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^-、CO3^2-、HCO3^2-、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%.
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 191.84 mg·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^-,SO4^2-,CO3^2-,HCO3^2-,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.
作者
徐楚天
李大鹏
张帅
耿雪
陈丽媛
宋小君
郭超然
黄勇
XU Chu-tian;LI Da-peng;ZHANG Shuai;GENG Xue;CHEN Li-yuan;SONG Xiao-jun;GUO Chao-ran;HUANG Yong(School of Environmental Science and Engineering,Suzhou University of Science and Technology,Suzhou 215009,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2020年第2期792-800,共9页
Environmental Science
基金
国家自然科学基金项目(51778393)
江苏省研究生实践创新计划项目(SJCX18_0870).
