Treatment and Recycling of Brine from Ion Exchange Process for Nitrate Removal in Drinking Water

摘要

Ion Exchange (Ⅸ) is the preferred treatment method for nitrate removal in drinkingwater. The main challenges of this process are the cost of brine used for regenerationand disposal of the spent brine which contains high concentrations of nitrate and othercontaminants in addition to the sodium chloride salt. The focus of this work is thepatented Calgon Carbon process for the treatment of the spent brine via a novelcatalytic process to destroy the nitrate and recycle the brine, thereby significantlyreducing the overall waste and operating costs. We evaluated the sensitivities of thecatalytic process to different parameters (e.g., active metal loading, temperature, brinecomposition, hydrogen loading) with both synthetic and plant spent brine in batch andlong term column studies. We compared the performance of the recycled spent brinevs. the virgin brine to regenerate the ion exchange resin. Specific objectives were to (ⅰ)understand the effectiveness of the nitrate removal process with spent brine recycle, (ⅱ)determine the key sizing criteria for a full scale spent brine treatment system, and (ⅲ)evaluate the overall economics of the ion exchange treatment process with recycling ofthe spent brine.