Enhancement of adsorption capacity of clay through spray drying and surface modification process for wastewater treatment
Enhancement of adsorption capacity of clay through spray drying and surface modification process for wastewater treatment
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DOI：
10.1016/j.cej.2017.11.084
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发表时间：
2018-02
影响因子：
15.1
通讯作者：
S. J. Olusegun;Luiz Fernando de Sousa Lima;N. Mohallem
中科院分区：
文献类型：
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作者：
S. J. Olusegun;Luiz Fernando de Sousa Lima;N. Mohallem
如今，从废水中去除染料等污染物已成为一项不折不扣的任务。有鉴于此，提高吸附剂的性能，以促进吸附技术和降低净化过程的总成本是工业部门的极大兴趣。在这项研究中，通过喷雾干燥分散的粘土溶液，并通过其表面改性来提高粘土的吸附能力。傅里叶变换红外光谱（FTIR）证实表面改性是成功的; X射线衍射（XRD）分析表明表面改性没有影响粘土的晶体结构; BET比表面积结果证明喷雾干燥粘土具有最高的比表面积102 m2/g。以亚甲基蓝为吸附剂进行吸附实验，结果表明，吸附量受溶液pH的影响，在pH 10、吸附时间为120 min时吸附量最大。吸附动力学数据符合准二级动力学模型。采用Langmuir和Freundlich吸附等温模型对吸附机理进行了探讨。Freundlich模型更适用于此过程。喷雾干燥粘土的吸附容量为168 mg/g（在333 K），优于改性粘土和生粘土。计算的热力学参数表明，吸附过程是自发的，在所有的研究温度（303-333 K）的喷雾干燥粘土。
Nowadays, removal of contaminants like dye from wastewater has become an uncompromising task. In view of this, enhancing the performance of adsorbents so as to facilitate the adsorption technique and reduce the overall cost of the purification process is of great interest to industrial sector. In this study, the adsorption capacity of clay was improved by spray drying a dispersed clay solution and also through its surface modification. Fourier transform infrared spectroscopy (FTIR) confirmed that the surface modification was successful; X-ray diffraction (XRD) analysis showed that surface modification did not affect the crystal structure of the clay, and BET specific surface area results attest that spray dried clay has the highest surface area of 102 m2/g. The adsorption tests were carried out using methylene blue and results showed that the adsorption capacity was influenced by solution pH, with maximum adsorption at pH 10 and 120 min contact time. Adsorption kinetics data were well fitted to pseudo-second order kinetics model. Langmuir and Freundlich adsorption isotherm models were used to investigate the mechanism of adsorption. Freundlich model is more applicable for this process. Spray dried clay performed better than the modified and raw clay with adsorption capacity of 168 mg/g (at 333 K). The calculated thermodynamics parameters revealed that the adsorption process is spontaneous at all the studied temperatures (303–333 K) for spray dried clay.