Effect of spray aeration on unregulated drinking water disinfection byproducts

Abstract

AbstractSpray aeration is a comparatively low‐cost option to reduce trihalomethane (THM) concentrations in distribution system storage. The effect of spray aeration on unregulated, toxic disinfection by‐products was investigated in a bench‐scale apparatus in closed‐tank and open‐tank experiments. In the closed‐tank experiments, initially over 90% of THMs, trichloroacetonitrile, and chloropicrin were removed, while 36% of dihaloacetonitriles were removed. However, due to the buildup of concentrations in the tank headspace, removal rates for all compounds decreased significantly with time, falling to 44% removal of THMs, 76% removal of trichloroacetonitrile, and 58% removal of chloropicrin. Removal of dihaloacetonitriles decreased to zero. In the open‐tank experiments, THM removal rates were high and did not decrease with time. Considering the results with open and closed tanks as approximate bounds for performance expected under real‐world conditions in storage tanks, the findings suggest that spray aeration may not significantly reduce haloacetonitrile‐related toxicity while halonitromethane‐related toxicity may be reduced.