关键词: 废水, 吸附, 氨氮, 苯酚, 褐煤

Abstract: Lignite could be used as a natural porous adsorbent treating the pollutants in wastewater. In this study, the unitary and binary adsorption behaviors of ammonia nitrogen and phenol on a lignite were tested at different temperature, contact time, initial concentration, etc. Dynamic, isothermal and thermodynamic models were introduced to analyze the reaction mechanism. The results indicated that the pseudo-second-order model and Freundlich isothermal model could well describe both adsorption behaviors of ammonia nitrogen and phenol on the lignite. Besides, both reactions were spontaneous, exothermic and entropy decreasing. Especially, the enthalpy change of the adsorption of phenol on the lignite reached -71.96 kJ/mol, indicating the existence of chemical adsorption. In binary adsorption experiments, the adsorption amount of phenol was increased through increasing the initial concentration of ammonia nitrogen, while that of ammonia nitrogen was decreased with the addition phenol without fluctuation. It could be concluded that there was no competition on adsorption site between ammonia nitrogen and phenol.