Complex ion exchange and adsorption methods were used for drinking water purification. Na-clinoptilolite was applied for selective removal of ammonium ions. The ion exchange capacity was 0.47 mg NH4+/g, and 0.2 mg NH4+/L breakthrough concentration was kept. The spent clinoptilolite was regenerated by 10-20 BV of 20 g NaCl/L at pH>12, then backwashed with purified water. Granulated activated carbon was used for removal of humic acids. The adsorption capacity was 91 mg/g of adsorbent. The average effluent concentration was <1 mg of humic acid/L. New adsorbent was used for arsenic removal, prepared by precipitation of Fe(OH)3 on Al2O3 as support material. The breakthrough capacity at 0.05 mg As/L was 0.10 mg of As/g absorbent. For the regeneration of the spent adsorbent, 15-30 BV of a 1 M NaOH solution was used. The results showed that the removal of ammonium and arsenic ions as well as humic acids was selective and was not affected by other components of the raw water.
ASJC Scopus subject areas
- Environmental Science(all)