Removing Precursors to Disinfection Byproducts

Bromide is a trace element in the Earth’s crust and can be found everywhere in the environment. Natural sources include shale deposits and seawater. Due to intrusion of seawater, we find bromide in higher concentrations in coastal groundwater and soils. Bromide is rarely observed naturally in inland surface waters, but there are many ways that it can enter those water systems via human activity, including oil and gas extraction, mining, pesticides, fertilizers, flame retardants, and pharmaceuticals.

While the presence of bromide is not a direct threat to the environment, the brominated organic compounds that it forms are. Negative human health outcomes including cancer, endocrine system problems, and reproductive harm are well documented consequences of long-term exposure to these compounds. Bromine in the water is hydrolyzed into hypobromous acid, a strong disinfectant similar to hypochlorous acid (bleach). This readily reacts with dissolved organic carbon molecules in the water to form brominated TTHMs, HAA5s, and other disinfection byproducts. If hypobromous acid is oxidized by ozone, it forms bromate, another EPA-regulated compound with carcinogenic activity.

Removing these compounds after they have been formed is expensive and time consuming. The recommended method for dealing with these contaminants is to prevent their formation through the removal of precursors. MICo® Bromide Resins have shown to be an effective method for removing both the bromide and DOC that react to form these dangerous contaminants.

Using the innovative MICo process, MIEX® DOC and Bromide Resins can be simultaneously fluidized to provide excellent removal of both precursors. Samples that IXOM tested from groundwater and surface water plants in Florida, South Carolina, and Texas showed excellent reduction of both DOC and bromide - up to 80% removal of each. This precursor co-removal stops DBPs before they can form, allowing water plants to use the disinfectant process of their choice without the worry of forming bromate and brominated organic compounds.

IXOM Watercare is exhibiting at AWWA’s ACE17 expo in Booth 1807.