Advanced treatment for municipal wastewater reuse in agriculture. UV disinfection: bacteria inactivation

A 100 m(3) h(-1) pilot plant was built at West Bari (southern Italy) Wastew ater Treatment Plant and operated from 1996 to 1998 to compare bacteria ina ctivation parasite removal disinfection,, by-products formation and cost ef fectiveness of advanced disinfection methods such as UV rays, peracetic aci d and ozone, alone or in proper combination, on differently treated municip al effluents. This paper reports the bacteria inactivation effectiveness of UV disinfection of secondary secondary-clarified (CL) or secondary-clarifi ed-filtered (F) effluent for meeting the Italian microbial standard for unr estricted reuse of municipal wastewater in agriculture (2 CFU 100 ml-1 of t otal coliforms). Such a 5 log inactivation target was effectively met With F and CL effluents at a dose of 100 and 160 MWS cm(-2) respectively, while it was only almost approached with effluent II at 430 mWs cm(-2) dose. Sign ificant removal of disinfection-resistant bacteria like Pseudomonas aerugin osa as well as full compliance with local agronomic regulation also was ach ieved for both CL and F disinfected effluents.