| 磁性硅藻土负载纳米过氧化钙对水中磷酸盐吸附 |
| 摘要点击 1725 全文点击 724 投稿时间：2019-09-10 修订日期：2019-10-09 |
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| 中文关键词 过氧化钙(CaO2) 磁性硅藻土 磷酸盐 吸附 |
| 英文关键词 calcium peroxide(CaO2) magnetic diatomite phosphate adsorption |
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| 中文摘要 |
| 本研究以磁性硅藻土为载体，负载纳米过氧化钙（CaO2），制备了一种可高效吸附磷酸盐且可回收的复合材料（MDCP），并利用SEM、EDX-mapping、XRD、XDS和VSM等技术对MDCP的微观形貌、内部结构、晶体组成以及元素组成进行了表征.结果表明，MDCP表面成功负载了CaO2，并具有良好的磁性.MDCP对水中磷酸盐的吸附数据符合Langmuir等温吸附模型，根据Langmuir模型确定当T=20℃时MDCP对水中磷酸盐的最大单位吸附容量为191.84 mg·g-1.吸附等温线与吸附动力学的结果表明，MDCP对磷酸盐的吸附过程属于化学吸附.pH对MDCP吸附磷酸盐具有显著的影响，MDCP对磷酸盐的有效吸附pH范围为4~10，且MDCP对溶液pH具有调节效果，可使溶液pH保持在7~9的水平.当溶液共存Cl-、SO42-、CO32-、HCO32-、F-和NO3-等阴离子时，MDCP对水中磷酸盐仍具有良好的选择吸附性.回收后的MDCP可用HCl溶液对其吸附的磷酸盐进行解吸，解吸后的MDCP再次负载CaO2后对磷酸盐去除率仍可达到初次吸附量的70%. |
| 英文摘要 |
| In this study,magnetic diatomite was used as a carrier to load calcium peroxide(CaO2) nanoparticles,fabricating a high efficiency phosphate adsorption and recovery composite material(MDCP).The micromorphology, inner structure,crystalline constituents and element composition of MDCP were characterized by SEM,EDX-mapping,XRD, XDS, and VSM,respectively.The adsorption isotherm data of MDCP exhibited good agreement with the Langmuir isotherm model. According to the Langmuir model,when T=20℃,the maximum monolayer phosphate adsorption capacities can reach 191.84mg·g-1 for MDCP. The isotherm and kinetics studies showed that MDCP has a regulating effect on the pH of the solution,which can maintain the pH of the solution at the level where adsorption of phosphate occurs on MDCP as a chemisorption process. pH plays a important role on the adsorption of phosphate by MDCP,the pH of effective adsorption ranges from 4 to 10,and the pH of the adsorbed solution can still be maintained in the range of 7 to 9.The MDCP exhibited a high selective adsorption for phosphate in the presence of anions,including Cl-, SO42-, CO32-, HCO32-, F-, and NO3-.The recovered MDCP could be desorbed by HCl solution,and after desorption, the phosphate removal rate of MDCP after re-loading CaO2 could still reach 70% of the initial adsorption. |
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