广西县级城镇污水处理厂建设及运行效果分析

广西72座县级城镇污水处理厂建设、投资、工艺、运行情况统计表明,广西县级城镇污水处理厂建设规模一般小于2万m3/d,主要采用SBR及其改良工艺、氧化沟、A2/O工艺。污水处理厂单位规模总投资（含管网）、单位规模污水厂建设投资及运行成本随处理规模增大而降低,〈1万、1～2万、2～5万m3/d规模污水处理厂单位规模总投资分别为17 300～4 700、4 700～3 500和3 500元/m3,单位规模建设投资分别为7 250～2 750、2 750～1 900和1 900元/m3,管网实际投资明显低于污水处理厂建设投资。〈2万、2～5万m3/d规模污水处理厂运行成本均值分别为0.48、0.36元/m3。2010年污水处理厂平均负荷率为60.8%,明显低于全国在线污水处理厂的平均水平;污水处理达标率平均值为96%,其中COD、BOD全部达标,但少数污水处理厂因工艺技术、碳源不足而出现氨氮超标。

Construction and Operation of County Wastewater Treatment Plants in Guangxi

The statistics about construction,process,investment,treatment effect of 72 municipal wastewater treatment plants show that the plant scale of county treatment plants is less than 50 000 m3/d in Guangxi.The main treatment processes are SBR,variants process and A2/O,oxidation ditch.The municipal wastewater treatment plant investment of unit total construction（including pipe network）,unit construction and operating costs are reduced with the treatment scale increase.While the treatment scales are below 10 000 m3/d,the investment of unit total construction（including pipe network） is among 17 300-4 700 yuan/m3,unit constructions is from 7 250 to 2 750 yuan/m3;but the scale in 10 000-20 000 m3/d is 4 700-3 500 yuan/m3,2 750-1 900 yuan/m3;and the scale in 20 000-50 000 m3/d is about 3 500 yuan/m3,1 900 yuan/m3.The average operating cost of scales below 20 000 m3/d and 20 000-50 000 m3/d is 0.48 and 0.36 yuan/m3,respectively.The pipe network actual investment is significantly lower than the municipal wastewater treatment plant construction investment.In 2010,the average load rate of the municipal wastewater treatment plant is only 60.8%,lower than the national online average level.96% of average wastewater treatment plant efficiency reaches the standard,COD and BOD of the effluent all reach the standards,but ammonia nitrogen in some municipal wastewater treatment plants is above the standards for less technology,and shortage of carbon source.