Surfactants are organic compounds which can be used in several applications. However, they can contaminate world water resources causing detrimental effects to human beings, aquatic life, and animals. This paper investigates the adsorption kinetics, isotherms, and thermodynamic properties for the removal of an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), using fly ash. Characteristics of fly ash such as surface area and pore size analysis and the point of zero charge (PZC) were determined. The effects of parameters such as pH, surfactant concentration, and temperature and the adsorption kinetics, isotherms, and thermodynamic properties and adsorption mechanism were determined. Fly ash is a mesoporous material having surface area and pore size of 1.079 m²/g and 9.813 nm and PZC at pH 6.58. pH 2 and the temperature 25 °C were optimum for adsorbing SDBS onto fly ash. The adsorption capacity and removal efficiency increased by increasing the concentration of SDBS from 100 to 2000 mg/L, indicating that the increase of surfactant concentration could not saturate the surface of fly ash. The pseudo-second-order and the Langmuir isotherm models showed best fit to the adsorption data and the thermodynamic properties described adsorption as an exothermic, barrierless, non-spontaneous, and entropy-reducing reaction which is more feasible at a lower temperature of 25 °C. This indicated that the adsorption occurs by both physisorption and chemisorption with monolayer coverage of SDBS on the surface of fly ash. SDBS surfactant adsorbed onto fly ash mainly through electrostatic interactions between oppositely charged SDBS and fly ash.

表面活性剂是可用于多种应用的有机化合物。但是，它们会污染世界水资源，对人类，水生生物和动物造成不利影响。本文研究了使用粉煤灰去除阴离子表面活性剂十二烷基苯磺酸钠（SDBS）的吸附动力学，等温线和热力学性质。确定了粉煤灰的特性，例如表面积和孔径分析以及零电荷点（PZC）。确定了pH，表面活性剂浓度和温度等参数对吸附动力学，等温线，热力学性质和吸附机理的影响。粉煤灰是介孔材料，其表面积和孔径为1.079 m ²/ g和9.813nm，并且在pH 6.58的PZC。pH 2和25°C的温度最适合将SDBS吸附到粉煤灰上。将SDBS的浓度从100 mg / L增加到2000 mg / L可以提高吸附能力和去除效率，表明表面活性剂浓度的增加不能使粉煤灰表面饱和。拟二阶和Langmuir等温模型显示出最适合吸附数据，热力学性质描述为吸附是放热，无障碍，非自发和减少熵的反应，在25°C的较低温度下更可行C。这表明吸附是通过物理吸附和化学吸附发生的，飞灰表面上单层覆盖了SDBS。