Inactivation of Enteric Microorganisms in Secondary Treated Municipal Wastewaters with Peracetic Acid (PAA) Disinfection
Abstract:The disinfection efficiency of peracetic acid (PAA) against enteric microorganisms in secondary treated municipal wastewaters was studied in pilot-scale. The aim was to get information on the level of disinfection achievable with PAA, by using different PAA doses and contact times in variable process conditions (effluent quality, temperature).
Experimental pilot-plant for disinfection was fed with secondary effluent of Kuopio municipal wastewater treatment plant, which is an activated sludge plant with simultaneous phosphorus precipitation and secondary settling. The plug-flow disinfection reactor consisted of chicane tank with 5 parting walls (volume approximately 1 m3, polyethylene basin). Peracetic acid equilibrium mixture (15% PAA, 13–16 % hydrogen peroxide and 21–26 % acetic acid) was used as a disinfectant chemical. The tested PAA doses for wastewater disinfection ranged from 2 to 7 mg/l. Each sampling session involved collection of samples from secondary effluent and different stages of disinfection reactor, corresponding disinfection contact times of 4–27 min. Samples were analysed for total coliforms and enterococci as well as for some principal physico-chemical parameters.
Peracetic acid was demonstrated to be an efficient disinfectant against enteric bacteria. PAA dose of 2–7 mg/l achieved 2.2–3.9 log reductions of total coliforms and 1.3–4.0 log reductions of enterococci during 27 minute of contact time. The most significant total coliform reductions occurred during the first 13 minute of contact time, showing fast disinfection action of PAA. The inactivation rate of enterococci was slightly slower, showing further microbial inactivation between 13 and 27 minute of contact time. No significant correlations between wastewater quality (SS, COD, turbidity or 253.7 nm absorbance) or temperature and microbial reductions were observed.
Document Type: Research Article
Publication date: 2005-01-01
More about this publication?
- Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.
WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
- Subscribe to this Title
- Membership Information
- About WEF Proceedings
- WEFTEC Conference Information
- Learn about the many other WEF member benefits and join today
- Ingenta Connect is not responsible for the content or availability of external websites