城市固体废弃物焚烧底灰特性表征实验及热力学分析

论文摘要

焚烧是处理城市固体废弃物的有效途径,但并不是其处理的最后阶段。由于固体废弃物焚烧比例日益提高,大量焚烧底灰的处理成为环境管理领域新的问题。因而,将底灰转化为对环境和人类健康无任何影响的产品是其管理的社会目标。为了进行垃圾焚烧底灰无害化、资源化管理,本文分别通过“天津和阿姆斯特丹垃圾焚烧厂现场取样”和“基本垃圾和特殊垃圾合成焚烧取样”两种方法采集不同底灰流,利用湿式物理分离实验、化学分析测试、毒性浸出测试、热力学平衡计算分别对不同粒径范围的底灰进行特性化分析,并系统地分析了焚烧垃圾特殊组分对底灰化学特性的影响,如小型电子垃圾、工业垃圾、生活淤泥、塑料垃圾。同时,对底灰再利用的资源价值潜力和相关的环境质量改善技术、政策等进行了调查分析。结果表明:底灰适合制成颗粒材料,等级性较好;与天然建筑材料的主要成分相似,具有连续的颗粒级配分布和较低比例的非塑性颗粒,其中75μm-28mm粒径的材料约占90%-95%,<75μm的极细颗粒占5%左右;工程特性分析显示天津底灰具有较低压实性能且细颗粒部分包含较高浓度的未燃尽有机质,这两方面不能满足路基材料要求,但其它参数基本符合要求;底灰物理组分的质量平衡分析表明,同天津底灰相比,阿姆斯特丹底灰具有较高含量的、玻璃碎片、合成建筑材料、金属（主要是9%-13%的废铁、2.1%的有色金属）等,Cu、Pb、Cl、SO42-等元素浸出浓度严重超标。尤其阿姆斯特丹底灰中包含1.5%金属铝和1000ppm贵重金属,可作为有色金属冶炼工业新的资源。并在干式物理分离系统基础上提出湿式物理分离系统,改善了对有色金属回收效率低的问题。同时,通过不同厚度的合金铝包装和小型电子垃圾的焚烧测试发现,铝的厚度对其焚烧后在底灰中的分布有决定性影响;小型电子垃圾中的贵重金属趋向于富集在0-2mm的底灰碎片中。电子垃圾、工业垃圾、生活淤泥、塑料垃圾在生活垃圾焚烧过程的参与,分别不同程度的提高了底灰中Cu,Zn,Pb,Mn,Mo和Cl的富集浓度和它们的毒性浸出性能,大多数重金属趋向于富集在较细底灰颗粒中。Cl和S的负载量也影响重金属在垃圾焚烧过程中的释放;垃圾的水分含量对重金属释放影响较小。实验结果与FactSage的热力学平衡计算结果基本吻合,但Pb在底灰中释放的实测浓度略高于理论模型预测值。研究结果为今后垃圾焚烧底灰的管理政策制定、资源化再利用及垃圾焚烧过程中重金属和氯释放污染问题的解决提供了可靠的数据。

论文目录

• 中文摘要
• ABSTRACT
• Chapter 1 Introduction
• 1.1 General background
• 1.2 Current MSW incineration
• 1.3 Overview of management and policies of MSWI bottom ash
• 1.4 Reutilizations and relative problems of MSWI bottom ash
• 1.4.1 Reutilizations of bottom ash
• 1.4.2 Problems associated with disposals and reutilization
• 1.5 Motivation of this work
• 1.6 Aim of the thesis
• 1.7 Layout of the thesis
• Chapter 2 Characterization of MSWI bottom ash
• 2.1 Introduction
• 2.2 Generation and disposals of MSW
• 2.2.1 Waste characteristics and qualities
• 2.2.2 Waste disposal methods
• 2.3 Materials and methodologies
• 2.3.1 Sampling and samples preparations
• 2.3.2 Measurement of physical components
• 2.3.3 Measurement of Chemical parameters
• 2.3.3.1 Chemical compositions
• 2.3.3.2 Leaching test
• 2.4 Results and discussions
• 2.4.1 Grain size distribution
• 2.4.2 Organic contents
• 2.4.3 Distribution of glass in the different size fractions
• 2.4.4 Distribution of synthetic ceramics in the different size fractions
• 2.4.5 Distribution of minerals in the different size fractions
• 2.4.6 Distribution of elemental compositions
• 2.4.7 Metals contents
• 2.4.7.1 Metals in <2mm fraction
• 2.4.7.2 Metals in 2-6mm fraction
• 2.4.7.3 Metals in 6-20mm fraction
• 20mm fraction'>2.4.7.4 Metals in >20mm fraction
• 2.4.8 Leaching tests
• 2.5 Overview of mass balances of MSWI bottom ash
• 2.6 Conclusions
• Chapter 3 Evaluation of MSWI bottom ash used for road construction materia Is
• 3.1 Introduction
• 3.2 Materials and Methodologies
• 3.2.1 Samples collection and preparation
• 3.2.2 Methods of measuring engineering and chemical parameters for evaluation
• 3.3 Results and discussion
• 3.3.1 Engineering parameters of MSWI bottom ash
• 3.3.1.1 Grain size distribution
• 3.3.1.2 Densities
• 3.3.1.3 Water sorption
• 3.3.1.4 Particle Morphology
• 3.3.1.5 Sand equivalent （SE）
• 3.3.1.6 Wear resistance
• 3.3.1.7 Protor Compaction
• 3.3.1.8 CBR index
• 3.3.1.9 Plasticity
• 3.3.2 Chemical parameters of Tianjin bottom ash
• 3.3.2.1 Chemical composition
• 3.3.2.2 Study of the bottom ash leachates
• 3.3.2.3 Reactivity with cement alkalis
• 3.4 Overall evaluation of MSWI bottom ash-based
• 3.4.1 Road constructions and its structure
• 3.4.2 Evaluation and discussions
• 3.5 Conclusions
• Chapter 4 Aluminum alloys and precious metals in MSWI bottom ash
• 4.1 Introduction
• 4.2 Aluminum alloys contents in MSWI bottom ash
• 4.2.1 Experimental materials
• 4.2.2 Experimental methodologies
• 2mm fraction'>4.2.2.1 Measuring aluminum alloys contents in >2mm fraction
• 4.2.2.2 Measuring aluminum content in the sand
• 4.2.3 General aluminum concentration distributions and recovery rates
• 4.2.4 Aluminum alloy 3140 （cans） concentration distributions
• 4.2.5 Cast aluminum alloy concentration distributions
• 4.3 Particle size distribution of Al cans and Al foils
• 4.3.1 Combustion tests
• 4.3.2 The footprint of Aluminum cans and foils during combustion
• 4.4 Distribution of precious metals of small WEEE
• 4.5 Conclusions
• Chapter 5 Legislations and treatment of MSWI bottom ash
• 5.1 Introduction
• 5.2 Management of recycling MSWI bottom ash
• 5.3 Overview of leaching test
• 5.3.1 Leachate production
• 5.3.2 Standards of leaching tests
• 5.3.2.1 NEN7353 and prEN15505 column tests
• 5.3.2.2 DIN38515-S5, EN12557/5 and NFX31-210 extraction tests
• 5.3.2.3 GB 5086.1-1997 shake test
• 5.4 Management of bottom ash landfilling
• 5.5 Treatment technologies of MSWI bottom ash
• 5.5.1 Stabilization/solidification
• 5.5.2 Carbonation
• 5.5.3 Chemical extraction of organic solution
• 5.5.4 Weathering
• 5.5.5 Vitrificaion of MSWI bottom ash
• 5.5.6 Physical separation technologies
• 5.6 Conclusions
• Chapter 6 Influences of MSW compositions on bottom ash characteristics
• 6.1 Introduction
• 6.2 Combustion experiments
• 6.2.1 Characteristics of selected wastes
• 6.2.3 Determination of target elements
• 6.2.4 Description of the used combustor
• 6.2.5 Sampling and analyses of the resulting bottom ash
• 6.3 Bottom Ash recovery
• 6.4 Basic bottom ash
• 6.4.1 Concentration distributions of the selected elements
• 6.4.2 Mass balances of selected heavy metals
• 6.4.3 pH and toxicity tests
• 6.5 Influences of the input specific wastes on bottom ash characteristics
• 6.5.1 Plastics wastes
• 6.5.1.1 Concentration variations of Chlorine
• 6.5.1.2 Concentration variations of selected heavy metals
• 6.5.1.3 pH and toxicity tests
• 6.5.2 WEEE
• 6.5.2.1 Concentration variations of selected elements
• 6.5.2.2 Selected elements balances
• 6.5.2.3 pH and toxicity tests
• 6.5.3 Shredder fluff
• 6.5.3.1 Concentration variations of selected elements
• 6.5.3.2 Selected elements balances
• 6.5.3.3 pH and toxicity tests
• 6.5.4 Sewage sludge
• 6.5.4.1 Concentration variations of the selected elements
• 6.5.4.2 pH and toxicity tests
• 6.6 Regression analyses
• 6.6.1 Influence of Cl content on HM partitioning
• 6.6.2 Sulfur
• 6.6.3 Water content
• 6.7 Influences of the specific wastes on the cost of incineration
• 6.7.1 Costs of incineration plant
• 6.7.2 Operation costs of incineration plant
• 6.8 Conclusions
• Chapter 7 Thermodynamic analysis of heavy metals partitioning during MSW combustion
• 7.1 Introduction
• 7.2 Thermodynamic simulations
• 7.2.1 Equilibrium calculation methods
• 7.2.2 Assumption of calculation
• 7.2.3 Air excess ratio
• 7.2.4 System definition and calculation conditions
• 7.3 Results of the theoretical study and discussion
• 7.3.1 Influence of temperature on the HM specification
• 7.3.2 Influence of oxygen content on the HM specification
• 7.4 Comparison between the theoretically predicted and experimentally obtained from real incinerator residues
• 7.4.1 HM partitioning
• 7.4.2 Chemical specification of HM
• 7.5 Conclusions
• Chapter 8 Conclusions and recommendations
• 8.1 Conclusions
• 8.2 Innovations
• 8.3 Recommendations
• References
• Publications
• Acknowledgements