Alternative Disinfection Technology Demonstrates Advantages for Wet Weather Applications – A Pilot Study of Powdered Bromine Technology

Abstract

A bromine disinfection technology currently utilized in Japan for Combined Sewer Overflow (CSO) disinfection was piloted by the City of Akron, Ohio. Bromochlorodimethylhydantoin (BCDMH) is a biocide in powdered form that, when dissolved in water, hydrolyzes to hypobromous acid, hypochlorous acid (the active biocides) and Dimethylhydantoin. This unique combination in active biocides can yield similar or better bacteria reductions in less time and with lower disinfection byproducts compared with a similar dose of sodium hypochlorite.The City of Akron expressed interest in this technology in anticipation of wet weather application of high-rate disinfection that would require intermittent operation and storage of chemicals between such operations. Consequently, Hatch Mott McDonald / Brown and Caldwell were hired to demonstrate this technology using a pilot facility at the Akron Water Pollution Control Station (WPCS).

Disinfection of Wastewater Effluent--Comparison of Alternative Technologies

“…For a given mass dose, BCDMH appears to be a more effective disinfectant than sodium hypochlorite, peracetic acid, or bromine chloride; it is also reacts quickly, with 90% of the log inactivation occurring within three minutes after addition (Boner et al, 2002;Moffa and Somerlot, 2007). Ammonia concentration, immediate chemical demand, pH, and temperature may vary widely and adversely affect performance and operations.…”

“…Moffa and Somerlot (2007) estimated that the capital cost for BCDMH would be 11% higher than for NaOCl for CSO disinfection at one site, with the extra cost of the BCDMH dissolution and injection equipment being slightly higher than the savings from the smaller contact chamber. The main differences are that BCDMH does not need chemical storage tanks, but does require a dissolution and injection unit because the chemical is typically supplied as a powder.…”

Degradation of Polyamide Nanofiltration Membranes by Bromine: Changes of Physiochemical Properties and Filtration Performance

“…Chlorine is commonly used as a disinfectant for biofouling control and as a membrane cleaning agent. Compared with chlorine-based disinfectants, bromine-based counterparts are widely used for industrial wastewater (mainly in water fountains and cooling towers), spa, and swimming pool water disinfection considering their lower toxicity, higher chemical stability with less odor, greater reactivity, and more efficient bactericide. − In spite of direct bromine addition, hypobromous acid (a predominant oxidizing agent) can be formed after the addition of chlorine to bromide ion-containing (waste) water, such as seawater disinfection.…”

Occurrence, formation and treatment of disinfection by-product (DBPS) in swimming pool waters

“…BCDMH is also sometimes used for SPW disinfection (Lourencetti et al, 2012;Richardson et al, 2010). BCDMH shows better fecal coliform killing efficiency compared to commonly used NaClO (Moffa et al, 2006 Liviac et al (2010) has pointed out that the combination of UV and chlorine reduced the genotoxicity compared to chlorine alone. The average total concentration of DBPs (including THMs, HAAs, HANs, and chloral hydrate) in SPWs disinfected by chlorine alone was significantly higher than that by combined chlorine and ozone based on an indoor pool survey (183 vs. 33 μg/L, n = 86) (Lee et al, 2010).…”

“…Askins (2013) swimming pool disinfection is increasing by 8-10% annually (Tilstam and Weinmann, 2002). Compared to NaClO, BCDMH has been proven as a more efficient bactericide, which is revealed by its better fecal coliform reduction in less time with an initial concentration of 1.9×10 6 CFU/100mL under the same disinfectant dosage (Moffa et al, 2006). BCDMH also shows its advantage when it is used to deal with other bacteria, e.g.…”