EVALUATION OF A SOUTH AFRICAN CLINOPTILOLITE FOR AMMONIUM-NITROGEN REMOVAL FROM AN UNDERGROUND MINE WATER

A South African clinoptilolite (Pratley) was evaluated for ammonia-nitrogen (NH3-N) removal and compared with Hector clinoptilolite from the USA. Very little difference in performance was experienced between the Pratley and Hector clinoptilolites for NH3-N removal. Pradey clinoptilolite, however, was found to be less friable and cheaper than Hector clinoptilolite. The operating capacity of Pratley clinoptilolite increased with decreasing flow rate in the range of 15 to 5 bed volumes per hour and decreasing particle size in the range of 0,5 to 1,0 mm and 0,25 to 0,7 mm. The waste regenerant could be renovated and reused at least three times without a serious reduction in output. The NH3-N stripped from the waste regenerant might be converted into fertilizer to offset some of the costs. NH3-N can be reduced from about 20 mg/lin the feedwater to less than 1 mg/l. The total costs for NH3-N removal for a 10 000 m /d plant with and without regenerant reuse were also estimated.