Studio sperimentale di trattamenti sostenibili per la disinfezione di flussi di scolmo di fognature miste

The present work has had, as its primary purpose, to investigate and verify the applicability and sustainability of various traditional and innovative disinfection techniques on CSOs (Combined Sewer Overflows) introduced into the Rio Valloscura canal. They, reaching the coastal strip, have involved increasing concentrations of fecal bacteria, such as Escherichia Coli and intestinal Enterococci, and the repeated prohibitions on bathing, as well as the loss of excellent water quality certification. This objective was pursued through two different and propaedeutic fields of study: the first, concerning the implementation of experimental laboratory and field tests, with the use of a pilot system; the second, relating to the drafting of a monitoring, management and treatment scenario, on site and at the wastewater treatment plant, aimed at reducing pollution linked to the discharge of CSOs directly into the environment. Chemical oxidizing agents were tested, such as peracetic acid, performic acid and ozone, physical disinfectant agents, such as ultraviolet rays, and an in-depth study was carried out for the conversion of some operating units of the plant into storage tanks for part of the volumes out of the net. The synergy of the various strategies proposed has allowed, in the first place, to determine the disinfection methods most similar to the characteristics of the CSOs in question and, secondly, to obtain a global percentage reduction, expressed as a spilled mass load of E. Coli, 78% compared to the state of affairs.