两种改性高岭土减排超细颗粒物的对比分析

选用盐酸加锰酸钾改性和氢氧化钠改性两种典型的改性方法,期望利用盐酸和锰酸钾的强酸性和强氧化性、氢氧化钠的强碱性改变高岭土的物理化学特性,提高其捕获超细颗粒物的效率。选用典型煤种,将改性前、后的高岭土吸附剂混煤并送入高温沉降炉中燃烧,获得颗粒物的质量粒径分布。结果表明,酸改性能明显提高高岭土捕获PM_0.2(空气动力学直径小于0.2 μm)的效率,但碱改性效果相反。根据表征分析,酸改性明显削弱了Al-OH、Al-O-Si、Si-O和Si-O-Si四个官能团,促进了高岭土捕获碱金属的反应,提高了捕获PM_0.2的效率;而碱改性虽然削弱了Si-O和Si-O-Si两个官能团,但增强了Al-OH和Al-O-Si两个官能团,增强的官能团抑制了高岭土捕获碱金属的部分反应,导致高岭土捕获PM_0.2的效率降低。     

水热法制备质子化钛纳米管的影响因素及其应用研究进展

水热合成法制备质子化钛纳米管（TNTs）是一种操作简单、条件温和、适合规模化生产的方法,受到广泛关注,由此方法得到的钛纳米管具有开放的管道结构、比表面积大、稳定性高、离子交换等特点。本文简述了水热法制备TNTs的机理,分析了前体材料、水热反应条件、后处理方法等因素对水热法制备TNTs的影响规律,介绍了近年来TNTs作为载体、光催化剂、酸催化剂、吸附剂的应用研究现状。分析表明,通过调控水热条件及后处理方法可获得结构、性能各异的TNTs材料,并且利用离子交换、掺杂、有机表面修饰等多样化方法获得改性TNTs材料,进一步提升了TNTs材料在光催化、酸催化、吸附等方面的性能。最后指出,未来主要研究热点是提高水热法合成效率、优化化学改性策略,获得性能各异的TNTs材料。     

吸附烟气中NOx 的吸附剂研究进展

工业和交通部门燃烧化石燃料产生的NOx是大气中最普遍的有害气体。降低由化石燃料燃烧造成的NOx排放迫在眉睫。通过对比研究多孔碳材料吸附剂、沸石分子筛吸附剂、金属有机框架材料吸附剂与金属氧化物吸附剂的结构特点以及NO的吸附量与选择性、反应特性及吸附剂的吸附机理,提出了这几种吸附剂作为NOx吸附剂的可能性以及存在的不足,为研发可实现NOx脱除并回收利用的资源化吸附剂提供参考。     

吸附树脂及其在水与废水处理中的应用

主要论述了吸附树脂的分类、合成、性能及其在水处理中的应用,重点讨论了人工合成及天然高分子改性吸附树脂的合成、性能及其在微污染水源给水处理及废水处理中应用的研究进展.其由于在废物处理和资源回收方面的良好前景而受到青睐,并有逐渐取代活性炭成为新一代吸附剂的趋势,但对其工程化的应用尚需继续研究.最后展望了高分子吸附剂(吸附树脂)的研究及应用前景,提出了今后吸附树脂的研究发展方向.     

Chlorobenzene, chloroform, and carbon tetrachloride adsorption on undoped and metal-doped sol-gel substrates (SiO(2), Ag/SiO(2), Cu/SiO(2) and Fe/SiO(2))

Adsorption isotherms of chlorobenzene, chloroform and carbon tetrachloride vapors on undoped SiO(2), and metal-doped Ag/SiO(2), Cu/SiO(2) and Fe/SiO(2) substrates were measured in the temperature range of 398-593K. These substrates were prepared from a typical sol-gel technique in the presence of metal dopants that rendered an assortment of microporous-mesoporous solids. The relevant characteristic of these materials was the different porosities and micropore to mesopore volume ratios that were displayed; this was due to the effect that the cationic metal valence exerts on the size of the sol-gel globules that compose the porous solid. The texture of these SiO(2) materials was analyzed by X-ray diffraction (XRD), FTIR, and diverse adsorption methods. The pore-size distributions of the adsorbents confirmed the existence of mesopores and supermicropores, while ultramicropores were absent. The Freundlich adsorption model approximately fitted the chlorinated compounds adsorption data on the silica substrates by reason of a heterogeneous energy distribution of adsorption sites. The intensity of the interaction between these organic vapors and the surface of the SiO(2) samples was analyzed through evaluation of the isosteric heat of adsorption and standard adsorption energy; from these last results it was evident that the presence of metal species within the silica structure greatly affected the values of both the amounts adsorbed as well as of the isosteric heats of adsorption.     

钙基吸附剂固定床吸附烟气中Hg~0的试验研究

在小型模拟燃煤烟气Hg吸附和形态转化试验台上研究了几种钙基吸附剂对模拟烟气中Hg的脱除效果。结果表明:Ca(OH2)对单质汞的吸附主要是物理吸附;CaO对单质汞的吸附则是物理吸附和化学吸附共同作用的结果;SO2和HCl可以通过与钙基吸附剂发生反应提供活性位或者将Hg0氧化成Hg2+来促进对汞的吸附,HCl对汞的促进作用更强;加入高锰酸钾浸渍煅烧改性后,由于化学吸附的发生,钙基类物质的吸附能力有所提高。     

Theoretical evaluation of pillared clay adsorbents: Part I. The microporosity of Al- and Ti-pillared montmorillonite

Fillared clays have become a well known class of porous materials. Due to the versatile porosity they seem to be complementary to zeolites and can be very useful for adsorption and catalytic processes. Despite intensive research, real industrial applications are still lacking. Somehow, the porosity of these pillared clays is not what was expected. The present study reports theoretical calculations, based on simple geometrical models in combination with experimental data, in order to obtain a better insight in the PILC structure and its limiting factors. Parameters such as interpillar free distance and maximum micropore volume were calculated and compared to experimental or literature data. The final goal is to find out the potential of pillared clays as adsorbents to be used as substituents or complements for zeolites. This part reports calculations, in terms of microporosity, performed for two types of pillared clays having completely different porosity properties: Al- and Ti-PILC.Nomenclature Al-pilM aluminium pillared montmorillonite - c number of collapsed interlayer volumes in a stack - CEC cation exchange capacity (meq/g) - d _pp interpillar free distance (Å) - IFS interlayer free spacing (Å) - L length of a clay layer (Å) - MW molecular weight (g/mol) - N _av Avogadro constant (molecules/mol) - P pillar height (Å) - pil/g number of pillars in 1 g clay - (pil/g)_in number of pillars, in 1 g clay, intercalated between the layers - (pil/g)_out number of pillars, in 1 g clay, not intercalated - pl/g number of clay layers in 1 g clay - quasi cryst/g number of stacks or quasi crystals in 1 g clay - s number of layers in a stack or quasi crystal - SA^av layer surface area available for pillaring (m²/g) - SA_BET BET surface area (m²/g) - SA_max maximum surface area of the clay layers (m²/g) - SA^unav layer surface area not contributing to the micropore volume (m²/g) - SA/pillar available surface area for a pillar on a clay layer (Ų) - SA_1pl surface area of a single clay layer (Ų) - Ti-pi1M titanium pillared montmorillonite - V _micro calculated micropore volume (cc/g) - V _micro ^exp experimental micropore volume (cc/g) - V _micro ^ideal calculated micropore volume for an idealised situation (cc/g) - V _pil total volume of the pillars (cc/g) - V _pil (inside) total volume of the pillars between the layers (cc/g) - V _tot total pore volume atp/p ₀ = 0.98 (cc/g) - W width of a clay layer (Å) - W _pil width of a pillar (Å) - Wt%_pil weight percentage Al₂O₃ or TiO₂ present as pillars     

硝酸锂改性钛系离子筛的制备及其吸附性能

钛系锂离子筛具有较高的锂吸附容量和稳定性,对其制备工艺及性能进行改进研究具有重要意义。使用硝酸锂和碳酸锂混合物作为锂源,与二氧化钛在500℃下进行固相反应,生成层状钛酸锂;使用0.2 mol·L ^-1盐酸对其酸洗24 h,得到了锂离子筛吸附剂;采用X射线衍射、扫描电镜、粒度分析、N ₂吸附-脱附方法等,对其性能进行了表征;通过锂离子的吸附实验,确定了吸附和再生性能;探究了该新型吸附剂的锂离子吸附机理。结果表明：吸附过程是单分子层化学吸附;经过改性,离子筛颗粒更加细小,孔体积和比表面积更大,结构完整;在70 mg·L ^-1的Li ⁺溶液中,吸附量为25.01 mg·g ^-1,准二级吸附速率常数为0.2762 g·(mg·h) ^-1,吸附速率较之未改性提高了54.56%;该离子筛对浓度为11.6 mg·L ^-1的Li ⁺溶液,其锂去除率可以达到99.77%。     

苯并咪唑连接聚合物吸附剂和膜研究进展

强的链内、链间作用力和丰富的官能团赋予苯并咪唑连接聚合物优异的化学稳定性、热稳定性、高孔隙率、高比表面积、介电性以及良好的力学性能,因此被用作高效分离材料。本文讨论了苯并咪唑连接聚合物的种类及性能,综述了其在吸附剂和膜分离领域的应用,总结了研究现状,并对未来发展进行了展望。     

吸附材料的低温等离子体再生法研究进展

低温等离子体再生法作为一种吸附材料再生的新方法,具有巨大的探究空间和应用前景。本文将低温等离子体再生法与传统再生方法进行了对比,指出了各种方法的优劣;简述了等离子体的概念、低温等离子体的产生方式及该方法的作用机理,详细介绍了国内外对于该技术的研究进展,总结了该方法的特点,并提出了该方法亟待解决的问题。分析表明,该方法与传统的变压吸附、变温吸附等再生方法相比具有低温、快速、高效的优势,但目前该方法仍处于实验室研究阶段,许多理论问题和工程问题还有待解决。