ANALYSIS OF TEMPORAL AND SPATIAL DISTRIBUTION OF RURAL DOMESTIC SEWAGE AND STATUS OF TREATMENT FACILITIES IN PLAIN RIVER NETWORK AREA

The study selected 160 inlet and outlet water treatment facilities in rural areas under Jiaxing City as the research object, and analyzed the spatial and temporal distribution characteristics of rural domestic sewage pollutants and the status of treatment facilities in order to improve the efficiency of treatment facilities. The results showed that the nitrogen and phosphorus pollution in rural domestic sewage in Jiaxing was more serious than organic pollution. The annual average values of ρ(COD), ρ(TP), ρ(TN) and ρ(NH₄⁺-N) were 142.23, 4.02, 44.19 and 27.74 mg/L, respectively. And there was a large optimization space for the treatment effect of each sewage treatment facility. The annual removal rates of COD, TP, TN and NH₄⁺-N were 50.5%, 29.7%, 36.8% and 51.7%, respectively. The spatial distribution of rural domestic sewage gradually decreased from west to east and from north to south. And the temporal distribution was in the sequence of winter > spring > autumn > summer. Correlation analysis showed that there was a significant positive correlation between COD, TP, TN and NH₄⁺-N (P<0.01), and the correlation coefficient was between 0.688±0.946. The annual carbon-nitrogen ratio and NH₄⁺-N/TN ratio of the influent water in the facility are 3.21 and 68.9%, respectively. The traditional single A²/O treatment process was proved not ideal for the treatment of low-carbon source wastewater. and the treatment effect of sewage treatment facilities can be further enhanced by combining process design, standardizing operation management, and strengthening post-monitoring work in the future.