一级A污水处理厂提标改造可行性分析:以青岛市某污水处理厂为例

FEASIBILITY ANALYSIS ON FURTHER UPGRADING WASTEWATER TREATMENT PLANT EXECUTING THE FIRST LEVEL A STANDARD:A CASE STUDY IN QINGDAO

采用达标保证率法评价了青岛市某市政污水处理厂出水的GB 18918-2002《城镇污水处理厂污染物排放标准》一级A标准达标情况,研究水质提升至GB 3838-2002《地表水环境质量标准》Ⅳ类、GB 3097-1997《海水水质标准》Ⅱ类的可行性。结果表明:该厂全年进、出水各指标稳定,处理工艺可达到GB 18918-2002一级A设计标准。但经处理后的出水每年仍向接纳海域排放COD 770 t,BOD576 t,SS 209 t,NH3-N 41 t,TN 255 t,TP 54 t,给环境带来较大负担。为了保护环境并考虑出水再生回用,分别以GB 3838-2002Ⅳ类、GB 3097-1997Ⅱ类作为提标改造目标,对6种污染物进行等标污染负荷计算及排序。结果表明:以GB 3838-2002Ⅳ类水质标准评价,TN、SS和NH3-N三者为主要污染物,总污染负荷比为80. 64%。以GB 3097-1997Ⅱ类水质标准评价,则TN、COD和TP为主要污染物,三者总污染负荷比为87. 39%。不论执行何种标准都应重点加强TN的去除。成本分析表明,提标改造成本增加主要为碳源。ρ(TN)从目前出水的9. 37 mg/L,分别下降到1. 5,0. 3 mg/L,单位运行成本提高分别为0. 13,0. 15元/m3。

We evaluated the first level A standard of effluent for a municipal wastewater treatment plant in Qingdao by adopting the standard guarantee rate method,and studied the feasibility on upgrading the standard to class Ⅳ surface water and second class sea water. The results showed that both influent and effluent were stable throughout the year and the treatment technique could steadily reach the designed criteria of the first level A for municipal wastewater treatment plant. However,there are still 76 tons of BOD5,770 tons of COD,209 tons of SS,41 tons of NH3-N,255 tons of TN and 54 tons of TP discharged into the circumstances,resulting in a large environmental burden. In order to protect the environment and consider the water reuse,classⅣ surface water and second class sea water were employed as the target effluent criteria,and the characteristics of all six pollution indicators were evaluated by the equal standard pollution load approach. Based on their pollution degree,TN,SS and NH3-N were identified as the main pollutants in terms of class Ⅳ surface water criteria with total pollution load ratio of 80. 64%,while TN,COD and TP were identified as the main pollutants in terms of second class sea water criteria with total pollution load ratio of 87. 39%. No matter what standards are implemented,emphasis should be placed on strengthening the TN removal. The cost analysis suggested that the main consumption in the upgrading was carbon source. The unit operating costs increased0. 13 yuan/m3 and 0. 15 yuan/m3,respectively,by reducing TN from the current 9. 37 mg/L to 1. 5 mg/L and 0. 3 mg/L.