Effects Of Particulate Organic Matter On The Nitrogen And Phosphorus Removal Of The A~2/O Process

When referring to the low C/N municipal sewage, particulate organic matter in sewage itself has gradually been paid much attention, which was the research hotspot of the carbon utilization in sewage treatment. With the background of the research of A2/O process in this paper, to explore the utilization and degradation of particulate organic matter in each processing unit and the impact for the removal of nitrogen and phosphorus, for deepening the understanding on the role of particulate organic matter in efficient removal of nitrogen and phosphorus in the low C/N sewage, which can provide theoretical support for the use of particulate organic matter in the A2/O process.The results prove that:(1)In the wastewater treatment plant, the influent components of particle organic matter fluctuated relatively larger, but the effluent concentration of particle organic matter maintained at a low concentration, the removal effect of the particle organic matter and nitrogen and phosphorus in each reaction section were good. When the influent concentration of soluble organic matter kept similar, increasing the concentration of particulate organic matter can promote the removal effect of TN. while the removal effect for TP is not obvious.(2)In the process of A2/O. in the view of the Organics removal area. the vast majority of particulate organic matter was removed in the pre-anoxic and the particulate organic matter removal capacity in each reaction section were the pre-anoxic> anaerobic> hypoxia> aerobic. The test results showed that:when the influent concentrations of total organic matter and particulate organic matter were 178.9mg/L and 121.6mg/L respectively, the removal concentration of particulate organic matter in pre-anoxic. anaerobic, anoxic. aerobic segment were 66.6mg/L.11.4mg/L.8.6mg/L and 5.1mg/L. respectively.(3)In the process of A2/O,when the influent concentrations of dissolved organic matter kept low.increasing the concentration of particulate organic matter had a greater role in promoting the removal of TN.The test results showed that:when the concentrations of dissolved organic matter were57.3mg/L,63.4mg/L,83.4mg/L.the concentrations of particulate organic matter were 121.6 mg/L,140.2mg/L,99.6mg/L, respectively,the actual removal rates of TN were increased by 15.2 %.17.4%,4.6% than the theoretical value.(4) When the influent concentration of particulate organic matter in aerobic tank kept high, it had an inhibitory effect on nitrification to some extent. The test results showed that:keeping that the influent concentration of total organic matter in aerobic tank was about 55mg/L, when the concentration of particulate organic matter was 35.0mg/L, the removal concentration of NH4+-N was 5.9mg/L, while the concentration of particulate organic matter was 28.7mg/L, the removal concentration of NH4+-N reached 9.1 mg/L.(5) In the process of A2/O, when replacing the sewage particulate organic matter with starch, the removal rate of particulate organic matter. TN, TP kept higher than raw sewage. The test results showed that:when replacing the sewage particulate organic matter with starch, the removal rate of particulate organic matter, TN, TP increased by about 5%, above 10%,5%-10%, respectively.