南方农村生活污水处理目标及工艺模式探讨

调研了南方城郊某区氮磷污染源,发现:由农村生活污水排放的氮与磷,分别为种植业的11.4%和11.1%,分别为养殖业和种植业之和的0.44%与0.55%.近年来,农村生活污水处理已初步形成了有别于城市的工艺模式,称之为分散处理技术.通过调研与运行研究,发现:分散处理技术各工艺模式,COD出水均低于60mg/L,其中有好氧段的工艺,运行效果更为稳定;但分散处理技术各工艺模式,均难以实现脱氮除磷目标,出水TN和TP最高为28mg/L和1.8mg/L.由此提出:广大农村生活污水处理,应以消除污水排放对水体产生的黑臭问题为目标,而没有必要、也难以实现污水的脱氮除磷处理目标.

Discussion on objective of rural domestic wastewater treatment and technology system in Southern China

After investigating sources of N and P pollution in a rural area of southern China, it was found that the ratios of amounts of N and P pollution from RDW over those from crop were about 11.4% and 11.1%, respectively. Corresponding values were 0.44% and 0.55% RDW over crop plus breeding. Recently, RDW treatment systems, belong to decentralized processing technologies, have been formed initially. They are different from municipal wastewater treatment technologies. It is found that each effluent COD of decentralized processing technologies was lower than 60mg/L, especial for aeration, by study for operation of demonstration projects and investigation for other projects. However, all decentralized processing technologies have not reached the purpose for the removal of N and P, the highest concentration of effluent TN and TP was 28mg/L and 1.8mg/L, respectively. Therefore, this paper suggests that the main objective of rural wastewater treatment should be eliminating the “black and stink” of waterbody in rural area resulted from RDW discharge by removing organic pollutants, rather than removing N and P which is not necessary and difficulty to be achieved.