干法厌氧消化在有机垃圾处理中的应用

目前生活垃圾中含有大量可利用的有机垃圾,其在厌氧条件下可消化产生沼气,有机垃圾直接填埋会造成可再生能源的浪费.提出了干法厌氧消化工艺,干法压氧消化器越来越多用于可再生能源作物材料产出沼气上.同时分析了各种控制参数对于法消化运行的影响及干法消化适用的领域.     

厨余垃圾厌氧消化处理难点及调控策略分析

厨余垃圾产量大、有机物含量高、营养元素丰富,对其进行适当处理后资源化利用是厨余垃圾处理的发展方向。厌氧消化可实现生物质能的高效利用,是厨余垃圾资源化、无害化处理的主要方法之一。提升餐厨垃圾厌氧消化效率获得清洁能源及对消化产物的综合利用是目前研究的热点。介绍了厨余垃圾的基本特性、厌氧消化的机理,总结厨余垃圾厌氧消化各阶段面临的问题,分析对应的国内外调控策略的优缺点及研究进展,并对今后厨余垃圾厌氧消化的调控新策略及产物再利用进行展望。     

接种对厌氧消化产气的影响研究进展

厌氧消化是一种高效的废物处理方法,接种是影响厌氧消化能否成功启动的重要因素。文章从接种物的种类、接种量两方面讨论了接种对厌氧消化产气的影响,包括对厌氧产气量、产气速率和产甲烷速率的影响,指出以猪粪为底物时,一定接种量范围内,厌氧消化的产气率和甲烷产率随接种量的增加而增大,而当接种量过大时,产气率和甲烷产率反而随着接种量的增大而减小。最后,对接种对厌氧消化影响的研究作了展望。     

有机废弃物厌氧消化生产生物天然气技术的现状和展望

自沼气发现以来，有机物厌氧消化生产生物天然气由于其污染治理和能源回收的功能开拓了一个经久不衰的领域。有机废弃物厌氧消化过程的实现和发展依赖于工艺技术和基础理论的进步。本文从技术形式和理论出发，介绍有机废弃物厌氧消化生产生物天然气技术的现状并进行展望。首先介绍了当前主流厌氧消化技术，总结其设计和构型，阐述内在改进和变革思维：泥水分离的实现区分了第一代和第二代厌氧消化技术，而颗粒污泥的出现则发展了第三代厌氧消化技术。其次总结了现代厌氧消化技术理论和其对厌氧消化技术的推动作用，介绍一些加强厌氧消化策略：厌氧消化理论细化和种间电子传递的发现直接改变厌氧消化设计理念和运行形式。随后描述一些对厌氧消化具有强烈推动作用的新技术和新理念：机器学习有助于了解厌氧消化这一复杂黑箱，而合成生物学更将从概念上重新定义厌氧消化。最后对未来厌氧消化技术进行了展望：厌氧消化的发展将趋向于高效化、智能化、定制化，未来更将成为一个绿色平台，实现能源和物质的社会循环。     

剩余污泥与柑橘渣协同厌氧消化特性研究

以剩余污泥和废弃柑橘渣为原料,在中温条件下,开展两者的协同厌氧消化产气研究。结果表明,废弃柑橘渣和剩余污泥联合厌氧消化,能有效提高消化系统性能,增加消化气和甲烷产量,具有良好的协同效应。但对消化产物的脱水性能有一定的负面影响。污泥和废弃柑橘渣的VS投配比是影响消化过程的关键参数。当剩余污泥和柑橘渣VS投加配比为2∶1时,产消化气产率和甲烷产率最高分别为296.4、151.7 mL/g VS;当剩余污泥和柑橘渣的VS投加配比为1∶2时,产甲烷的协同效应最好,为217%;当污泥和柑橘渣的配比过低为1∶4时,消化系统p H值降低幅度大且回升速度慢、VFAs积累,有机物利用低,协同效应不明显。     

厌氧消化过程氨抑制研究进展

厌氧消化作为一种可获得能源的可持续生物处理技术,在实际工程中得到了广泛应用。在厌氧消化过程中,氨抑制被认为是影响其整体效能的重要因素。虽然氮是厌氧消化系统中微生物新陈代谢所必须的元素,但是厌氧消化体系中过高的氨氮往往会抑制微生物的正常生命活动,尤其是产甲烷菌。重点介绍了国内外厌氧消化氨抑制最新的机理研究,详细阐述了其主要的影响因素和消除措施,包括微生物驯化、p H值调节、温度控制及C/N比调节等,为厌氧消化技术工程应用的未来研究提供一定的借鉴和参考。     

污泥生物处理技术在长江大保护中的应用前景

污泥是污水处理的副产物,是污水处理过程的延续和必然要求.截至2017年,长江经济带11省市污泥产量接近2 000×104 t/a,大量污泥没有得到妥善处置,严重制约着“长江水质根本好转”目标的实现.厌氧消化与好氧发酵是两种主流的污泥生物处理技术,都已有广泛的应用案例,但是也存在运营不畅的现象.为识别长江大保护中污泥生物处理项目的问题并提出解决方案,分析了长江经济带的污泥产率及性质,梳理了污泥生物处理技术的发展及适用性.结果表明:长江经济带各省市污泥产量约占全国污泥产量的40%,污泥产率普遍低于全国平均水平,长江经济带各省市污泥有机质含量低于55%,pH为中性、总养分含量超过5.0%、重金属含量存在超过GB 4284—2018《农用污泥污染物控制标准》标准限值的风险;高级厌氧消化、协同厌氧消化和高含固厌氧消化等技术的发展破解了由于长江经济带污泥有机质含量普遍较低而导致的污泥厌氧消化稳定性低的问题,降低了污泥厌氧消化工程的成本;污泥好氧发酵过程重金属钝化技术的发展在一定程度上破解了由于长江经济带污泥重金属含量过高而导致的污泥发酵产物出路不畅的问题.研究显示,污泥生物处理技术仍具有一定的局限性,但通过合适的规划,污泥生物处理技术可与其他污泥处理处置技术高效耦合,具有广泛应用于长江大保护污泥处理处置项目的潜力.      

污泥有机成分与污泥厌氧消化潜能的研究进展

污泥厌氧消化产甲烷因其高效的能量回收和较低的环境影响是目前国内外广泛应用的污泥稳定化和资源化的有效方法。污泥有机成分是影响污泥厌氧消化产甲烷效果的主要因素之一。本文分析总结了国内外污泥成分特征与污泥厌氧消化效果关系的研究,阐述不同污水处理工艺段污泥的厌氧消化产甲烷的效果,污泥有机质转化生成甲烷的机制及性能。比较和评述几种评估污泥厌氧消化产甲烷性能的模型特点和适用条件。     

低温厌氧消化技术在废水处理中的应用

低温厌氧消化(low-temperature anaerobic digestion,LTAD)技术是低温条件下实现废水有机能源的回收,因其巨大的经济、社会和环境效益在废水处理领域具有广阔的应用前景。该文介绍了厌氧消化技术的原理和应用现状,结合在当前低温厌氧膜生物反应器在工业废水处理中的发展趋势,综述了低温厌氧消化技术发展的挑战和机遇,并在此基础上对LTAD在废水处理中的应用进行了总结。     

氨氮对有机废弃物厌氧消化的影响及调控策略

厌氧消化是一种有机废弃物无害化、资源化处理方式,它能够产生清洁能源沼气。含氮有机废弃物降解过程中容易产生氨氮,当其浓度过高时厌氧消化微生物活性受到抑制、甲烷产量下降,严重时会导致反应体系崩溃,造成严重的经济损失。文章通过查阅大量文献,综述了氨氮对有机废弃物厌氧消化的抑制作用及抑制模型,讨论了氨氮对厌氧微生物的抑制作用机理,并重点探究了应对氨氮抑制的调控策略,旨在为消除厌氧消化体系的氨氮抑制提供理论基础,促进利用厌氧消化技术处理含氮有机废弃物的工业应用。     

蒸汽爆破对污泥和餐厨垃圾联合厌氧消化的促进效果

鉴于蒸汽爆破（简称"汽爆"）预处理对污泥和餐厨垃圾联合厌氧消化的影响还鲜有报道,为探讨汽爆预处理对污泥和餐厨垃圾联合中温厌氧消化的促进效果及经济可行性,利用小型发酵罐在35℃下开展了未预处理污泥和餐厨垃圾联合消化、汽爆污泥单独消化、汽爆污泥和餐厨垃圾联合消化的试验,并进行能耗分析.结果表明,未预处理污泥与餐厨垃圾联合消化阶段,VS（挥发性固体）去除率为33.9%,沼气产率为311.0 mL/g（以投料VS计）;汽爆污泥单独消化阶段,VS去除率和沼气产率均略高于未预处理污泥与餐厨垃圾联合消化阶段,但反应器ρ（NH₄+-N）过高,影响产气稳定性,沼气φ（CH₄）较低.汽爆污泥与餐厨垃圾联合消化阶段,VS去除率和沼气产率分别达到49.5%和420.5 mL/g,显著优于未预处理联合消化阶段.能耗分析表明,预处理的升温过程使汽爆预处理整体能耗偏高,但若能有效回收70%的热量,则汽爆预处理可提高污泥-餐厨垃圾联合中温厌氧消化工艺3.34 kW·h/t（以污泥量计）的能量产率.研究显示,汽爆预处理可提高污泥和餐厨垃圾联合中温厌氧消化工艺35.2%的沼气产率,但由于预处理能耗较高,预处理过程中热能的有效回收是汽爆预处理应用于污泥和餐厨垃圾联合中温厌氧消化经济可行的关键.      

餐厨垃圾和剩余污泥厌氧混合发酵过程的动态膜强化特性研究

比较了厌氧动态膜生物反应器（DMBR）与完全混合式反应器（CSTR）在处理餐厨垃圾（FW）和剩余污泥（WAS）时的发酵产气过程,验证了高负荷餐厨垃圾和剩余污泥混合发酵时DMBR系统运行的稳定性,考察了动态膜（DM）基材孔径（300目、200目和100目）对DMBR运行性能及其固液分离效果的影响.结果表明：一体式DMBR能够强化餐厨垃圾和剩余污泥混合发酵的高负荷稳定运行,DMBR过膜滤液中平均总挥发性脂肪酸（TVFA）为86.1 mg·L^-1,低于CSTR排泥中TVFA的浓度（527.3 mg·L^-1）.当动态膜基材孔径为300目时,DMBR过膜滤液中总有机物（TCOD）为（1.6±1.1）g·L^-1,相应的固液分离效果优于200目（（3.2±1.9）g·L^-1）和100目（（32.0±1.3）g·L^-1）动态膜基材,即当动态膜基材孔径为100目时,DMBR过膜滤液中TCOD比300目动态膜基材高6.7倍.与200目动态膜基材孔径相比,300目动态膜基材相应的跨膜压差增长缓慢,反洗频率和运行能耗均较低,而100目动态膜基材孔径过大,固液分离效果较低.因此,在高负荷餐厨垃圾和剩余污泥混合发酵系统中,选用300目动态膜基材形成的动态膜过滤效果最优.此外,本文还对比分析了有机废物和废水处理领域中较优的动态膜基材孔径及DMBR的应用情况,为拓展DMBR在有机物处理领域的应用提供依据.     

Recovery of organic wastes in the Spanish wine industry. Technical,economic and environmental analyses of the composting process

The main organic wastes produced in modern wine industries include grape pomace (62%), lees (14%), stalk (12%) and dewatered sludge (12%). Some of these wastes are being used as by-products (grape pomace and lees) whereas the rest of organic wastes (stalk and wastewater sludge) has been traditionally incinerated or disposed in landfill. In this work, composting is proposed for the recovery of stalk and wastewater sludge to produce a sanitized organic amendment for application in the vineyard, closing the organic matter cycle. The environmental and economical analyses of the different alternatives to manage organic wastes from the wine industry are also presented. Composting costs are almost negligible when compared to other management options. From the environmental point of view, in-situ composting presents the best performance in 8 of the 10 impact categories analysed. Finally, the energy balance shows that the 4 composting systems involved less energy than the systems based on Mineral Fertilizer consumption.     

LCA studies comparing biodiesel synthesized by conventional and supercritical methanol methods

Biodiesel is one of the candidates for alternative fuels since it is renewable, sustainable and produced from domestic or non-food crop resources with less detrimental environmental impact. There are several different approaches to the production process. In this paper a new production method, the supercritical methanol process, was investigated and its environmental performance was compared with the conventional alkali-catalyzed process using LCA as a tool. The supercritical process is technically a simpler production process and offers the advantages of higher yields and the production of less environmentally damaging wastes. However, it still generates a significantly higher environmental load since the methanol recovery unit requires a large amount of energy.     

我国常规焦炉危险废物产生和利用处置现状及对策

我国是世界上最大的焦炭生产国和供应商,以常规焦炉炼焦工艺为主,常规焦炉会排放气体、液体和固体污染物.常规焦炉危险废物的产生现状是种类多、产生工艺节点多样、产生量大、污染物种类繁杂、对生态环境和人体的潜在危害大.对高附加值的高温煤焦油采取深加工的方式生产多种化工原料,脱硫废液的利用方式是提取单品精盐和制酸,其他低附加值的常规焦炉危险废物回配煤单元炼焦.当前,我国常规焦炉危险废物利用处置存在3个问题:①部分高温煤焦油深加工技术不属于清洁生产技术;②脱硫废液提取的盐缺乏污染控制标准或技术规范,脱硫废液制酸设备稳定运行难度较大;③危险废物回配煤单元可能引起炼焦产品质量下降和环境风险增大.针对我国常规焦炉危险废物产生和利用处置存在的问题,建议从3个方面提高炼焦危险废物利用率和加强安全处置:①遵循《国家危险废物名录》中"危险废物豁免管理清单"利用环节豁免条件,采取先进的清洁生产技术,促进高温煤焦油利用;②制定以脱硫废液为原料提取盐的污染控制标准或技术规范,将小规模企业产生的脱硫废液"点对点"集中输送至专门利用脱硫废液制酸的企业生产硫酸,开发易于推广、平稳高效连续运行和自动化控制的提盐和制酸技术,提高脱硫废液利用水平;③常规焦炉危险废物返回配煤工序炼焦时应精准管控,确保炼焦产品质量,防范环境风险.      

Life cycle assessment of an industrial symbiosis based on energy recovery from dried sludge and used oil

Recovering energy from wastes is a useful strategy for integrated waste and energy management in an eco-industrial park (EIP) and gives promising reduction of wastes, total energy consumption and operation cost. In Jinqiao EIP, Pudong New Area, Shanghai, an industrial symbiosis, based on the energy recovery from municipal sewage sludge and re-refined oil, was proposed in the central heat-supplying company of Jinqiao EIP. It is expected that hot off-gas or part of the steam from the central heat-supplying company could be used for sludge drying and used oil re-refining while the dried sludge and refined oil can be partial substitution for fossil fuel. For the purpose of assessing the environmental performance of this industrial symbiosis, life cycle assessment (LCA) was used and different scenarios were set up in this study to evaluate the Global warming Potential (GWP), Acidification Potential (AP), Eutrophication Potential (EP), Human toxicity air (HTA) and Total Environmental Impact Potential (TEIP) of the system. Results indicate that when the substitute ratio of coal by sludge is 14%, the proposed industrial symbiosis has the least environmental impact. Compared with the current situation (sludge is landfilled), co-combustion of dried sludge and re-refined oil with coal at optimal scale will release less CO₂, CH₄, NO_x, N₂O and CO, but more SO₂, H₂S, NH₃, HCl, polycyclic aromatic hydrocarbons (PAHs), non-methane volatile organic compounds (NMVOC) and heavy metals.     

含锌钢铁冶金固体废弃物提取金属元素的试验研究

根据含锌钢铁冶金固体废弃物的基本特性,提出了火法冶金-湿法冶金联合提取钢铁冶金固体废弃物中Fe、Zn等金属元素的工艺流程,并通过实验对该工艺流程的回收效率进行了验证。实验结果表明:该工艺能够实现冶金固体废弃物中Fe、Zn等金属元素的分离提取,而且能够合理地利用C元素。获得的金属铁中全铁含量能够达到95.52%,金属铁含量为94.81%,铁回收率为91.53%;锌纯度高达99.41%,回收率为93.82%。     

Solid and liquid residues as raw materials for biotechnology

In the past few decades huge amounts of solid and paste-like wastes of domestic and industrial origin have been deposited on sanitary landfills worldwide. Only a small proportion was incinerated, where incineration plants were available. Since primary resources, such as ores for metal production or crude oil for the production of gasoline, diesel, solvents and plastics, or coal and natural gas as sources for energy or chemicals are not available in unlimited quantities, and because the deposition of residues, wastes and worn-out commodities on sanitary landfills causes pollution of the atmosphere, the soil and the groundwater due to hazardous gaseous emissions and toxic leachates, wastes from households and from industry must be avoided or minimized at an early stage. Whenever waste material can be recycled it must be re-introduced into production processes and the non-recyclable fractions should be used as a fuel for energy recovery. After incineration, the highly toxic dust fractions of ashes and slags resulting from burning the wastes should be deposited on sanitary landfills, while the granulated mineral slag fractions could be used as a substitute for the sand in cement as a construction material. Here we review various processes for the treatment of organic fractions of differently composed wastes to upgrade them to more valuable, re-usable products or at least to recover their energy content. Upgrading processes of organic wastes include composting, biogas fermentation, production of organic acids and solvents, and biopolymer or biosurfactants production. We also include biological purification procedures for the most important components of wastes, such as chitin from the shells of Crustaceae. Typical examples from pilot-scale or full-scale studies are discussed for each process.     

新型三维多孔光热材料制备及其高盐废水处理应用

高盐废水处理存在处理难度大和能耗成本高等问题.近年来发展的界面光蒸汽水处理技术以绿色、高效和低能耗等特点成为了目前水资源回收利用领域的研究热点.本研究以纤维状结构的碳化氮（h-CN）修饰石墨烯（r-GO）,通过水热反应制备了新型三维多孔石墨烯复合材料（3D h-CN/r-GO）,并以硝基苯和苯酚作为模拟污染物,考察了其光热蒸发处理高盐废水的性能.研究结果表明,所制备的3D h-CN/r-GO材料具备宽光谱吸收范围和多级孔道结构,并呈现出快速热响应的特点.在模拟太阳光照条件下,光蒸汽转化效率可达90.4%.并且在处理过程中可实现硝基苯和苯酚等常见挥发性污染物的吸附,其吸附容量分别为67.6 mg·g^-1和57.5 mg·g^-1.而且,3D h-CN/r-GO可实现长时间稳定的光热水体蒸发回收,且对污染物及盐分截留率高达98%左右,冷凝水体达到污水处理的排放标准.因此,本研究为高盐废水的低能耗和低成本处理提供了一种新的技术.     

Development of alternative energy sources for GHG emissions reduction in the textile industry by energy recovery from cotton ginning waste

The agricultural sector and primarily its cotton subsector are of great importance for Greece, due to the intensive agricultural activities. The wastes from cotton ginning plants are also considerable and can be valorized for bioenergy production. The substitution of conventional by green fuels, which can be produced from cotton ginning wastes, is a step towards: (a) economic and environmental sustainability for the textile industry and (b) the development of alternative energy supplies, contributing to the reduction of GHG emissions. Furthermore, it consists an especially attractive opportunity to invest in rural areas. The present paper concerns the feasibility study for energy recovery from cotton ginning waste with GHG emissions reduction in a textile plant located in Northern Greece. The aim was to replace part of heavy fuel oil used for the thermal needs of the plant by biomass. The results showed that the most economically interesting energy option for a bioenergy unit in the above textile plant is 5 MW for the coverage of the 52% of the plant's thermal requirements.