13X沸石分子筛对饮用水中NH_4~+-N吸附性能的实验研究

研究了 13X沸石分子筛对饮用水中低浓度NH+4 N的吸附性能 ,包括影响吸附的主要因素、沸石对NH+4 N的吸附效果、沸石的再生效果及沸石对NH+4 N的吸附机理。实验表明用NaOH处理的沸石比未处理的沸石对NH+4 N的吸附效果要好。在 pH值为 6 5～ 7 5、吸附时间为 2 0min、吸附温度为 2 0～ 30℃的条件下 ,沸石对NH+4 N的吸附率接近 10 0 % ,沸石对NH+4 N的吸附量可达 16 32mg/g。用直接焙烧法进行再生活化处理后的沸石对NH+4 N的吸附率仍接近 10 0 % ,沸石对NH+4 N的吸附机理是以离子交换吸附作用为主。 13X沸石吸附NH+4 N的过程符合Langmuir吸附等温模式。实验证明 ,利用 13X沸石净化含低浓度NH+4 N的饮用水具有良好的工业化应用前景。

EXPERIMENTAL STUDY OF THE ADSORPTION CAPABILITY OF 13X ZEOLITE TO NH+4-N IN DRINKING WATER

The primary influential factors,capacities of adsorption and desorption and mechanism for the removal of NH+ 4-N in drinking water by using 13X zeolite are experimentally investigated.The results show that pretreatment of 13X zeolite with sodium ions has been shown to improve the ammonium exchange capacity of the zeolite more efficiently.The optimum conditions for the removal of NH+ 4-N are:the pH value of the solutions is 6.5-7.5,the adsorption time is 20 minutes and the adsorption temperature is 20-30℃.The adsorption capacity can reach 16.32 mg of NH+ 4-N per gram of zeolite.Saturated 13X zeolite can be regenerated by heating at 550℃ without noticeable loss of capacity. The ratio of removal of NH+ 4-N attains nearly 100 per cent.It is suggsted that ion exchange is the major mechanism for the removal of NH+ 4-N in drinking water.The process of 13X zeolite to the adsorption of NH+ 4-N is fitted to Langmuir adsorption isotherm.The experimental results show that the 13X zeolite is suitable for the removal of NH+ 4-N in drinking water.