上海城市生活垃圾焚烧飞灰的性质分析

垃圾焚烧飞灰是我国城市垃圾焚烧新技术发展过程中产生的一个新问题,飞灰中有大量有害物质。必须予以安全处置。而飞灰的性质对如何处置以及处置的效果非常重要。飞灰的性质有很大的地域性差异。我们对上海浦东御桥垃圾焚烧厂产生的飞灰的相关性质如化学组成、重金属浸出率、重金属挥发特性等进行了检测。并对结果进行了分析。结果表明：上海市飞灰中SiO2含量较高。有利于进行熔融固化。但飞灰在熔融过程中。重金属的挥发量较大,需要引起注意。     

城市生活垃圾焚烧飞灰处理研究进展

垃圾焚烧飞灰已被明确规定为危险废物,必须经过合理的处理才能填埋.介绍了近年来国内外对飞灰处理的研究进展,重点从水泥固化、玻璃化/熔融固化、化学药剂稳定法3个方面对飞灰的处理进行论述,并对比分析了各项技术的优缺点,突出阐述了飞灰的资源化利用,最后对飞灰处理的发展前景进行了展望.     

Use of municipal solid waste incineration fly ash in concrete

With a view of reducing the quantities to be landfilled, the Solvay Company has been working on the development of a new physicochemical treatment for municipal solid waste incineration (MSWI) fly ashes: the Revasol process. This process allows reducing the soluble fraction, fixing heavy metals and eliminating dioxins. This article reports on the characteristics of a treated ash and on its use in concrete. For the latter point, three characteristics were chosen: the compressive strength and the durability of the hardened concrete and its behavior to leaching. From mechanical and durable points of view, the ash incorporated in the concrete behaves like ordinary sand. The leaching tests carried out on the concrete confirm that the process makes it possible to obtain materials without major risks for the environment. Also, these results as a whole suggest that the use of waste in concrete constitutes a potential means of adding value.     

重金属螯合剂处理垃圾焚烧飞灰的稳定化技术

引言随着我国社会经济的发展、城市化进程的加快以及人们物质生活的提高,全国城市生活垃圾年产生量已达1.5亿吨以上,并以每年8%～10%的速率增加[1-3]。城市垃圾焚烧是我国垃圾处置的重要手段,在焚烧过程中将产生大量飞灰,飞灰产量与垃圾种类、焚烧条件、焚烧炉型及烟气处理工艺有关,一般约占被焚烧垃圾量的3%～5%。分析表     

水热法稳定垃圾焚烧飞灰中重金属研究进展

随着社会经济的发展和垃圾焚烧的应用,产生了大量属于危险废物的垃圾焚烧飞灰。其无害化处理技术的研发变得日益迫切,而水热处理技术是最具潜力的垃圾焚烧飞灰无害化技术之一。本文综述了水热法处理垃圾焚烧飞灰稳定重金属的研究进展。首先阐述了垃圾焚烧飞灰的理化性质;然后系统介绍了针对垃圾焚烧飞灰的水热处理方法,将其细分为传统水热法、添加剂辅助水热法和微波水热法,并分别总结了各类水热处理方法影响重金属稳定效果的因素,包括反应时间和温度、碱性激发剂及其浓度、液固比等;最后探讨了水热法稳定垃圾焚烧飞灰中重金属技术的优化途径,为后续的研究提供了研究思路,其中探究水热过程中硅铝酸盐矿物的合成及其稳定重金属机理极具发展潜力。     

Preparation of low melting temperature glass-ceramics from municipal waste incineration fly ash

Glass-ceramics have been prepared from air pollution control residues (fly ash) of a municipal solid waste incineration (MSWI) plant in southern China. The use of additives was investigated in order to decrease the melting temperature of the waste and thus to reduce the costs of production of glass-ceramics from the vitrified waste. Results showed that the melting temperature can be decreased significantly from 1500 to 1200 °C, which was achieved by combining the MSWI fly ash with silica sand powder and a Fe₂O₃-rich and CaO-rich iron slag to form a glass in the SiO₂-CaO-Al₂O₃-Fe₂O₃ quaternary phase system. Sodium carbonate and borax were used as fluxing agents and TiO₂ of chemical grade was added as a nucleation agent. The main crystalline phase in both high and low melting temperature glass-ceramics was found to be diopside (Fe-bearing), and the microstructure exhibited the presence of fine crystals of size in the range 100-200 nm which developed at crystallization temperatures in the range 800-900 °C for 1-2 h. The leaching behaviour of the glass-ceramic materials was tested, and it was found to be lower than that of a cement-stabilized body that was fabricated using the same waste for comparison. The results demonstrate the feasibility of reusing MSWI fly ash for glass-ceramic production at relatively low melting temperature, e.g. in a less energy-intensive process, as a viable approach for tackling the problem of hazardous MSWI residues.     

Vitrification of municipal solid waste incineration fly ash: An approach to find the successful batch compositions

Incineration is the most common way to reduce the mass and the volume of municipal solid wastes. One of the most dangerous by-products of the incineration process is fly ash that contains a considerable amount of heavy metals. Therefore, its treatment is crucial to prevent the leaching of heavy metals into the environment. In the present work, two different sources of municipal solid waste incinerator fly ash have been vitrified in order to inhibit the release of potentially toxic heavy metals. Two different sources of silica, i.e. silica sand and glass cullet, have been added to each type of fly ash in an attempt to obtain vitrifiable batches. The standard leaching test on vitrified products was performed according to EN12457-2 confirming no heavy metal leaching and, therefore, they all pass waste acceptance criteria to be classified as an inert material. Furthermore, the previously reported data for vitrification of fly ash was combined with the present work and their compositions were presented in the SiO₂–Al₂O₃–CaO, and SiO₂-ΣM₂O₃-Σ(MO + M₂O) ternary phase diagrams to identify the region in which successful compositions are concentrated. This analysis could facilitate the attempt to find the right composition for vitrification of fly ash.     

垃圾焚烧底渣中重金属的研究

采用Tessier四步分级提取法对垃圾焚烧飞灰中的4种重金属(锌、镍、铜、镉)的化学形态进行了研究。结果表明,金属Cd主要以底渣态的形式存在(占总镉质量的61.22%~62.41%),Ni,Zn以底渣态和铁锰氧化态为主,Cu主要以有机结合态为主(占总铜质量的60.97%~62.29%)。同时4种金属的生物有效性由高到低顺序依次为Ni,Cd,Zn,Cu。     

Characterisation of bottom ash from municipal solid waste incineration in Catalonia

Bottom ash from municipal solid waste incinerator plants in Catalonia was characterised to investigate some alternatives for its utilisation and their potential environmental impact. After a detailed chemical and mineralogical characterisation, physical and geotechnical properties were investigated. The study focused on the use of bottom ash as an aggregate substitute in pavement applications. The results show that this material may be successfully used as a compacted material in unbound road sub‐bases. According to Spanish Specifications for road construction, bottom ash complies with the technical requirements for sub‐bases. Data obtained from the leaching test satisfy the limit values established by Catalan Specifications for bottom ash utilisation. The use of bottom ash in the envisaged application should therefore not result in any environmental impact. © 2002 Society of Chemical Industry     

Application of a combination of municipal solid waste incineration fly ash and lightweight aggregate in concrete

This paper highlights significant findings from focusing on developing a sustainable lightweight aggregate (LWA) concrete, which replaced Portland cement partially with municipal solid waste incineration fly ash (MSWI FA) and all of the conventional coarse aggregate with LWA sintered by MSWI FA, shale, and sludge. A series of four experiments, differing in dosage of MSWI FA and aggregate, were conducted for this project. The results of this study generally showed that appropriate amount of MSWI FA substitution for cement has no significantly lowered the compressive strengths of LWA concrete, while it can lower the oven-dry density and the thermal conductivity. The optimum performance of LWA concrete (after 28 days of curing) is as follows: (1) slump flow of 700 mm, (2) compressive strength of 30.14 MPa, (3) dry apparent density of 1.66 g/cm³, (4) thermal conductivity of 0.73 W (m K)^?1; the mixture ratio of LWA, fly ash, cement, and fine sand is 3.0: 0.1: 0.9: 2.0 based on dry weight. Meanwhile, the results of leaching test are much lower than the concentration limits of hazardous constituents of hazardous waste identification standard (GB/T 5083.3-2007) and landfill standard (GB16889-2008).     

Electrodialytic extraction of Cu,Pb and Cl from municipal solid waste incineration fly ash suspended in water

The possibility of using fly ash from municipal solid waste incineration (MSWI) in, for example, concrete is considered. MSWI fly ash, however, has too high a concentration of heavy metals, which may cause leaching problems during use or problems with waste handling at the end of the lifetime of the concrete. The Cl content in MSWI fly ash is also too high and will cause corrosion problems in reinforced concrete. The possibility of removing some of the unwanted heavy metals (Cu and Pb) together with Cl from an MSWI fly ash suspended in water using an electrodialytic separation method was investigated. The removal of Pb and Cu was found to be highly pH dependent and the highest contents removed were 41 and 90%, respectively. The Cu concentration of the ash decreased from 2200 to 860 mg kg^?1 but the Pb concentration increased from 8560 to 16 800 mg kg^?1, showing that Pb is mainly found in the ash fraction that is least soluble. Hence electrodialytic treatment of the ash suspended in water is not a solution to improve the ash quality in terms of Pb. The water‐soluble Cl content per unit weight of the original ash was 12.4%. The removal of water‐soluble Cl was efficient and >98% of Cl was removed (calculated on the basis of mean initial and final concentrations). This result indicates that electrodialytic extraction may be a method that can be used for the removal of Cl from ash prior to its utilization in concrete. Copyright © 2006 Society of Chemical Industry     

固化材料在生活垃圾焚烧飞灰处置中的应用概况及前景

焚烧方式因其减量化、无害化等优点将逐步成为我国城市生活垃圾的主要处理方式。飞灰是焚烧方式的主要副产物,其高含量且易浸出的重金属是急需解决的难题。本文从介质固化技术中固化材料的角度系统地总结了国内外的处理现状,展示了水泥、粉煤灰、偏高岭土、赤泥、矿渣、塑料和其他材料在飞灰固化上的应用情况,分别从重金属固化效率以及机械性能等两个主要方面对其固化效果进行评估,分析了各个材料的优缺点,并且给出了工程应用实例和经济性分析。最后在固化材料的工业应用前景和未来发展方向提出了研究建议。     

掺烧生活垃圾焚烧飞灰和炉渣对水泥熟料矿物组成的影响

分别对掺烧20%生活垃圾焚烧炉渣的熟料和掺烧10%生活垃圾焚烧飞灰的熟料进行化学成分分析、相萃取、XRD分析与岩相分析,并与用化学纯试剂配料煅烧的基准样熟料进行对比研究。研究结果发现,受灰渣中较高含量的硫、氯等阴离子的影响,熟料KH值会降低;受灰渣当中微量重金属元素的影响,掺烧灰渣熟料的铁相中有少量C2F存在,并且其C4AF特征峰的d值增大。     

The leachability of heavy metals in hardened fly ash cement and cement-solidified fly ash

The effect of mix proportion, leachant pH, curing age, carbonation and specimen making method etc. on the leaching of heavy metals and Cr(VI) in fly ash cement mortars and cement-solidified fly ashes has been investigated. In addition, a method for reducing the leaching of Cr(VI) from cement-solidified fly ashes is proposed. The results mainly indicate that: (1) either Portland cement or fly ash contains a certain amount of heavy and toxic metals, and the leaching of them from hardened fly ash incorporated specimens exists and is increased with fly ash addition and water to cement ratio; (2) the leachability of some heavy metals is greatly dependent on leachant pH; (3) when carbonation of cement mortars occurs the leaching of chromium ions is increased; (4) the amount of heavy metals leached from cement-solidified fly ashes depends more on the kind of fly ash than their contents in fly ash; and (5) with ground granulated blast furnace slag addition, the leaching of Cr(VI) from solidified fly ashes is decreased.     

利用城市垃圾焚烧飞灰煅烧水泥熟料初探

针对垃圾焚烧飞灰化学组成上的特点,进行了利用垃圾焚烧飞灰烧制水泥熟料的探索研究,通过试验研究了其对水泥生料的易烧性、烧制的水泥熟料的力学性能和水化速率等的影响规律。研究结果表明,垃圾焚烧飞灰可以用作水泥原料从而有效地降低其处置成本,减少其对环境造成的二次污染,硬化水泥浆体水化28d时各重金属浸出量低于鉴别标准规定的指标,是一种有待开发的潜在的水泥原料资源。     

柱淋滤模式下生活垃圾焚烧炉渣中Cu2+和Zn2+浸出规律

垃圾焚烧炉渣是一种活性材料,在其储存、预处理及应用等过程与雨水频繁接触时,炉渣中重金属随着水域环境发生迁移和浸出现象。本研究采用连续柱淋滤试验装置模拟自然降雨,开展了0～5mm和5～10mm焚烧炉渣的动态淋滤毒性浸出分析,重点研究了pH和降雨强度对Cu²⁺和Zn²⁺的浸出影响。结果表明,动态淋滤过程中,淋滤液pH变化对Cu²⁺和Zn²⁺的浸出水平影响显著,且在酸性较强淋滤液作用下Cu²⁺浸出水平比Zn²⁺更强,与Ⅴ类地表水环境浓度限值对比,在整个淋滤时间内Cu²⁺浸出浓度严重超标,在炉渣工程应用时需预防相关的环境风险;原生炉渣粒径大小与重金属浸出水平无直接相关性,但是0～5mm细炉渣中可浸出Zn²⁺含量更高,这与细颗粒物中Zn赋存形态和可溶出态含量较高有关;淋滤强度对重金属浸出水平影响主要反应了动态淋滤过程液固比和水分运移速率情况,当较低淋滤强度时具有低液固比,溶出液中重金属含量较高。     

垃圾焚烧飞灰中典型重金属形态分布研究

采用原欧洲共同体参考物质署指导制定的标准三步分级提取法对垃圾焚烧飞灰中的7种重金属(锌、镍、铅、铜、锰、镉、铬)的化学形态进行了研究.结果表明:金属镉主要以弱酸提取态的形式存在(含量占总镉质量的75.66%～89.09%),同时铅、铜的弱酸提取态含量也较高(含量占总质量的32.12%～41.36%),对环境具有潜在的影响;铅、铜、锰、锌的可还原态及可氧化态含量相对较高,铬、镍主要以残渣态形式存在(含量占总质量的57.17%～86.90%).     

垃圾焚烧飞灰重金属药剂稳定化研究进展

生活垃圾焚烧飞灰中存有大量高毒性的重金属物质,若不规范处置容易对土壤、地下水造成严重污染,目前通常采用添加化学药剂的方法来稳定飞灰中的重金属。本文在梳理国内外文献的基础上,归纳评述了飞灰重金属的性质、固化稳定化填埋工艺以及目前已被研究或应用的飞灰重金属稳定药剂,包括硫化钠、磷酸、无定形硅材料、铁化合物等无机药剂以及硫脲、EDTA接聚体、壳聚糖、氨基硫代羧酸盐等有机螯合剂,阐明了药剂作用机制和存在的问题,总结了不同药剂作用下的重金属稳定效果,同时针对新形势下的飞灰重金属稳定化要求进行了探讨,提出今后的研究方向为：选择特征性重金属药剂复配稳定飞灰;以改性、成环方式改良氨基硫代羧酸盐类物质（DTC）物质或以交联接枝等方式开发新型螯合剂。     

利用响应面法优化皂角苷浸提飞灰中重金属的处理条件

通过响应面法对皂角苷浸提飞灰中Cu、Zn、Pb和Cd 4种重金属的实验条件进行优化,选取pH、皂角苷浓度、离子强度、温度、时间和固液比6个因素进行中心组合设计,使用design-expert8.0软件进行数据拟合,建立了Cu、Zn、Pb和Cd去除总量的工艺数学模型,通过方差分析得到6个因素对浸提液中4种重金属去除总量的主效应关系为： pH>固液比>离子强度>皂角苷浓度>温度>时间。对重金属去除总量数据进行design-expert8.0软件优化,得到皂角苷浓度为41.2g·L^-1、时间为13.54 h、离子强度为0.64 mol·L^-1、pH为2、固液比为1%和温度为23.4℃时,重金属总去除量达最大值,Cu、Zn、Pb和Cd的去除率分别达到55.12%、6.20%、17.80%和78.11%。     

垃圾焚烧飞灰在污染物控制领域中的应用探讨

随着垃圾焚烧处置技术的推广和应用,垃圾焚烧飞灰产量逐年增加,传统填埋处置方式存在成本高、填埋场资源不足等问题,因此飞灰的综合利用问题广受关注。由于飞灰富含SiO₂、Al₂O₃等活性物质,在污染物的吸附脱除领域具有良好的应用前景。本文主要结合垃圾焚烧飞灰的理化特性,介绍了垃圾焚烧飞灰在不同废水废气中的污染物吸附脱除效果。综合近年来污染物脱除研究情况,着重介绍了原始飞灰和改性飞灰在重金属、磷盐、染料等污染物脱除中的应用效果、机理,指出了目前存在的主要问题,并对不同的应用工艺进行了成本分析和优缺点对比。最后提出了需要继续深入微波水热在提高飞灰吸附性的应用研究和进一步完善飞灰在污染物控制领域应用的全过程研究的建议与展望。