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1.
Volatile organic compounds(VOCs) play an important role in the formation of ground-level ozone and secondary organic aerosol(SOA), and they have been key issues in current air pollution prevention and control in China. Considerable attention has been paid to industrial activities due to their large and relatively complex VOCs emissions. The present research aims to provide a comprehensive review on whole-process control of industrial VOCs, which mainly includes source reduction, collection enhan...  相似文献   

2.
Reticulated foam shaped adsorbents are more efficient for the removal of volatile organic compounds(VOCs),particularly from low VOC-concentration indoor air streams. In this study composite structure of zeolite and metal organic frameworks(MOFs),referred as ZMF,has been fabricated by immobilization of fine MOF-199 powder on foam shaped Zeolite Socony Mobil-5(ZSM-5)Zeolitic structure,referred as ZF. The ZMF possess a uniform and well-dispersed coating of MOF-199 on the porous framework of ZF. It shows higher surface area,pore volume,and VOCs adsorption capacity,as compared to ZF-structure.Post-fabrication changes in selective adsorption properties of ZMF were studied with three common indoor VOCs(benzene,n-hexane,and cyclohexane),using gravimetric adsorption technique. The adsorption capacity of ZMF with different VOCs follow the order of benzene n-hexane cyclohexane. In comparison with MOF-199 and ZF,the composite structure ZMF shows improvement in selectivity for benzene from other two VOCs. Further,improvement in efficiency and stability of prepared ZMF was found to be associated with its high MOF loading capacity and unique morphological and structural properties. The developed composite structure with improved VOCs removal and recyclability could be a promising material for small to limited scale air pollution treatment units.  相似文献   

3.
Reticulated foam shaped adsorbents are more efficient for the removal of volatile organic compounds (VOCs), particularly from low VOC-concentration indoor air streams. In this study composite structure of zeolite and metal organic frameworks (MOFs), referred as ZMF, has been fabricated by immobilization of fine MOF-199 powder on foam shaped Zeolite Socony Mobil-5 (ZSM-5) Zeolitic structure, referred as ZF. The ZMF possess a uniform and well-dispersed coating of MOF-199 on the porous framework of ZF. It shows higher surface area, pore volume, and VOCs adsorption capacity, as compared to ZF-structure. Post-fabrication changes in selective adsorption properties of ZMF were studied with three common indoor VOCs (benzene, n-hexane, and cyclohexane), using gravimetric adsorption technique. The adsorption capacity of ZMF with different VOCs follow the order of benzene > n-hexane > cyclohexane. In comparison with MOF-199 and ZF, the composite structure ZMF shows improvement in selectivity for benzene from other two VOCs. Further, improvement in efficiency and stability of prepared ZMF was found to be associated with its high MOF loading capacity and unique morphological and structural properties. The developed composite structure with improved VOCs removal and recyclability could be a promising material for small to limited scale air pollution treatment units.  相似文献   

4.
大气中挥发性有机物(VOCs)严重威胁生态环境和人类健康,其治理迫在眉睫。吸附法因操作简单、效率高、能耗低等优势成为目前处理VOCs最经济有效的方法之一。但传统吸附材料如分子筛、活性炭、硅藻土等存在吸附容量小、易堵塞、选择性低且再生困难等问题。因此,发展高效稳定的VOCs吸附材料仍是目前的研究热点。金属有机框架材料(metal-organic frameworks,MOFs)是一种比表面积高、孔道结构丰富的新型多孔材料,在VOCs吸附净化方面具有良好的应用潜力。针对近10年MOFs基多孔材料吸附去除VOCs的研究,从MOFs的结构和特点出发,详述MOFs的分类及其复合材料的类型,基于MOFs基多孔材料吸附VOCs过程中的影响因素和机制,对其在VOCs吸附应用方面的研究进展进行总结,并对其在该领域的未来发展进行展望。  相似文献   

5.
吸附法净化挥发性有机物的研究进展   总被引:6,自引:2,他引:4  
陆豪  吴祖良  高翔 《环境工程》2013,31(3):93-97
吸附法是净化挥发性有机物(VOCs)的主要方法之一,具有工艺成熟、操作简单、能耗低、净化效率高等优点。吸附剂的选择是VOCs净化的关键,同时如VOCs分子结构、外界环境因素也会影响净化效果。重点介绍了不同吸附剂对VOCs的净化,分析了影响VOCs吸附的其他因素,并展望了吸附法净化VOCs的研究方向。  相似文献   

6.
由于挥发性有机化合物(VOCs)对人类健康和生态环境的危害巨大,因此VOCs控制技术的研究显得尤为重要。活性炭吸附法具有技术成熟、操作简单、净化效率高、能耗低以及可回收等优势,是净化VOCs最经济、有效的方法之一。主要综述了活性炭在脱除VOCs方面的研究进展,包括活性炭的制备和改性技术及其对VOCs的吸附性能、活性炭吸附VOCs的影响因素以及活性炭在实际工业中的应用。通过探究不同制备及改性方法对活性炭孔结构、表面化学性质、比表面积的改变与VOCs吸附效果之间的联系,并结合实际应用实例,对活性炭吸附技术在实际应用中的发展方向提出了一些合理见解。  相似文献   

7.
The adsorption/plasma decomposition with the combination of adsorption honeycomb-sheets and a plasma element is a new technology for small-sized apparatuses to decompose volatile organic compounds (VOCs) at concentrations lower than about 100 ppm. The feasibility of the prototype adsorption/plasma decomposition apparatus was evaluated with the simulated exhausts containing one VOC component and with real exhausts from a painting booth and an adhesion factory. The apparatus decomposed VOCs e ectively at the painting booth exhaust but not always satisfactorily at the adhesion factory exhaust. The performance test results with real exhausts were discussed with respect to the concentration and discharge pattern of the exhausts and the basic properties of the system such as cooperation of adsorption and plasma reaction and the concentration dependence of the performance.  相似文献   

8.
大气中二次有机气溶胶(SOA)是PM25中的重要组成部分,挥发性有机物(VOCs)的光化学氧化是其主要来源之一.从VOCs转化生成SOA的过程非常复杂,参数化方法是一种相对简化的估算方式,可以用于区分不同VOCs物种对SOA生成的贡献.本文介绍了基于二产物和基于挥发性分级两种常用的参数化估算方法,并总结分析文献报道的SOA估算结果.文章中也指出现在的参数化估算还存在一些问题,如何准确量化VOCs向SOA的转化过程将是大气化学未来的重要研究工作.  相似文献   

9.
两种介孔分子筛动态吸附VOCs的研究   总被引:8,自引:2,他引:6       下载免费PDF全文
采用模板剂法制备了孔道规整、大比表面积的2种介孔分子筛MCM-41和SBA-15,并以甲苯、二甲苯、三甲苯为吸附对象,考察了介孔分子筛动态吸附VOCs的性能.结果表明,增加VOCs分子尺寸和浓度,降低床层温度可大幅提高介孔分子筛吸附性能.SBA-15由于介孔壁上的微孔结构适合吸附低浓度、小分子VOCs;MCM-41更适合吸附高浓度、大分子VOCs.TPD脱附试验表明,VOCs在介孔材料表面150℃下就能基本脱附完全.  相似文献   

10.
Volatile organic compounds (VOCs) are major precursors for ozone and secondary organic aerosol (SOA), both of which greatly harm human health and significantly affect the Earth''s climate. We simultaneously estimated ozone and SOA formation from anthropogenic VOCs emissions in China by employing photochemical ozone creation potential (POCP) values and SOA yields. We gave special attention to large molecular species and adopted the SOA yield curves from latest smog chamber experiments. The estimation shows that alkylbenzenes are greatest contributors to both ozone and SOA formation (36.0% and 51.6%, respectively), while toluene and xylenes are largest contributing individual VOCs. Industry solvent use, industry process and domestic combustion are three sectors with the largest contributions to both ozone (24.7%, 23.0% and 17.8%, respectively) and SOA (22.9%, 34.6% and 19.6%, respectively) formation. In terms of the formation potential per unit VOCs emission, ozone is sensitive to open biomass burning, transportation, and domestic solvent use, and SOA is sensitive to industry process, domestic solvent use, and domestic combustion. Biomass stoves, paint application in industrial protection and buildings, adhesives application are key individual sources to ozone and SOA formation, whether measured by total contribution or contribution per unit VOCs emission. The results imply that current VOCs control policies should be extended to cover most important industrial sources, and the control measures for biomass stoves should be tightened. Finally, discrepant VOCs control policies should be implemented in different regions based on their ozone/aerosol concentration levels and dominant emission sources for ozone and SOA formation potential.  相似文献   

11.
室内空气中挥发性有机物的污染及其控制   总被引:30,自引:0,他引:30  
陈清  余刚 《上海环境科学》2001,20(12):616-620
分析了室内空气中挥发性有机物(VOCs)的来源、特征、污染状况等,并阐述了VOCs对人体健康的危害。介绍了国内外的VOCs污染控制标准,以及源头控制、光催化氧化技术、吸附技术等主要的污染控制对策。据文献统计表明,室内空气中含有大量的VOCs,污染控制标准及源头控制、光催化氧化技术、吸附技术等主要的污染控制对策。据文献统计表明,室内空气中含有大量的VOCs,污染状况相当严重,对人体健康的危害亦十分明显,应引起重视。在污染控制策略上,应先从源头加以控制,同时保证室内环境有很好的通风能力,在此基础上积极开发和应用新的污染控制技术。  相似文献   

12.
我国工业VOCs减排控制与管理对策研究   总被引:5,自引:11,他引:5  
王海林  张国宁  聂磊  王宇飞  郝郑平 《环境科学》2011,32(12):3462-3468
对我国工业挥发性有机物(VOCs)排放进行了研究,其中包括工业VOCs的排放特征、控制现状与管理政策.我国工业VOCs具有排放强度大、波动范围宽、地域分布不平衡等特点,集中分布在京津地区、山东半岛、长三角和珠三角地区.现有的主流控制技术包括吸附回收、催化燃烧、蓄热燃烧、生物净化以及吸附浓缩/催化燃烧联用技术,污染控制的重点领域在石油化工、油气回收、造船与集装箱以及印刷、制药、皮革加工等行业.VOCs管理比较薄弱,相关的法律/法规/标准较少,监管尚不到位.研究认为VOCs治理应以重点区域、典型行业为对象,逐步推进,以实际削减量为目标,通过技术筛选、示范工程等途径,建立健全相关行业VOCs排放法规/标准,并辅助于相关的排放登记制度与分级收费制度,可有效减少VOCs的整体排放量.  相似文献   

13.
VOCs气体在活性炭上的二元吸附过程研究   总被引:1,自引:1,他引:0  
采用穿透曲线法研究了4种VOCs在活性炭上的的二元吸附过程。研究表明:对于甲苯-苯、甲苯-丙酮、甲苯-乙酸乙酯、苯-丙酮、丙酮-乙酸乙酯二元吸附体系,吸附过程存在置换作用,即随着高沸点组分在床层内吸附量的逐渐增加,相对挥发性大的低沸点组分重新汽化而脱附,出现高沸点组分置换低沸点组分的现象,表现为被置换组分的穿透曲线上出现峰值。之后随着高沸点组分吸附趋于饱和,置换作用停止,低沸点组分吸附也趋于平衡。但对于沸点相近的苯-乙酸乙酯二元体系,吸附过程没有明显的置换现象。吸附量的计算结果表明,有机物在二元体系中的吸附量较同等条件时的单组分吸附量均有不同程度的降低,其中被置换组分降低程度较大,但总吸附量可近似按照浓度为二元组分总浓度低沸点组分的平衡吸附量的近似法计算,平均误差为7.9%。  相似文献   

14.
根据滑动弧放电等离子体适于降解高浓度有机物废气的特性,结合活性炭吸附法,提出了吸附器的吸附浓缩和热脱附-等离子体氧化净化有机废气技术。实际运行结果表明:对于处理低浓度、大风量的有机废气,该技术与其他技术相比具有净化效率高、二次污染小和节省能耗等优点。  相似文献   

15.
目前,我国面临严重的挥发性有机物(VOCs)污染问题。吸附法是研究与应用最为广泛的VOCs治理技术。主要介绍了吸附净化VOCs原理和几种常见的VOCs吸附材料,包括活性炭、新型多孔炭材料、沸石分子筛、黏土基吸附剂、金属有机框架和介孔硅。详述了各吸附材料的VOCs吸附能力和优缺点,判断了其应用价值,并指出了为提升大规模工业化应用潜力,后续研发的VOCs吸附材料应满足高吸附量、高疏水性、高热稳定性和再生能力强4个特征。  相似文献   

16.
Sb(Ⅲ) is often detected in contaminated soil and groundwater. Hence, high-efficiency technology is needed. In this study, bimetallic organic frameworks were used for the first time to immobilize Sb(Ⅲ) from contaminated soil and groundwater. The materials were synthesized by the hydrothermal method. Both ends of the prepared material were hexagonal tip rods,and the length became shorter as the ratio of Fe/Mg decreased. The bimetallic organic framework with a Fe/Mg feeding ratio of 0.5 was the opt...  相似文献   

17.
污染场地土壤气被动采样技术研究进展   总被引:1,自引:1,他引:0       下载免费PDF全文
马杰 《环境科学研究》2020,33(2):494-502
在VOCs(挥发性有机物)污染场地调查中,土壤气采样的重要性日益受到重视.常规的土壤气采样主要依赖吸附管和采样罐等主动采样方法,但主动采样有很多缺点.作为一种新兴的采样技术,被动采样具有成本低、操作简单、更能代表长时间人体暴露、可用于低渗透性地层等优点,已经成为污染场地调查领域的研究热点.对被动采样的理论基础、采样器类型、吸附剂类型、采样误差的来源进行了介绍,对土壤气被动采样中存在的技术难题以及前沿研究方向进行了讨论,并对该技术在我国场地调查领域的应用前景进行了展望和建议.结果表明:在被动采样中准确控制采样器的采样速率(uptake rate)是保证其定量能力的关键,当控制采样速率低于土壤气中VOCs的补给速率时,可以实现良好的定量效果.影响采样速率的主要因素包括待测VOCs的性质、吸附剂种类、采样器结构以及各类环境因素,挥发性强的VOCs较难被捕集且容易发生逃逸.不同被动采样器用于不同种类VOCs采样时的采样速率可以相差6个数量级,从最低的0.005 5 mL/min到最高的125 mL/min.因此,建议在实际采样中应选用结构合理的采样器,控制采样速率不宜过大,以降低饥饿效应的产生;应选用与待测物匹配的吸附剂,对待测物兼具良好的保留能力和脱附能力;应加强环境因素(温度、湿度、土壤性质)对采样速率影响机制及场地校准方法的研究;应该结合研究和实践经验制定符合我国国情的土壤气被动采样技术指南.   相似文献   

18.
借助TOUGH3/TMVOC软件对华北地区某典型污染场地进行模型概化,模拟再现了挥发性有机化合物(VOCs)在层状低渗透性介质中的运移和分布特征;同时,设置了不同情景的多相抽提方案,分析了渗透率对多相抽提技术(MPE)去除效率的影响.结果表明,VOCs在该介质中主要以非水相液体(NAPL)相形式存在,且NAPL相饱和度...  相似文献   

19.
VOCs生物净化技术研究现状与发展趋势   总被引:1,自引:0,他引:1  
生物法处理挥发性有机化合物(VOCs)具有反应条件温和、运行费用低,二次污染小等优点。文章综述了生物过滤、生物滴滤、生物洗涤、膜生物反应器等4种净化工艺;总结了前人就废气性质、降解菌、填料结构与特性、pH与温度等因素对反应体系降解性能的影响;综述了研究废气生物降解过程和研究生物量积累与运行性能关系等的动力学模型。最后论述了该技术当前存在的问题和发展趋势。  相似文献   

20.
为了解南宁市冬季期间挥发性有机物(VOCs)污染特征及来源,采用在线连续监测系统于2020年12月9日~2021年2月22日在南宁市区对116种VOCs进行了在线连续观测.结果显示,观测期间VOCs体积分数为37.57x10-9,烷烃、烯烃、芳香烃、OVOCs及卤代烃体积分数占VOCs比例分别为44%、15%、8%、19%和11%.VOCs体积分数白天低,夜晚高;采用OH消耗速率(LOH)和臭氧生成潜势(OFP)估算了观测期间VOCs大气化学反应活性,结果表明醛酮类、芳香烃和烯烃是主要的活性物质;使用气溶胶生成系数法(FAC)估算了VOCs对二次有机气溶胶(SOA)的贡献,发现芳香烃对SOA生成贡献最大,占比为98%,其中苯、间/对二甲苯和甲苯为优势物种;正交矩阵因子(PMF)解析结果表明,冬季期间南宁市VOCs主要来源于:机动车尾气排放源(30.1%)>固定燃烧及生物质燃烧源(22.2%)>工业工艺排放源(16.8%),而OFP贡献较高的源分别为溶剂使用源(23.9%)、固定燃烧及生物质燃烧源(22%)、机动车尾气排放源(21.8%).因此,机动车尾气排放源和固定燃烧及生物质燃烧源应为南宁市冬季的优先管控源类,其次为工业工艺排放源、溶剂使用源.  相似文献   

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