Use of biocides in the control of filamentous bulking in activated-sludge

Abstract

[Excerpt] Filamentous bulking can be controlled by specific and/or non-specific methods. Specific methods intend to recognize and resolve the major causes of filamentous bacterial proliferation and are preferred because they are selective for the target microorganism and cause limited damage to the remaining biomass. In what concerns non-specific methods, chlorination was one of the first methods to be used to control filamentous bulking and is still used, but its action is only temporary and tend to damage flocforming bacteria, leading to floc and process breakdown [1]. The use of alternative biocides has attracted the attention of wastewater treatment technicians and researchers for the potential of its use in the control of filamentous overgrowth (ability to induce filamentous cell lysis) and is presently one of the most commonly used methods for the control of filamentous bulking under critical conditions [2]. [...]