Ammonia-containing waste waters treatment by ion exchange on natural clinoptilolite zeolite

摘要

The removal of NH_4~+ ions by ion exchange can be efficient if selective zeolites, presenting a good affinity for NH_4~+ ion are used. The natural clinoptilolite zeolite presents ion exchange activity and can easily retain the NH_4~+ ions from aqueous solutions. The retention capacity for the NH_4~+ ion from wastewaters is high, even at low concentrations, and this is a motivation for the use of the zeolite on advanced purification. The ion exchange isotherm show a good selectivity for NH_4~+ ion the separation factor values are greater than unity, a maximal value being reached at an exchange degree of about 0.80 the use of natural clinoptilolite zeolite sodium form present the advantage of the regeneration by means of NaCl solutions, low priced and not generating secondary pollution problems.