Full-Scale evaluation of UV and peracetic acid as alternative disinfecting agents to chlorine in WWTPs

Experimental studies were carried out with the aim of improving the disinfection process efficiency of the final effluents from wastewater treatment plants of the city of Rome. Two different agents were tested and compared to sodium hypochlorite (SH): (1) ultraviolet (UV) radiation with the aim of achieving a final effluent suitable to be reused according to the Italian legislation in force (D.M. 185/2003); (2) peracetic acid (PAA). Several tests under different operating conditions (dosage and contact times) were carried out in full-scale wastewater treatment plants (WWTPs) where the UV and PAA disinfection systems were installed. The study on UV disinfection showed removal efficiency of Escherichia coli ranging from 99.9% to 90%, with an average value of 97%. The use of PAA allowed to achieve removal efficiency of E. coli always about 99%; the optimal dose, and therefore the economical convenience of PAA with respect to the use of SH, was found to be strongly dependent on the E. coli

Lo studio riporta i risultati sperimentali di una ricerca condotta su impianti di depurazione in piena scala per valutare l'efficacia di agenti disinfettanti quali radiazioni ultraviolette e acido peracetico a confronto con il cloro.