent of wastewater from industrial park in Jiangsu was taken as treatment objective. The wastewater of industrial park is difficult to be treated to meet the emission standards due to its characteristics of large shock load, complex water components, and poor biodegradability. A new combined advanced oxidation process reactor (Co-AOP) was designed, and the Co-AOP and Biological Aerated Filter was established for the advanced wastewater treatment of industrial park for aiming at water reuse, which provide the technical support to solve the problem.Different AOPs were compared, including ozonation (O3), ozone and ultraviolet combined AOPs (O3/UV),ozone and hydrogen peroxide coupling AOPs (O3/H2O2) by a bench-scale device, in mineralization degree of effluents and improvement of biodegradability. The results showed that the order of three AOPs was 03/UV> O3/H2O2>O3. When O3/UV was employed in advanced wastewater treatment of industrial park, the analysis results indicated that the removals of UV254, Color and CODCrwere 39.8%,33.3% and 12.2%.Principles of reactor design were researched, and the Co-AOP for the pilot test and one for demonstration engineering was designed and manufactured. The Co-AOP consists of 4 parts:Ozone generator unit, ozone aeration unit, ozone reactor unit and ozone destruct unit, which were manufactured with a 100g/h discharging ozone generator and air oxygen generator, a static mixer for aeration and 316L steel. The pilot reactor consists of three series same units, which is DN100×1600mm, and the disposal throughput is 12.96t/d; the reactor for demonstration engineering consists of six units, which is DN260x 1750mm, and the disposal throughput is 300t/d.Pilot test of Co-AOP&BAF was conducted in the industrial park in Jiangsu. Long-term running data showed that the CODCr removal of AOPs unit is 18.3%. With O3/UV pretreatment, which improved the biodegradability of wastewater. Though the Co-AOP&BAF treatment, CODCr is reduced from 82mg/L to 43mg/L and the CODCr removal increased to 47.6%, which met the A grade of first level in the national discharge standard of pollutants for municipal wastewater treatment plant (GB18918-2002).Demonstrate project of Co-AOP&BAF was conducted in the industrial park Though long-term running data and economic technical analysis, the treatment cost for Co-AOP was 0.47 yuan/t, proving the reactor is not only technically feasible, but also economically with actual demand.