Sludge bulking and its control in cold region

Analyzes the main causes for and dominant bacteria causing sludge bulking in activated sludge systems， and points out that, from the experience gained with the sludge bulking control in five years operation in Daqing Chengfengzhuang WWTP(wastewater treatment plant)， besides low oxygen concentration and low F／M load， low temperature is also a reason causing bulking in the cold region， and bulking can be control effectively by reducing the MLSS in the aeration tank or alternative continuous operation of the two aeration tanks to increase the F／M load and increase water temperature of aeration tank by heating air at the aerator inlet．