 |
Influence of Humic Substances and Sulfate on Ion Exchange ResinsLas Vegas, NVSource: Batista, Jacimaria, Adriano Vieira, and Frank X. McGarvey "The Influence of Humic Substances and Sulfate on the Removal of Perchlorate from a Groundwater by Ion-Exchange Resins" in Perchlorate Treatment Technology Workshop, 5th Annual Joint Services Pollution Prevention & Hazardous Waste Management Conference & Exhibition, August 21-24, 2000, Henry B. Gonzalez Convention Center, San Antonio, Texas. Project Summary: The following text was excerpted from Batista, Jacimaria, Adriano Vieira, and Frank X. McGarvey "The Influence of Humic Substances and Sulfate on the Removal of Perchlorate from a Groundwater by Ion- Exchange Resins" in Perchlorate Treatment Technology Workshop, 5th Annual Joint Services Pollution Prevention & Hazardous Waste Management Conference & Exhibition, August 21-24, 2000, Henry B. Gonzalez Convention Center, San Antonio, Texas: The objectives of this study were to examine the potential of ion exchange to remove perchlorate from a "real" water from a contaminated site in the Las Vegas valley using different types of resins. Ion exchange resins were provided to UNLV for this work by Sybron Chemicals and Purolite. Ion exchange technology was immediately investigated for perchlorate treatment because of its previous use for nitrate and arsenate removal, and because it is a familiar technology to the water industry. Several strong and weak-base anionic exchange resins were tested. Fixed-bed column tests were performed using 1.5-2.5 cm ID glass columns with one-foot resin beds. Columns were fed with the contaminated groundwater from the Las Vegas Valley. Regeneration was performed with sodium chloride. Anions were analyzed by ion-chromatography. Organic carbon was analyzed by TOC analyzer. The average concentration of major anions in the "real" water, given in mg/L was perchlorate - 80.3; chlorine - 2,009; nitrate - 48.8; sulfate - 1,968; TOC - 45.3. The following conclusions were made, based on the study. 1. For two styrenic strong-base (ASB1 and ASB2), the total column utilization were only 48% and 36% respectively, indicating that about 50% of the resin capacity was occupied by anions other than perchlorate. 2. High concentrations of sulfate in the water rapidly saturated the resin. Perchlorate was continuously removed from the water by pushing sulfate out of the resin. 3. For a macroporous strong-base syrenic resin (ASB1 PC), about 21% of the column capacity were utilized by perchlorate. This resin exchanged considerable amount of humic acids and perchlorate and they could be stripped out easier from ASB1 PC than from ASB1 and ASB2. 4. The capacity of the styrenic weak-base (AFP 329) for perchlorate was moderately affected by the presence of humic substances as compared to other resins. Humic acids were not exchanged with this resin. 5. The efficiency of the strong-base acrylic resin (Macro T) was significantly affected by the presence of humic substances contained in the "real" water. Perchlorate did not exchange with this resin. This resin showed the highest TOC concentration in the regenerant brine. 6. The presence of humic acids in waters may significantly affect the removal of perchlorate by ion exchange resins. A research recommendation made was to examine the effects of humic acids and other anions (e.g. sulfates, nitrate) on perchlorate removal by ion exchange resins, by using binary solutions of humic acids and different anions at different concentrations. Additional Info Source: Batista, Jacimaria, Adriano Vieira, and Frank X. McGarvey "The Influence of Humic Substances and Sulfate on the Removal of Perchlorate from a Groundwater by Ion-Exchange Resins" in Perchlorate Treatment Technology Workshop, 5th Annual Joint Services Pollution Prevention & Hazardous Waste Management Conference & Exhibition, August 21-24, 2000, Henry B. Gonzalez Convention Center, San Antonio, Texas. |
|
||||
      
|
||||||