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.

摘要: 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 MUCWTP is seeking alternative methods for disinfection achieve a 2- 3-log fecal coliform reduction. Liquid chemical disinfectants were attractive options because their low capital costs. This led investigation feasibility using hydrogen peroxide or peracetic acid. A method measuring peroxycompounds (hydrogen acid plus peroxide) was developed peroxidase-based oxidation 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfuric acid) diammonium salt (ABTS) with peroxide. validity confirmed effluent from MUCWTP. Recovery higher than 90% levels as 1.0 mg/L. Quenching achieved 50-mg/L catalase; quenching 100 mg/L sodium thiosulfate, followed by 50 catalase. Batch tests conducted on effluent. Hydrogen over time could be modeled second-order decay, decay "constant" function initial concentration peroxycompounds. same both acid, possibly indicating similar decomposition pathways matrices. Disinfection modified Hom equation. Required doses reach target ranged 106 285 mg/L, occurring when ferric chloride instead alum used coagulant. Hence, infeasible disinfectant this application. On other hand, dose needed level only 0.6 1.6 Therefore, seems promising primary effluent, combined sewer overflows.