改良型氧化沟污泥膨胀原因的分析与控制

Analysis and control of activated sludge expansion causes in modified oxidation ditch

为了有效控制低负荷改良型氧化沟工艺的污泥膨胀现象，对该工艺的运行参数进行了系统的分析。结果表明，工艺发生污泥膨胀的主要原因是由于氧化沟循环廊道内的溶解氧浓度分级不明显。针对污泥膨胀原因及相关的膨胀机理，采用在循环廊道内加设插板来保证缺氧区、好氧区溶解氧浓度的合理分布。确定了试验装置的最佳运行条件为：好氧区溶解氧含量为1．5—2．0mg／L，缺氧区溶解氧含量小于0．5mg／L，污泥指数为120～150mL／g，污泥质量浓度为3．5-4．0g／L。

In order to control expansion of activated sludge in low load modified oxidation ditch process, the operational parameters of this process were systematically analyzed. The results indicated that the main reason of activated sludge expansion was the non-obvious gradient of dissolved oxygen concentration in circulating corridor of oxidation ditch. Aimed at the sludge expansion reason and relative expansion mechanism, flashboard was adopted in circulating corridor in order to ensure the reasonable distribution of dissolved oxygen concentration in anoxic and aerobic zones. The optimal operational condition of experimental equipment was that the dissolved oxygen concentration was from 1.5 to 2.0 mg/L in aerobic zone, the dissolved oxygen concentration was below 0.5 mg/L in anoxic zone, the sludge index was from 120 to 150 mL/g and the sludge concentration was from 3.5 to 4.0 g/L.