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Abstract

This manuscript addresses the treatment explosives-impacted mining wastewaters (EIMWW) using ion-exchange to remove elevated levels of ammonia. Repeated batch loading-regeneration cycles were conducted for two commercially available zeolite media used in the treatment of ammonia-ladenEIMWW to establish the effects of competing ions and regeneration solution composition. The Northern Ontario EIMWW tested contained 3.87 meq/L total ammonia (TA) as well as 2.85 meq/L Kþ and 3.9 meq/L Ca2þ.The media studied were a natural clinoptilolite and a modified clinoptilolite (SIR-600). Five regenerant solutions with different NaCl and KCl concentrations were evaluated. The presence of potassium in the regenerant was found to hinder the TA exchange capacity of both zeolites. The SIR-600 and the natural clinoptilolite used in conjunction with the 10% NaCl solution featured the best TA exchange capacities, 0.46 ± 0.02 meq TA/g and 0.36 ± 0.05 meq TA/g, respectively. The batch tests showed that both media had a slight preference for Kþ over TA. The continuous flow column tests performed using SIR-600 media greatly accentuated the selectivity of Kþ over TA. In reaching the same 0.55 meq TA/L breakthrough level, the same modified zeolite column was able to treat five time more volume of a synthetic TA solution than EIMWW.

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Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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