工业源常见VOCs治理技术的研究进展

随着经济不断发展,工业生产会产生大量的挥发性有机化合物(VOCs),VOCs不经过有效处理排放到大气中,会产生严重的环境问题,影响人们的健康。本文综述了2010年以来工业源VOCs治理的几种常见方法(如燃烧法、低温等离子体法、光催化氧化法和生物法)的研究进展,阐述上述方法的优缺点、适用范围、去除效果和存在的问题,以期为工业源VOCs治理方法研究和应用提供有益参考。     

生物净化强化技术治理VOCs的研究进展

综述了利用表面活性剂、真菌微生物和优化生物反应器的生物净化强化技术,该技术在治理疏水性、难降解VOCs中具有独特优势,重点阐述了生物净化强化技术在治理大气VOCs中的研究进展,指出表面活性剂因其具有良好的增溶性、低能耗、无二次污染等特性,在强化生物技术方面成为目前研究的重点。提出了生物净化强化技术面临的主要问题及未来的研究方向,将该技术逐渐推向工业化,并与其他治理技术根据实际情况进行联合使用,以产生最大的经济、环境效益。     

沸石分子筛用于VOCs吸附脱除的应用研究进展

挥发性有机化合物（volatile organic compounds,VOCs）作为空气中有机污染物的主要成分,对环境与人类健康造成了严重的危害。吸附法可有效富集低浓度VOCs气体,成本低、易操作,是末端治理去除VOCs的主要技术。沸石分子筛具有高度有序、孔径可调的微孔孔道,可实现VOCs分子的选择性吸附,且热稳定性极佳,易于脱附再生,是一种优良的VOCs气体吸附剂。本文分别从沸石分子筛的结构性质、复合型分子筛吸附剂以及整体式分子筛吸附剂三方面详细介绍了沸石分子筛用于VOCs吸附脱除的研究进展。结果表明,变换骨架拓扑结构以及补偿阳离子类型,可实现对VOCs分子进行选择性吸附;提高结构疏水性可有效降低高湿度条件下水分子对VOCs的竞争吸附,增强分子筛吸附剂的环境适应性;通过孔道多级化或与其他介/大孔构建复合型吸附剂,可提高分子筛吸附剂的比表面积和孔容,增大对VOCs的吸附容量;沸石分子筛可构建为整体式吸附剂,相较于颗粒型吸附剂,其机械强度更高,应用性更强。文章还指出,作为整体式分子筛吸附剂的典型代表,分子筛转轮吸附技术在高通量、高压降等吸附工况条件下均表现出极佳的VOCs吸附脱除效率,已广泛应用于工业排放VOCs的有效治理。     

分子筛材料在VOCs吸附中的研究进展

挥发性有机化合物（VOCs）的大量排放对我国大气环境已造成严重污染。本文综述了针对工业VOCs排放浓度低、风量大、含水等特点,分子筛作为较成熟的吸附材料在VOCs吸附处理中的应用。影响分子筛吸附VOCs的因素有孔径结构、表面性质、疏水性等。研究表明,与吸附质动力学尺寸相匹配的孔径和具有多级孔的分子筛吸附性能优良,引入适宜补偿阳离子也可加强吸附。文中指出：提高硅铝比或硅烷化改性来提高分子筛疏水性以及免除模板剂使用,降低成本,减小污染成为当下发展主流;在制备方法上打破传统水热合成法,使用固相法、微波辅助、晶种导入来降低能耗,实现绿色合成已成为新兴话题;研发多功能整体式材料以及吸附法和多种方法相结合来处理VOCs已成为未来发展趋势。     

工业废气中VOCs废气的分析与治理

随着我国工业化的迅速发展,工业废气污染成为了我国在环境问题上的一个较为严重的问题,很多企业在生产的过程中会产生污染,工业废气的种类繁多,大致可分类为有机废气和无机废气,工业产生的废气如无设施处理,则会对周围环境造成污染,本文将介绍工业废气中VOCs废气的治理。     

亲水/疏水性在宝石学中的应用探讨

亲水/疏水性在宝石领域中有一定的应用,但相关研究极少.本文总结了其在宝石学中的应用案例,分别通过表面自由能和分子结构两个方面直接和间接的分析固体表面润湿性的主要机理.从分子结构角度对钻石、合成立方氧化锆、蓝宝石进行分析,得出合成立方氧化锆和蓝宝石是极性分子所以表现为亲水性,而钻石是非极性分子所以表现为疏水性的结论.并对亲水/疏水性在宝石学中的应用提出展望.     

浅谈涂装车间VOCs废气处理工艺

通过简述挥发性有机物的危害,介绍了几种典型的涂装车间VOCs废气处理工艺。首先通过分析喷粉车间VOCs废气中颗粒物的特性,介绍过滤处理方式的选择以及几种常用过滤材料的特性,其次是讲述了活性炭吸附催化处理的工艺过程,然后简单描述了沸石转轮吸附脱附后蓄热氧化燃烧的工艺过程,并展示了我公司设计的涂装生产线现场运行的一个活性炭吸附催化工艺案例的PLC控制界面和两个沸石转轮吸附脱附+RTO工艺案例的PLC控制界面。     

Synthesis and characterisation of organo-silica hydrophobic clay heterostructures for volatile organic compounds removal

Mesostructured materials belonging to a new class of solid acids known as porous clay heterostructures (PCHs) have been prepared by chemical modification of a natural clay, by using a cationic surfactant, a neutral amine, and an equimolar mixture of bis(triethoxysilyl)benzene (BTEB) and tetraethyl orthosilicate (TEOS). The effect of different polymerisation times of the silica sources and of the hydrocarbon chain length of the neutral amine was studied. The materials retained their layered structure after the formation of stable pillars by the polymerisation of hydrolysed TEOS and BTEB. All materials were characterised by low temperature nitrogen adsorption isotherms, ¹³C CP MAS, ²⁹Si MAS and CP MAS NMR spectroscopy, thermal analyses and infrared spectroscopy. The specific surface BET areas of the materials were in the range 550–800 m² g⁻¹ and the corresponding microporous volume were near 0.2–0.3 cm³ g⁻¹. The reduction of the reaction time from 12 to 4 h avoids the extra-gallery polymerisation, contributing for a larger specific surface area. The increase of two carbon atoms in the neutral amine chain does not show much effect on the available surface area.

These materials were very effective as adsorbents of volatile organic compounds (VOCs), according to tests on methanol, methyl ethyl ketone, toluene and trichloroethylene. The water adsorption isotherms proved the hydrophobicity of the materials, suggesting their capabilities for VOC adsorption in the presence of water.     

Liquid and vapor phase adsorption of chlorinated volatile organic compounds on hydrophobic molecular sieves

This work focused on the potential application of various hydrophobic molecular sieves for the sorption of four model chlorinated volatile organic compounds (CVOCs, i.e., chloroform, trichloroethylene, tetrachloroethylene, and carbon tetrachloride) from dilute liquid water streams.

Results obtained thus far have shown that silicalite-1 has a high affinity for these CVOCs, higher in fact than Centaur^® activated carbon, used as a benchmark in this study. Loading results for trichloroethylene from both liquid and vapor phase indicated that the liquid phase did not penetrate the pores of silicalite-1, while the solution did penetrate the pores of Centaur^® and a dealuminated NaY used for comparison.

Finally, three definitions from the literature for the “hydrophobicity” of molecular sieves were considered. An alternative definition for hydrophobicity is introduced here, which is easy to determine and is based on water retention.     

挥发性有机化合物及其分析方法的研究现状

介绍了挥发性有机化合物(VOC)的定义、来源以及与非甲烷总烃的定量关系;详细介绍了VOC测定方法及国内外相关标准;指出在未来发展中,在线VOC监测和便携式VOC快速分析将占据主导地位.     

生物表面活性剂对疏水性有机物的增溶特性

在提高疏水性有机污染物的生物可利用性方面,生物表面活性剂的增溶效果是关键.通过实验测试了单一鼠李糖脂生物表面活性剂、复配表面活性剂(鼠李糖脂-非离子表面活性剂)对疏水性有机污染物增溶性能的影响,在此基础上,进一步考察了无机盐对复配表面活性剂增溶效果的影响.结果表明:鼠李糖脂质量浓度在临界胶束质量浓度之上时,长链烷烃和多...     

挥发性有机化合物催化氧化技术

基于环境友好,对使用催化氧化法去除挥发性有机化合物(VOCs)的原理、特点以及催化剂、工艺流程等研究进行综述。挥发性有机化合物完全催化氧化机理分为:Mars-van Krevelen(MVK)模型、Langmuir-Hinshelwood(L-H)模型和Eley-Rideal(E-R)模型。复合金属氧化物催化剂是研究的热点,去除VOCs的核心是使反应温度降低,即具有低温和高活性的催化剂。延长催化剂寿命、提高去除效率也可以带来良好的节能效果和降低投资成本。对于低浓度和大体积VOCs排放,可通过吸附+催化混合法先进技术实现去除,且成功应用于实践。     

挥发性有机化合物的净化处理技术

有机废气中大多含有低浓度的苯、甲苯、苯乙烯、多环芳烃等挥发性有机化合物（VOCs）。治理VOCs污染是大气污染治理的重要组成部分。叙述了吸收法、吸附法、生物法和低温等离子体4种废气净化技术的原理和国内外研究进展情况,并对其发展前景和研究方向进行了探讨。最后认为有机废气的联合协同处理方法是今后的一个重要研究方向。     

Modeling of the volatile organic compounds biodegradation process in the trickle-bed bioreactor—Analysis of the model parametric sensitivity

Mathematical models of the process of air purification from hydrophobic (styrene) or hydrophilic (vinyl acetate, VA) compounds carried out in a co-current trickle-bed bioreactor were presented. These models were marked as TSM (two-substrate model), OSM (one-substrate model) and AOSM (approximate one-substrate model). The experimental database was exploited to validate the TSM which approximated very well the experimental data; the mean percentage error of RE prediction did not exceed 3% for styrene and 4.1% for VA. For the tested systems, TSM was only sensitive to the changes in biomass dry density X_b and effective diffusion coefficient D_j,ef values. The percentage relative error of the state variable computed using OSM/AOSM in relation to the value obtained from TSM was the quantitative criterion for comparison of the results obtained using different mathematical models of the process. It was shown that the simplified models describe the process investigated with satisfactory accuracy.