天然斜发沸石除硅补铝改性对海水中K+的吸附性能研究
Study of desilication and realuminization modification of natural clinoptilolite on its adsorption properties to K+ in seawater

以浙江缙云天然斜发沸石为原料，研究通过焙烧后超声碱洗除硅，再经超声补铝后用钠盐复合改性对沸石吸附K+性能的影响，提高对海水中K+的吸附量. 结果表明：采用0.18~0.38 mm的天然沸石，200 ℃下焙烧1.5 h，0.2 mol·L-1的NaOH溶液超声处理2.0 h，0.5 mol·L-1的AlCl3溶液超声处理2.0 h，20%(质量分数)NaCl溶液煮沸30 min的方法复合改性得到的沸石对K+吸附性能最佳，吸附量可达到25.64 mg·g-1，为天然斜发沸石吸附量的4.2倍. 对最适宜条件改性后的沸石进行吸附K+的动力学研究，其吸附过程符合准二级动力学模型.
In order to enhance the adsorption properties of natural clinoptilolite to K+ in seawater，the natural clinoptilolite was desilicated by calcination and wash by ultrasonic alkali solution，then it was realuminized by ultrasonic aluminum solution and modified by sodium solution. The influence of desilication，realuminization and salt modification of natural clinoptilolite on its adsorption properties to K+ was researched. The results showed that when the 0.18-0.38 mm natural clinoptilolite was calcinated for 1.5 h at 200 ℃，ultrasonic processed with 0.2 mol·L-1 NaOH for 2.0 h，followed by ultrasonic processing by 0.5 mol·L-1 AlCl3 for 2.0 h，and boiled by 20%(mass fraction)NaCl for 30 min，the optimum adsorption capability to K+ (25.64 mg·g-1) was abtained，which was 4.2 times of natural clinoptilolite. In addition，the adsorption dynamics of the optimum modified clinoptilolite to K+ in seawater was researched. The results showed that the adsorption process was conform to the pseudo-second-order model