1Université libre de Bruxelles (ULB), Brussels, Belgium.
Waste Manag Res. 2014 May;32(5):406-13. doi: 10.1177/0734242X14527637. Epub 2014 Apr 9.
Carbonation was applied to a Pb- and Zn-contaminated fraction of municipal solid waste incineration electrofilter fly ashes in order to reduce heavy metal leaching. Carbonation tests were performed in solution, by Na2CO3 addition or CO2 bubbling, and were compared with washing (with water only). The injection of CO2 during the washing did not modify the mineralogy, but the addition of Na2CO3 induced the reaction with anhydrite, forming calcite. Microprobe analyses showed that Pb and Zn contamination was rather diffuse and that the various treatments had no effect on Pb and Zn speciation in the residues. The leaching tests indicated that carbonation using Na2CO3 was successful because it gave a residue that could be considered as non-hazardous material. With CO2 bubbling, Pb and Zn leaching was strongly decreased compared with material washed with water alone, but the amount of chromium extracted became higher than the non-hazardous waste limits for landfilling.
碳酸化作用被应用于城市固体废物焚烧电除尘器飞灰的 Pb 和 Zn 污染部分，以降低重金属浸出率。碳酸化试验在溶液中进行，通过添加 Na2CO3 或 CO2 鼓泡，并与洗涤（仅用水）进行了比较。在洗涤过程中注入 CO2 并没有改变矿物学，但添加 Na2CO3 会与硬石膏发生反应，形成方解石。微探针分析表明，Pb 和 Zn 污染相当弥散，并且各种处理方法对残留物中 Pb 和 Zn 的形态没有影响。浸出试验表明，使用 Na2CO3 的碳酸化作用是成功的，因为它得到了一种可以被认为是无害物质的残留物。与单独用水洗涤相比，用 CO2 鼓泡强烈降低了 Pb 和 Zn 的浸出率，但提取的铬量变得高于用于填埋的无害废物限值。
