【作者】 楼敏晓；

【导师】 韩怀芬； 金漫彤；

【作者基本信息】 浙江工业大学 ， 环境工程， 2007， 硕士

【摘要】 垃圾焚烧处理技术的崛起是目前固体废弃物处理研究的重大热点。由于其处理速度快、减容减重明显和热能回收利用等特点，该处理技术已成为当代城市生活垃圾处理方法的主流，在国内得到了迅速的应用和推广。然而焚烧法产生的飞灰浓缩了重金属等一些高毒性当量的危险成分，如果处理不当会产生二次污染，因此焚烧飞灰被认为是危险废物，必须进行特殊处理。土壤聚合物是一种新型的无机聚合物，由硅铝氧化合物经土壤聚合反应后形成的，终产物具有牢笼型结构，对重金属离子有良好的固定作用。本课题对土壤聚合物固化垃圾焚烧飞灰的工艺及养护条件做了大量的实验研究，包括原料的元素组成分析、X射线衍射分析、浸出毒性测试等。以抗压强度和重金属浸出毒性为效果表征量，研究不同条件（氧化物配比、飞灰掺量、养护时间、养护条件等）对土壤聚合物固化飞灰效果的影响。结论：（1）氧化物配比为n（Na₂O）／n（SiO₂）=0.30，n（SiO₂）／n（Al₂O₃）=4.7时，飞灰掺量为40％的固化体在养护7天后抗压强度仍能达到31.25MPa，满足建筑使用的强度要求。（2）随着养护时间的增加固化体的抗压强度继续增强，7d的抗压强度达到28d的90％左右。（3）降低养护湿度有利于提高固化体的抗压强度。（4）焚烧飞灰固化前后的浸出特性表明土壤聚合物对飞灰的固化效果好，固化后飞灰中各重金属的浸出浓度均远低于我国危险废物鉴别标准浸出毒性标准的浸出液最高允许浓度。（5）固化体的浸出特性及抗压强度测试表明，当飞灰的掺量不大于40％时，固化体不仅浸出毒性低，抗压强度也较高，资源化利用的潜力很大。最后对土壤聚合物固化焚烧飞灰的机理进行了探讨。通过对所用的偏高岭土、垃圾焚烧飞灰、土壤聚合物及土壤聚合物固化垃圾焚烧飞灰所得的固化体进行红外光谱分析，证实了土壤聚合反应的发生。更多还原

【Abstract】 With the advantages of remarkable volume-reduction, weight-reduction and energy-recovery, in recent years, disposal of MSW byincineration is becoming applicated and promoted rapidly in China.However, MSWI fly ash concentrates toxic substances such as heavymetals, if treated improperly it would lead to secondary pollution.Therefore, MSWI fly ash is considered as hazardous waste, and needspecial treatment.Geopolymer is a new kind of inorganic polymer, the molecularityconsists of Si, O, Al and mainly connected by electrovalent bond andcovalent bond, it is able to solidify heavy metal ion effectively because ofits cage shape like zeolite.A lot of research works has been done on solidification of heavy metalsin MSWI fly ash with geopolymer. The characterization of MSWI fly ashinvolve mineral, chemical compositions and leaching toxicity, wereobserved under X-ray diffraction analyses, energy-dispersive X-rayspectroscopy （EDS）, Toxicity Characteristic Leaching Procedure tests. Itwas studied that the effect of oxide proportion, the volume of fly ash,curing time and curing conditions on geopolymerization reaction.Conclusion: （1） When oxide proportion was confirmed as n（Na₂O）/n（SiO₂）=0.30,n（SiO₂）/n（Al₂O₃）=4.7, the compressive strengths ofthe solidfied matrices which 40% MSWI fly ash was added-reached31.25MPa after 7d of curing, and could meet the strength requirements inconstruction. （2） The compressive strengths continued to strengthen withthe increase in curing time. The compressive strengths of solidfied matriceswhich cured for 7d could achieve about 90% of what cured for 28d. （3）Lower humidity was beneficial for the compressive strength. （4） Theleaching characteristics of heavy metals of solidified matrices were muchlower than our criteria for hazardous waste toxicity leaching standards. （4）The use of solidified matrices was promising potential when the amount ofMSWI fly ash did not exceed 40%.The synthesizing mechanism of solidification of MSWI fly ash withgeopolymer was sicussed in the end. FTIR analyses of metakaolin, MSWIfly ash, geopolymer and solidified matrices confirmed geopolymerization.更多还原