Synthesis, performance, and nonlinear modeling of modified nano-sized magnetite for removal of Cr(VI) from aqueous solutions
Synthesis, performance, and nonlinear modeling of modified nano-sized magnetite for removal of Cr(VI) from aqueous solutions
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DOI：
10.1080/19443994.2013.846238
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发表时间：
2015-01-16
影响因子：
1.1
通讯作者：
Ahmadi, Mehdi
中科院分区：
文献类型：
--
作者：
Babaei, Ali Akbar;Baboli, Zeynab;Ahmadi, Mehdi
有毒且不可生物降解的重金属污染水体是一个严重的环境问题。铬是土壤、工业废水、地下水和地表水中非常重要的污染物。研究了改性磁铁矿纳米颗粒对六价铬（Cr(VI)）的吸附性能。考察了吸附剂剂量、pH、接触时间、初始Cr（VI）浓度、吸附量以及Cr（VI）的动力学和等温吸附模型的影响。采用共沉淀法合成了改性磁铁矿纳米颗粒，并利用扫描电镜（SEM）和x射线衍射（XRD）对其结构和织构性能进行了研究。pH值为4.0时，Cr（VI）的去除率最大。达到平衡需要60分钟的接触时间。实验数据采用不同的非线性等温线和动力学模型进行拟合。结果表明，吸附数据与Redlich、Peterson和Freundlich等温线模型拟合良好。动力学数据最适合拟二阶动力学模型。结果表明，改性纳米磁铁矿可以作为吸附剂有效去除水中的Cr（VI）。
Contamination of water bodies with toxic and non-biodegradable heavy metals is a serious environmental problem. Chromium is a very important contaminant in soil, industrial waste, groundwater, and surface water sources. This study was conducted to assess hexavalent chromium (Cr(VI)) adsorption onto modified magnetite nanoparticles from aqueous solution. The effects of adsorbent dose, pH, contact time, initial Cr(VI) concentrations, adsorption capacity, and modeling of kinetic and isotherm adsorption of Cr(VI) were investigated. Modified magnetite nanoparticles were synthesized by using a co-precipitation method, and its structural and textural properties were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The maximum removal of Cr(VI) was achieved at pH 4.0. A contact time of 60 min was required to reach the equilibrium. Experimental data were fitted with different nonlinear isotherm and kinetic models. The results showed that the adsorption data were fitted well by the Redlich and Peterson and Freundlich isotherm models. The kinetic data were best fitted to pseudo-second-order kinetic model. The results indicate that modified nano-sized magnetite could be employed as adsorbent for the removal of Cr(VI) in aqueous environments effectively.