南方城市河流水质变化趋势与稳定对策研究

Research of change trend and the stabilizing strategy of water quality in southern urban rivers

正值南方城市河流基本完成水污染治理工作之际,对主要汇入河段监测断面的氨氮、总磷和溶解氧浓度进行4年跟踪监测(2018—2021),以期探讨河流污染治理的持续成效、影响因素以及发展方向。结果显示,该城市河流考核断面氨氮和总磷浓度均值逐年下降,水质持续改善,稳定达到《地表水环境质量标准》(GB 3838-2002)IV类考核标准;常规监测断面水质各项指标持续改善,超标断面和超标倍数减少,说明“十三五”期间水污染整治工作卓有成效。但部分断面尤其是跨界断面存在总磷波动及超标风险,降雨期间凸显水质季节性波动和超标问题,跨界河段以及初期降雨面源污染防控需要持续关注。水污染治理后的水生态系统重建与自净功能恢复对城市河流水环境稳定与发展至关重要。

The concentration of ammonia nitrogen,total phosphorus and dissolved oxygen in the main monitoring sections of the southern urban rivers were monitored for four years(2018—2021)to discuss the sustained effectiveness,influencing factors and development direction after completion water pollution control.The results showed that the average concentration of ammonia nitrogen and total phosphorus in examination section of the urban river decreased year by year,reaching class IV of the Surface water environmental quality standard(GB 3838-2002).The water quality in the conventional monitoring section continued to improve,and the exceedance sections and the exceedance multiples were reduced,indicating the efficience of the remediation work during the"13th Five-Year Plan"period.But the transboundary sections still had the fluctuation and exceedance risk of total phosphorus.The seasonal fluctuation and exceeding the standard of water quality always remained during rainfall.The prevention and control of pollution from transboundary sections and initial rainfall needs continuous attention.The restoration of hydroecosystem and self-purification function after pollution remediation is very important for the stability and development of urban river.