Multi-Barrier Disinfection Pilot Study for Water Recycling

The growing concerns for chlorine disinfection byproducts lead number of wastewater facilities to look at the alternatives to chlorine for effluent disinfection. This work presents results of a disinfection pilot study testing of three disinfection alternatives: ultraviolet (UV), peracetic acid (PAA) and UV and PAA combined with a 0.4 mgd pilot set up. The objective of using PAA as a disinfectant to UV is to provide a supplement during times when UV system is at the capacity or overloaded. UV disinfection, with and without the injection of PAA, were tested to determine if equivalent or better performance could be obtained at a series of UV and PAA doses than when each technology is applied alone. The results indicated the effectiveness of UV and UV/PAA combination in achieving Title 22 non-restricted reuse effluent quality criteria, while PAA alone was shown not to be able to achieve similar results, at the concentrations tested in the pilot study.