Disinfection of an Advanced Primary Effluent with Peracetic Acid and Ultraviolet Combined Treatment: A Continuous‐Flow Pilot Plant Study

Abstract

BSTRACT: Disinfection of an advanced primary effluent using a continuous-flow combined peracetic acid/ultraviolet (PAA/UV) radiation system was evaluated. The purpose was to determine whether the maximum microbial content, established under Mexican standards for treated wastewaters meant for reuse-less than 240 most probable number fecal coliforms (FC)/100 mL-could be feasibly accomplished using either disinfectant individually, or the combined PAA/UV system. This meant achieving reduction of up to 5 logs, considering initial concentrations of 6.4-10^'' to 5.8-10*' colony forming units/100 mL. During the tests performed under these experiments, total coliforms (TC) were counted because FC, at the most, will be equal to TC. Peracetic acid disinfection achieved less than 1.5 logs TC reduction when the Ct-t product was less than 2.26 mg-minimum (min)/L; 3.8 logs for Ct't 4.40 mg-min/L; and 5.9 logs for Q-t 24.2 mg-min/L. In continuousflow UV irradiation tests, at a low-operating flow (21 L/min; conditions which produced an average UV fluence of 13.0 mj/cm^), the highest TC reduction was close to 2.5 logs. The only condition that produced a disinfection efficiency of approximately 5 logs, when both disinfection agents were used together, was the combined process dosing 30 mg PAA/L at a pilot plant flow of 21 L/min and contact time of 10 minutes to attain an average C,-t product of 24.2 mg-min/L and an average UV fluence of 13 mj/cm . There was no conclusive evidence of a synergistic effect when both disinfectants were employed in combination as compared to the individual effects achieved when used separately, but this does not take into account the nonlinearity (tailing-off) of the doseresponse curve. Water Environ. Res., 84, 247 (2012).

Oxidation of amino acids by peracetic acid: Reaction kinetics, pathways and theoretical calculations

“…Thus, as a disinfectant or sterilant, PAA has a wide application in various industries including water treatment, food processing, medical, and textile (Kitis, 2004; Falsanisi et al., 2006). A number of pilot- or full-scale trials of using PAA as an alternative to chlorine for wastewater disinfection have been conducted in Europe and North America (Veschetti et al., 2003; Koivunen and Heinonen-Tanski, 2005; González et al., 2012; Eckert, 2013). In the U.S., the Environmental Protection Agency has authorized the use of PAA in fruits, vegetables and meat processing as well as in wastewater and storm water disinfection (EPA, 1998, 1999, 2012).…”

Peracetic acid disinfection kinetics for combined sewer overflows: indicator organisms, antibiotic resistance genes, and microbial community

“…9 More researchers have reported disinfection of total coliforms as measured by cultivation based techniques in WW influent indicating treatment with 20 mg/L PAA 10 min may be optimal for reducing target organisms. 10 Given the cost of PAA, 8 PAA demand of organic matter in CSO effluent, 11 and small footprint available for end-of-pipe treatment, understanding the impact of lower doses and shorter contact times for a range of CSO effluents is needed to provide economical recommendations for application.…”