微波辐射紫茎泽兰制备优质活性炭的研究

以紫茎泽兰为原料,碳酸钾为活化剂,采用超声波浸渍,微波辐射法制备活性炭.研究了浸渍方式与时间、微波功率、微波辐射时间、剂料比对活性炭吸附性能和得率的影响.得到了本实验条件下的优化工艺条件:超声波浸渍20min、120℃脱水2h,微波功率700W、微波辐射时间12min、剂料比1.25∶1.优化工艺条件下制备的活性炭碘吸附值为1470.27mg/g,亚甲基蓝吸附值为300mL/g,得率为16.35%.浸渍时间极大的缩短,微波辐射时间只有传统法活化时间的1/15左右,活性炭的吸附指标超过了国标GB/T 13803.1-1999和GB/T 13803.2-1999一级品的标准,其中碘吸附值是国家一级标准的1.47倍,亚甲基蓝吸附值是国家一级标准的2.73倍.同时,测定了该活性炭氮吸附,其BET比表面积为1540.97m2/g,总孔容为0.7393mL/g,并通过DFT表征了活性炭的孔径分布,结果表明该活性炭为微孔型活性炭.     

微波辐射在制备竹节活性炭中的应用研究

研究了以竹节废料为原料，采用微波辐射氯化锌法制备优质活性炭的可行性．探讨了微波功率．活化时间及氯化锌浓度对产品各项指标的影响．得到了微波辐射氯化锌法制备活性炭的最佳工艺：微波功率350W、活化时间5min、氯化锌浓度40%．用此工艺制得的活性炭碘吸附值1088．4mg／g、亚甲基蓝脱色力22．0ml/0．1g．得率39．2％．该工艺所需活化时间为传统方法的1／36，产品活性炭亚甲基蓝脱色力为国家一级标准的1．83倍(GB/T13496.10-1999)．微波辐射法所制活性炭比传统方法所制活性炭具有更加发达的孔隙结构，且孔隙的分布更加均匀．     

烟气脱硫活性炭微波再生特性的实验研究

研究了烟气脱硫活性炭的微波再生特性。通过扫描电镜、N₂吸附、元素分析、Boehm滴定表征微波再生对活性炭孔隙结构和表面化学性质的影响,分析微波再生对活性炭吸附烟气中SO₂的影响规律。结果表明,微波再生功率越高,SO₂再生曲线越窄,峰值浓度越高,有利于载硫活性炭的解吸和高浓度再生气的获取。微波再生对活性炭起到了活化作用,使活性炭的孔结构变狭长。随着微波再生功率的提高,活性炭的微孔比表面积、微孔孔容增加,酸性官能团含量上升,碱性官能团含量下降。100 W再生后,活性炭再生不完全,残留的H₂SO₄影响了活性炭的吸附,活性炭的SO₂吸附性能下降。200、300、400 W工况下,活性炭的SO₂吸附容量均得到提高,且随着再生功率的提高,活性炭的碱性官能团含量上升,微孔比表面积、微孔孔容增加,SO₂吸附性能逐渐增强。     

基于微波辅助芬顿法对活性紫K-3R脱色研究

探讨了活性紫K-3R的微波辅助芬顿（Fenton）法脱色工艺.试验结果表明,微波与Fenton法联用可以产生良好的协同效果,当活性紫K-3R溶液的pH为4、30%过氧化氢的加入量为0.6 mL/L、硫酸亚铁的质量浓度为0.3 g/L时,以400 W微波功率辐射3 min,并静置25 min后,活性紫K-3R的脱色率可以达到98.13%.     

微波辐照活性炭床烟气脱硝实验研究

微波诱导催化作用结合活性炭的吸附和还原能力可以实现烟气中氮氧化物的还原脱除. 利用微波反应器开展了微波辐照活性炭烟气脱硝实验, 研究了微波辐照功率(反应温度)、烟气流率、NO浓度以及烟气共存成分对脱硝效率的影响. 实验结果表明, 微波功率越高, 脱硝效率也越高, 在560 W可达80%左右的脱硝效率|活性炭质量越大脱硝反应越完全, 50 g活性炭可脱除83%的NO|烟气流率增加脱硝效率降低|烟气中氧的存在对脱硝有一定促进作用, 烟气含湿量过大对脱硝不利. 脱硝反应动力学研究表明, NO的反应级数近似为1, 速率常数为k＝1.33 min^－1. BET测试表明, 微波辐照活性炭后其表面积有少量下降.     

响应面优化微波辅助Fenton法降解活性艳蓝KN-R

以活性艳蓝KN-R为降解目标,通过单因素和响应面法优化了微波辅助Fenton法降解工艺.探讨了FeSO_(4)·7H_(2)O浓度、30%H_(2)O_(2)投加量、溶液酸度、微波功率、反应与静置时间等因素对脱色率的影响,并利用响应面法优化了脱色条件.结果表明,在FeSO_(4)·7H_(2)O物质的量浓度为0.10 mmol/L、30%H_(2)O_(2)加入量为1.74 mL/L、溶液pH值为3.8、微波功率为222 W、微波时间为6 min、静置时间为40 min时,活性艳蓝KN-R脱色率可达95.26%.     

川佛手中多酚类物质的微波和超声波联合提取工艺优化

采用微波和超声波提取技术,实现了川佛手中多酚类物质的有效提取.在微波功率800 W和微波提取时间40 min的条件下,通过单因素实验条件优化,考察了超声功率、乙醇浓度、提取温度、超声时间和提取料液比对提取效率的影响;通过正交试验设计,确定了最佳提取工艺条件参数,即超声功率800 W、乙醇体积分数60%、提取温度55℃、超声时间1.0 h和提取料液比1∶20 g/m L;通过验证实验,得到川佛手多酚的提取率约为20.79 mg/g.     

微波促进活性炭负载四氯化锡催化合成乙酰乙酸乙酯缩酮

在微波辐射下,以活性炭负载四氯化锡(SnCl4·5H2O/C)为催化剂,不用溶剂,合成了乙酰乙酸乙酯乙二醇缩酮和乙酰乙酸乙酯1,2-丙二醇缩酮。以乙酰乙酸乙酯与乙二醇缩合为模型反应进行优化,其优化条件是:负载量为20%的SnCl4·5H2O/C催化剂0.1 g,乙酰乙酸乙酯5 mL,乙二醇6 mL,微波辐射功率600 W,辐射时间2.5 min,产率达81.6%。产物经过红外光谱表征。     

微波辅助法提取香根净油的研究

采用微波辅助法提取香根净油,通过实验确定了最佳提取工艺条件。研究结果表明,最佳提取工艺条件为：提取液中乙醇体积分数为80%,固液比1∶10（g/mL）,微波频率2450MHz,功率1190W,微波时间5min。最佳提取工艺条件下香根净油提取率为6.41%。     

微波辐射超稳Y沸石负载硅钨酸催化合成肉桂酸β-苯乙酯

在微波辐射下,以超稳Y沸石负载硅钨酸(HSW/USY)为催化剂,不使用溶剂,合成了肉桂酸β-苯乙酯。其优化反应条件是:负载量为20%的HSW/USY催化剂1.2 g,肉桂酸27 mmol,β-苯乙醇43 mmol,微波辐射功率600 W,辐射时间10 min,产率达91.5%。产物经过红外光谱表征。     

Ultrasound‐enhanced and microwave‐assisted extraction of lipid from Dunaliella tertiolecta and fatty acid profile analysis

Microalgal lipid is considered as a potential biodiesel resource due to its advantages compared to other bioresources. The production of biofuel from microalgae includes several stages like microalgae cultivation, biomass harvest, biomass treatment, lipid extraction, and the ultimate biodiesel synthesis. Lipid extraction is closely associated with the productivity and cost of energy production. In the present study, lipid of green algae Dunaliella tertiolecta was extracted by chemical agents with involvement of ultrasound and microwave. The optimization of experimental conditions was carried out by response surface methodology and orthogonal test design. Using the ultrasonic technique, an extraction rate of 45.94% was obtained under the optimum conditions of ultrasonic power 370 W, extraction time 5 min and liquid/solid ratio 125 mL/g. The extraction rate of 57.02% was obtained by the means of microwave assistance under the optimized conditions of extraction time 160 s, microwave power 490 W and liquid/solid ratio 100 mL/g. The comparison of the two results indicated microwave was more effective than ultrasound in extracting process. When the two techniques were utilized in combination, the optimized condition was ultrasonic power 320 W, ultrasonic time 4 min, microwave power 280 W, microwave time 120 s and liquid/solid ratio 100 mL/g, and the extraction rate was 49.97%.     

Determination of polycyclic aromatic hydrocarbons in aqueous samples by microwave assisted headspace solid-phase microextraction and gas chromatography/flame ionization detection

The novel pretreatment technique, microwave-assisted heating coupled to headspace solid-phase microextraction (MA-HS-SPME) has been studied for one-step in situ sample preparation for polycyclic aromatic hydrocarbons (PAHs) in aqueous samples before gas chromatography/flame ionization detection (GC/FID). The PAHs evaporated into headspace with the water by microwave irradiation, and absorbed directly on a SPME fiber in the headspace. After being desorbed from the SPME fiber in the GC injection port, PAHs were analyzed by GC/FID. Parameters affecting extraction efficiency, such as SPME fiber coating, adsorption temperature, microwave power and irradiation time, and desorption conditions were investigated.Experimental results indicated that extraction of 20 mL aqueous sample containing PAHs at optional pH, by microwave irradiation with effective power 145 W for 30 min (the same as the extraction time), and collection with a 65 μm PDMS/DVB fiber at 20 °C circular cooling water to control sampling temperature, resulted in the best extraction efficiency. Optimum desorption of PAHs from the SPME fiber in the GC hot injection port was achieved at 290 °C for 5 min. The method was developed using spiked water sample such as field water with a range of 0.1-200 μg/L PAHs. Detection limits varied from 0.03 to 1.0 μg/L for different PAHs based on S/N = 3 and the relative standard deviations for repeatability were <13%. A real sample was collected from the scrubber water of an incineration system. PAHs of two to three rings were measured with concentrations varied from 0.35 to 7.53 μg/L. Recovery was more than 88% and R.S.D. was less than 17%. The proposed method is a simple, rapid, and organic solvent-free procedure for determination of PAHs in wastewater.     

微波辐射活性炭负载磷钨酸催化合成季戊四醇双缩酮(醛)

在微波辐射下，以活性炭负载磷钨酸为催化剂，不用溶剂，合成了8种季戊四醇双缩酮（醛），以环己酮与季戊四缩的缩合为模型反应进行优化，其优化反应条件为：季戊四醇2．0g，催化剂0．3g，环己酮4．0mL，微波输出功率600W，辐射时间3min，产率达95．4％，该条件下的反应速度是常规加热反应速度的30倍，所得产物经元素分析，IR和1H NMR表征。     

Determination of chlorophenols in soil samples by microwave-assisted extraction coupled to headspace solid-phase microextraction and gas chromatography-electron-capture detection

Microwave-assisted extraction coupled to headspace solid-phase microextraction was studied and applied for one-step in-situ sample preparation prior to analysis of chlorophenols (CPs) in soil samples. The CPs in soil sample were extracted into the aqueous solution and then directly onto the solid-phase microextraction (SPME) fiber in headspace under the aid of microwave irradiation. After being desorbed from SPME fiber in the GC injection port, CPs were analyzed with a GC-electron-capture detection system. Parameters affecting the extraction efficiency such as the extraction solutions, the pH in the slurry, the humic acid content in the soil, the power and the irradiation time of microwave as well as the desorption parameters were investigated. Experimental results indicated that the extraction of a 1.0 g soil sample with a 6-ml aqueous solution (pH 2) and a polyacrylate fiber under the medium-power irradiation (132 W) for 9 min achieved the best extraction efficiency of about 90% recovery and less than 10% RSD. Desorption was optimal at 300 degrees C for 3 min. Detection limits were obtained at around 0.1-2.0 microg/kg levels. The proposed method provided a simple, fast, and organic solvent-free procedure to analyze CPs from soil sample matrix.     

微波辅助-旋转回流提取仪的组装及其在叶下珠有机酸提取中的应用

组装了一种新型的微波辅助旋转回流装置,该装置的基本原理与微波辅助溶剂萃取的原理相同,但采用了旋转的技术以加速提取.应用该装置以正交实验筛选优化叶下珠中有机酸的提取工艺,并利用毛细管电泳技术分离测定了提取液中有机酸的含量以评价提取效果.最佳提取工艺:乙醚为溶剂,微波功率800 W,提取时间4 min,溶剂用量300 mL.在该提取条件下,平行5次提取叶下珠中丁二酸、原儿茶酸、没食子酸、咖啡酸、阿魏酸的平均含量分别为42.2、103.5、436.2、123.8、67.4 μg/g,相对标准偏差为0.87% ～3.7%,加标回收率为94% ～104%.将该法与常规的微波辅助提取法及回流提取法进行比较,结果表明,微波辅助旋转回流提取法提取效率明显优于其它2种方法.     

Microwave-assisted catalytic oxidative desulfurization of gasoil fuel using synthesized CuO-ZnO nanocomposites

Recently,organosulfur removal from liquid petroleum fuels is very significant aspect of environment protecting and fuel cell requests.Therefore,improved approaches to remove sulfur are still essential.In the present work,a simple catalytic oxidative desulfurization(CODS)system for Iraqi gasoil fraction has been successfully developed using CuO-ZnO nanocomposites as catalysts,and H_2O_2 as oxidant under microwave irradiation.The main reaction parameters influencing sulfur conversion including microwave power,irradiation time,catalyst dosage and H_2O_2 to gasoil volume ratio have been investigated.The CuO-ZnO nanocomposites was synthesized with different weight ratios and characterized by XRD,FE-SEM,AFM and BET surface area methods.The results reveal that,high sulfur conversion(93%)has been achieved under suitable conditions of microwave CODS as follows:microwave power of 540 W,irradiation time of 15 min,catalyst dosage of 8 g/L(0.4 g),and H_2O_2:gasoil volume ratio of 0.3.The catalyst reusability shows that the synthesized catalyst can be reused five times without an important loss in its activity.     

Green Synthesis of Some Calix[4]Resorcinarene Under Microwave Irradiation

A green synthetic procedure for the preparation of some calix[4]resorcinarenes using a household microwave oven has been carried out. This method represents a very rapid heating alternative to the conventional method that involves very long time of reactions (from 20-24 h in conventional heating to 5-8 min in microwave irradiation). C-4-hydroxy–3-methoxycalix[4]resorcinarene (CHMPCR), C-4-methoxyphenylcalix[4]resorcinarene (CMPCR) and C-2–phenylethenilcalix[4]resorcinarene (CPECR) was achieved by placed of resorcinol, an aldehyde, HCl and ethanol inside a household microwave oven. The product was recrystallized by methanol and analyzed by spectral analysis (FTIR, H-NMR and MS). Optimization of reaction was carried out in variation of microwave power, reaction times and reactant composition. The result shows that optimum condition of synthesis of C-4-hydroxy-3–methoxycalix[4]resorcinarene (CHMPCR) with microwave irradiation were at microwave power 332 W, reaction time 8 min and the mole ratio of resorcinol and 4-hydroxy-3-methoxyphenylbenzaldehyde 1:1. This parameter gave product in 97.8% (53.7% after recrystallization). The CPECR synthesis using resorcinol and cynnamaldehyde (1:1) at microwave power 332 W for 5 min afforded the product in 97.3% (44.5% after recrystallization). Whereas the reaction of resorcinol and 4-methoxyphenylbenzaldehyde (1:1.2) at microwave power 264 W for 5 min gave CMPCR in 99.5% (68.6% after recrystallization).     

Investigation of the species-specific degradation behaviour of methylmercury and ethylmercury under microwave irradiation

The degradation behaviour of methylmercury (MeHg) under microwave irradiation is investigated, as is the (different) degradation behaviour of ethylmercury (EtHg) under similar irradiation. A simple and highly sensitive SPME-GC-pyrolysis-AFS system was used to analyse the aqueous MeHg and EtHg standard solutions after derivatization with sodium tetraphenylborate (NaBPh₄). Samples were irradiated in a microwave digester at microwave powers ranging from 20 to 160 W for durations of 2 to 10 min. The different tolerances towards microwave treatment of the two organomercury species were evident. Practically no degradation was experienced for MeHg for up to 8 minutes of irradiation at 120 W or for up to 4 minutes at 160 W. Significant analyte loss was observed for EtHg after 2 minutes at 40 W of microwave power. Awarded a Poster Prize on the occasion of the European Winter Conference on Plasma Spectrochemistry, February 2005, Budapest, Hungary