THE BENEFITS OF NATURAL ZEOLITE TO AMMONIA REDUCTION TECHNOLOGIES

Surface water, ground water, and wastewater contain many pollutants, including inorganic and organic compounds, that are hazardous to humans, animals, and plants. One of the most potent pollutants is ammonia because it contributes to accelerated eutrophication of lakes and rivers, dissolved oxygen depletion, and fish toxicity (Wang & Peng, 2010).

Hundreds of studies have examined how zeolite application can remove ammonia through adsorption. Findings suggest that ion exchange, particularly the adsorption of ammonium ions onto the surface of natural zeolites, contributes to its success in ammonia reduction technologies (Wang & Peng, 2010). Scientists have also found that the exhaustion and regeneration cycle (the process of removing adsorbed liquids and gases) increase the ongoing adsorption capacity in natural zeolite. Essentially this means that zeolite can be reused time and time again, and that its capacity to remove ammonia increases over time.

Bolan et al. (2003) tested the effect of clinoptilolite zeolite on the removal of ammonium ions from wastewater streams. Results indicated that zeolite could hold up to 18.7–20.1 mg NH4+/g because of its superior cation exchange capacity. After zeolite minerals were cation-loaded, scientists regenerated and reused zeolite grains by leaching ammonium ions with 0.5 M of hydrogen chloride. The leaching process did not impact zeolite’s adsorption capacity and the minerals remained effective after 12 regeneration cycles (Bolan et al., 2003).

Jorgensen and Weatherley (2006) examined the use of clinoptilolite as a cationic exchanger for the purpose of removing ammonia from wastewaters. The results indicated that clinoptilolite had a significant increase in performance after cycles of exhaustion and regeneration; regenerated clinoptilolite showed a maximum adsorption capacity of 450 bed volumes (Jorgensen & Weatherley, 2006). Again, the results demonstrate that zeolite is not only capable of removing ammonia from wastewaters, it can also be reused time and time again.

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