Feasibility/development study for the removal of ammonia from wastewater using biologically regenerated clinoptilolite

Ammonium nitrogen may be readily removed from wastewaters by means of an ammonium selective ion exchanger, clinoptilolite. The major cost in this process is the cost of regenerating the exchanger in order that it may be reused. This report presents the results of a study to develop a process in which nitrifying bacteria were employed to regenerate the exchanger. The biological regeneration process is shown feasible in both batch and column studies. The mechanism of regeneration was shown to be ion exchange followed by nitrification of the liberated ammonium. The influence of salt concentration, salt composition, particle size, dissolved oxygen, aeration tank configuration, aeration tank size on the r a t e o f regeneration were identified. The selectivity of clinoptilolite for barium, lead, copper, cadmium and zinc was measured in exchange for sodium. To further identify possible toxic effects of heavy metals toxicity studies were conducted with free and complexed copper.U.S. Department of the InteriorU.S. Geological SurveyOpe