Iranian Association of Environmental Health (IAEH)
Abstract
The purpose of this study was to regenerate clinoptilolite natural
zeolite by air stripping followed by removal of ammonium from aqueous
solutions. The research was carried out in continuous system. The
characteristics of graded clinoptilolite from Semnan (one of the
central provinces in Iran) mines were determined and then regeneration
tests were done by contacting of 1 N NaCl solution with given weights
of ammonium saturated zeolite. Then the brine of column was transferred
to the air stripping column for regeneration. The pH of brine solution
before entrance to a stripping column was increased to 11. Air stripped
ammonia from the brine was converted to the ammonium ion by using acid
scrubber. The outlet effluent from stripping column was collected for
reuse. The results showed that the cation exchange capacities were
17.31 to 18.38 mg NH4+/g of zeolite weight. Regeneration efficiency of
zeolite by NaCl solution and air stripping was in the range of 92%-97%
under various operational conditions. However, the efficiency of acid
absorption of released ammonia in stripping process was 55% with a
major rejection of the surplus ammonia to the atmosphere. It could be
concluded that the method studied may be considered as an advanced and
supplementary process for treating effluents of aqueous solution and
fishponds in existing treatment plants
