[载氧化钙磁性硅藻土对水中磷酸盐的吸附]

[Phosphate Adsorption from Water on CaO-loaded Magnetic Diatomite].

作者信息

Xu Chu-Tian, Li Da-Peng, Zhang Shuai, Geng Xue, Chen Li-Yuan, Song Xiao-Jun, Guo Chao-Ran, Huang Yong

机构信息

School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.

出版信息

Huan Jing Ke Xue. 2020 Feb 8;41(2):792-800. doi: 10.13227/j.hjkx.201909094.

DOI:10.13227/j.hjkx.201909094

PMID:32608739

Abstract

In this study,magnetic diatomite was used as a carrier to load calcium peroxide(CaO) 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 =20℃,the maximum monolayer phosphate adsorption capacities can reach 191.84mg·g 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, SO, CO, HCO, F, and NO.The recovered MDCP could be desorbed by HCl solution,and after desorption, the phosphate removal rate of MDCP after re-loading CaO could still reach 70% of the initial adsorption.

摘要

在本研究中，以磁性硅藻土为载体负载过氧化钙（CaO₂）纳米颗粒，制备了一种高效的磷吸附与回收复合材料（MDCP）。分别采用扫描电子显微镜（SEM）、能谱仪X射线能谱面扫描分析（EDX-mapping）、X射线衍射仪（XRD）、X射线光电子能谱仪（XDS）和振动样品磁强计（VSM）对MDCP的微观形貌、内部结构、晶体成分和元素组成进行了表征。MDCP的吸附等温线数据与朗缪尔等温线模型吻合良好。根据朗缪尔模型，当温度为20℃时，MDCP对磷的最大单层吸附量可达191.84mg·g⁻¹。等温线和动力学研究表明，MDCP对溶液pH有调节作用，能将溶液pH维持在MDCP发生磷化学吸附的水平。pH对MDCP吸附磷起着重要作用，有效吸附的pH范围为4至10，吸附后溶液的pH仍可维持在7至9范围内。在存在Cl⁻、SO₄²⁻、CO₃²⁻、HCO₃⁻、F⁻和NO₃⁻等阴离子的情况下，MDCP对磷表现出高选择性吸附。回收后的MDCP可用盐酸溶液解吸，解吸后重新负载CaO₂的MDCP对磷的去除率仍可达初始吸附量的70%。