我国城镇污水处理厂运行药耗分析

Analysis of Chemicals Consumption in Urban Sewage Treatment Plants in China

随着我国城镇污水处理规模的不断扩大和排放标准的不断提高,外部碳源、除磷药剂以及脱水药剂等药耗对污水处理厂运行成本的影响不容忽视。通过对"全国城镇污水处理信息管理系统"数据的分析可知,全国范围内投加外碳源、除磷药剂和脱水药剂的污水处理厂比例分别占6%、35%和76%。季节变化和排放标准对外部碳源和除磷药剂的投加影响明显,温度降低时碳源投加厂数量和投加量都会增加,而较低或较高的温度条件下除磷药剂投加量有升高的趋势,执行一级A、一级B、二级标准的污水处理厂的碳源投加量分别为23.28、18.90和16.60 mg/L,除磷药剂投加物质的量之比分别为2.36、2.01和1.95。脱水药剂聚丙烯酰胺(PAM)的月均投加量均在7kg/tDS上下波动,总体上,污水处理厂规模越大,单位投加量越小,规模在(10~20)×10~4m^3/d时投加量最为经济。此外,污泥性质和脱水方式对PAM投加量也有影响。

With the continuous expansion of the scale of urban sewage treatment and continuous improvement of discharge standards in China, the impact of external carbon sources, phosphorus removal chemicals and sludge dewatering agents on operation cost of treatment plants must be considered. The data of chemicals consumption collected from national urban sewage treatment information management system were analyzed, and the results showed that the proportion of plants using external carbon source, phosphorus removal chemicals and dewatering agents accounted for 6%, 35% and 76%, respectively. The effect of seasonal variation and discharge standards on the external carbon source and phosphorus removal chemicals was obvious. Decrease in temperature could lead to increase in the number of treatment plants using external carbon source and dosage of carbon source, and there was an increasing trend of phosphorus removal chemicals dosage in lower or higher temperature conditions. Carbon source dosages of the treatment plants enforcing the first level A criteria, the first level B criteria and the second level criteria were 23.28 mg/L, 18.90 mg/L and 16.60 mg/L, while their amount of substance ratios of phosphor us removal chemicals were 2.36, 2.01 and 1.95, respectively. Monthly average dosage of polyacrylamide （PAM） was around 7 kg/tDS. Generally speaking, the larger the scale, the smaller the dosage, when the scale was （10 to 20） × 10^4 m^3/d, the dosage of PAM was lowest. In addition, the nature of sludge and the way of dewatering also affect on the dosage of PAM.