【作者】 裘娜；

【导师】 冯素萍；

【作者基本信息】 山东大学 ， 环境科学， 2008， 硕士

【摘要】 在目前的城市生活垃圾处理方法中,焚烧法能较好的实现垃圾的减容化、无害化和资源化而成为很多国家处理垃圾的主要方式。在我国由于城市生活垃圾并未经过妥善的分拣处理,因而垃圾中常混入许多含有重金属的物质。城市生活垃圾经焚烧处理后最终的产物为烟气及焚烧飞灰（底灰和飞灰）,其中焚烧飞灰是重金属污染物质的主要载体。目前垃圾焚烧飞灰的处置主要是安全填埋或用于制造建材的原料,飞灰中的重金属在自然环境中经过风化及侵蚀后,易随着渗滤液而重新进入环境危害生态环境安全。化学形态分析是一种认识重金属环境行为的有效方法。通过分析焚烧飞灰中的重金属及存在形态,可进一步了解经焚烧后的垃圾飞灰中的不同形态重金属在环境中的迁移转化行为,从而为焚烧飞灰的处置利用研究提供科学依据。本文以济南市无害化处理厂垃圾焚烧炉飞灰样品为研究对象,采用微波消解法对城市生活垃圾焚烧飞灰样品进行预处理,在此基础上优化了城市生活垃圾焚烧飞灰的微波消解酸体系及消解程序。优化后的微波消解酸体系及用量比例为HNO₃:HF:HClO₄=3:4:1;消解程序的四个工步分别为:3min（5×101kPa）,3min（10×101kPa）,4min（15×101kPa）,6min（20×101kPa）。该方法的相对标准偏差为1.2%-4.5%,加标回收率为95.9%-103.7%,应用于实际的城市生活垃圾焚烧飞灰样品取得了良好的效果。实验结果表明,与其他三种飞灰相比,除尘器飞灰中六种重金属元素Cu、Pb、Zn、Mn、Fe和Cr含量均较高,从重金属污染的角度看,除尘器飞灰应作为研究治理的重点。本文同时采用连续化学萃取法对不同粒径城市生活垃圾焚烧飞灰中重金属的化学形态进行了研究。实验结果表明,除尘器飞灰中可提取态的重金属元素Cu、Pb、Zn、Mn和Fe含量均比底灰、锅炉飞灰和酸洗飞灰中可提取态重金属含量高;元素Cr在底灰中的可提取态大于锅炉飞灰、酸洗飞灰和除尘器飞灰。不同粒径焚烧飞灰样品中重金属元素含量的研究结果表明,焚烧飞灰不同粒径样品中元素Cr的含量变化与粒径变化的相关性较小。底灰不同粒径样品中元素Cu、Pb、Zn和Mn含量随粒径的减少呈增加趋势,元素Fe的含量变化与粒径变化的相关性较小;锅炉飞灰不同粒径样品中元素Cu和Fe的含量随粒径的增加呈增加趋势,元素Pb、Zn、Mn的含量变化与锅炉飞灰粒径变化的相关性较小:酸洗飞灰不同粒径样品中元素Pb和Fe的含量随粒径的增加呈增加趋势,元素Cu、Zn、Mn的含量变化与酸洗飞灰粒径变化的相关性较小;除尘器飞灰不同粒径样品中元素Zn含量随粒径的减小呈增加趋势,元素Cu、Pb、Mn、Fe含量变化与其粒径变化的相关性较小。更多还原

【Abstract】 In the present city life garbage disposal methods, burning down becomes the main method for that it could be able to better realize the reducing of volume, harmless and turning to resources. In our country, garbage was not precisely sorted which contained much harmful heavy metal matter. The end products of the incineration are ash （bottom ash and fly ash） and flue gas. The fly ash is the primary carrier of the heavy metals and their compounds. The final disposal of the fly ash is to landfill or to be used as construction material. The side effect is that by corrade and erode action, the metals especially the volatilizable ones would stand a good chance to re-enter the environment and then do harm to the balance of the nature.The sequential chemical extraction （SCE） method is one effective method for cognition of environment behavior of metals. Using this method, the metal toxicity of municipal solid waste incineration （MSWI） fly ash will not only depend on their total content, but also relate to transferring and transforming behavior of different forms of metals in the environment. Based on results of SCE, different existing forms of metals in MSWI fly ash can be understood to provide scientific basis for the treatment and utilization of MSWI ashes.This paper takes incinerator flash ash of Jinan harmless processing factory as sample. A research of microwave digestion process of municipal solid waste incineration fly ash sample is developed. The purpose of the research is to improve the reagent selection and microwave heating process. The improved reagent is HNO₃: HF: HClO₄=3: 4: 1 and the improved microwave heating process is 3min （5×101kPa）, 3min （10×101kPa）, 4min （15×101kPa）, 6min （20×101kPa）. The RSD of this method is 1.2%-4.5% and the recovery is 95.9%-103.7%. The results indicated that the improved method could be used in municipal solid waste incineration fly ash samples and yielded highly desirable results.This paper use BCR method to extract different fraction of heavy metal, analyses heavy metal fraction in MSWI ashes. The results shows that the contents of extracted heavy metal Cu、Pb、Zn、Mn and Fe in fly ash are higher than these in bottom ash、flue ash and acid cleaning ash, the contents of extracted heavy metal Cr in bottom ash is higher than its in flue ash、acid cleaning ash and fly ash.The result of analysis on the contents of heavy metals in various size fraction of MSWI fly ash shows that, the contents of heavy metal Cr have only a little relativity with various size fraction in MSWI fly ash. In bottom ash samples, the contents of heavy metals Cu、Pb、Zn and Mn have an increasing trend with the size reduction, the contents of heavy metal Fe have only a little relativity with various size fraction. In flue ash samples, the contents of heavy metals Cu and Fe have an increasing trend with the size increase, the contents of heavy metal Pb、Zn and Mn have only a little relativity with various size fraction. In acid cleaning ash, the contents of heavy metals Pb and Fe have an increasing trend with the size increase, the contents of heavy metal Cu、Zn and Mn have only a little relativity with various size fraction. In fly ash, the contents of heavy metals Zn have an increasing trend with the size reduction, the contents of heavy metal Cu、Pb、Mn and Fe have only a little relativity with various size fraction.更多还原