TY - JOUR EP - 243 KW - Activation energy; Adsorption; Animals; Anionic surfactants; Biophysics; Chemisorption; Dyes; Fly ash; Free energy; Geopolymers; Gibbs free energy; Inorganic polymers; Isotherms; Monolayers; Morphology; Remediation; Surface active agents; Water resources KW - Adsorption capacities; Adsorption parameters; Amorphous morphology; Isotherms and thermodynamics; Langmuir isotherm models; Pseudo second order kinetics; SDBS; Sodium dodecylbenzene sulfonate KW - Physisorption N2 - Contamination of the world's water resources is a growing issue and its remediation requires the development of highly efficient, environmentally friendly and economical processes. Water contaminated with surfactants can cause detrimental health effects in humans and aquatic animals. Removing surfactants using adsorption is effective, simple and economical. This paper describes the development of a fly ash based geopolymer (FAGP)adsorbent for adsorbing the anionic surfactant sodium dodecyl benzene sulfonate (SDBS). The adsorption parameters of the geopolymers were optimized using batch adsorption. The adsorption kinetics, isotherms and thermodynamics were also determined. The FAGP had an amorphous morphology and a surface area of 31.873 m2/g. The optimum parameters for adsorbing the SDBS using FAGP were pH 2, contact time 180 min, adsorbent dosage 1 g/L for an initial SDBS concentrations of 880 mg/L. The maximum adsorption capacity of 714.3 mg/g was obtained. The adsorption followed pseudo second order kinetics and Langmuir isotherm models suggesting that the adsorption process was chemisorption with monolayer adsorbate coverage. SDBS was adsorbed onto FAGP by electrostatic interactions between the positively charged FAGP and negatively charged SDBS. The activation energy of adsorption was 4.052 kJ/mol and the Gibbs free energy was negative, suggesting the adsorption process was physisorption, endothermic, spontaneous and more favorable at a temperature of 65 °C. The adsorption of SDBS onto FAGP occurs through both physisorption and chemisorption. FAGP was proven as a low-cost adsorbent to remove SDBS and could be potentially used for the adsorption of other water contaminating surfactants. © 2019 Elsevier Ltd VL - 229 JF - Journal of Cleaner Production AV - none TI - Fly ash based geopolymer for the adsorption of anionic surfactant from aqueous solution SN - 09596526 ID - scholars11388 A1 - Siyal, A.A. A1 - Shamsuddin, M.R. A1 - Rabat, N.E. A1 - Zulfiqar, M. A1 - Man, Z. A1 - Low, A. Y1 - 2019/// N1 - cited By 93 SP - 232 PB - Elsevier Ltd UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065425003&doi=10.1016%2fj.jclepro.2019.04.384&partnerID=40&md5=18b40efccaff27952f8047ccd09c5bcf ER -