摘要：

某城镇污水处理厂来水主要是工业企业处理后尾水，废水B/C在0.1左右，可生化性差，易造成氧化沟内污泥生长不佳、污泥浓度低，导致出水不能达标排放。针对该污水处理厂现存问题通过中试研究提出了添加碳源与运行调控相结合的技术方案。结果显示，以乙酸钠为补充碳源对氧化沟内的污泥增长、污水处理厂的出水水质以及运行成本等最为有利。经现场调控，确定污水处理厂最终技改方案：1）乙酸钠投加量为135 mg/L，投加位置为污水处理厂缺氧池进水口处；2）在缺氧池前1/3段底部敷设穿孔管，通过曝气使缺氧池内污泥的氧化还原电位（ORP）维持在-50 mV左右。此方案可使污水处理厂氧化沟内的污泥质量浓度维持在2 700~3 000 mg/L，出水COD、NH₃-N与TP满足《城镇污水处理厂污染物排放标准》（GB 18918—2002）一级A标准。

关键词: 企业尾水, 废水可生化性, 碳源补充, 城镇污水处理

Abstract:

The main wastewater flowing into urban sewage treatment plants is the tail water treated by industrial enterprises. The B/C of the wastewater is around 0.1，which has poor biodegradability and is prone to poor sludge growth and low sludge concentration in the oxidation ditch，resulting in the effluent can not meet the discharge standards. Aiming at the existing problems of the sewage treatment plant，the technical scheme of combining carbon source supplement with operation regulation was proposed through pilot studies. The results showed that sodium acetate was the most favorable carbon source for sludge growth in oxidation ditch，effluent quality of sewage treatment plant and operation cost. According to the field regulation，the final technical transformation plan of the sewage treatment plant was as follows：1）the dosage of sodium acetate 135 mg/L，the dosing position at the inlet of the anoxic tank of the sewage treatment plant， 2）a perforated pipe laid at the bottom of the first 1/3 section of the anoxic tank to maintain the oxidation-reduction potential（ORP） of sludge in the anoxic tank at about -50 mV by aeration. Through this scheme，the sludge mass concentration in the oxidation ditch of the sewage treatment plant could be maintained at 2 700-3 000 mg/L，and the effluent COD，NH₃-N and TP could meet the Class Ⅰ A standard of the Discharge Standard of Pollutants for Urban Sewage Treatment Plants（GB 18918—2002）.

Key words: enterprise tail water, wastewater biodegradability, carbon source supplement, urban sewage treatment

中图分类号: 

• X703.1