Application of the Integrative Membrane-bioreactor for Treatment of Hospital Wastewater
DING Hang-jun，WEN Xiang-hua，HUANG Xia，LIU Ruo-peng，LIU Rui
(State Key Joint Lab for Environmental Simulation and Pollution Control,Tsinghua University,Beijing 100084,China)

　　Abstract：The results of engineering application of integrative hollow fiber membrane-bioreactor for treatment of hospital wastewater show that the use of this process for treatment of hospital wastewater is technically feasible.The removal rate of 80%,93%,and 83% is achieved respectively for COD,NH3-N,and turbidity in hospital wastewater.The effluent is colorless and odorless with good and stable quality,and surpasses the hospital wastewater discharge standard issued by the ministry of construction.The system has run for more than 6 months without any chemical cleaning.The transmembrane pressure increases slowly and steadily.
　　Keywords：membrane-bioreactor;hospital wastewater;treatment efficiency

1　工程装置与污水水质

　　一体式膜—生物反应器处理医院污水的工程装置设在北京海淀乡卫生院内，设备的内部构造见图1，设计处理能力为20m³/d。
　　整个装置主要由生物反应池和膜组件组成。生物反应池采用好氧完全混合式活性污泥反应池，有效容积为6m³，设有隔板将其分为大小相等的两个池子，内置聚乙烯中空纤维膜组件24块，每块膜组件的面积为4 m²，膜总面积为96m²。膜组件下设有穿孔管曝气，曝气量控制在80～90m³/h。中空纤维膜采用间歇运行，抽吸频率为开13 min，关2 min。压差计用于监测膜过滤压力的变化。液位计控制活性污泥反应器液面的恒定。流量计用于测定膜出水的流量。
　　接种污泥取自北京高碑店污水处理厂二沉池回流污泥。污水先流入调节池，然后由泵提升经细筛网过滤后进入膜—生物反应器。在反应器中，污水中的有机物主要被微生物分解，混合液在泵的抽吸作用下，经膜过滤后得到处理水。

　　工程装置所采用的膜组件是日本三菱公司生产的聚乙烯中空纤维膜，膜组件形状为板状，长为0.8m，宽为0.5m，膜孔径为0.4μm，中空纤维膜外径为0.44mm，内径为0.27mm。海淀乡卫生院是一家规模较小的综合性医院，用水量平均为20m³/d，具体水质情况如表1所示。