A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K2S. Raw coal was mixed with K2S powder and then heated at 800℃ for 30 min in nitrogen to...A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K2S. Raw coal was mixed with K2S powder and then heated at 800℃ for 30 min in nitrogen to produce K2S char. The sulfur content and form in K2S char were determined, and the ability of K2S char to adsorb Zn^2＋, Cd^2＋ and Pb^2＋ was examined. The K2S impregnation was effective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of K2S char was higher than those of raw coal and pyrolysis char. The Zn^2＋ removal in 2.4 mmol/L of Zn^2＋ solution by K2S char was higher than raw coal with the removal rate of 100%. K2S char adsorbed Pb^2＋ and Cd^2＋ in 24 mmol/L of Pb^2＋ and Cd^2＋ solution with the removal rate of 97% and 35%, respectively. The elution extents of adsorbed Pb^2＋ and Cd^2＋ were zero in distilled water and 27% in 0.1 mol/L HCl solution. These results indicated that an effective adsorbent for heavy metal ions was prepared from coal using K2S sulfur impregnation, and that the adsorbed metals were strongly retained in K2S char.展开更多
文摘A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K2S. Raw coal was mixed with K2S powder and then heated at 800℃ for 30 min in nitrogen to produce K2S char. The sulfur content and form in K2S char were determined, and the ability of K2S char to adsorb Zn^2＋, Cd^2＋ and Pb^2＋ was examined. The K2S impregnation was effective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of K2S char was higher than those of raw coal and pyrolysis char. The Zn^2＋ removal in 2.4 mmol/L of Zn^2＋ solution by K2S char was higher than raw coal with the removal rate of 100%. K2S char adsorbed Pb^2＋ and Cd^2＋ in 24 mmol/L of Pb^2＋ and Cd^2＋ solution with the removal rate of 97% and 35%, respectively. The elution extents of adsorbed Pb^2＋ and Cd^2＋ were zero in distilled water and 27% in 0.1 mol/L HCl solution. These results indicated that an effective adsorbent for heavy metal ions was prepared from coal using K2S sulfur impregnation, and that the adsorbed metals were strongly retained in K2S char.
