Sioukri Evilambia, Bandosz Teresa J
Department of Chemistry, The City College of New York, 138th Street and Convent Avenue, New York, New York 10031, USA.
Environ Sci Technol. 2005 Aug 15;39(16):6225-30. doi: 10.1021/es0503985.
Two commercial low-cost activated carbons and wood-based char were mixed with dewatered sludge and pyrolized at 950 degrees C. The sludge content on a dry basis was 23%. The obtained composite adsorbents were characterized from the point of view of surface chemistry (pH) and texture (adsorption of nitrogen at its boiling point: surface area, pore volume, pore size distributions). Then hydrogen sulfide breakthrough capacities were measured using the home-designed dynamic test. The results revealed a significant increase in the capacity of the composite adsorbents compared to the unmodified carbons. Moreover, that increase was a few times greater than the hypothetical one predicted when desulfurization performance would be the sum of the contributions of both the sludge-derived and carbon phases. This is attributed to a synergetic effect related to the dispersion of the catalysts and the presence of small pores. Mixing activated carbon provides the active centers for oxidation (coming from sludge) and the developed pore system (from the activated carbon) where products of oxidation can be stored. Moreover, in the hydrophobic pore space the volatile organic compounds present in effluent air from a municipal waste treatment plant can be adsorbed. The selectivity for H2S oxidation, as in the case of pure activated carbon, depends on the pore sizes. Smaller pores lead to a higher yield of sulfuric acid; larger pores lead to a higher yield of sulfur.
将两种商用低成本活性炭和木质基炭与脱水污泥混合，并在950℃下进行热解。污泥的干基含量为23%。从表面化学（pH值）和质地（氮气在其沸点下的吸附：表面积、孔体积、孔径分布）的角度对所得复合吸附剂进行了表征。然后使用自行设计的动态试验测量硫化氢穿透容量。结果表明，与未改性的炭相比，复合吸附剂的容量显著增加。此外，这种增加比假设脱硫性能为污泥衍生相和碳相贡献之和时预测的增加大几倍。这归因于与催化剂分散和小孔存在相关的协同效应。混合活性炭为氧化提供了活性中心（来自污泥）以及发达的孔系统（来自活性炭），氧化产物可以储存在其中。此外，在疏水孔空间中，可以吸附城市污水处理厂排放空气中存在的挥发性有机化合物。与纯活性炭一样，对H2S氧化的选择性取决于孔径。较小的孔导致硫酸产率较高；较大的孔导致硫产率较高。
