宁波市典型居民小区出水BOD_(5)现状及影响因素研究

Study on the Status of BOD_(5)in the Effluent of a Typical Residential District in Ningbo and the Influencing Factors

为落实城镇污水处理提质增效三年行动方案要求、了解宁波市居民小区出水水质基本情况,于2022年7月、9月、10月、12月对宁波市新周净化水厂服务片区内10座典型居民小区生活污水进行采样检测,以BOD_(5)数据为基础,进一步对COD、TN、TP、NH_(4)^(+)、重金属离子等进行检测,系统分析了出水BOD_(5)变化规律及影响因素。结果表明:BOD_(5)在不同居民小区间差异显著,且在不同采样月份存在差异,但其晨昏变化不显著。BOD_(5)/COD均值为0.3987,比值超过0.3的百分比为80.0%,污水可生化性在可接受范围内。BOD_(5)受自然因素影响较为明显,居民生活习惯也会对BOD_(5)产生一定影响,但人为因素影响较为复杂。所选居民小区生活污水中重金属、余氯等指标均较低,COD、TN、TP、NH_(4)^(+)和TOC与BOD_(5)呈现出较强相关性。宁波市典型居民小区出水中BOD_(5)受到多重因素影响,应继续加强生活污水中BOD_(5)的监测及其主控因素分析,结合管网特征全面提升污水处理厂进水BOD_(5)浓度。

In order to implement the requirements of the three-year action plan for urban wastewater treatment quality and efficiency,and to understand the basic situation of the effluent water quality in Ningbo residential district,sampling and testing of domestic wastewater from 10 typical residential districts in Ningbo were conducted in July,September,October and December 2022,based on BOD_(5)data and further testing of COD,TN,TP,NH_(4)^(+),heavy metal ions,etc.The variation pattern of effluent BOD_(5)content and the influence of different factors on it were systematically analyzed.The results showed that the BOD_(5)content varied significantly among different residential areas and in different sampling months,but its morning and evening variation was not significant.The mean value of BOD_(5)/COD was 0.3987,and the percentage of the ratio over 0.3 was 80.0%,and the biochemical properties of the effluent were within the acceptable range.The BOD_(5)concentration is more obviously influenced by natural factors,and the living habits of residents also have some influence on the BOD_(5)concentration,but the influence of human factors is more complicated.The indexes of heavy metals and residual chlorine in the selected residential community domestic wastewater were low,and COD,TN,TP,NH_(4)^(+)and TOC showed a strong correlation with BOD_(5).BOD_(5)in the effluent of a typical residential district in Ningbo is affected by multiple factors,and the monitoring of BOD_(5)in domestic wastewater and the analysis of its main control factors should continue to be strengthened,combined with the characteristics of the pipe network to comprehensively improve the concentration of BOD_(5)in the influent water of the wastewater treatment plant.