The decreased release of heavy metals from fly ashes by adding alunite

作者：Qian Liping^*; Ma Minghai

来源：Journal of Molecular Liquids, 2014, 198: 323-328.

DOI：10.1016/j.molliq.2014.07.027

• Alunite
• Fly ash
• Heavy metal
• Inner-sphere complexation
• Leaching

The fly ashes from hospital waste incinerator were blended with natural alunite to decrease the release of heavy metals. The change in surface chemistry of fly ashes in the absence and presence of alunite was characterized by XRD, TEM, FTIR and potentiometric titration. According to potentiometric titration, the concentration of surface reactive sites of fly ashes blended into alunite (FA1) was 3 times higher than fly ashes (FAO). The release of Cu2+, Pb2+, Cd2+ and Zn2+ from FAO and FM as a function of extracted time and add concentration was investigated by batch techniques. The kinetics showed that extracted amount of heavy metals from FAO and FA1 was in the order of Zn2+ > Cu2+ > Cd2+ > Pb2+. According to the analysis of FTIR spectra, the heavy metals were adsorbed to the amorphous alumina hydrolyzed from alunite under acidic conditions. The batch extractions dictated that the leached amount of heavy metals from FM was significantly lower than FAO, suggesting that natural alunite can potentially be served as an efficient retardant for the immobilization of heavy metals from fly ashes.

• 出版日期2014-10
• 单位黄山学院