Xanthate modified magnetic activated carbon for efficient removal of cationic dyes and tetracycline hydrochloride from aqueous solutions

Abstract

The removal of cationic dyes and hydrochloride tetracycline from aqueous solutions has attracted more attention. In this paper, magnetic activated carbon (mAC) was first prepared by one-step co-precipitation method, and xanthate was grafted onto the surface of magnetic activated carbon by xanthation reaction, and the x-mAC functionalized magnetic activated carbon material (x-mAC) was successfully synthesized. x-mAC is used to remove cationic dyes and tetracycline hydrochloride. The physical and chemical properties of AC, mAC and x-mAC were characterized by FTIR, SEM, TEM, XRD, BET and VSM. It is found that x-mAC has good removal ability on malachite green (MG), methylene blue (MB), crystal violet (CV) and tetracycline hydrochloride (TC). The adsorption process of x-mAC on cationic dyes and tetracycline hydrochloride obeys Langmuir adsorption model and pseudo-second-order kinetic model. The kinetic data has a good correlation with the pseudo-second-order equation. The Langmuir and Freundlich models are suitable for isotherm data. The calculated adsorption capacities of MG, MB, CV and TC are 595.24 mg/g, 314.3 mg/g, 394.14 mg/g and 210.94 mg/g, respectively. The results of thermodynamic research (△G <0, △H> 0, △S> 0) showed that the adsorption process was endothermic and spontaneous proceeding. The adsorption-desorption process went through five cycles. After five cycles, the removal rates of MG, MB, CV and TC remained above 81.40 %, 91.78 %, 93.69 % and 91.29 %, respectively. The results showed that due to the good adsorption performance and simple preparation process, x-mAC has potential application prospects in the field of wastewater treatment.