城市污泥水解压滤混合液厌氧消化处理研究

Treatment of Municipal Sludge Hydrolysate and Press Filtrate by Anaerobic Digestion Process

为了有效回用城市污泥深度脱水产生的大量水解压滤液，分析了实际工程运行的厌氧消化系统的pH值、VFA和碱度等工艺参数和产气量的关系，并研究了该系统对COD、NH3-N和TP的去除能力。研究结果表明：水解压滤液产气率较高，系统稳定后每去除lkgCOD可以产生0．19m。的沼气；进出水pH值变化范围在7．0—7．4之间，适合厌氧菌正常的生理活动条件，进出水VFA值低于850mg／L会影响产气效果，进出水碱度控制在2300～3000mgCaCO3/L之间能有效维持酸碱平衡；系统对COD和TP的去除效果远优于脱氮效果，去除率最高可达63％、67％，出水COD、TP浓度均达到《城镇污水处理厂污染物排放标准》（GB18918—2002）的二级标准。城市污泥水解压滤液大部分都能直接回用，这为推流式厌氧消化工程实践提供了有力的科学依据。

To effectively recycle the large quantity of hydrolysate and press filtrate from advanced dewatering of municipal sludge, the relationship between the gas production and the pH, VFA, alkalinity and other parameters of the anaerobic digestion system in the practical operation was analyzed, and the removal of COD, ammonia-nitrogen and TP in the anaerobic digestion system was measured. The results showed that municipal sludge hydrolysate and press filtrate had good performance of gas production （0.19 m3 methane/kgCOD）. The influent and effluent pH both were 7.0 to 7.4 which was suitable for growth of anaerobic bacteria. The influent and effluent VFA both were lower than 850 mg/L, and the alkalinity of them both were 2 300 to 3 000 mgCaCO3/L. The 67% respectively, which were much better than the highest removal rates of COD and TP were 63 % and removal of ammonia nitrogen. The concentrations of COD and TP in the effluent could meet the second class criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （ GB 18918 - 2002）. Most of municipal sludge hy-drolysate and press filtrate could be directly reused, which provided strong scientific basis for engineering practice of plug-flow anaerobic digestion.