Construction of Layered Double Hydroxides/Hollow Carbon Microsphere Composites and Its Applications for Mutual Removal of Pb(II) and Humic Acid from Aqueous Solutions
Construction of Layered Double Hydroxides/Hollow Carbon Microsphere Composites and Its Applications for Mutual Removal of Pb(II) and Humic Acid from Aqueous Solutions
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DOI：
10.1021/acssuschemeng.7b01717
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发表时间：
2017-12-01
影响因子：
8.4
通讯作者：
Wang, Xiangke
中科院分区：
文献类型：
--
作者：
Huang, Shuyi;Song, Shuang;Wang, Xiangke
开发具有大比表面积的高效材料对于同时消除废水中的无机和有机污染物具有重要的科学和技术意义。本文以碳球为模板，通过水热法制备了层状双氢氧化物涂层（LDHs-coated）中空碳微球复合材料（hcms; LDHs/ hcms），并在不同的实验条件下，即pH、离子强度、接触时间、添加顺序和共存离子，对Pb（II）和腐殖酸（HA）进行了相互去除。结果表明，pH < 8.0时，Pb（II）和HA的存在有利于单目标污染物[Pb（II）或HA]的吸附。吸附的HA主要通过形成HA-Pb- ldhs / hcms三元配合物改善了对Pb（II）的吸附。研究了LDHs/ hcms对Cu（II）、Co（II）、Pb（II）、Ni（II）离子的竞争吸附，结果表明LDHs/ hcms的亲合力顺序为Co(II) < Ni(II) < Cu(II) < Pb（II）。有趣的是，在二元/四元体系中，Cu（II）、Co（II）和Ni（II）离子的存在对Pb（II）的吸附有轻微的抑制作用。然而，随着重金属离子的增加，LDHs/ hcms吸附的重金属离子总量增加。x射线光电子能谱和傅里叶变换红外光谱结果表明，铅（II）在LDHs/ hcms上的吸附主要是外球表面络合作用，而HA的吸附主要是游离HA在LDHs/ hcms上的表面络合作用。研究结果强调了LDHs/ hcms的新合成方法及其在环境污染净化中同时去除废水中不同金属离子和天然有机污染物的潜在应用。
Development of a highly efficient material with large specific area was scientifically and technologically important for simultaneous elimination of inorganic and organic pollutants from wastewater. In this work, layered-double-hydroxides-coated (LDHs-coated) hollow carbon microsphere composites (HCMSs; LDHs/HCMSs) were fabricated using carbon spheres as templates via a hydrothermal method and were then applied for mutual removal of Pb(II) and humic acid (HA) under various experimental conditions, i.e., pH, ionic strength, contact time, addition sequences, and coexisting ions. The results indicated that the copresence of Pb(II) and HA facilitated single target pollutant [Pb(II) or HA] adsorption at pH < 8.0. The adsorbed HA was responsible for the improvement of Pb(II) adsorption, primarily as a result of the formation of HA-Pb-LDHs/ HCMSs ternary complexes. Competitive adsorption of Cu(II), Co(II), Pb(II), and Ni(II) ions on LDHs/HCMSs was also investigated, and the LDHs/HCMSs had the affinity in the order of Co(II) < Ni(II) < Cu(II) < Pb(II). Interestingly, in binary/quaternary systems, the results showed that the presence of Cu(II), Co(II), and Ni(II) ions exhibited slight inhibition on Pb(II) adsorption. However, the total amounts of heavy metal ions adsorbed on LDHs/ HCMSs increased with the increase of the heavy metal ions. Results of X-ray photoelectron spectroscopy and Fourier transformed infrared spectroscopy indicated that outer-sphere surface complexation mainly dominated the adsorption of Pb(II) on LDHs/HCMSs, while the adsorption of HA was attributed to surface complexation of the disassociated HA on LDHs/ HCMSs. The findings highlighted the novel synthesis of LDHs/HCMSs and its potential application for simultaneous removal of different metal ions and natural organic contaminants from wastewater in environmental pollution cleanup.