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采用热力学平衡计算方法,研究了垃圾和污泥焚烧过程Cu、Mn、Zn重金属的迁移规律,考察了温度、HCL、S以及焚烧中污泥水分高低对重金属迁移特性的影响.研究结果表明:除焚烧温度外,HCl是影响重金属迁移的主要因素,HCl的存在会促进难挥发重金属(Cu、Zn)低温时就挥发出来;污泥含水率的降低会增加氯化锌的挥发量,但影响较小,含水率由72%降至12%,氯化锌百分含量增加不到5%. 相似文献
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《动力工程学报》2016,(11):934-940
利用Aspen Plus软件对污泥半干化焚烧和掺烧发电2种工艺过程进行模拟,探讨了不同工艺下4种污泥的能量利用情况及污染物排放特性.结果表明:半干化焚烧时,4种污泥的干基热值低于11.5MJ/kg时均需补燃辅助燃料,且随着污泥热值的降低,补燃量显著增加;重金属含量高的污泥易造成大气污染,灰渣也难满足利用要求.污泥掺烧发电时,掺烧热值高的污泥对发电效率有利;对于同种污泥,随着污泥能量份额降低,发电效率提高,且污泥能量份额较低时,重金属含量高的污泥也能满足环保要求,适宜的污泥能量份额建议为5%~8%.当污泥热值低、重金属含量高时,建议采用掺烧发电工艺,反之采用半干化焚烧工艺. 相似文献
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为了得到燃煤电厂掺烧生活污泥燃烧及环保特性规律,基于国内某电厂的330 MW亚临界四角切圆燃煤锅炉,针对6个工况开展现场试验研究。结果表明:燃煤、污泥与混合后的燃料在成分含量上区别较大;掺烧污泥会导致锅炉燃烧温度与热效率降低,最大的降幅分别为28℃和0.19%,总体降幅较小;掺烧污泥后,飞灰与炉渣中重金属含量及氯含量稍微上升,不会明显提高结渣风险;掺烧污泥后,现有的净化工艺仍能确保常规烟气污染物的排放浓度能满足燃煤烟气超低排放要求;随着掺烧比例的提高,NOx的排放量呈现先增加后降低的趋势,SO2的排放量逐渐降低,粉尘颗粒的排放量稍微提高;掺烧污泥不会对二噁英类和重金属及其化合物等非常规烟气污染物造成明显影响,排放情况能够满足燃煤电厂限制要求;风烟系统各级风机用电量普遍随着掺烧污泥量增加而提升,最大的提升幅度为5.4A,适当调整后均能够正常运行。 相似文献
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竹园污泥焚烧污染物排放特性的试验研究 总被引:1,自引:0,他引:1
选取上海竹园污泥,将原始污泥样品分为全干污泥、均匀干化污泥(含水率10%)和干湿混合污泥(含水率20%,干湿污泥质量比例为10∶3)三种样品,分别送入小型流化床焚烧炉中焚烧。试验研究了全干污泥在750℃、850℃、950℃三个工况下的燃烧特性,并研究了均匀干化污泥和干湿混合污泥在850℃工况下的燃烧特性。研究发现,上海竹园污泥在小型流化床焚烧炉中燃烧时,排放的主要常规污染物包括CO、SO2、NOx、HCl等以及二噁英和Cd、Hg、Pb等重金属。不同燃烧温度和含水率对污染物的排放有一定影响,提高燃烧温度,CO、SO2、NOx、HCl等的排放基本呈现出下降趋势,而烟气中Pb的排放随着温度上升而升高,相同燃烧温度下含水率升高能降低二噁英的排放总量,随着含水率的提高飞灰中重金属含量有所降低,而底渣中重金属含量呈上升趋势。 相似文献
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如何处理水利水电工程污泥是全球性的环保问题,资源化处理处置技术是解决该问题的最好出路。文章详细介绍了法国Novosol新型污泥处理技术先通过化学处理方法,在污泥中加入磷酸,将其中的重金属转变成难溶的金属磷酸盐固化在处理产物中;再通过热处理方法降低其有机物的含量,从而使固体残留物无害化的工艺流程,并简述了其技术原理和实际应用效果。 相似文献
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稠油污水处理场的初沉池中,通常产生大量的高含水污泥,其主要是由原油、泥砂颗粒、水及少量化学药剂和部分工业杂质形成的混合物.稠油油泥成分复杂、处理难度大.对稠油油泥进行脱水并掺混一定比例的煤作为燃料,是一种有效的稠油油泥资源化利用和无害化处理方式.利用自制实验装置进行实验,考察了油泥、原煤掺混比例对燃烧烟气污染物和灰分中重金属含量的影响.结果表明:油泥与原煤按1∶3的掺混比例燃烧时的效果最佳,烟气中主要的污染物NOx、SO2以及CxHy平均含量为147 μL/L 、420μ L/L以及106μL/L,均符合国家排放标准;重金属Pb、Hg、Cr和非金属污染物As在稠油油泥燃烧后的灰分中的平均含量分别为2.75mg/kg、0.05mg/kg、91.5mg/kg和0.68mg/kg,也都符合国家排放标准. 相似文献
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The increasing levels of sewage sludge production demands research and development to introduce more commercially feasible options for reducing socio-economic and environmental problems associated with its current treatment. Sewage sludge may be processed to produce useful products or as a feedstock for energy generation. Initially, the characteristics of sewage sludge are discussed in terms of composition and the current options for its treatment with the associated environmental impacts. Processes to valorize sewage sludge are discussed, including heavy metal removal from sewage sludge, production of bio-char, production and use of activated carbon and use of sewage sludge combustion ash in cement and concrete. Thermochemical processes i.e., pyrolysis, co-pyrolysis and catalytic pyrolysis, also gasification and combustion for process intensification, energy and resource recovery from sewage sludge are then critically reviewed in detail. The pyrolysis of sewage sludge to produce a bio-oil is covered in relation to product bio-oil composition, reactor type and the use of catalysts. Gasification of sewage sludge focusses on the characteristics of the different available reactor types and the influence of a range of process parameters and catalysts on gas yield and composition. The selection and design of catalysts are of vital importance to enhance the selectivity of the selected thermochemical pyrolysis or gasification process. The catalysts used for sewage sludge treatment need more research to enable selectivity towards the targeted desired end-products along with optimization of parametric conditions and development of innovative reactor technologies. The combustion of sewage sludge is reviewed in terms of reactor technologies, flue gas cleaning systems and pollutant emissions. In addition, reactor technologies in terms of technological strength and market competitiveness with the particular application to sewage sludge are compared for the first time for thermochemical conversion. A critical comparison is made of the drying techniques, co-feedstocks and catalytic processes, reaction kinetics, reactor technologies, operating conditions to be optimized, removal of impurities, fuel properties, their constraints and required improvements. The emphasis of this review is to promote environmental sustainability for process intensification, energy and resource recovery from pyrolysis, gasification and combustion involving the use of catalysts. 相似文献
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Combustion performance and slagging characteristics during co-combustion of Zhundong coal and sludge
Zhundong coal (ZDc) with a very large reserve is faced with severe problems of slagging and fouling during combustion in boilers because of the high-Na content. Sludge, the by-product of urban sewage treatment, is also faced with the problem in utilization. In this study, the co-combustion of ZDc and sludge was investigated in a laboratory-scale experimental apparatus before further studies in larger-scale setups. The experimental results confirm an interaction between ZDc and sludge during co-combustion, which was mainly caused by the Na catalytic action and improved the combustion performance of the co-fuels. The catalytic effect was particularly significant at low sludge mixing ratios. The reactions between Na-based compounds in ZDc and Si/Al/P-rich minerals in sludge, forming high-melting-point phosphates and aluminosilicates, not only increased Na retention in residual ash reducing the risk of fouling on tail-heating surfaces in boilers, but also raised the ash fusibility of the co-fuels avoiding low-temperature sintering. Even so, to prevent slagging, the high combustion temperature above 900 °C should be avoided during co-combustion because of the high Na retention in residual ash. Moreover, the high heavy metal retention in residual ash decreased the pollution caused by heavy metal volatilization during sludge combustion. 相似文献
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运用DEST软件分析了山西省太原市某洗浴中心采用洗浴废水源热泵系统供暖的逐时负荷的情况,得出,采用洗浴废水源热泵供暖比常规地下水源热泵系统供暖具有明显的节能优势。 相似文献
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研究了污泥干化设备的干化效率以及干化污泥掺烧后对300 MW燃煤锅炉的影响。通过对污泥干化设备的物料和能量平衡计算发现其干化效率达到了89.5%;通过污泥的不同掺烧比例试验,分析了掺烧干化污泥后对烟气和飞灰中二恶英和重金属含量、烟气中SO2等以及其他运行情况的影响,结论表明掺烧一定比例的污泥对锅炉的正常运行没有明显影响,而且添加适当比例的污泥可以优化锅炉的运行,对环境保护方面的贡献不言而喻。 相似文献
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叙述了发达国家将城市污泥施用于林地改善土壤的微生物活动和数量,提高土壤的可利用性,N,P,K,有机质的含量以及促进林木生长的研究状况及中国在这方面的研究现状,指出,污泥林地利用存在着污染地下水、增加土壤重金属和有害化学物质等环境风险,认为有必要开展对土地的承载能力、树木的敏感程度、食物链风险、树木需肥量等综合因素的研究。 相似文献