Simultaneous removal of Congo red and cadmium(Ⅱ) from aqueous solutions using graphene oxide–silica composite as a multifunctional adsorbent

作     者：Ebrahim Mahmoudi Sepehr Azizkhani Abdul Wahab Mohammad Law Yong Ng Abdelbaki Benamor Wei Lun Ang Muneer Ba-Abbad Ebrahim Mahmoudi;Sepehr Azizkhani;Abdul Wahab Mohammad;Law Yong Ng;Abdelbaki Benamor;Wei Lun Ang;Muneer Ba-Abbad

作者机构：Department of Chemical and Process EngineeringFaculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia43600 BangiSelangor Darul EhsanMalaysia Department of Chemical and Environmental EngineeringFaculty of EngineeringUniversiti Putra Malaysia43400 SerdangSelangorMalaysia Department of Chemical EngineeringLee Kong Chian Faculty of Engineering and ScienceUniversiti Tunku Abdul RahmanJalan Sungai LongBandar Sungai LongCheras43000 KajangSelangorMalaysia Centre for Sustainable Process Technology(CESPRO)Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia43600 BangiSelangor Darul EhsanMalaysia Gas Processing CentreQatar UniversityP.O.Box 2713DohaQatar 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2020年第32卷第12期

页      面：151-160页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：NPRP Grant # 10-0127-170270 from Qatar National Research Fund MI-2017-002 grant from Universiti Kebangsaan Malaysia 

主　　题：Graphene-oxide Multifunctional adsorbent Competitive removal Heavy metal-dye removal 

摘      要：Graphene oxide is a very high capacity adsorbent due to its functional groups and π-π interactions with other compounds. Adsorption capacity of graphene oxide, however, can be further enhanced by having synergistic effects through the use of mixed-matrix composite. In this study, silica-decorated graphene oxide(SGO) was used as a high-efficiency adsorbent to remove Congo red(CR) and Cadmium(Ⅱ) from aqueous solutions. The effects of solution initial concentration(20 to 120 mg/l), solution pH(pH 2 to 7), adsorption duration(0 to 140 min) and temperature(298 to 323 K) were measured in order to optimize the adsorption conditions using the SGO adsorbent. Morphological analysis indicated that the silica nanoparticles could be dispersed uniformly on the graphene oxide surfaces. The maximum capacities of adsorbent for effective removal of Cd(Ⅱ) and CR were 43.45 and 333.33 mg/g based on Freundlich and Langmuir isotherms, respectively. Langmuir and Freundlich isotherms displayed the highest values of Q max for CR and Cd(Ⅱ) adsorption in this study, which indicated monolayer adsorption of CR and multilayer adsorption of Cd(II) onto the SGO, respectively. Thermodynamic study showed that the enthalpy( H) and Gibbs free energy( G) values of the adsorption process for both pollutants were negative, suggesting that the process was spontaneous and exothermic in nature. This study showed active sites of SGO( π-π, hydroxyl, carboxyl, ketone, silane-based functional groups) contributed to an enormous enhancement in simultaneous removal of CR and Cd(Ⅱ) from an aqueous solu-tion, Therefore, SGO can be considered as a promising adsorbent for future water pollution control and removal of hazardous materials from aqueous solutions.