Utilization of coal fly ash and municipal sewage sludge in agriculture and for reconstruction of soils in disturbed lands： results of case studies from Greece and China

Coal fly ash （CFA） and municipal sewage sludge （MSS） management is a great concern worldwide. An alternative gaining high interest, is their use in agriculture and for reclamation of degraded lands. The purpose of this paper was to present very briefly the results of some case studies carried out in China and Greece related to land reclamation and agricultural use of CFA and MSS separately or combined. An experiment in Platanoulia area, central Greece showed clearly that CFA applied together with MSS at appropriate rates increased substantially wheat grain and biomass yield and improved soil quality （increased soil pH, organic matter content, total nitrogen, available P and boron）. In a long-term experiment carried out in Huaibei city, Anhui province, China with a reconstructed soil in a subsided land by using CFA, it was found that physicochemical characteristics （infiltration rate, bulk density, total nitrogen, available P and extractable K） tended to be improved over time. In another experiment in Rodia area central Greece, MSS application improved soil quality of limestone mining spoils from bauxite mining activities. Several other experiments with MSS in Greece showed a clear positive effect on cotton and maize yield and on soil quality.

Comparative Characteristics of Hydrated Lime with Fine Sewage Sludge Ash (FSSA) and Coal Fly Ash (CFA)

The disposal of waste has become an environmental issue due to the limited available landfilling space. This paper aims to compare the characteristics of hydrated lime with fine sewage sludge ash (FSSA) and coal fly ash (CFA). Multiple techniques, X-ray fluorescence (XRF), X-ray diffraction (XRD), the Fourier transform infrared (FTIR), compressive strengths, thermophysical properties, and setting time were used to assess the physicochemical characteristics of the lime-based materials. X-ray fluorescence and X-ray diffraction were used to determine the chemical composition and phases of ashes, lime and binders. The results showed that the chemical composition of ashes is similar to that of cement. Besides glass, the main minerals identified in CFA and FSSA are quartz (SiO2) and anhydrite (CaSO4). Moreover, calcium aluminium oxide (Ca3Al2O6) was detected for CFA and phosphorus calcium silicate (Ca2SiO4-Ca3(PO4)2) for FSSA and minor phases were detected for both. FTIR measurements were carried out to characterize the inorganics components of different samples. Compressive strengths of mortars with different formulations have shown that both have a long-term positive effect which might be related to a pozzolanic activity. For the CFA the L3 binder consisting of 60% of coal fly ash and 40% lime has a higher compressive strength than the others while for the FSSA the L4 binder consisting of 80% fine ash and 20% lime has a higher compressive strength than the others. Both binders setting start times are greater than that of cement but shorter than that of lime. The study of the thermophysical properties of binders shows that they have a higher thermal resistance than cement mortar. Moreover, binders heat up less quickly because of their low effusivity compared to cement. Lime-based materials system could be a promising option to both relieve the waste disposal pressure and provide a potential sustainable construction material.

Influence of fly ash and sewage sludge application on wheat biomass production,nutrients availability,and soil properties

The influence of fly ash(FA)applied alone and/or with sewage sludge(SS)on wheat(Triticum vulgare)grain yield,biomass production and soil properties was studied in a field experiment.The results showed that both FA and SS significantly increased grain yield and plant biomass.FA applied alone increased significantly soil pH and EC while FA applied together with SS did not significantly affect them compared to mono FA treatment.Soil pH and EC values increased with time in FA and FA-SS treatments.SS increased soil organic matter and total N content and SS applied together with FA increased also available soil B.From the plant nutrients tested only tissue N concentration was increased significantly in all treatments compared to control.Copper,Zn,Mn,Ni,and Pb at both available and total concentrations are significantly affected.

Combustion of Sewage Sludge as Alternative Fuel for Cement Industry

The combustion of sewage sludge and coal was studied by thermogravimetric analysis.Both differential scanning calorimetric analysis and derivative thermogravimetric profiles showed differences between combustion of sewage sludge and coal,and non-isothermal kinetics analysis method was applied to evaluate the combustion process.Based on Coats-Redfern integral method,some reaction models were tested,the mechanism and kinetics of the combustion reaction were discussed.The results show that the combustion of sewage sludge is mainly in the low temperature stage,meanwhile the ignition temperature and Arrhenius activation energy are lower than that of coal.The combustion of sewage sludge has the advantage over coal in some aspects,thus sewage sludge can partly replace coal used as cement industry fuel.

Systematic physicochemical characterization,carbon balance and cost of production analyses of activated carbons derived from(Co)-HTC of coal discards and sewage sludge for hydrogen storage applications

Hydrothermal carbonization(HTC)technologies for producing value-added carbonaceous material(hydrochar)from coal waste and sewage sludge(SS)waste might be a long-term recycling strategy for hydrogen storage applications,cutting disposal costs and solving waste disposal difficulties.In this study,hydrochars(HC)with high carbon content were produced using a combination of optimal HTC(HTC and Co-HTC)and chemical activation of coal tailings(CT),coal slurry(CS),and a mixture of coal discard and sewage sludge(CB).At 850℃and 800℃,respectively,with a KOH/HC ratio of 4:1 and a residence time of 135 min,activated carbons(ACs)with the highest Brunauer–Emmett–Teller specific surface(S_(BET))of 2299.25 m^(2)g^(−1)and 2243.57 m^(2)g^(−1)were obtained.The hydrogen adsorption capability of the produced ACs was further studied using gas adsorption isotherms at 77 K.At 35 bars,the values of hydrogen adsorbed onto AC-HCT(AC obtained from HTC of CT),AC-HCS(AC obtained from HTC of CS),and AC-HCB(AC obtained from HTC of the blending of coal discard(CD)and SS)were approximately 6.12%,6.8%,and 6.57%in weight,respectively.Furthermore,the cost of producing synthetic ACs for hydrogen storage is equivalent to the cost of commercial carbons.Furthermore,the high proportion of carbon retained(>70%)in ACs synthesized by HTC from CD and SS precursors should restrict their potential carbon emissions.

Heavy Metal Migration Characteristics of Co-Combustion between Sewage Sludge and High Alkaline Coal on Circulating Fluidized Bed

The migration characteristics of heavy metals in co-combustion of sewage sludge and high alkali coal in circulating fluidized bed were studied by experiments and simulations. Temperature plays a crucial role in thermodynamic equilibrium distribution and migration characteristics of heavy metals. At the temperature range of 700℃-1200℃, Hg is completely gaseous and the proportion of Pb, Ni, and Cd in the gas phase is also high. As is mainly elemental in the system, and the proportion of Cr in the solid phase is large. Zn compounds are diverse and mostly solid materials. The volatility of Cu is not strong, and it will become gaseous when the temperature exceeds 1700℃. The proportion of heavy metals in the gas phase decreases as the excess air ratio increases. In an oxygen-rich atmosphere, most of Zn and Ni are converted to oxides;Pb and Cd are converted to crystalline silicate;Cu is converted to partial aluminate;Cr compound is decomposed to form Cr_(2)O_(3);they are good for the solidification and controlling of heavy metals. The elemental Hg is converted to HgCl_(2) and the elemental As is converted to AsCl_(3). Temperature also has a great influence on the volatilization rate of heavy metals. The higher the temperature, the shorter the time they reach the maximum volatility.

燃煤电站掺烧污泥热力学与经济性分析

我国污泥产量逐年增加,如何对其进行无害化、资源化处理成为亟待解决的问题,拟将燃煤电站与污泥干燥系统耦合,湿污泥干燥后进行掺烧。以某典型超临界660MW机组为研究对象,在THA工况下,通过对锅炉进行热力计算和对系统整体进行热力学分析及经济性分析,研究掺烧不同含水率(10%、20%、35%、50%、65%)不同掺烧量(2%、4%、6%、8%、10%)的干化污泥对排烟温度、锅炉效率、净发电效率、湿污泥发电折合净效率和干化污泥发电折合净效率等参数的影响。结果表明:当干化污泥含水率超过50%时会导致参数恶化且随掺烧量的增加变化趋势加剧;干化污泥的含水率应控制在50%及以下,若超过此值,掺烧量应小于4%;掺烧污泥导致系统的㶲效率降低,主要原因是锅炉和干燥设备的㶲损失增加;当掺烧含水率为20%,掺烧量为10%的干化污泥时,系统经济性最好,动态回收周期仅为4.02年。

K_(2)CO_(3)活化低阶煤和污泥共水热炭制备多孔炭及其对CO_(2)和SO_(2)吸附性能

我国低阶煤储量大,低阶煤材料化利用是当前国家重大需求。另外,我国城市污泥排放量逐年增加,高含水率污泥资源化利用至关重要。低阶煤和污泥水热碳化可有效资源化利用原料内的硫氮元素,制备硫氮掺杂水热炭。水热炭孔隙较不丰富,对其进行活化造孔可丰富其孔隙结构,制备得到硫氮掺杂多孔炭。选用较为温和K_(2)CO_(3)作为活化剂,探究K_(2)CO_(3)活化不同次烟煤与污泥水热炭制备多孔炭材料的性质,并研究多孔炭对CO_(2)和SO_(2)的吸附性能。结果表明,次烟煤和污泥水热炭经K_(2)CO_(3)活化改性后,硫氮元素含量相较于原来的水热炭均有所减少,多孔炭的比表面积由原水热炭的23.92m^(2)/g增至331.77m^(2)/g,孔体积由原水热炭的0.07cm^(3)/g增至0.23cm^(3)/g。制备的多孔炭对CO_(2)和SO_(2)具有一定的吸附效果,次烟煤与污泥质量比为7∶3,水热碳化温度为160℃时,经700℃K_(2)CO_(3)活化所制备的多孔炭在25℃下,对CO_(2)吸附量为1.56 mmol/g;次烟煤与污泥质量比为1∶1,水热碳化温度为160℃时,所制备的水热炭经活化后,其在吸附温度为120℃时,对SO_(2)的吸附量为52.2 mg/g,且随着水热碳化温度升高,其吸附量有所下降,共水热炭相比于单一水热炭对CO_(2)和SO_(2)的吸附性能更好。研究结果可为低阶煤和污泥清洁高效利用和低成本CO_(2)、SO_(2)吸附剂开发提供理论依据。

A^(2)/O一体化设备在农村生活污水处理中的应用

随着我国大力实施乡村振兴战略,农村生活污水治理不断推进。本研究基于A^(2)/O一体化设备处理农村生活污水的调试数据,考察DO浓度、硝化液回流比、污泥回流比等参数对工艺的影响,分析各参数相互影响规律,探究最佳运行参数。研究结果表明:A^(2)/O工艺处理农村生活污水最佳运行参数应控制DO浓度区间2~3 mg/L,硝化液回流比200%,污泥回流比100%。调控最佳工艺参数后,经处理后,出水满足《农村生活污水集中处理设施水污染物排放标准》(DB33/973-2021)表1中的一级标准,对A^(2)O一体化设备在农村生活污水治理中的应用提供案例支撑和经验借鉴。

氧化物组成对煤气化渣-污泥基地聚物力学性能和微观结构的影响

以煤气化渣和污泥为原料,通过水玻璃和氢氧化钠为复合碱激发剂制备地聚物,研究了氧化物组分摩尔比(n(H_(2)O)/n(Na_(2)O)、n(Na_(2)O)/n(Al_(2)O_(3))和n(SiO_(2))/n(Al_(2)O_(3)))对地聚物抗压强度和微观结构的影响,利用扫描电子显微镜(SEM)和比表面吸附仪(BET)对地聚物的表观形貌和孔结构进行了观察和分析,结合X射线衍射仪(XRD)和傅里叶变换红外光谱仪(FT-IR)对地聚物的化学结构分析,初步探索了氧化物组分摩尔比对地聚物抗压强度和微观结构的影响机制。结果表明:高n(H_(2)O)/n(Na_(2)O)在一定程度上有助于原料中硅铝活性成分的溶解,但同时也会引起体系碱性降低,阻碍地聚合反应,过多水量还将增加样品内部孔隙率;高n(Na2O)/n(Al_(2)O_(3))能促进反应进行,但也会造成凝胶物质包裹未溶解的煤气化渣-污泥灰颗粒,并加重碳化反应;n(SiO_(2))/n(Al_(2)O_(3))的增加能促进生成硅酸盐寡聚物,有利于地聚物强度的发展。试验得出最佳配比为n(H_(2)O)/n(Na_(2)O)=12,n(Na_(2)O)/n(Al2O3)=0.8,n(SiO_(2))/n(Al_(2)O_(3))=3.0,所制得的地聚物1 d、3 d、7 d和28 d抗压强度分别达到58.1MPa、62.9 MPa、70.1 MPa和73.0 MPa。研究结果可为煤气化渣和污泥等大宗固废的循环利用拓展新途径。

气化细灰高碳组分和化工污泥与煤协同制浆研究

对气化细灰高碳组分和化工污泥与煤协同制浆进行研究,有助于气化细灰和煤化工污泥的减量化及资源化利用,可为开发煤化工固废与煤协同制备高质量气化水煤浆技术提供支撑。针对气化细灰高碳组分和化工污泥在与煤协同制浆过程中存在的煤浆质量差的关键问题,采用气化细灰高碳组分和改性化工污泥与煤掺混制浆,通过分析固废不同研磨时间和掺混比例对混合煤浆黏度、流动性、粒度分布、纳米CT技术和接触角的影响,揭示煤化工固废的掺入对煤浆性能的作用机制。结果表明,改性污泥和高碳细灰与煤直接掺混制浆,掺混量每增加1个百分点,煤浆浓度降低约0.3~0.7个百分点;通过细磨或超细磨则可改善改性污泥、高碳细灰对煤浆成浆浓度的影响,在相同条件下与不进行研磨的制浆工艺相比,细磨后的煤浆浓度提升0.3~0.4个百分点。由于细灰和污泥的加入而使制浆原料与水的接触角降低,成浆性变差,煤浆浓度降低;细磨后的细灰、污泥与煤之间形成粒度级配,超细颗粒包覆在粗颗粒表面而具有润滑的作用,从而导致研磨后的固废掺入对煤浆浓度的影响降低。

Influence of dissolved organic matter on methylmercury transformation during aerobic composting of municipal sewage sludge under different C/N ratios

Current knowledge about the transformation of total mercury and methylmercury(Me Hg) in aerobic composting process is limited. In this study, the composition and transformation of mercury and dissovled organic matter(DOM) in aerobic composting process of municipal sewage sludge were were comprehensively characterized, and the differences among the three C/N ratio(20, 26 and 30) were investigated. The main form of mercury in C/N 20 and 26 was organo-chelated Hg(F3, 46%-60%);while the main form of mercury in C/N 30 was mercuric sulfide(F5, 64%-70%). The main component of DOM in C/N 20 and 26 were tyrosine-like substance(C1, 53%-76%) while the main fractions in C/N 30 were tyrosine-like substance(C1, 28%-37%) and fulvic-like substance(C2, 17%-39%). The mercury and DOM varied significantly during the 9 days composting process. Compared to C/N 20 and 26, C/N 30 produced the less Me Hg after aerobic composting process, with values of 658%(C/N 20), 1400%(C/N 26) and 139%(C/N 30) of the initial, respectively. Meanwhile, C/N 30 produced the best compost showed greater degree of DOM molecular condensation and humification. Hg fraction had been altered by DOM, as indicated by a significant correlation between mercury species and DOM components. Notably, C/N 30 should be used as an appropriate C/N ratio to control the methylation processes of mercury and degration of DOM.

添加剂对污泥堆肥过程中气体排放和酶活性的影响

针对市政污泥与秸秆混合在传统堆肥过程中温室气体排放量与氮损失量较高的问题,采用玉米秸秆生物炭(CSB)与煤矸石基沸石(ZL)联合堆肥,为减少堆肥过程中CH_(4)、NH_(3)、N_(2)O气体排放.将10%的CSB与0%、10%、20%、30%的ZL混合(百分比为添加剂与污泥秸秆混合物质量之比),同时,无添加剂作为对照组,结果表明,与对照组相比,CSB与ZL联合添加(记为10%CSB+ZL)显著提高了堆肥过程中温度和pH值,增加了堆肥有机质降解,且降解速率高于对照组和10%CSB处理.两种添加剂联合添加降低了堆肥过程中氮损失,10%CSB+10%ZL、10%CSB+20%ZL、10%CSB+30%ZL处理中CH_(4)、NH_(3)、N_(2)O累积排放量比对照组分别降低87.81%~90.87%、41.61%~57.45%、85.01%~94.92%,CO_(2)累积排放量比对照组提高55.45%~86.55%;同时,在堆肥过程中脱氢酶、蛋白酶、木聚糖酶、磷酸酶活性增强.生物炭作为膨松剂,提高堆肥孔隙率促进微生物生长和相关酶活性提高,煤矸石基沸石通过吸附减少气体排放,10%CSB+20%ZL处理通过减少堆肥过程中CH_(4)、NH_(3)、N_(2)O排放速率实现降低氮损失的效果最佳.

掺混城市污泥对神木煤成浆特性的影响

将城市污泥以不同质量比掺入神木煤制备污泥煤浆,利用安东帕C-LTD80/QC型旋转流变仪考察了污泥掺混质量比(α)对污泥煤浆的最大成浆浓度、流变性、触变性和稳定性等成浆特性的影响。借助FTIR和SEM表征煤、污泥及水煤浆,探讨掺混城市污泥影响神木煤成浆性能机制。结果表明:水煤浆及污泥煤浆流变特性均符合幂定律模型τ=Kγn,随着α的增大,污泥煤浆表观黏度增大,最大成浆浓度降低,浆体流变性指数n减小,剪切稀化特性明显,浆体更加趋向于假塑性流体;同时,α的增大也会使得浆体触变环面积增大,进一步导致浆体触变性增强;此外,加入污泥制备的污泥煤浆,浆体产生沉淀时间明显延长,其析水率与相同成浆浓度下的水煤浆的析水率相比明显降低,说明适当的污泥掺混量有利于改善浆体的稳定性。通过FTIR及SEM分析可知,污泥填充了煤粉颗粒之间的空隙,在浆体内部形成较强的空间结构,这种作用是导致掺混污泥后浆体的表观黏度增大、最大成浆浓度降低、稳定性提高的主要原因。在尽可能提高污泥掺混比例的条件下,当α为0.12,污泥煤浆的最大成浆浓度为60.42%时,浆体的成浆性能良好,满足工业要求。

污泥和聚氯乙烯共热解三相产物特性

伴随着社会发展和城市扩张,生活污泥和废塑料的处置压力越来越大,同时热解作为一种资源化处置有机固体废弃物的手段受到普遍关注。本文通过开展生活污泥(SS)和废聚氯乙烯塑料(PVC)在500~900℃共热解实验,探究了温度和PVC掺混比对热解三相产物分布及其性质的影响。结果表明:伴随温度的升高,热解的固相产率下降,气相产率上升,液相产率先上升后下降;与此同时,热解气中的CH_(4)和CO含量上升,CO_(2)的含量下降;热解油中有机物含碳数减小,烃类和芳香类有机物比例增大;热解炭表面孔隙结构变得不规则,官能团减少。与污泥单独热解相比,PVC的加入会在降低产炭率的同时提高产气率,且高温下将抑制液相产物的产生。除此之外,PVC有利于提升热解气品质,提高高温热解油中重质组分的含量,并在增大热解炭表面不规则程度的同时使其含氧官能团更为丰富。

燃煤循环流化床锅炉混燃污泥研究与应用进展

燃煤循环流化床(CFB)锅炉对污泥进行混燃是一种有效处置污水污泥的方法。在适当的污泥掺烧比例下,污泥与煤混燃不会对电厂生产造成显著不利影响,并且可以使污泥的热值得到合理利用。综述了燃煤CFB锅炉混燃污泥的研究与应用进展,包括煤与污泥混燃过程中污染物的排放和控制、锅炉可靠运行的掺烧比例和污泥干化等情况。分析了混燃湿污泥所带来的运行问题,介绍了采用水煤浆悬浮燃烧技术及富氧燃烧技术对污泥进行处置和利用的情况。指出结合先进烟气净化技术的污泥干化与焚烧综合利用是目前燃煤CFB锅炉混燃污泥应用的较为成熟的工艺之一,在对多种污染物进行有效控制的同时,可以避免污泥贮存、干燥、输送过程中产生臭气对环境的影响。相关调查和分析结论可为燃煤CFB锅炉混燃污泥的设计和安全运行提供参考和依据。

污泥和煤泥的共燃烧行为研究

山西省乃至全国大量煤泥和城市污泥处理面临前所未有的挑战。清洁燃烧技术是污泥-煤泥协同处理的优选方法。为探究污泥-煤泥混燃过程中的相互作用,为清洁高效燃烧利用提供依据,采用热重质谱联用技术(TG-MS),研究了污泥和煤泥单独燃烧和共燃烧过程中的燃烧特性和污染性气体产物(CH_(4)、CO、CO_(2)、NH_(3)、HCN、NO、NO_(2)、H_(2)S、CH_(3)SH、COS、SO_(2)、CS_(2)、SO_(3))的析出特性,同时采用Coats-Redfern积分法对污泥和煤泥单独燃烧和共燃烧过程进行动力学特性分析,对两者的相互作用机制进行了深入探讨。结果表明:在污泥和煤泥共燃烧过程中,存在很明显的交互作用。污泥和煤泥相互促进,提高了整体的反应性能,其中煤泥掺混20%时燃烧特性最优,表明污泥比例的增加不会对燃料整体的燃烧性能造成影响。污泥和煤泥的质均活化能Em分别为51.170 kJ/mol和78.538 kJ/mol,混燃时污泥可以降低混合样品的质均活化能Em,协同作用使得混合样品的实际质均活化能Em低于计算值。污泥单独燃烧时动力学模型为(D3→D4);煤泥单独时的燃烧动力学模型为(F1);混合样品的区间动力学模型为(D3→D1→D3/F1),表明交互作用可以改变燃烧过程中的反应机理。当煤泥掺混20%时对温室气体(319.742%)的抑制效果最好;当煤泥掺混80%时对含硫气体(636.492%)和含氮气体(534.811%)的抑制效果最好;表明相互作用对混合样品的气体生成有较大的抑制作用,其中煤泥掺混20%时对污染性气体排放总量的抑制效果最强(319.740%)。

城市污泥与煤混合燃烧特性和污染物排放特性研究进展

城市污泥和煤混合燃烧可以对污泥实现减量化处理,但城市污泥与煤的成分差异较大,研究污泥与煤的混合燃烧特性和污染物排放特性对实现污泥与煤稳定燃烧和低污染排放有积极的意义。综述了城市污泥与煤的混合燃烧特性、动力学分析、污染物排放特性、重金属分布规律和灰熔融特性。一定比例的污泥和煤混合燃烧可以提高混合燃料的综合燃烧特性,但不同种类的污泥因其自身特性不同,与煤混合燃烧将表现出不同的特性,在实际应用中应根据掺混的污泥种类进行具体的研究分析。现阶段的研究更多关注的是污泥和煤混合燃烧的稳定性和污染物排放特性,工程实践中,电厂的锅炉设备和污染物控制排放控制设施能够满足一定比例的污泥和煤混合燃烧的稳定性和低污染排放的要求。污泥中Cl元素含量比煤的更大,Cl元素对污泥和煤混合燃烧中二噁英生成、锅炉受热面腐蚀和煤粉灰及脱硫石膏回收利用有着直接的影响,应在后续研究中重点研究关注污泥和煤混合燃烧过程中Cl元素的对上述方面的影响机制及相关控制优化措施。

630 MW机组超临界直流锅炉煤粉与污泥混烧数值模拟

采用Fluent仿真软件,对某630 MW超临界直流锅炉煤粉与污泥混烧进行数值模拟,研究了污泥掺混比、含水率和锅炉负荷对锅炉温度场以及污染物NO_(x)、SO_(2)和CO质量浓度的影响。研究结果表明,掺混比低于10%时对锅炉的整体影响较小,锅炉整体温度变化约10 K,NO_(x)、SO_(2)排放浓度略增加,炉膛内燃料燃烧充分、燃烧过程稳定;污泥含水率在35%~40%时有利于该煤粉锅炉掺烧城市污泥,锅炉整体温度下降5~10 K,出口CO排放浓度与原煤燃烧工况相比有所降低,出口NO_(x)和SO_(2)排放浓度显著低于含水率25%的掺烧工况;锅炉负荷由30%增至100%时,锅炉各受热面出口烟气温度以及NO_(x)、SO_(2)和CO的浓度呈增加趋势,在所研究锅炉负荷下,锅炉出口污染物排放浓度均在可接受范围,表明在该煤粉锅炉全负荷下均可实现城市污泥掺烧。

污泥与煤泥混燃过程中颗粒物的排放特性及汞成核机理

为实现城市污泥协同低热值煤泥的高效资源化利用,以单组分污泥、煤泥以及耦合燃料作为研究对象,针对燃烧过程中所生成的可吸入颗粒物,利用多种表征手段及自行建立的流化床实验系统,结合耦合燃料以及燃烧产物的微观特性及元素分布,并基于成核控制理论,在揭示多参数耦合条件下颗粒物排放特性以及粒径分布的基础上,研究混烧条件下Hg在颗粒物表面的成核机理。研究结果表明:样品所含挥发分与矿物质在燃烧过程中存在交互作用,主要包括焦炭、无机矿物质与易气化元素之间的反应,对颗粒物的形成具有较大影响。所生成颗粒物的粒径均呈双峰分布的特征,其中燃烧温度对排放特性的影响存在临界值(800℃)。随着粒径的减小,粗细2种模态颗粒物的分布范围均呈现减小的趋势,且对应峰值均逐渐增大(800℃燃烧条件所对应峰值分别可达3.6%和18.0%)。PM1与PM1~10的组成元素分别主要为易气化元素(如K、Mg、S、Cl和P等)与难熔性元素(如Si、Al、Fe和Ca等)。均相成核和异相凝结是Hg由气相向粒子成核转变的基本途径,并存在不同的成核控制机制,其中异相凝结过程又包含扩散控制与表面反应控制2种机制。