EN
Removal of nickel from water using granular iron-based adsorption materials Bayoxide E33, CFH12, CFH18, and GEH, and the comparison of their efficiency at different pH values was investigated. The results proved that the iron-based sorption materials have a capacity to reduce the content of nickel in water to values that meet the requirements set under the Regulation of the Government of the Slovak Republic No. 496/2010 on drinking water (20 µg/L Ni). This maximum contaminant limit (MCL) complies with the recommendations of WHO, the US EPA, and EU Directive 2008/105/EC. Based on the pilot column tests, the most suitable adsorbent for nickel removal is Bayoxide E33. However, its effectiveness increases with decreasing water pH. For this material it is better to treat the water at lower pH, i.e. 6.5 to 7.5. According to the model tests (concentration of nickel in raw water of about 50 µg/L, filtration rate 5.8 m/hour, concentration Ni 20 µg/L at the outlet of media with the height of 58 cm, pH 7.0), the adsorption capacity of nickel for Bayoxide E33 was set to 198 µg/g and ratio V/V₀ = 4808. The results proved that the materials CFH12, CFH18 and GEH can also be used to decrease the concentration of Ni in drinking water below the limit value. The pH value of water affects the efficiency of nickel removal. In the case of CFH 12 the best results were obtained at pH 7. The highest efficiency of GEH was reached in water pH above 7.5. The adsorption capacities and V/V₀ ratio are lower for these sorption materials. Chemical composition of used sorption materials was determined.