微波辐射强化再生技术:一种环保节能型吸附剂再生技术

微波辐射强化脱附作为一种环保节能的吸附剂再生技术受到了越来越多的关注。文章介绍了微波辐射强化脱附技术的原理、综述了国内外微波再生吸附剂的研究进展、总结了实现微波脱附技术大规模工业化应用存在的关健问题,并展望了微波脱附再生技术未来的发展方向和趋势。只有尽快开发微波适用型吸附材料和设计大型的微波加热器件,才能更好地将微波辐射强化脱附技术工业化。     

CS_2在超高交联树脂上的吸附脱附特性研究

研究超高交联树脂对二硫化碳的吸附与脱附性能。以静态法测定了二硫化碳在吸附树脂上的吸附等温线,采用Dubinin-Radushkevich(D-R)方程和Langmiur方程对吸附平衡数据进行拟合,显示D-R方程拟合效果更好,R2均大于0.99;研究了不同温度(303,313,323 K)下二硫化碳的穿透曲线,结果表明,温度对于树脂吸附二硫化碳具有显著影响,323 K时吸附穿透时间比303 K时减少44.08%;热脱附实验显示,当温度上升到363 K时,吸附树脂能完全再生,且随着温度的升高,其再生速率加快。     

炼油废水活性炭纤维快速脱附技术研究

对吸附剂吸附平衡状态的分析表明活性炭纤维具有特殊的孔结构和表面性质,这种性质决定可对其进行快速脱附再生。以炼油污水为吸附对象,进行了活性炭纤维的过热蒸汽再生、电流加热再生、电加热再生、微波再生等技术研究,结果表明：电流加热、电加热、微波方法均能达到快速脱附再生的目的,并具有良好的应用前景。     

D001树脂吸附铁离子后的脱附研究

通过脱附试验,选用HCl对D001树脂进行再生,考察了脱附剂浓度、脱附时间、脱附温度对树脂脱附效果的影响;通过吸附试验,考察了D001树脂在不同HCl浓度下对铁离子的吸附.试验结果表明,25℃时,质量分数为20%的HCl在对吸附铁离子的D001树脂(吸附量为11.729mg/g)进行脱附,60min时可达到较大的脱附量...     

4种分子筛对VOCs静态吸附与脱附性能研究

采用干燥器-静态吸附法测定3A、4A、5A、10X四种分子筛对甲醇、苯、正己烷等VOCs的吸附性能。结果表明,10X分子筛在吸附量上明显高于其它3种分子筛,对苯、甲醇、正己烷的吸附量分别达到了96,88,75 mg/g。微波脱附和热脱附的脱附能力差别甚微,微波脱附时间短。分子筛再生率>95%,与之前吸附量相当,未对分子筛的内部结构产生影响。     

4种分子筛对VOCs静态吸附与脱附性能研究

采用干燥器-静态吸附法测定3A、4A、5A、10X四种分子筛对甲醇、苯、正己烷等VOCs的吸附性能。结果表明,10X分子筛在吸附量上明显高于其它3种分子筛,对苯、甲醇、正己烷的吸附量分别达到了96,88,75 mg/g。微波脱附和热脱附的脱附能力差别甚微,微波脱附时间短。分子筛再生率>95%,与之前吸附量相当,未对分子筛的内部结构产生影响。     

翅片同心管吸附器解吸过程传热性能实验研究

为了研究翅片同心管吸附器在加热解吸过程中的传热性能,采用水浴式加热方法对30、40、50 cm三种高度不同的翅片同心管吸附器进行了实验研究。研究结果表明:在加热解吸的过程中,吸附质的脱附热随着吸附剂温度的升高而增大;在相同吸附剂温度下,冷凝管的冷凝温度越低,吸附质的脱附热越大;翅片同心管内吸附剂和吸附质的显热随吸附剂温度的升高而增大,且在相同温度下,吸附剂的显热远大于吸附质的显热;翅片同心管内传质通道的温度与吸附管中段的吸附剂温度最为接近,两者的温度相差0.1~1.5℃;与30、50 cm翅片同心管吸附器相比,40 cm翅片同心管吸附器传质通道内温度的变异系数相对比较稳定。     

复合功能树脂NXD-2对水中邻苯二甲酸单丁酯的去除性能

酞酸单酯是水体环境中一类新型的环境激素污染物。以含叔胺基的复合功能树脂NXD-2为吸附剂,以邻苯二甲酸单丁酯(MBP)为目标污染物,通过吸附等温线、热力学、动力学和柱吸附脱附实验,考察了NXD-2对MBP的吸附性能。研究结果表明,NXD-2对MBP的吸附以氢键作用为主,在288~313 K的温度范围内,平衡吸附量随温度的升高而升高;升高温度有利于加快NXD-2对MBP的去除速率。柱吸附脱附研究表明,在进水浓度为300mg·L-1的高浓度条件下,吸附出水的前100 BV中,溶液中MBP的浓度低于检测限(10-g·L-1),说明NXD-2对MBP具有较高的处理深度;同时NXD-2具有较好的脱附效果,脱附体积达到20 BV时,脱附率接近100%。因此,复合功能树脂NXD-2作为一种吸附剂,在水体中酞酸单酯的去除方面具有良好的应用前景。     

低挥发性有机物脱附活化能估算模型

提出了一种新的低挥发性有机物程序升温脱附(TPD)活化能估算模型.与经典 TPD 模型相比,所提出的新的 TPD理论模型不仅考虑了脱附过程中存在的吸附质分子再吸附现象的影响,而且还考虑了脱附分子在吸附剂孔内扩散的影响.通过 TPD 实验,运用所建立的活化能估算模型,技术测定了二苯并呋喃在 Norit RB1、Monolith 和 Chemviron三种活性炭上的脱附活化能.结果表明经典TPD 模型所估算出来的二苯并呋喃的活化能要比非线性 TPD 模型估算结果偏高约8.2%～9.6%,这表明脱附过程中存在吸附质分子再吸附现象和内扩散过程对脱附活化能有一定的影响.     

微波加热改性再生骨料试验研究

包裹在再生骨料表面的砂浆被认为是导致骨料性能劣化的主要原因.微波加热改性法利用砂浆和天然骨料的电磁性能和吸水率的差异,在砂浆内部特别是砂浆与骨料界面处产生高的温度应力以达到部分剔除粘附砂浆和破碎砂浆团块的目的.通过试验研究了影响砂浆脱附率的主要因素及其影响规律,对比了不同改性方式对再生骨料的物理力学性能的影响.结果 表明,微波功率、单次加热持续时间、骨料干湿状态和循环次数是影响砂浆脱附率的主要因素,浸水冷却有利于提高砂浆脱附率,但提高幅度不大.微波加热—冷却循环5次砂浆脱附率可达45.1％,结合机械研磨砂浆脱附率可进一步提高30.8％.微波加热改性可显著提高再生骨料物理力学性能.     

聚乙烯吡啶树脂吸附乳酸的研究

本文系统地研究了乳酸在聚乙烯毗啶(PVP)树脂上的吸附和解吸特性。测定了乳酸在PVP树脂上的吸附动力学曲线和吸附等温线,研究了温度、无机盐浓度及液相pH值等因素对乳酸在PVP树脂上的吸附特性的影响。用动态实验比较了不同有机溶剂的洗脱性能。选择甲醇作解吸剂,考察了乳酸进液浓度、流速、床层的初始状态等因素对乳酸在PVP树脂柱中的动态吸附及解吸特性的影响,并对动态吸附过程进行了数学模拟。     

大孔吸附树脂纯化芹菜黄酮的研究

研究6种大孔吸附树脂对芹菜黄酮类物质的吸附和解吸性能,筛选出吸附率较高的XAD-16树脂,并对XAD-16树脂静态吸附和动态吸附解吸工艺做了研究。优化出XAD-16树脂纯化芹菜黄酮的最佳工艺参数为：室温下吸附;上样流速4 BV/h,在上样浓度0.55 mg/mL下,上样体积为15倍柱床体积;洗脱溶剂采用体积分数50%的乙醇,洗脱流速为6 BV/h,洗脱液量为4倍柱床体积。     

微波辐照下载乙醇活性炭的解吸研究

用颗粒活性炭吸附水中低浓度的乙醇,饱和后在氮气氛围中用微波辐照解吸,以实现乙醇的回收和活性炭的再生。研究了吸附过程及解吸过程的影响因素及规律,探索了将微波作为载乙醇活性炭解吸热源的可行性,并进行了工艺条件优化。研究测定了常温下颗粒活性炭对水中低浓度乙醇的吸附等温线,发现可用Freundlich吸附模型较好地拟合。设计了载乙醇活性炭微波解吸的试验流程,对反应器的设计、微波场中的温度测量进行了探讨。     

Heat Transfer during Microwave-Assisted Desorption of Water Vapor from Zeolite Packed Bed

This study attempted to quantify the effect of microwave-assisted desorption of water vapor from a zeolite packed bed. Specifically, an experiment was carried out comparing water vapor desorption using hot air and microwave heating. In the experiment, the temperature in the zeolite packed bed and humidity at the inlet and outlet of the adsorption column were measured.Then, the heat transfer behavior was quantified by calculating the heat balance of a zeolite packed bed, and the effect of microwave irradiation was examined. The results showed that microwave heating is effective for desorption at the beginning.     

新型微波适应型复合活性炭的研制及其微波再生性能

微波再生技术被广泛认为是一种高效、节能的绿色再生技术。本文通过引入高热导率物质--膨胀石墨制备出新型微波适应型复合活性炭,解决目前活性炭在微波脱附过程中存在的温度梯度问题,同时开发VOCs活性炭吸附-微波再生技术。结果表明,制得的复合活性炭具有与普通商业活性炭相当的吸附性能,且其热导率提高6倍。同时,其甲苯脱附活化能为18.08 kJ·mol^-1,低于其在商业活性炭上的微波脱附活化能（24.84 kJ·mol^-1）25%以上;相同微波功率下,其脱附床层温度低于实验室制备的普通活性炭10～30℃。所制备的高热导率复合活性炭不仅具有良好的吸附性能,而且具有很好的微波适应性。     

Sulfamethoxazole Removal from Synthetic Solutions by Ion Exchange using a Strong Anionic Resin in Fixed Bed

Numerous antibiotics like sulfonamides have been found in effluents from drug manufacturers due to the fact that these pollutants cannot be removed completely in STPs. Removal of pharmaceuticals by adsorption and ion exchange comprise some of the most promising techniques due to their low cost, easy regeneration, and selective removal of pollutants. This article studies the removal of sulfamethoxazole (SMX), a common antibiotic that prevents the formation of dihydrofolic acid and which is the most frequently detected as sulfonamide in municipal sewage. The SMX retention capacity of an anionic ion exchange resin, Lewatit MP-500 (Lanxess Chemical), was initially determined. Equilibrium and kinetics were studied and equilibrium constants and diffusivity values were obtained using different models. Load and elution breakthrough curves were plotted to evaluate ion exchange operation in a fixed bed column. In the elution step, 100% SMX was recovered in all cycles and could be concentrated up to nine times, thus facilitating the treatment of this compound. Load and elution breakthrough curves were simulated using a fixed bed model in which axial dispersion was considered the parameter model fit. A good correlation between experimental results and the numerical solution of the fixed bed model demonstrates the validity of the model.     

Sulfamethazine Retention from Water Solutions by Ion Exchange with a Strong Anionic Resin in Fixed Bed

Veterinary antibiotics such as sulfonamides were detected in the environment from animal excreta in soils, contaminating soil surface and then groundwaters by percolation. The contaminated waters can enter in this way into drinking water treatment plants (DWTPs). On the other hand, direct wastewaters from humans or animals or pharmaceutical industries disposals are discharged in wastewater treatment plants (WWTPs). These water and wastewater treatment plants are not designed to remove highly polar micropollutants like antibiotics. Removal of pharmaceuticals by adsorption and ion exchange constitutes a promising technique for its low cost, easy regeneration, and selective removal of pollutants. This work studies the removal of sulfamethazine (SMZ). The SMZ retention capacity of an anionic ion exchange resin, Lewatit MP500, was determined. Equilibrium and kinetics were studied and equilibrium constants and diffusivity values were obtained using different models. Load and elution breakthrough curves were plotted to evaluate ion exchange operation in a fixed bed column. In the elution step, 100% SMZ was recovered in all cycles and could be concentrated up to twelve times, thus facilitating its final treatment or removal. Load and elution breakthrough curves were simulated using a fixed bed model in which axial dispersion was considered the parameter model fit.     

Diesel Desulfurization Using Reactive Adsorption on Metal Impregnated Functionalized Polymer

Organosulfur compounds were removed from commercial diesel by reactive adsorption on metal impregnated functionalized polymers at ambient temperature and pressure. The equilibrium adsorption capacities of Ag⁺ and Cu⁺ impregnated resins for dibenzothiophene (DBT) are 13 mg/gm and 9.6 mg/gm. Adsorption and desorption cycle studies in a column packed with Ag⁺ and Cu⁺ loaded BSR resin showed intraparticle resistance affecting uptake of the sulfur compounds. Only 40% of the adsorbed organo-sulfur compounds was recovered by solvent regeneration using toluene, but complete regeneration of the bed was possible by simultaneous microwave heating. Density functional theory (DFT) calculations show stronger interaction between organosulfur compounds and Cu(I) on the polymer resins. The interaction energy increases with the number of substituents around ‘S’ in the structure, giving stronger interaction of the metal ions with dialkyl-substituted dibenzothiophene than monosubstituted and unsubstituted thiophene.     

大孔树脂吸附分离酶解法苦楝素提取液的研究

研究了大孔树脂吸附分离酶解法苦楝素提取液的工艺条件及参数,LS-100型大孔吸附树脂明显优于AB-8型和NAK-Ⅱ型,其吸附分离苦楝素的吸附优化条件为:溶液pH值7.0,吸附温度45℃,平衡吸附时间4 h;解吸优化条件为:解吸剂为80%乙醇-水溶液,pH值5.0,解吸操作温度35℃,时间2.5 h。在此优化条件下,苦楝素的饱和吸附量可达201.6 mg/g,解吸率达88.9%。     

Modeling the Regeneration of a Polymeric Resin Column Saturated with Ethanol by Air Purge and External Heating

In this work, the regeneration of a polymeric resin column saturated with ethanol with air purge and external heating has been studied. A theoretical model is proposed for describing the mass and heat transfers in the system, and it has been validated with experimental data. This model can be used for simulating the regeneration step in a concentration-thermal swing adsorption process for fuel-grade ethanol production. The model has been used to analyze the process dynamic behavior, and to compare the performance of the regeneration step using external heating and hot air purge.