乙醇的活性炭吸附及微波解吸

微波辐照再生活性炭是一种很有应用前景的方法。本文测定了微波辐射条件下新炭碘值的变化,研究了吸附了乙醇的活性炭的微波再生条件。通过正交试验,探讨了活性炭再生率与微波功率、载气线速、微波辐照时间、活性炭的吸附量等因素的关系。     

微波再生技术在废水处理中的应用

微波技术作为一种新型物化处理手段已广泛应用于环境领域,微波处理溶液中的污染物有两种方式,一种是直接用微波辐射含有污染物的溶液,采用微波场助化学反应的方法加速污染物的降解;另一种是先将污染物吸附到活性炭或其它吸附剂上,然后置于微波场中辐射,使污染物降解,也即微波再生技术在水处理中的应用。探讨了物质在微波辐射中发生的变化,再生的机理,并对目前在废水处理领域中,微波再生技术的应用,特别是微波再生活性炭技术的应用进行了全面的总结和概括。     

Electrochemical regeneration of activated carbon loaded with p-nitrophenol in a fluidized electrochemical reactor

This paper described a novel electrochemical process for the regeneration of activated carbon (AC) loaded with p-nitrophenol (PNP), aiming to reduce regeneration time and improve cost-effectiveness of the process by adoption of a novel non-active anode of modified lead dioxide and operation of AC in a fluidized mode. The regeneration parameters such as current density, liquid flow rate, NaCl concentration, pH of the solution and regeneration time were systematically investigated. Under the optimum conditions, the regeneration efficiency of AC could reach 90% in 1.5 h, and no significant declination was observed after five-times continuous adsorption-regeneration cycles, confirming the reuse feasibility of the regenerated AC. The adsorption of organic pollutants was confirmed occurring in the micropore of AC, and AC regeneration was mainly due to the decomposition of organics by the attack of active species such as hydroxyl radical that were generated by electrochemical oxidation. The time-space production for AC regeneration has been greatly improved in the present modified process, indicating this regeneration process is much more potentially cost-effective for application.     

膨润土吸附处理污染物的再生研究进展

膨润土对重金属离子等污染物表现出良好的吸附性能,但吸附饱和后的膨润土成为危险固废,如何处理成为棘手问题,研究其再生循环利用具有较大的经济价值,为其高效利用提供了有力借鉴和参考.对近年来国内外关于膨润土吸附污染物后再生研究进行总结分析:再生方法处于探索阶段,吸附剂再生机理研究较少,解吸下的污染物回收资源化研究鲜有报道,膨润土吸附污染物后再生仍需进行深入系统的研究探索.     

沸石材料的改性及其对水体污染物的吸附性能

吸附法以其选择性强、操作简易、二次污染少等优势逐步成为污水处理的重要方法。天然沸石材料具有孔腔结构丰富、吸附成本低廉以及吸附性能高等优势,但存在选择吸附性差、与水相分离困难、再生成本偏高等问题。通过改性,可以为沸石吸附剂对阴离子污染物的吸附提供更多吸附活性位点。本文基于沸石材料改性制备的国内外最新研究进展,总结了不同改性材料制备复合吸附材料的研究工作,重点介绍了沸石材料改性方法及其应用,进一步回顾了改性沸石材料对水中污染物的吸附性能和影响因素。通过改性提高沸石材料的选择吸附性能及吸附后的绿色再生将是推动沸石吸附材料规模化应用发展的核心。     

Catalytic dry oxidation of aniline,benzene, and pyridine adsorbed on a CuO doped activated carbon

Adsorption of aniline, benzene and pyridine from water on a copper oxide doped activated carbon (CuO/AC) at 30 °C and oxidation behavior of the adsorbed pollutants over CuO/AC in a temperature range up to 500 °C are investigated in TG and tubular-reactor/MS systems. Results show that the AC has little activity towards oxidation of the pollutants and CuO is the active oxidation site. Oxidation of aniline occurs at 231–349 °C and yields mainly CO₂, H₂O and N₂. Oxidation of pyridine occurs at a narrower temperature range, 255–309 °C, after a significant amount of desorption starting at 150 °C. Benzene desorbs at temperatures as low as 105 °C and shows no sign of oxidation. The result suggests that adsorption-catalytic dry oxidation is suitable only for the strongly adsorbed pollutants. Oxidation temperatures of CuO/AC for organic pollutants are higher than 200 °C and pollutants desorbing easily at temperatures below 200 °C cannot be treated by the method. This work was presented at the 7 ^th China-Korea Workshop on Clean Energy Technology held at Taiyuan, Shanxi, China, June 26–28, 2008.     

Regeneration of phenol‐saturated activated carbon in an electrochemical reactor

The regeneration of phenol‐saturated activated carbon in an electrochemical reactor was investigated in order to develop a novel regeneration method of activated carbon. The regeneration of spent activated carbon saturated with phenol was conducted in a stirred electrochemical reactor under different operating conditions. The influences of operating parameters, such as regeneration current intensity and time, on regeneration efficiency were systematically investigated. The regeneration efficiency can reach over 80% under continuous stirring in the reactor, and it only decreases by less than 5% after four regeneration cycles. Electrochemical regeneration in the stirred electrochemical reactor is shown to be an effective method for the regeneration of phenol‐saturated activated carbon with a much higher regeneration efficiency compared with a process using NaOH solution. © 2002 Society of Chemical Industry     

用于环境净化的TiO2/AC复合材料的制备及其改性研究进展

二氧化钛（TiO₂）在光照下可以产生具有强氧化性能的活性基团,活性炭（AC）具有良好的吸附性能。将TiO₂负载在AC上制备的TiO₂/AC复合材料可以有效去除大部分难降解的有机污染物,因此在环境净化领域具有良好的应用前景。本文综述了TiO₂/AC复合材料的研究现状,介绍了目前TiO₂/AC复合材料的三种主要制备工艺：溶胶-凝胶法、溶剂热法和微波合成法。其中溶胶-凝胶法所制备的材料稳定性好、溶剂热法制备条件温和、微波合成法制备周期短。针对TiO₂/AC复合材料可见光吸收率低和量子利用率低等问题,介绍了离子掺杂、半导体复合、贵金属沉积等现有的TiO₂/AC复合材料改性方法。之后,概述了所制备的TiO₂/AC复合材料在去除难降解有机污染物（染料废水、药物类、酚类、挥发性有机物）中的应用。最后展望了TiO₂/AC复合材料在改性研究与实际应用过程中存在的挑战性问题及可行的解决方法,为TiO₂/AC复合材料深入研究和大规模工业生产应用提供参考。     

Bioregeneration of spent activated carbon: Review of key factors and recent mathematical models of kinetics

The disposal of spent activated carbon (AC) will inevitably create secondary pollution.In overcoming this problem,the spent AC can be regenerated by means of biological approach.Bioregeneration is the phenomenon in which through the action of microorganisms,the adsorbed pollutants on the surface of the AC will be biodegraded and this enables further adsorption of pollutants to occur with time elapse.This review provides the challenges and perspectives for effective bioregeneration to occur in biological activated carbon (BAC) column.Owing to very few reported works on the bioregeneration rate in BAC column,emphasis is put forward on the recently developed models of bioregeneration kinetic in batch system.All in all,providing potential solutions in increasing the lifespan of AC and the enhancement of bioregeneration rate will definitely overcome the bottlenecks in spent AC bioregeneration.     

活性炭再生新方法的研究

本文对被阳离子艳蓝染料溶液吸附饱和的活性炭进行了再生试验研究。根据复极性粒子群电极理论,提出了新的活性炭再生方法。此法再生效率高,能耗低,炭损和再生成衣低,操作简单,再生后的活性炭可反复使用。此法特别适用于吸附质是易吸附又易氧化还原的活性炭的再生。     

Optimization of activated carbon‐based decontamination of fish oil by response surface methodology

The effect of activated carbon (AC) adsorption on the reduction of persistent organic pollutants (POP) in fish oil was studied based on response surface methodology at a 5‐g/kg AC inclusion level. Pretreatment of the oil by alkali refining and bleaching increased the POP levels. The tested process variables (contact time and temperature) affected the AC adsorption rate and significant first‐ and second‐order response models could be established. Polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/F) showed a very rapid adsorption behavior and the concentration and toxic equivalent (TEQ) level could be reduced by 99%. Adsorption of dioxin‐like polychlorinated biphenyls (DL‐PCB) was less effective and depended on ortho substitution, i.e. non‐ortho PCB were adsorbed more effectively than mono‐ortho PCB with a maximum of 87 and 21% reduction, respectively, corresponding to a DL‐PCB‐TEQ reduction of 73%. A common optimum for both PCDD/F and DL‐PCB adsorption could not be identified. AC treatment had no effect on the level of polybrominated diphenyl ether flame retardants. The differences in adsorption patterns may be explained based on molecular conformation. No change in oil quality could be observed based on oxidation parameters. Compliance with present PCDD/F and DL‐PCB legislation levels in fish oil can be achieved based on AC adsorption.     

Optimal multi‐period operational planning for steam power system in petrochemical enterprise with consideration of environmental costs in China

Steam power system (SPS) is a major source of both energy consumption and pollutants. In order to reduce the operational costs for petrochemical industry, the SPS should be operated under an optimal scheme. A SPS model is proposed to take into account the depreciation of equipments, changeover costs, and environmental costs. By applying an improved particle swarm optimisation (PSO) algorithm, the optimal operation scheme has been obtained. One example has been investigated to compare the different units and fuel selection in SPS and also the operation periods of SPS taking in account the power import/export policy and environmental cost.     

A superstructure‐based optimal synthesis of PSA cycles for post‐combustion CO2 capture

Recent developments have shown pressure/vacuum swing adsorption (PSA/VSA) to be a promising option to effectively capture CO₂ from flue gas streams. In most commercial PSA cycles, the weakly adsorbed component in the mixture is the desired product, and enriching the strongly adsorbed CO₂ is not a concern. On the other hand, it is necessary to concentrate CO₂ to high purity to reduce CO₂ sequestration costs and minimize safety and environmental risks. Thus, it is necessary to develop PSA processes specifically targeted to obtain pure strongly adsorbed component. A multitude of PSA/VSA cycles have been developed in the literature for CO₂ capture from feedstocks low in CO₂ concentration. However, no systematic methodology has been suggested to develop, evaluate, and optimize PSA cycles for high purity CO₂ capture. This study presents a systematic optimization‐based formulation to synthesize novel PSA cycles for a given application. In particular, a novel PSA superstructure is presented to design optimal PSA cycle configurations and evaluate CO₂ capture strategies. The superstructure is rich enough to predict a number of different PSA operating steps. The bed connections in the superstructure are governed by time‐dependent control variables, which can be varied to realize most PSA operating steps. An optimal sequence of operating steps is achieved through the formulation of an optimal control problem with the partial differential and algebraic equations of the PSA system and the cyclic steady state condition. Large‐scale optimization capabilities have enabled us to adopt a complete discretization methodology to solve the optimal control problem as a large‐scale nonlinear program, using the nonlinear optimization solver IPOPT. The superstructure approach is demonstrated for case studies related to post‐combustion CO₂ capture. In particular, optimal PSA cycles were synthesized, which maximize CO₂ recovery for a given purity, and minimize overall power consumption. The results show the potential of the superstructure to predict PSA cycles with up to 98% purity and recovery of CO₂. Moreover, for recovery of around 85% and purity of over 90%, these cycles can recover CO₂ from atmospheric flue gas with a low power consumption of 465 k Wh tonne^?1 CO₂. The approach presented is, therefore, very promising and quite useful for evaluating the suitability of different adsorbents, feedstocks, and operating strategies for PSA, and assessing its usefulness for CO₂ capture. Published 2009 American Institute of Chemical Engineers AIChE J, 2010     

Green aspects of techniques for the determination of currently used pesticides in environmental samples

Pesticides are among the most dangerous environmental pollutants because of their stability, mobility and long-term effects on living organisms. Their presence in the environment is a particular danger. It is therefore crucial to monitor pesticide residues using all available analytical methods. The analysis of environmental samples for the presence of pesticides is very difficult: the processes involved in sample preparation are labor-intensive and time-consuming. To date, it has been standard practice to use large quantities of organic solvents in the sample preparation process; but as these solvents are themselves hazardous, solvent-less and solvent-minimized techniques are becoming popular. The application of Green Chemistry principles to sample preparation is primarily leading to the miniaturization of procedures and the use of solvent-less techniques, and these are discussed in the paper.     

吸附剂再生技术的研究进展

吸附法是废水处理技术中最有效的物化方法,吸附剂可以有效的去除废水中各种污染物,尤其是采用其他方法难以有效处理的有毒和难降解的污染物.吸附剂吸附了大量吸附质会逐渐趋向饱和并失去继续吸附的能力,需要对其进行再生处理.本文总结热再生法、化学再生法、生物再生法、溶剂再生法、以及微波辐射再生法等目前常用的再生方法,并对这几种方法的优缺点进行了概述.     

A novel adsorbent obtained by caging activated carbon by konjac glucomannan gel for elimination of organic compounds

In this study, the adsorptive ability of the konjac glucomannan gel containing activated carbon (KGMG–AC) was investigated by measuring the removal of several organic compounds with different charges, such as nitrobenzene (NB), methylene blue (MB), and rose bengale (RB). The physical and chemical properties, adsorption dynamics, adsorption isotherms, and the effect of pH of the adsorbents were compared with those of a commercially available powdered activated carbon (AC). The results of the present study indicate that the removal ratio of NB, MB, and RB onto KGMG–AC was slightly higher than that of the AC. The adsorption equilibrium constant (K_L) value (0.02 L/mg) of KGMG–AC for NB was similar to that of AC (0.03 L/mg). However, the saturated adsorption amount (Q₀) of KGMG–AC (368 mg/g) for NB was slightly larger than that of AC (354 mg/g). The saturated adsorption amounts of MB and RB on KGMG–AC were 302 and 259 mg/g, respectively. On the other hand, a high molecular weight humic acid was not adsorbed by KGMG–AC. Thus, entrapping AC into KGMG resulted in the selective adsorption. Therefore, this study could show that KGMG–AC was a new environmental friendly adsorbent that can be easily prepared, used, and recovered in environments. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40542.     

Mass Transfer in Micro‐ and Mesoporous Materials

Mass transfer in micro‐ and mesoporous materials is of crucial importance in their practical application for separation and catalysis, since the mobility of adsorbed molecules ultimately limits the rate of the overall processes. Diffusion, i.e. the irregular thermal motion of the molecules, is the dominating process. Diffusion measurements are therefore indispensable for the evaluation of the quality parameters of porous materials. Due to their ability to directly follow the diffusion path of the molecules, microscopic techniques are to the forefront, amongst the various methods of diffusion measurement. Besides describing their fundamentals, this contribution describes the application of these techniques to investigate structure‐mobility‐relations in zeolites and in mesoporous materials of type MCM‐41. Some features of particular technological relevance, e.g., the phenomena of correlated diffusion anisotropy, of single‐file diffusion and of molecular traffic control, are discussed in detail.     

Microbial production,immobilization and applications of β‐D‐galactosidase

β‐D ‐Galactosidase (β‐D ‐galactoside galactohydrolase, E.C. 3.2.1.23), most commonly known as lactase, is one of the most important enzymes used in food processing, which catalyses the hydrolysis of lactose to its constituent monosaccharides, glucose and galactose. The enzyme has been isolated and purified from a wide range of microorganisms but most commonly used β‐D ‐galactosidases are derived from yeasts and fungal sources. The major difference between yeast and fungal enzyme is the optimum pH for lactose hydrolysis. The application of β‐D ‐galactosidase for lactose hydrolysis in milk and whey offers nutritional, technological and environmental applications to human life. In this review, the main emphasis has been given to elaborate the various techniques used in recent times for the production, purification, immobilization and applications of β‐D ‐galactosidase. Copyright © 2006 Society of Chemical Industry     

Stofftransport in mikro‐ und mesoporösen Materialien

Mass Transfer in Micro‐ and Mesoporous Materials Mass transfer in micro‐ and mesoporous materials is of crucial relevance for their practical application to separation and catalysis, since the mobility of adsorbed molecules ultimately limits the rate of the overall processes. Diffusion, i.e. the irregular thermal motion of the molecules, is the dominating process. Diffusion measurements are therefore indispensable for the evaluation of the quality parameters of porous materials. Being able to directly follow the diffusion path of the molecules, microscopic techniques hold a key position among the various methods of diffusion measurement. Besides their fundamentals, the contribution describes the application of these techniques to the investigation of structure‐mobility relations in zeolites and in mesoporous materials of type MCM‐41. As features of particular technological relevance, the phenomena of correlated diffusion anisotropy, of single‐file diffusion, and of molecular traffic control are discussed in detail.     

Microwave-induced regeneration of activated carbons polluted with phenol. A comparison with conventional thermal regeneration

Thermal regeneration of activated carbons (AC) was carried out at 1123 K and under N₂ atmosphere. Experiments have been carried out using a single mode microwave device operating at 2450 MHz and a conventional electric furnace (EF) so as to compare the effect of the different heating mechanisms on the adsorptive capacities of the regenerated AC. The adsorbents were saturated with phenol in columns. Adsorptive capacities after subsequent regeneration cycles were evaluated from the breakthrough curves. Additionally, a complete textural and chemical characterization of the regenerated samples was also carried out in order to study the influence of the subsequent regeneration cycles on the texture and the adsorptive capacities of the AC. Textural characterization of the regenerated samples was carried out by means of N₂ adsorption isotherms at 77 K.