新型厌氧膜生物反应器城市污泥消化研究

Research on Sludge Digestion Using New Anaerobic Membrane Bioreactor

基于转盘膜过滤和沼气升流循环搅拌技术构建了新型厌氧膜生物反应器,厌氧消化反应器有效容积为20L,膜有效面积为0.55m^2。采用该反应器对某城市污水厂的剩余污泥进行厌氧消化处理,考察了膜过滤、厌氧消化过程参数、污泥特性和出水水质等的变化情况。结果表明:当温度为30℃、污泥浓度为10.3g/L时转盘膜组件的临界通量在18~21L/(m^2·h)之间;运行周期内污泥混合液ρ(MLVSS)∶ρ(MLSS)由0.61下降到0.42,挥发性固体的累积降解率为58%;污泥过滤比阻从消化前的2.93×10^(15) m/kg下降至9.59×1014,有效改善了剩余污泥的过滤性能;滤液中COD,TN,NH+4-N,TP的平均质量浓度分别为266,514,247,84mg/L。新型厌氧膜生物反应器对剩余污泥具有良好的消化效果,可以达到较高的有机物降解率并改善污泥的过滤性能,出水经消毒处理后可以应用于园林绿化或农业生产,充分利用其营养物质。

A new type of anaerobic membrane bioreactor was constructed based on rotary membrane filtration and biogas up-flow circulation stirring technology.The effective volume of the reactor is 20 L and the effective area of the membrane is 0.55 m^2.Anaerobic digestion of excess sludge from a municipal wastewater treatment plant in Changzhou was carried out by using this new anaerobic membrane bioreactor.And the efficiency of anaerobic digestion was investigated from the following aspects：membrane filtration,parameters of anaerobic digestion process,sludge characteristics and the quality of effluent.The results showed that the critical flux of rotary membrane module was between 18 and 21 L/（m^2·h）when the temperature was 30℃ and the sludge concentration was 10.3 g/L.During the whole operation,the sludge mixtureρ（MLVSS）∶ρ（MLSS）decreased from 0.61 to 0.42 and the cumulative degradation rate of VS was 58%.The specific resistance to filtration of the sludge decreased from 2.93×10^15 m/kg to 9.59×1014 m/kg,which effectively improved the filtration performance of the sludge.The average concentration of COD,TN,NH＋4-N and TP in the filtrate were 266,514,247,84 mg/L,respectively.On the whole,the new anaerobic membrane bioreactor has good digestion effect on the excess sludge,which can achieve higher organic degradation rate and improve sludge filtration performance.Moreover,the effluent can be applied to landscaping or agricultural production after disinfection and its nutrients can be fully utilized.