GAO Yu, LUO Litao, CHANG Fengmin, CHEN Zhaolin, YUAN Jing, QIU Huagang
The study on adsorption performance and mechanism of aniline on coal granular activated carbon is important technical support for removing a large number of aniline pollutants in dye wastewater. Through adsorption experiments of aniline on coal based granular activated carbons with different concentrations, carbon dosages/COD, adsorption times and pH values, and the adsorption isotherm and adsorption kinetics curves it is shown that the removal rate of aniline and the unit adsorption capacity of aniline are 17.28 mg/g and 98.8%, respectively when the single control variable is carbon dosage/COD of 4.5, under the premise of other conditions being unchanged. When pH value is 5, the aniline removal efficiency is the best. Aniline removal rate and unit adsorption capacity are 16.17 mg/g and 92.47%, respectively. Similarly, when other variables remain unchanged, the higher the concentration, the higher the unit adsorption capacity, but the lower the removal rate; the longer the adsorption time, the higher the adsorption capacity and removal rate. The fitting degree of Langmuir isotherm equation is 0.9929, indicating that a monomolecular layer of aniline is adsorbed on the surface of coal granular activated carbon. The Freundlich characteristic constant 1/n is 0.3363, indicating that this adsorption process is easy to occur. In addition, the adsorption process is more in line with the quasi-second-order kinetics, and the adsorption rate is controlled by internal diffusion and internal surface adsorption process. This study provides reference for improving operating efficiency and reducing treatment cost of activated carbon adsorption process.