垃圾焚烧飞灰药剂稳定化矿物学特性

发布时间：2018-12-20 18:32

【摘要】：筛选出多种无机药剂和有机药剂对江苏某地生活垃圾焚烧飞灰进行稳定化处理,在考察不同药剂对飞灰中重金属固定效果的同时,重点关注了药剂处理后飞灰体系的矿物学特性,分析了飞灰中Pb、Cr、Cd等重金属在矿物相和非矿物相的分布特性.结果表明:无机药剂中磷酸可显著降低Pb浸出浓度,从97.55mg/L降到2.16mg/L;有机药剂中聚二硫代氨基甲酸盐等3种药剂在2%~3%的药剂添加量下,Pb、Zn等重金属浸出浓度显著降低.原灰中Pb和Cd主要分布在矿物相中,Cu、Cr和Zn主要分布在非矿物相中.无机药剂和有机药剂的添加会造成飞灰基体的溶解,可溶性离子移动和二次矿物的生成.螯合处理后,飞灰中非矿相含量从14.41%增加至21.52%,非矿物相中的Cr含量降低可能由于在螯合反应过程中转移至铬酸盐矿物相中,矿物中Cd含量显著增加可能由于螯合处理生成了含Cd沉淀矿物.螯合处理前后重金属在矿物中分布行为相似,Cr、Zn和Pb主要赋存于方解石中,Cr、Cu主要赋存于赤铁矿中.
[Abstract]:A variety of inorganic and organic chemicals were selected to stabilize the fly ash from MSW incineration in Jiangsu Province, and the effects of different pesticides on heavy metal fixation in fly ash were investigated at the same time. The mineralogical characteristics of fly ash system after medicament treatment were focused on, and the distribution characteristics of Pb,Cr,Cd and other heavy metals in mineral and non-mineral phases were analyzed. The results show that phosphoric acid can decrease the leaching concentration of Pb from 97.55mg/L to 2.16 mg / L; The leaching concentration of Pb,Zn and other heavy metals in organic chemicals decreased significantly with the addition of 2% dithiocarbamate. Pb and Cd are mainly distributed in mineral phase and Cu,Cr and Zn are mainly distributed in non-mineral phase in primary ash. The addition of inorganic and organic chemicals will result in the dissolution of fly ash matrix, the movement of soluble ions and the formation of secondary minerals. After chelation treatment, the content of non-mineral phase in fly ash increased from 14.41% to 21.522.The content of Cr in non-mineral phase decreased possibly due to the transfer to chromate mineral phase during the chelation reaction. The significant increase of Cd content in minerals may be due to the formation of Cd precipitated minerals by chelating treatment. The distribution behavior of heavy metals in minerals is similar before and after chelation treatment. Cr,Zn and Pb mainly occur in calcite and Cr,Cu in hematite.
【作者单位】：中国矿业大学(北京)化学与环境工程学院;清华大学环境学院;环境保护部对外合作中心;
【基金】：中国清洁发展机制基金赠款项目(20140179) 环保部公益性行业科研专项(201509055)
【分类号】：X70

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