曹祎男, 罗津晶, 孙士强. 垃圾焚烧飞灰浸出特性及理化性质研究[J]. 燃料化学学报(中英文), 2021, 49(8): 1208-1218. DOI: 10.1016/S1872-5813(21)60119-6
引用本文: 曹祎男, 罗津晶, 孙士强. 垃圾焚烧飞灰浸出特性及理化性质研究[J]. 燃料化学学报(中英文), 2021, 49(8): 1208-1218. DOI: 10.1016/S1872-5813(21)60119-6
CAO Yi-nan, LUO Jin-jing, SUN Shi-qiang. Characteristics of MSWI fly ash with acid leaching treatment[J]. Journal of Fuel Chemistry and Technology, 2021, 49(8): 1208-1218. DOI: 10.1016/S1872-5813(21)60119-6
Citation: CAO Yi-nan, LUO Jin-jing, SUN Shi-qiang. Characteristics of MSWI fly ash with acid leaching treatment[J]. Journal of Fuel Chemistry and Technology, 2021, 49(8): 1208-1218. DOI: 10.1016/S1872-5813(21)60119-6

垃圾焚烧飞灰浸出特性及理化性质研究

Characteristics of MSWI fly ash with acid leaching treatment

  • 摘要: 文章研究了福建某垃圾焚烧厂飞灰的化学、矿物学特征以及不同处理工艺对飞灰中重金属脱除效率的影响。结果表明:垃圾焚烧飞灰表面结构复杂,比表面积较小,而飞灰中的碱性氯化物和金属化合物对酸洗处理过程中的浸出效率有明显影响。飞灰中的金属浸出效率与其性质和形态有关。水洗处理可造成飞灰中组成物质和化合物形态的变化,并显著去除飞灰中水溶性化合物如KCl、NaCl和CaCl2,对Cl、Na、K和Ca的去除率分别为93.1%、41.4%、48.5%和24.8%。酸灰比为40∶1(kg/L)、处理时间为120 min的酸洗处理可显著降低垃圾焚烧飞灰中Cu、Zn、Cd和Pb的毒性浸出浓度(80%−100%),在一定程度上降低As的毒性浸出浓度(30%−80%),但对Ni的脱除效果较差(< 30%)。而采用二次水洗+酸洗的组合处理工艺可进一步降低垃圾焚烧飞灰的环境风险。

     

    Abstract: The chemical and mineralogical characteristics of fly ash from a municipal solid waste incineration (MSWI) in China and the influence of processing parameters on heavy metals removal during leaching were investigated in this work. The fly ash particles had complex surface structure with limited specific surface area. The alkali chloride and metal salts in MSWI fly ash showed evidently impact on leaching efficiency. Metal leachability was related to their properties and speciation in fly ash. Water-soluble salts such as KCl, NaCl and CaCl2 in fly ash were easily washed out. In this study, removal efficiency by water washing was achieved to 93.1% for Cl, 41.4% for Na, 48.5% for K and 24.8% for Ca, respectively. Mineralogical analysis also revealed change of fly ash mineral phases and specification distribution after water washing. Under liquid to solid ratio of 40∶1 L/kg and treatment time of 120 min, the leaching process achieved high dropping yields of toxicity characteristic leaching procedure (TCLP) concentrations for Cu, Zn Cd and Pb (80%−100%), moderate dropping yields for As (30%−80%) and relatively low dropping yields of Ni (< 30%). In addition, heavy metals such as Pb and Zn in fly ash with twice water washing treatment at a low liquid-solid ratio could reach lower TCLP concentrations. The result indicated that the combination process of twice water washing and one acid washing could significantly reduce the environmental risk of MSWI fly ash.

     

/

返回文章
返回