What technique can be used to control filamentous organisms in an activated sludge process?

Controlling filamentous organisms in an activated sludge process is essential for maintaining the efficiency of wastewater treatment. The use of oxidants, such as hydrogen peroxide or chlorine, serves a distinct purpose in mitigating the presence of filamentous bacteria, which can promote bulking and other operational issues.

When oxidants are introduced into the return sludge, they can help to selectively target these filamentous organisms without significantly harming the floc-forming, beneficial bacteria that are crucial for effective treatment. This technique can improve settling characteristics and prevent bulking, enhancing the overall performance of the activated sludge system.

Other options, while they can influence the system indirectly, do not target filamentous organisms as effectively. For example, increased aeration can enhance the overall oxygen availability but doesn’t specifically target filamentous growth. Diluting the sludge may lower concentrations but can also dilute the beneficial microbial population and lead to loss of treatment efficiency. The addition of enzymes may change the dynamics of the biological reactions but does not directly address filamentous control. Hence, the selective use of oxidants is a focused approach to managing this specific issue in the activated sludge process.