Disinfection of Wastewater by Hydrogen Peroxide or Peracetic Acid: Development of Procedures for Measurement of Residual Disinfectant and Application to a Physicochemically Treated Municipal Effluent

Abstract

The Montreal Urban Community Wastewater Treatment Plant (MUCWTP) located in Montreal, Quebec, Canada, uses physicochemical treatment processes prior to discharging wastewater into the St. Lawrence River via an outfall tunnel of 2 hours retention time. Although chlorination facilities exist, they are not being used, and the MUCWTP is seeking alternative methods for disinfection to achieve a 2-to 3-log fecal coliform reduction. Liquid chemical disinfectants were attractive options because of their low capital costs. This led to an investigation of the feasibility of using hydrogen peroxide or peracetic acid.A method for measuring peroxycompounds (hydrogen peroxide or peracetic acid plus hydrogen peroxide) was developed using the peroxidase-based oxidation of 2,2Ј-azino-bis(3-ethylbenz-thiazoline-6sulfuric acid) diammonium salt (ABTS) with hydrogen peroxide. The validity of the method was confirmed using effluent from the MUCWTP. Recovery was higher than 90% for peracetic acid levels as low as 1.0 mg/L. Quenching of hydrogen peroxide was achieved with 50-mg/L catalase; quenching of peracetic acid was achieved with 100 mg/L of sodium thiosulfate, followed by 50 mg/L of catalase.Batch disinfection tests were conducted on MUCWTP effluent. Hydrogen peroxide and peracetic acid in wastewater over time could be modeled as a second-order decay, with the decay "constant" being a function of the initial concentration of peroxycompounds. This function was the same for both hydrogen peroxide and peracetic acid, possibly indicating similar decomposition pathways in wastewater matrices.Disinfection was modeled using a modified Hom equation. Required doses of hydrogen peroxide to reach the target fecal coliform levels ranged from 106 to 285 mg/L, with the higher doses occurring when ferric chloride instead of alum was used as the coagulant. Hence, hydrogen peroxide was infeasible as a disinfectant for this application. On the other hand, the peracetic acid dose needed to achieve the target fecal coliform level was only 0.6 to 1.6 mg/L. Therefore, peracetic acid seems to be a promising disinfectant for physicochemical or primary effluent, or combined sewer overflows. Water Environ. Res., 74, 33 (2002).

Treatment of Arctic wastewater by chemical coagulation, UV and peracetic acid disinfection

“…Residues of PAA were neutralized in laboratory experiments by adding 100 mg/L sodium thiosulphate to destroy PAA, followed by 50 mg/L catalase to destroy hydrogen peroxide (Wagner et al, 2002). E. coli was enumerated using Colilert-18 methods and Enterococcus were enumerated using the Enterolert methods from IDEXX (IDEXX laboratories, Maine, United States), as described by Chhetri et al (Chhetri et al, 2014).…”

Assessment of occupational exposure to gaseous peracetic acid

“…Active sampling with an air flow of 1 l/min for 15 min was performed by MTSO basic silica gel cartridge (Giotto Biotech, Sesto Fiorentino, Italy) connected to GilAir Plus pumps (Sensydine, St. Petersburg, USA) for personal sampling, and to a 16-position automatic collector box/Bravo M Plus pump (TCR Tecora, Milano, Italy) for area sampling [7]. The cross sensitivity to hydrogen peroxide (HP) was avoided through a 37-mm cassette with quartz filter coated with titanium oxysulfate hydrate and connected to the cartridge.…”

“…The Steri-Trac Area Monitor was connected for area sampling to a management platform for data collection. The 4th method using a novel visual test strip PAA Detector (Giotto Biotech, Sesto Fiorentino, Italy) based on reaction of ABTS to its radical cation, for sampling time of 15 min and quantification by a color scale to 0.4 ppm [5,13,14]. The iodide-catalyzed oxidation of the ABTS by PAA leads to the formation of a green product with 4 strong absorption maxima between 405 nm and 810 nm (highest absorbance was observed at 415 nm).…”

Utilização do ácido peracético na desinfecção de esgoto sanitário: uma revisão

“…Um cromóforo parecido é comumente utilizado em kits comerciais na forma de ampola, o DDPD uma forma de metil substituída do reagente DPD (CHEMetrics®), segundo FALSANISI et al (2008) A limitação dos métodos espectrofotométricos está na distinção dos oxidantes, esse inconveniente pode ser amenizado adicionando o tiossulfato de sódio para o consumo do APA e então o peróxido de hidrogênio pode ser determinado, ou ainda, determina-se somente o APA com a adição da catalase que decompõe o peróxido de hidrogênio. Porém em ambos os casos a concentração final pode ser superestimada se o oxidante a ser neutralizado não for consumido totalmente, ou subestimando, como no caso da catalase que pode decompor parte do APA (WAGNER; BRUMELIS; GEHR, 2002;SHIKISHIMA, 2008). Outra possível explicação quanto ao consumo do APA durante a utilização da catalase é deslocamento químico da reação, por se tratar de uma reação em equilíbrio.…”