Control Strategeis Of Activated Sludge Bulking And Foaming And Exploitation Of Database System

The sludge bulking and foam are worldwide problems and are also a major factor to limit the development of activates sludge process. The bulking and foaming are mainly caused by the excessive growth of filamentous microorganisms. Filamentous bulking and foaming are difficult to control and it needs long time to recover. Combining the growth mechanism of filamentous bacteria and the running parameter of the waste water treatment plant and establishing the forewarning monitoring and control strategies, which is important to the operation of waste water treatment plant.Literature summarization and experiment were studied. The affecting factor of sludge bulking and control strategies were obtained. Forewarning monitoring system of sludge bulking and foaming was put forward. The identifying and controlling database system of filamentous bacteria was established with Visual C++. Here were some primary conclusion.Firstly, amount of filamentous bacteria, running parameter, environmental factors and wastewater characters were suggested as monitoring target of sludge bulking, index of amount grade of filamentous bacteria, SVI(Sludge Volume Index), loading, DO(Dissolved Oxygen), SRT (Sludge Retention Time), temperature, pH and wastewater quality were suggested to forewarn sludge bulking, and indicating range were given. For example, level of filamentous bacteria=3, SVI>150ml/g, F/M<0.25 kgBOD/kgMLSS·d, DO<0.3mg/L, SRT>10d, temperature<15℃ , pH<5, and so on. If two or more indexes were involved in these ranges, the treatment system should be aroused to guard, and some control strategies should be applied to resolve the problem.Secondly, four parts including identifying system of filamentous, estimation system of running parameter, observation system of biological status, and system of controlling measure were used as frame. The database system of activated sludge filamentous which could be used for identifying filamentous bacteria and giving control strategies was set up with Visual C++. The database system could be used easily by operator to identify the kinds of filamentous bacteria arousing sludge bulking and foaming as well as the level of sludge bulking and foaming and the control strategies.Thirdly, the database system was tested with control of sludge bulking in the industrial wastewater treatment plant and foaming in the municipal wastewater treatment plant. The information of database system was proved by lab scaleexperiment, and detail control information could be obtained which could be applied to resolve the problems of sludge bulking and foaming in these waste water treatment plants. The database system was proved to be reliable and practicable.