Laboratório de Pesquisa em Ciências Interfaciais, Departamento de Química, Universidade Estadual do Centro-Oeste, 85040-080, Guarapuava, PR, Brazil.
Inorganic Chemistry Laboratory, University of Oxford, Oxford, OX1 3QR, United Kingdom.
J Hazard Mater. 2018 Aug 5;355:136-144. doi: 10.1016/j.jhazmat.2018.02.041. Epub 2018 Mar 1.
Montmorillonite clay (MC) yields after modification of the interlamellar spacing and the chemical character of its surface by treatment with cetyltrimethylammonium bromide (CTAB) a solid product (MCCTA). This has been used as an adsorbent for the removal of p-nitrophenol (PNP) from aqueous solutions. The MCCTA samples were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TG/DTA), FT-IR spectroscopy, zeta potential measurements, X-ray diffraction (XRD), and specific surface area. Investigations were also carried out to assess how the adsorption of PNP was affected by factors such as contact time, initial PNP concentration, adsorbent dosage and temperature. Of the two models tried the Freundlich isotherm gave a better account of the equilibrium data than did the Langmuir one. The kinetics could be successfully replicated by a pseudo-second order model with an activation energy of 55.0 kJ mol, while the thermodynamic parameters indicated an exothermic (ΔH = -15.8 kJ mol), non-spontaneous (ΔG = + 3.9-5.9 kJ mol) adsorption process. The experimental results showed MCCTA, unlike natural MC, to have a significant adsorption capacity for PNP removal from aqueous media.
蒙脱石粘土（MC）经过十六烷基三甲基溴化铵（CTAB）处理，层间距和表面化学性质发生变化，生成固体产物（MCCTA）。该产物已被用作从水溶液中去除对硝基苯酚（PNP）的吸附剂。MCCTA 样品通过扫描电子显微镜（SEM）、能谱（EDX）、热重分析（TG/DTA）、傅里叶变换红外光谱（FT-IR）、动电位测量、X 射线衍射（XRD）和比表面积进行了表征。还研究了吸附时间、初始 PNP 浓度、吸附剂用量和温度等因素对 PNP 吸附的影响。尝试的两种模型中， Freundlich 等温线比 Langmuir 等温线更能描述平衡数据。动力学可以通过准二级模型成功复制，其活化能为 55.0 kJ/mol，而热力学参数表明该吸附过程是放热（ΔH=-15.8 kJ/mol）、非自发的（ΔG=+3.9-5.9 kJ/mol）。实验结果表明，与天然 MC 不同，MCCTA 对从水介质中去除 PNP 具有显著的吸附能力。
