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Title: Nitrogen removal by ion exchange: biological regeneration of clinoptilolite

Journal Article · · J. - Water Pollut. Control Fed.; (United States)
OSTI ID:5212044

A small-scale, pilot-plant study, in which a slurry of nitrifying bacteria in a 300 meq/l. salt solution was recirculated through a column of exhausted clinoptilolite that had been used to remove ammonium ion from a synthetic waste water, showed that the biological process provided reproducible column performance in short regeneration times (about two hours); the rate of biological regeneration was controlled by the rate of nitrification; the dissolved oxygen concentration had to be maintained above 6 mg/l. in the aeration tank by using pure oxygen; no significant fouling, zeolite capacity loss, or column deterioration of the clinoptilolite occurred over more than 40 exhaustion and biological regeneration cycles; column performance after chemical regeneration with 0.3 M NaCl was better than that after biological regeneration due to accumulated calcium and magnesium ions in the latter cycle; and humic acid and phenol in concentrations normally toxic to nitrifying bacteria did not affect the biological regeneration.

Research Organization:
University of Illinois, Urbana
OSTI ID:
5212044
Journal Information:
J. - Water Pollut. Control Fed.; (United States), Vol. 49:12
Country of Publication:
United States
Language:
English