Adsorption of dye from wastewater using chitosan–CTAB modified bentonites

• Published in: Journal of colloid and interface science 2012-09, Vol.382 (1), p.61-66
• Main Authors: Guo, Jianzhong, Chen, Shunwei, Liu, Li, Li, Bing, Yang, Ping, Zhang, Lijun, Feng, Yanlong
• Format: Article
• Language: English
• Subjects: activated carbon; Adsorbent; Adsorbents; adsorption; Adsorption isotherm; bentonite; cetyltrimethylammonium bromide; Chemistry; Chitosan; dyeing; Exact sciences and technology; Fourier transform infrared spectroscopy; General and physical chemistry; Hexadecyl trimethyl ammonium bromide; Modified bentonite; sorption isotherms; Surface physical chemistry; wastewater; water treatment; Weak acid scarlet; X-ray diffraction
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2012.05.044

[Display omitted] ► Adsorption capabilities of Na-Bent are low, but higher for 1CTS–10CTAB-Bent. ► The removal efficiency of weak acid scarlet on 1CTS–10CTAB-Bent was higher than 85%. ► The adsorption capacity of the 1CTS–10CTAB-Bent was 102.0mgg−1. ► The adsorptions are spontaneous. ► The Langmuir and Temkin models both described the adsorption isotherm data well. Dyeing wastewater removal is important for the water treatment, and adsorption is an efficient treatment process. In this study, three modified bentonites, chitosan modified bentonite (CTS-Bent), hexadecyl trimethyl ammonium bromide (CTAB) modified bentonite (CTAB-Bent), and both chitosan and hexadecyl trimethyl ammonium bromide modified bentonite (CTS–CTAB-Bent) were prepared and characterized by FTIR and XRD analysis. Batch experiments were conducted to evaluate the adsorptive removal of weak acid scarlet from aqueous phase using modified bentonites under different conditions. The results show that the adsorption capacity of weak acid scarlet onto natural bentonite was low (4.9%), but higher for 1CTS-Bent and 1CTS–10CTAB-Bent. The optimal conditions for weak acid scarlet adsorption were 1% chitosan, 10% CTAB, at 80°C and reaction time 2.5h. The best removal efficiency was ∼85%, and the adsorption capacity of weak acid scarlet was around 102.0mgg−1, much higher than that of commercial activated carbon (27.2mgg−1). These results suggest that 1CTS–10CTAB-Bent is an excellent adsorbent for effective weak acid scarlet removal from water. The adsorption isotherms of weak acid scarlet were investigated. It was found that Langmuir and Temkin models fitted the data very well (R2>0.99).