γ-Al2O3膜改性污泥活性炭的制备及其脱硫性能

PREPARATION AND DESULFURIZATION PROPERTIES OF ACTIVATED CARBON FROM SEWAGE SLUDGE MODIFIED BY γ-ALUMINA MEMBRANE

用溶胶-凝胶法制得γ-Al2O3膜改性污泥炭。用扫描电镜、红外光谱、BET(Brunauer-Emett-Teller)分析了改性污泥活性炭的表面结构、羟基种类和孔结构。结果表明:与污泥活性炭相比,改性污泥活性炭孔径均匀,孔径明显减小,γ-Al2O3膜与污泥活性炭结合良好;改性污泥活性炭的脱硫率显著地提高,最佳值达到87.48%。这主要是由于改性污泥活性炭后,一方面,其表面羧酸的游离—OH向稳定态转化,减弱了表面酸性,利于酸性气体SO2吸附;另一方面,γ-Al2O3膜附于污泥活性炭内壁,缩小孔径,同时也将膜微孔结构复合于污泥活性炭的孔结构中,增加了微孔和小孔的数量,增大比表面积和总孔容,利于SO2气体的吸附。

Activated carbon from sewage sludge modified by γ-alumina membranes was prepared by the sol-gel method. The pore structure and the surface composition were investigated by scanning electron microscopy, infrared spectroscopy and Brtmauer-Emett-Teller （BET） surface area measurement. The results indicate that compared to modified activated carbon from sewage sludge, the pore diameters of activated carbon from sewage sludge modified by γ-Al2O3 membranes are even and smaller, with more mesopores or micropores, and the binding between the activated carbon from sewage sludge and the membrane is good. Its desulfurization property is markedly better, and the highest desulfurization ratio can reach 87.48%. Since γ-Al2O3 membranes transform the free --OH of carboxylic acid into some stable forms, the surface acidity of activated carbon from sewage sludge is reduced, and the adsorption of SO2 is promoted. On the other hand, γ-Al2O3 membranes exist inside the pores in activated carbon from sewage sludge, and sol particles gap shrink to form micropores. Because of this, the mesopore and micropore numbers in activated carbon from sewage sludge increase. Then the BET surface area and total pore volume of the activated carbon increase.