Abstract:

The treatment of mine water has become increasingly difficult due to the afflux of hydraulic support emulsion. With the advantages of large specific surface area and adsorption capacity, powdered activated carbon （AC） has been widely used in water treatment. However, for ordinary AC, there are difficulties in separation and recycling after adsorption of organic pollutants. Herein, activated carbon supported Fe₃O₄ （AC@Fe₃O₄） was prepared with chemical coprecipitation by using AC, FeCl₃·6H₂O and FeCl₂·4H₂O as raw materials, and the product was used to adsorb the hydraulic support emulsion from water. The results showed that the adsorption equilibrium could be reached at 90 min. At the volume fraction of emulsion of 0.5%, temperature of 25 ℃ and oscillation rate of 200 r/min, the adsorption capacity was 1.07 mL/g. The study of adsorption kinetics showed that the adsorption of emulsion at AC@Fe₃O₄ was more consistent with pseudo-second-order model, indicating that the adsorption of emulsion on magnetic activated carbon was mainly chemical adsorption. The Langmuir isotherm model had a high fitting degree for the adsorption of emulsion on magnetic activated carbon, in which the theoretical saturated adsorption capacity calculated by fitting was 1.51 mL/g. In the experiment, the optimized adsorption capacity could reach 1.07 mL/g. After adsorption, external magnetic force was used to realize complete liquid-solid separation. In methanol, more than 90% emulsion could be desorbed from the AC@Fe₃O₄ after adsorption. After 5 cycles, the AC@Fe₃O₄ still maintained excellent performance of adsorption and desorption. This work could provide a novel strategy for efficient recycling and reutilization of activated carbon in treatment of the waste water containing emulsion.

Key words: magnetic activated carbon, hydraulic support emulsion, adsorption