摘要
一般可通过水泥固化生活垃圾焚烧飞灰中重金属,但不同标号水泥的固化效果与经济效益不同。研究了3种标号(325、425、525)的普通硅酸盐水泥在不同用量(30%、40%)下对飞灰中重金属的固化作用。结果表明,飞灰中5种特征重金属Cr、Zn、Cd、Pb、Ni中仅有Pb和Ni的浸出质量浓度超过《生活垃圾填埋场污染控制标准》,水泥添加量为30%时,3种标号325、425、525的固化块中Pb的浸出质量浓度分别为46.266、61.122、67.423μg·L^(-1),相较于40%添加量为80.315、31.791、25.392μg·L^(-1),其浸出结果差异较小,Ni的浸出结果与Pb类似。分析重金属化学形态发现,随着水泥标号的上升,Pb和Ni的残渣态百分比呈上升趋势。对比固化块的XRD结果、电镜图像、孔隙结构和累计孔隙度发现,随着水泥标号上升固化块结构更密实,飞灰中的重金属固化效果更好,但3种标号的水泥对飞灰的固化效果差异较小。因此,掺加30%的325水泥即可较好地固化垃圾焚烧飞灰。本研究结果可为控制填埋场中飞灰固化块的浸出浓度提供参考。
Heavy metals in fly ash from municipal solid wastes incineration can generally be cured by cement,but the curing effects and economic benefits vary among different grades of cement.The curing effects of three grades(325,425,525) of ordinary silicate cement at different dosages(30%,40%) on heavy metals in fly ash were studied.The results showed that among the five heavy metals Cr,Zn,Cd,Pb,and Ni,only Pb and Ni exceeded the original fly ash leaching mass concentration of the "Pollution Control Standard for Municipal Solid Landfill",and the leaching mass concentrations of Pb in the cured blocks of the three grades 325,425,and 525at 30% cement addition were 46.266,61.122,and 67.423 μg·L^(-1),respectively,which were less different compared to the 40% additions of 80.315,31.791,and 25.392 μg·L^(-1),and the leaching results of Ni were similar to those of Pb.Analysis of the chemical forms of heavy metals revealed that the percentage of residue states of Pb and Ni tended to increase with the increase of cement grade.Comparison of XRD results,electron microscope images,pore structure and cumulative porosity of the cured blocks revealed that the structure of the cured blocks was denser and the heavy metals in the fly ash were cured better as the cement grade rose,but the difference in the curing effect of the three grades of cement on the fly ash was small.Therefore,the addition of30% of 325 cement can cure waste incineration fly ash better.The results of this study can provide a reference for controlling the leaching concentration of fly ash curing blocks in landfills and reducing the operating cost of landfills.
作者
慕宗宇
王菲
杨玉飞
郭明坤
黄启飞
杨延梅
罗中力
MU Zongyu;WANG Fei;YANG Yufei;GUO Mingkun;HUANG Qifei;YANG Yanmei;LUO Zhongli(State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;State Environmental Protection Key Laboratory of Hazardous Waste Identification and Risk Control,Chinese Research Academy of Environmental Sciences,Beijing 100020,China;School of River and Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Organic Materials Research Laboratory,Tosoh Corporation,Shunan 746-8501,Japan)
出处
《环境工程学报》
CAS
CSCD
北大核心
2023年第6期1987-1996,共10页
Chinese Journal of Environmental Engineering
基金
国家重点研发计划资助项目(2021YFE0112100)。
关键词
焚烧飞灰
普通硅酸盐水泥
浸出
化学形态
重金属
固化机理
municipal solid waste incineration fly ash
ordinary silicate cement
leaching
chemical forms
heavy metals
curing mechanism
