Investigation Of Effects And Influence Factors By Adsorption To Remove Tetracycline

In this research, we choose the activated carbon fibers and lignin as two kinds of different raw materials, which were prepared out different nature of the adsorbents. The properties of the two adsorbents were characterized. And then, the effects of experimental factors such as initial concentration, pH, contact time and temperature on the adsorption were investigated. The adsorption kinetics and thermodynamics were also discussed.Activated carbon fibers heated by microwave under nitrogen (N2) atmosphere were applied in this study. WACF was obtained under the condition of the microwave radiation temperature was600℃and the radiation time was15min. The properties of which was characterized by scanning electron microscope (SEM), N2adsorption-desorption isotherms, and X-ray diffraction (XRD) compared with activated carbon fibers (ACF) without any treatment. The results showed that the surface of WACF was etched and mesopore appeared. It could also be seen that WACF had lower surface area (1008m2/g) but higher external surface area (73.2%) than ACF (surface area:1153m2/g; external surface area:57.4%).LGAC was prepared from ligin by phosphoric acid activation. The preparation condition of LGAC was at H3PO4concentration of40%, an impregnation ratio of2:1, with impregnation time was12h. And activated temperature was450℃, with activated time was1h. The surface area of LGAC was found to be931.53m2/g. The adsorbent found to have a rough surface, with rich irregular pores. There were more acidic groups and carboxylic was the main group. The isoelectric point was2.61The result of adsorption experiment showed that both WACF and LGAC could effectively remove tetracycline, with the adsorption capacities of309and320mg/g, respectively. The adsorption on both WACF and LGAC were highly affected by pH, the adsorption capacity was decreased with the increasing pH. The pseudo-second-order kinetic model, showing the chemical adsorption, was well described the couple adsorption progress. The equilibrium adsorption data was represented by the Langmuir model. Thermodynamic study showed that the adsorption was a spontaneous and endothermic process.NaOH was considered as a good desorption reagent for LGAC which had been adsorbed the tetracycline.