Study on Adsorption of Ammonia Nitrogen from Water by Modified Bentonites

In this paper, three modified bentonites of surfactant cetyltrimethylammonium bromide (CTMAB), polymeric aluminum and polymeric iron solution as modifiers, CTMAB organo-bentonite, hydroxy-aluminum pillared bentonite and hydroxy-iron pillared bentonite were prepared, and its adsorption properties for the removal of ammonia nitrogen from water were evaluated in batch experiments. The results showed that the adsorption ability of ammonia nitrogen by modified bentonites was far more than that of raw bentonite. The adsorption capacity followed the order: Al-bentonite Fe-bentonite CTMAB-bentonite raw bentonite. The adsorptive rate of ammonia nitrogen was rapid and can be equilibrium within 60 minutes. The Freundlich model and the Langmuir model were both described the adsorption isotherm data well.