Correlation analysis of sewage removal rate and microbial quantity in plateau environment

Abstract

Based on A2O process in plateau environment, the correlation between the removal rate of chemical oxygen demand (COD), the total phosphorous (TP), total nitrogen (TN) and ammoniacal nitrogen (NH4+-N) in anaerobic tank, anoxic tank and aerobic tank and the quantity of indicator microorganisms was analyzed with temperature, dissolved oxygen (DO) and the hydraulic retention time (HRT) as working conditions, and the curve regression model of water removal rule and the optimal working conditions were obtained through SPSS analysis. The results showed that the removal rates of COD, TN, TP and NH4+-N were positively and negatively correlated with some indicator microorganisms. The three sets of curve regression models passed the significance test. The DO and COD were cubic models, HRT and COD were quadratic models, HRT and NH4+-N were S curve models. When DO is 2∼3 mg/L, the removal rate of COD can reach 87%. When HRT is 30∼40 h, the removal rate of COD can reach more than 90%, and the removal rate of NH4+-N can reach more than 50%.