State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
Waste Manag. 2011 Aug;31(8):1790-6. doi: 10.1016/j.wasman.2011.04.006. Epub 2011 May 4.
Bio-drying has been applied to improve the heating value of municipal solid waste (MSW) prior to combustion. In the present study, evolution of heavy metals in MSW during bio-drying and subsequent combustion was studied using one aerobic and two combined hydrolytic-aerobic scenarios. Heavy metals were concentrated during bio-drying and transformed between different metal fractions, namely the exchangeable, carbonate-bound, iron- and manganese-oxides-bound, organic-matter-bound and residual fractions. The amounts of heavy metals per kg of bio-dried MSW transferred into combustion flue gas increased with bio-drying time, primarily due to metals enrichment from organics degradation. Because of their volatility, the partitioning ratios of As and Hg in flue gas remained stable so that bio-drying and heavy metal speciation had little effect on their transfer and partitioning during combustion. In contrast, the partitioning ratios of Pb, Zn and Cu tended to increase after bio-drying, which likely enhanced their release potential during combustion.
生物干化已被应用于提高城市固体废物（MSW）在燃烧前的热值。在本研究中，采用一种好氧和两种水解-好氧组合方案，研究了 MSW 在生物干化过程中以及随后燃烧过程中重金属的演变情况。重金属在生物干化过程中浓缩，并在不同的金属组分之间转化，即可交换的、碳酸盐结合的、铁和锰氧化物结合的、有机物质结合的和残余组分。随着生物干化时间的延长，每公斤生物干化 MSW 中转移到燃烧烟道气中的重金属量增加，主要是由于有机物降解导致重金属富集。由于其挥发性，As 和 Hg 在烟道气中的分配比保持稳定，因此生物干化和重金属形态对其在燃烧过程中的迁移和分配影响不大。相比之下，Pb、Zn 和 Cu 的分配比在生物干化后趋于增加，这可能会增加它们在燃烧过程中的释放潜力。
