Microwave/ultrasound-assisted modification of montmorillonite by conventional and gemini alkyl quaternary ammonium salts for adsorption of chromate and phenol: Structure-function relationship

Wuhui Luo; Jiping Ouyang; Philip Antwi; Meng Wu; Zhiqiang Huang; Weiwei Qin

doi:10.1016/j.scitotenv.2018.11.329

Microwave/ultrasound-assisted modification of montmorillonite by conventional and gemini alkyl quaternary ammonium salts for adsorption of chromate and phenol: Structure-function relationship

Sci Total Environ. 2019 Mar 10:655:1104-1112. doi: 10.1016/j.scitotenv.2018.11.329. Epub 2018 Nov 22.

Authors

Wuhui Luo¹, Jiping Ouyang², Philip Antwi³, Meng Wu³, Zhiqiang Huang⁴, Weiwei Qin⁵

Affiliations

¹ School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, PR China; Jiangxi Academy of Environmental Sciences, Nanchang 330077, PR China.
² School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, PR China; School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510000, PR China.
³ School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, PR China.
⁴ School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, PR China. Electronic address: zhiqiang@jxust.edu.cn.
⁵ Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 610000, PR China; Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO 80401, USA. Electronic address: weiwei.qin@swjtu.edu.cn.

PMID: 30577104
DOI: 10.1016/j.scitotenv.2018.11.329

Abstract

Butane-1,4-bis(dodecyl dimethyl ammonium bromide) (gBDDA) and dodecyl trimethyl ammonium bromide (DTMA) in same stoichiometric amounts were applied to modify montmorillonite (Mt) under microwave and ultrasound conditions. The composition and structure of products were obtained through multiple characterizations including XRD, FTIR, TG/DTG, SEM, TEM, and N₂ adsorption/desorption measurements, and the adsorption performance of chromate and phenol on these products were also investigated. Intercalations of gBDDA and DTMA into interlayer space of Mt were observed, but the amount of anchored modifier on the external surface was larger for gBDDA compared with DTMA when the stoichiometric amount of modifier larger than 1.0 times cation exchange capacity of Mt was added. Although there was no significant difference in morphology among products, the interlayer space distance, specific surface area, and pore size distribution were closely associated with the species and amount of applied modifier. Adsorption of phenol on products through partition mechanism relied on not only organic content, but also the configuration of modifier. Meanwhile, adsorption of chromate mainly depended on the presence of counter ion (bromide), which accounted for the high adsorption capacity and initial adsorption rate on gOMt-0.75. The fitting parameters of adsorption results using pseudo-second order model and Freundlich model suggested that gBDDA-modified Mt could sequester phenol or chromate in the faster manner with higher affinity. Compared with the conventional surfactant such as DTMA, the study revealed that, using gemini surfactant such as gBDDA to modify Mt would significantly reduce or even has the potential to eradicate the secondary pollution by modifier release during adsorption process. This study provides a new direction for Mt modification intended to be used as adsorbents to treat polluted water with high standards such as drinking water.

Keywords: Chromate; Conventional quaternary ammonium compounds; Gemini quaternary ammonium compounds; Montmorillonite; Phenol.