共查询到17条相似文献,搜索用时 125 毫秒
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垃圾焚烧飞灰中重金属和二恶英等痕量污染物分析 总被引:8,自引:1,他引:8
对国内外垃圾焚烧飞灰进行收集并着重利用GC-MS、原子吸收光谱等手段对二恶英和重金属等痕量污染物进行系统研究,并结合国内外研究成果进行对比分析.结果表明,飞灰中不同种类重金属含量差异很大,Cu、Pb和Zn的含量较多,Cr的含量次之,Ni、Cd的含量较少.垃圾焚烧飞灰中二恶英含量差别很大,总含量在1.36~31.54ng/g,各种飞灰中二恶英的毒性当量更为悬殊.飞灰中二恶英和重金属含量及分布受垃圾成分、焚烧炉型、焚烧温度、停留时间等因素影响. 相似文献
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污泥流化床焚烧技术的研究及应用 总被引:10,自引:0,他引:10
在综述国内污泥处理现状的基础上,结合一系列污泥在流化床中的能量利用、结团特性及燃烧过程等基础及中试研究结果,研究开发出污泥流化床焚烧新技术。结果表明,污泥水分将使污泥能量利用率降低;污泥的结团性能有利于在流化床中的焚烧,良好的结团特性有利于流化床的稳定运行和减少飞灰损失,流化床焚烧处理技术可实现低污染焚烧的目的。 相似文献
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生活垃圾综合处理厂在堆肥过程中产生堆肥剩余物,占总垃圾量的10%~20%,热值较高适于焚烧处理.文章对城市生活垃圾堆肥剩余物的组成、工业分析及元素分析进行分析研究,表明该类堆肥剩余物具有热能回收利用价值.采用TGA方法研究垃圾堆肥剩余物的燃烧特性,结果表明,垃圾的燃烧过程包括水分析出、挥发分燃烧和焦炭燃烧三段进行.挥发分在320℃左右剧烈燃烧,焦炭在420~450℃左右开始强烈燃烧,燃尽温度达750℃左右.在实际流化床焚烧炉上焚烧结果表明,垃圾堆肥剩余物能够在800~950℃内稳定燃烧,并且NOx、SO2、CO、HCl以及重金属等污染物的排放浓度达到国家环保排放标准.为了减少焚烧飞灰量,建议采用炉排炉焚烧此类垃圾,以降低飞灰的处置成本. 相似文献
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在发电厂焚烧烟气净化收集过程中,垃圾焚烧之后产生的残余粉状物质则是飞灰,其属于危险废物(编码为HW18)且处理难度较大,其中含有有机污染物二噁英与Cr、Cd、Hg等重金属。本文重点分析水泥窑协同处置垃圾焚烧飞灰问题,探究水泥窑协同处置垃圾焚烧飞灰的技术途径,以便更好的提升其技术应用效果,并为类似水泥窑层面的研究提供参考依据。 相似文献
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对7种城市垃圾焚烧飞灰的物理化学性质进行了详细表征。针对飞灰中重金属成分复杂的特点对重金属含量、形态分布和浸出毒性进行了分析,并进行了风险评估指数和风险指数计算。飞灰的化学组分和晶相结构分析显示,城市垃圾焚烧飞灰中含有大量的CaO、CaSO4、SiO2、Al2O3、NaCl和KCl等化合物,具有资源化利用的潜力。但同时飞灰中含有大量的重金属,其中Pb和Cd的生态风险高,浸出毒性高于飞灰直接处理和处置要求。研究结果表明,垃圾焚烧飞灰需进行处理至达到一定要求后才能进行资源化利用。 相似文献
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阐述了城市垃圾焚烧飞灰的基本性质和不同粒径颗粒所含各种重金属含量以及它们对水体和环境的危害,介绍了不同粒径飞灰的物理化学性质和在不同条件下的处理方式,在此基础上提出了一种"无害化"、"资源化"、"减量化"的有效措施处理飞灰,即水泥窑煅烧处理;还介绍了城市垃圾焚烧产物中二噁英的基本性质、毒性和对人体的危害,从垃圾入炉前、焚烧时、烟气中等三个方面进行处理,并提出了减少二噁英的生成防治措施及去除的方法;介绍了城市垃圾焚烧底灰的物理化学性质,提出了一种资源化利用的方案,即制成烧结砖. 相似文献
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R. C. Tripathi S. K. Jha L. C. Ram 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(17):2568-2574
Coal contains various organic and inorganic substances including trace quantities of the heavy metals. Therefore, the combustion of coals releases some of the ultimately to the environment of some heavy metals elements in the form of their oxides and in a redistribution of these heavy metals in the surface soil and water bodies, particularly in the vicinity of coal-fired power plants. The fly ash and pond ash of different thermal power stations of India were mixed with soil at different doses separately to compare their impact on crop produce and soil. The present study deals with the presence of the heavy metals in the coal ash and its movement through the amendment of coal ash to the soil and crop produce. 相似文献
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介绍了5000kg/d垃圾焚烧飞灰熔融固化试验炉结构特点,分析研究了垃圾焚烧飞灰化学成分、灰熔点对熔融固化炉炉膛截面热负荷、容积热负荷值的选取以及炉内衬耐火材料抗碱浸蚀抗高温性能的影响因素.对试验装置炉内各点温度变化和随着温度水平提高,炉内阻力减少的原因进行了分析,对飞灰熔融物用722S分光光度计和IRIS1000等离子体发射光谱仪进行浸出毒性鉴别,结果显示检测值均低于浸出毒性鉴别标准.应用数值模拟方法对炉内的速度场、温度场和飞灰颗粒浓度分布进行了计算分析,指出采用单通道送风比双通道送风对飞灰熔融颗粒收集更有利. 相似文献
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Effect of wood fly ash and compost on nitrification and denitrification in agricultural soil 总被引:1,自引:0,他引:1
Wood ash from biofuel combustion plants and compost from source-separated household waste are commonly spread on forest, agricultural and horticultural soils as a valuable source of plant nutrients. However, due to anthropogenic activities, wood ash may contain high concentrations of heavy metals. Heavy metals are toxic to microorganisms and therefore, soil microbial response to wood ash should be considered when soil is amended with ash. Compost is known to improve soil structure and may also act as a bioremediating agent, mitigating any toxic effects of wood ash on soil microorganisms. In the present study, the aim was to investigate whether wood ash has any toxic effect on soil microbial activity and, if this is the case, whether compost could mitigate these effects. The effect of wood fly ash on potential ammonium oxidation rate (PAO) and potential denitrification rate (PDA) in arable soil was investigated in one dose–response assay and in two pot experiments with or without plants, respectively. The treatments were amendment with wood fly ash, compost or a combination of wood fly ash and compost. PAO and PDA were assessed immediately or after 7 and 90 days in the different experiments. Wood fly ash decreased PDA to 16–56% compared to the control, while PAO varied between 82% and 205%. Sole compost addition stimulated both processes. This positive effect was also observed in the combined wood fly ash–compost treatment. In conclusion, wood ash had a toxic effect on PDA, both on an immediate, short-term and long-term basis. Amendment of compost clearly mitigated this toxic effect. The observed toxicity could be an effect of the metal content of ash. 相似文献
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