Peracetic Acid as an Alternative Disinfection Technology for Wet Weather Flows

Abstract

Rain‐induced wet weather flows (WWFs) consist of combined sewer overflows, sanitary sewer overflows, and stormwater, all of which introduce pathogens to surface waters when discharged. When people come into contact with the contaminated surface water, these pathogens can be transmitted resulting in severe health problems. As such, WWFs should be disinfected. Traditional disinfection technologies are typically cost‐prohibitive, can yield toxic byproducts, and space for facilities is often limited, if available. More cost‐effective alternative technologies, requiring less space and producing less harmful byproducts are currently being explored. Peracetic acid (PAA) was investigated as one such alternative and this research has confirmed the feasibility and applicability of using PAA as a disinfectant for WWFs. Peracetic acid doses ranging from 5 mg/L to 15 mg/L over contact times of 2 to 10 minutes were shown to be effective and directly applicable to WWF disinfection.

Fast Disinfection of Contaminated Stormwater Using Peracetic Acid

“…For samples 1 and 2 it reached 5 log units reduction, higher than the results obtained by Atasi et al (2001) and Andreoli et al (2013), for whom doses of 10 to 20 mg.L -1 PAA removed 3 log units of E. Coli in stormwater sewers, and the results obtained by Au et al (2016), with maximum inactivation of 3.65 log units for 15 minutes PAA contact time (2, 3, 5 and 7 mg.L -1 ) when PAA was added to domestic and industrial effluents after the activated sludge treatment. Coyle et al (2014) observed an average of 4,77 log units of E. Coli inactivation with PAA dose of 10 mg.L -1 after 10 min, which was similar to the value obtained with the present work. That information allows us to understand that in effluents with low organic matter (sample 1), contact time was the most important factor for disinfection, whereas in effluents with higher pollutant content (sample 2), dosage is the factor that mostly affects the efficiency of disinfection.…”

“…Traditional technologies of wastewater disinfection such as UV radiation and ozonisation would require significant capital investment and maintenance if installed in an existing network. Chlorination in various interception points in the stormwater collection network using either NaClO solution or Ca(ClO) 2 tablets would be effective and require low investment, but would bring further limitations when considering the generation of various chlorinated organics as ecotoxic by-products (Coyle et al, 2014). The wide composition variation of contaminated stormwater streams and the high volumes of effluent drainage require a disinfectant that is not only effective, easy to use, low in cost, and fast acting to rapidly knock out microorganisms in an in-situ treatment, but also does not leave toxic residuals in the receiving aquatic environment.…”

“…Several studies of the disinfection efficiency in wastewaters, (Atasi et al, 2001;Kitis, 2004;Koivunen & Heinonen-Tanski, 2005;Cavallini et al, 2012;Andreoli et al 2013;Chhetri et al, 2014;Coyle et al, 2014;Au et al, 2016) mention inactivation values of Escherichia Coli and Enterococcus greater than 3 log units, in effluents with an initial count of 10 2 to 10 6 MPN/100 mL. In those studies various doses were tested, from 2 mg.L -1 up to 100 mg.L -1 PAA, but there is a general consensus that 2 to 15 mg.L -1 are sufficient to reach satisfactory levels of disinfection, provided sufficient contact time is allowed.…”

Side-Stream Comparison of Peracetic Acid and Chlorine as Hypochlorite for Disinfection of Municipal Wastewater Effluent at a Full-Scale Treatment Facility, Ontario, Canada

“…In the last 2 decades, PAA has been recognized as a strong disinfectant with a wide spectrum of antimicrobial activity . It has been widely used in municipal applications, such as the disinfection of primary-, secondary-, and tertiary-treated effluents, as well as for wet weather flows . Although PAA has been used as a wastewater disinfectant in Europe since the early 2000’s, it is only recently that PAA has gained interest in North America as an alternative to chlorine (and NaClO), in view of its strong oxidation potential, potentially short contact time requirements, rapid decomposition of its residual, absence of chlorinated DBPs, and bacterial inactivation at competitive costs over a wide range of wastewater characteristics. , Although PAA has been shown to be effective against bacteria in wastewater through many pilot and full-scale studies, , there are only limited data on its efficacy against enteric viruses and bacteriophages.…”

A deployable decentralized biofilm system for degrading organic carbon and benzene in wastewater

“…Natural disasters such as hurricanes, tornadoes, floods, and earthquakes can cause significant damages to civil infrastructures including municipal wastewater treatment facilities. When the treatment systems fail, human health and environmental quality are at risk . In addition, there are situations in which centralized wastewater treatment facilities are not available or unpractical, such as remote sites or small communities.…”