4A分子筛处理高浓度氨氮废水

REMOVAL OF HIGH-CONCENTRATION AMMONIA-NITROGEN IN WASTEWATER WITH 4A MOLECULAR SIEVE

采用水热法合成了4A分子筛,并讨论了合成过程中的影响因素.用粉末X射线衍射(XRD)对产物进行了表征.以水溶液中氨氮为目标,用4A分子筛对其进行吸附处理;通过一系列对比实验,评价所合成的4A分子筛及其工业品对高浓度模拟氨氮废水中氨氮的吸附性能.结果表明,所合成的4A分子筛对水中氨氮的吸附效果远好于工业品4A分子筛;并且吸附效果与4A分子筛投加量有关;在氨氮量为100 ml×1000mg.l-1时,沸石的最佳投加量是3 g,去除率可达到76.50%.此外,吸附剂对氨氮的对数吸附等温线符合Langmu ir方程,表明吸附为化学单分子层吸附,等温线的斜率为0.4766,在0.1—0.5之间,从理论上表明4A分子筛可作为吸附剂用于高浓度氨氮废水的处理.

4A molecular sieve was synthesized by hydrothermal process,and the synthesis conditions were investigated in this paper.The product was characterized by XRD.Adsorption capacity of the 4A molecular sieve for ammonia-nitrogen was also evaluated.Compared with commercial 4A molecular sieve,the 4A molecular sieve synthesized in this paper demonstrated better adsorption performance.In addition,it is found that the adsorption capacity of the 4A molecular sieve was dependent on its dosage.The optimum ratio of the dosage of 4A molecular sieve to the amount of ammonia-nitrogen is 3g∶100 ml×1000 mg·l^-1.The adsorption capacity of the 4A molecular sieve is 76.5%.Moreover,the adsorption curve accords with Langmuir equation;and suggests it is monomolecular layer adsorption.