Sequestration of toxic congo red dye from aqueous solution using ecofriendly guar gum/ activated carbon nanocomposite

• Published in: International journal of biological macromolecules 2020-09, Vol.158, p.1310-1318
• Main Authors: Gupta, Vinod Kumar, Agarwal, Shilpi, Ahmad, Rais, Mirza, Anam, Mittal, Jyoti
• Format: Article
• Language: English
• Subjects: Congo red dye; Freundlich; Langmuir; Nanocomposite; Regeneration; Thermodynamic
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.05.025

In the present study, a potential Guar gum/activated carbon nanocomposite as an adsorbent was synthesized and utilized for the sequestration of toxic congo red dye from synthetic wastewater. The nanocomposite was characterized using different techniques such as SEM, EDX, TEM, FTIR and XRD. Various physico-chemical parameters such as influence of contact time, pH, adsorbent dose, temperature and initial dye concentration were investigated to optimize conditions for maximum adsorption of congo red. Equilibrium data fitted well with Langmuir isotherm model having maximum adsorption capacity of 831.82 mgg−1 at 313 K. The kinetic studies demonstrated that the adsorption followed a pseudo-second order kinetic model. The thermodynamic study showed that the adsorption of congo red onto nanocomposite was spontaneous, exothermic with decreased in randomness at solid/liquid interface. The regeneration study indicated that the nanocomposite could be reused successfully upto five consecutive cycles. Therefore, the present material can be effectively and efficiently urilized for the removal of congo red dye from aqueous solution as well as industrial wastewater. [Display omitted] •Greener synthesis of Guar gum/ activated carbon nanocomposite•Excellent removal of congo red dye from synthetic wastewater•Characterized using TEM, SEM, FTIR and XRD techniques•Followed Pseudo-second order and Langmuir adsorption isotherm model•Regeneration upto five cycles using NaOH solution