粉煤灰基沸石分子筛对水中氨氮的吸附OA北大核心CSTPCD

Three zeolite molecular sieves were prepared using fly ash as the raw material through an alkali fusion-hydrothermal method,and characterized by XRD,XRF,SEM,and BET methods.These molecular sieves were used to adsorb ammonia nitrogen from solutions,and the main factors affecting the adsorption efficiency,isothermal adsorption characteristics and adsorption kinetics of ammonia nitrogen were investigated.The experimental results show that:The zeolite molecular sieve B(Na20.8Al23Si36O117·7.69 H2O)exhibits the best adsorption performance,and under the conditions of initial ammonia nitrogen mass concentration 100 mg/L,molecular sieve B addition 2 g/L,pH 7,temperature 25℃,rotation speed 50 r/min,and adsorption time 60 min,the adsorption amount and removal rate of ammonia nitrogen are 40.61 mg/g and 90%,respectively;The order of influence of 4 cations on the adsorption of ammonia nitrogen is K+>Ca2+>Na+>Mg2+;The adsorption of ammonia nitrogen by molecular sieve B is a single-layer adsorption with chemical adsorption characteristics.The optimal process conditions for the adsorption of ammonia nitrogen by molecular sieve B are solution pH 7,temperature 45℃,and initial ammonia nitrogen mass concentration 40 mg/L.Under these conditions,the removal rate of ammonia nitrogen is 93%.