| UV disinfection units are becoming increasingly popular in the wastewater treatment industry. However, the effectiveness of UV disinfection is closely related to the water quality parameters, and inactivation of microorganisms has been shown to decrease in presence of particles. Several studies have reported results on the effect of particle size on UV disinfection, but the importance of the bioflocculation process and the effect of final floc size and structure on UV disinfection have been largely ignored. This study is the first of its kind to study effects of flocs and flocculation on UV disinfection in a completely controlled synthetic system via induced bioflocculation. The study was divided into three phases. In the first phase, it was found that larger sized particles protected E. coli to a lesser extent from UV disinfection. In the second phase, flocculation was observed to decrease disinfection efficiency based on floc size and structure. Finally, the third phase showed that extracellular polymers played an important role in disinfection kinetics by absorbing UV light. |
