Simultaneous Organic Pollutant Removal And Odor Elimination In Integrated A/O Reactor

Integrated wastewater treatment system became a promising process in our country due to its economic feasibility, lower requirement for land and energy, high removal efficiency and easiness for management. In this study, a novel integrated A/O reactor was developed which was consist of an Upflow Anaerobic Sludge Blanket and a Hybrid Biological Reactor. In an integrated A/O reactor, the organic pollutant could be removed as in the conventional wastewater treatment process, while the odor emitting from the anaerobic compartment could be treated directly in the aerobic compartment by sparging and microorganisms. Therefore, the integrated reactor was suitable for the simultaneous organic pollutant removal and odor elimination. In order to improve the function, efficiency and stability of the integrated system, reactor start-up and performance for the simultaneous organic pollutant removal and odor elimination were investigated.During the start-up of the anaerobic compartment, cultivation of anaerobic granular sludge with aerobic activated sludge as seed could be achieved in 80 days by controlling the COD loading rate properly. Diameter of the granular particles was 0.5-1.0 mm, and the sedimentation velocity was 10-45 m/h. Different carriers and their filling patterns were studied, and the aerobic compartment obtained the best performance when Patent Carrier ZL96251960.X was stacked in. Its interlaced reticulation provided coarse surface and interspace for microorganisms to attach and contact with oxygen and nutritionThe COD removal efficiency of the integrated A/O reactor was higher than 94% when the loading rate ranged from 5.33 kgCOD/m3·d to 14.4 kgCOD/m3·d. The best reactor performance was obtained at loading rate of 9.0-14.4 kgCOD/m3·d when the removal efficiency of COD was maximum. When treating organic pollutant and odor together, the removal efficiency of COD, TOC, H2S gas and aqueous S2- was above 96.6%, 97.1%, 95.4% and 99%, respectively. The maximum influent SO42- concentration was 150 mg/L when the outlet H2S could meet the required standard. When microorganisms were present, the oxidation rate of sulfide was 4 to 5 times of that of chemical oxidation. The degradation of organic compounds would not be affected by sulfide of lower concentration, but oxidation of sulfide would become slower as the concentration increase of organic compounds. Degradation rate of sulfide did not depend on concentration ranging from 40 mg/L to 250 mg/L. Using mass balance of C and S, it was known that the organic pollutant mainly converted to CO2 (67.58%) to leave the aqueous system, while the main oxidation product of sulfide was SO42- (88.88%) with the left to sulfur (10.93%).