Nitrate Removal from Drinking Water using Organo-Silane Modified Natural Nano-Zeolite

Nitrate-containing compounds are considered as groundwater contaminants, the concentration of whichhas been growing in these resources during recent years. As a result, it seems necessary to use effectivemethods to remove nitrate from water and wastewater. Adsorption is generally considered moreeconomical in water treatment compared to other feasible alternative techniques. Natural Clinoptilolitezeolite is one of the best absorbents because of its high capacity and low cost. Surfactants such ashexadecyl trimethyl ammonium (HDTMA) are usually used for modification but they are not stable andremoved as a result of subtle temperature variations. In this research, zeolite nanoparticles arechemically modified by 3-aminopropyl triethoxysilane. The advantage of this modification method is itsstability at different environmental conditions. Adsorbent properties have been analyzed by PSA, FTIR,XRD, FESEM and CHN elemental analysis. Also, nitrate adsorption capacity of modified zeolite wasexamined by UV-Vis spectroscopy. NH2 groups are developed on the zeolite surface as a result oforgano-silane modification, which must be converted to NH4+ so that nitrate adsorption becomespossible in acidic conditions. Based on the results, the best nitrate removal capacity is achieved at thelowest concentration and pH values. 80.12 % nitrate removal was obtained at pH=3, nitrateconcentration = 50 mg/l and adsorbent concentration = 4 g/l.