Defluoridation of Black Creek Aquifer Waters

摘要

Because waters of the Black Creek Aquifer, located in Horry and Georgetown Counties of South Carolina, contain concentrations of fluoride that exceed the maximum contaminant level (1.6 mg/l) allowed by the National Interim Primary Drinking Regulations, water utilities in the region must either seek an alternate supply or must defluoridate. Those that have no option but to defluoridate will likely do so through the application of activated alumina, an exchange adsorbent. The study showed that the presence of chloride, sulfate, and bicarbonate anions in the Black Creek Aquifer waters did not affect, in a statistical sense, the fluoride exchange adsorption capacity of activated alumina for the range of concentrations found in the aquifer. In contrast, the pH of the water dramatically affected the exchange adsorption capacity of the activated alumina. The effect was effectively described by an impirical regression. Finally, the optimum pH for minimizing the cost of operating a defluoridation facility was found to lie in the range of 6 to 7.