Ning Ping, Bart Hans-Jörg, Li Bing, Lu Xiwu, Zhang Yong
Department of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China.
J Environ Sci (China). 2008;20(6):670-4. doi: 10.1016/s1001-0742(08)62111-7.
Phosphorus is one of the primary nutrients which leads to eutrophication and accelerates aging process in enclosed water bodies. Because of the poor phosphorus selectivity of other adsorbents, the novel La(III)-modified zeolite adsorbent (LZA) was prepared by modifying 90 nm zeolite with lanthanide to selectively remove phosphate in the presence of various omnipresent anions, such as sulfates, bicarbonates, and chlorides. Through batch and fixed bed operation, the following optimum conditions were obtained: concentration of lanthanum chloride solution 0.05 mol/L; solid/liquor ratio 1/25; pH 10; calcination temperature 550 degree C time 1 h. The value of the Freundlich model constants Kf and 1/n were found to be 16.76 mg/L and 0.2209, respectively. In addition, when calculated at pH 6.0, distribution coefficient K(D) could be as high as 36.6. Furthermore, in the alkaline pH range, solution of 0.8 mol/L NaCl was used to regenerate the saturated LZA, which could reach the high regeneration efficiency as high as 100%. Because of the good selectivity and regenerability of LZA, it might serve as a potential way for advanced phosphate removal from the sewage containing other anions.
磷是导致水体富营养化并加速封闭水体老化进程的主要营养物质之一。由于其他吸附剂对磷的选择性较差，通过用镧系元素对90纳米的沸石进行改性，制备了新型镧（III）改性沸石吸附剂（LZA），以便在存在各种常见阴离子（如硫酸盐、碳酸氢盐和氯化物）的情况下选择性去除磷酸盐。通过间歇式和固定床操作，获得了以下最佳条件：氯化镧溶液浓度0.05 mol/L；固液比1/25；pH值10；煅烧温度550℃，时间1小时。发现Freundlich模型常数Kf和1/n的值分别为16.76 mg/L和0.2209。此外，在pH值为6.0时计算，分配系数K（D）可高达36.6。此外，在碱性pH范围内，使用0.8 mol/L NaCl溶液对饱和LZA进行再生，再生效率可高达100%。由于LZA具有良好的选择性和可再生性，它可能是从含有其他阴离子的污水中深度去除磷酸盐的一种潜在方法。
