基于非曝气区关键点流速的污水厂运行状况分析  

Analysis on Operating Condition of WWTP by Measuring Flow Velocity at Key Points in Non-aeration Zone

作　　者：杨亚红[1] 彭党聪[2] 郑阳光[2] 

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]西安建筑科技大学环境与市政工程学院,陕西西安710055

出　　处：《中国给水排水》2015年第3期112-115,共4页China Water & Wastewater

基　　金：国家水体污染控制与治理科技重大专项(2009ZX07317-009)

摘　　要：流速是水处理工艺的关键运行参数之一，基于测定活性污泥处理构筑物单元的关键点流速，对试运行的新建污水厂运行状况进行后评价。结果表明：①4#厌氧池池底流速最高达0．16m／s，而池顶流速低至0．059rn／s，确保了污泥混合效果、降低了搅拌功率、确保了厌氧环境；而5”厌氧池内断面大部分流速远小于活性污泥悬浮所需最小流速（0．15m／s），可能存在污泥沉淀。②缺氧池内混合液回流量过大，造成缺氧池内硝酸盐氮浓度过高，能量浪费，消耗进水中有限的碳源，造成对总氮的去除率降低。③缺氧池出水廊道中的水流速度为0．20～0．26m／s，设计合理。④混合液回流廊道宽为2000mm，而缺氧区出水廊道宽为1500mm，这是造成混合液回流廊道的流速远小于出水廊道流速和污泥悬浮所需最小流速的主要原因。Flow velocity is one of the key operation parameters of wastewater treatment processes. The commissioning condition of a new WWTP was post-evaluated by measuring flow velocity at the key points in the activated sludge treatment unit. The results showed that： ①The maximum velocity value was 0.16 m/s in the bottom of the 4# anaerobic tank and the minimum velocity value was 0.059 m/s in the top, which ensured the mixing effect of sludge, reduced the stirring power and achieved the anaerobic environment. However, most of cross-section velocity in the 5# anaerobic tank was far less than the minimum flow velocity （0.15 m/s） required for activated sludge suspension, which meant that sludge sedimentation might take place ; ② The mixed liquor that returned into the anoxic tank was too large, causing too high concentration of nitrate, energy waste, consumption of limited carbon source and low removal rate of TN ; ③ The flow velocity in the effluent corridor of the anoxic tank was 0.20 to 0.26 m/s, showing the reasonable design ; ④ The width of the corridor for the returned mixed liquor was 2 000 mm and the width of the effluent corridor for anoxic zone was 1 500 mm, which was the main reason for the fact that the flow velocity in the corridor of the returned mixed liquor was far less than that in the effluent corridor and the minimum flow velocity required for activated sludge suspension.

关 键 词：污水厂 运行状况 流速 非曝气区关键点 活性污泥法 

分 类 号：X703[环境科学与工程—环境工程]