陕甘汉麻秆基活性炭的制备及表征

以陕甘汉麻秆为原料、氢氧化钾(KOH)为活化剂制备活性炭,通过正交试验探讨浸渍比、浸渍时间、活化温度、活化时间对活性炭吸附性能和得率的影响;采用扫描电子显微镜、比表面积分析仪、傅立叶变化红外光谱仪对样品的微孔结构和化学结构进行分析。结果表明：陕甘汉麻秆的最佳制备工艺为浸渍比3∶1,浸渍时间24 h,活化温度700℃,活化时间2 h;在最佳制备条件下,活性炭的碘吸附值为1389.27 mg/g,亚甲基蓝吸附值为357 mg/g,得率为68.32%,比表面积为1750.86 m²/g,孔容为0.47 cm³/g,平均孔径为1.769 nm;该活性炭微孔结构发达,含有少量介孔和大孔,此外还含有碳碳双键(C=C)、羰基(C=O)、羟基(O-H)等化学结构。该研究为陕甘汉麻秆的资源化利用奠定了良好基础。     

蔗渣基生物质炭的制备、表征及吸附性能

以甘蔗渣为前驱物,采用持续升温限氧法在350、450、550℃温度下制备生物质炭(分别标记为BC350、BC450、BC550),并对其结构和组成进行表征。结果表明,3种生物质炭的产率分别为25.27%、22.28%、18.20%,pH值分别为5.97、6.45、7.96,比表面积为110.52、160.36、298.40 m2/g,阳离子交换量为:42.87、52.69、108.53 cmol/kg。此外,通过对生物质炭进行元素分析,生物质炭中含量最高的是碳元素,通过Boehm滴定测定,生物质炭表面含氧官能团含量随着制备温度的升高而逐渐减少。在3种温度下制备的3种生物质炭对诺氟沙星具有较好的吸附性能,其log(Kf)值大小顺序为:BC550(13.74)BC450(11.47)BC350(4.52)。可用作去除水和土壤中诺氟沙星的吸附功能材料。     

枇杷果皮中多酚物质提取和纯化工艺的优化

以枇杷果皮为材料,提取分离和纯化枇杷多酚类物质,试验确定乙醇为多酚浸提溶剂,通过正交试验优化乙醇浸提枇杷果皮多酚的工艺参数。结果表明：液料比10.0 ∶ 1(mL ∶ g),80 ℃下,在50％体积分数的乙醇中浸提90 min,连续浸提2次,多酚得率可达34.76 mg/g DW(干重）。运用静态吸附和动态吸附试验对大孔吸附树脂及对多酚纯化工艺条件进行筛选,从AB-8、LX-1、NKA-9、D101、XAD-5和DM301等6种大孔吸附树脂中筛选出的XAD-5型树脂具有较好的吸附及解吸性能,吸附率和解吸率分别达到76.44％和74.32％。XAD-5型树脂纯化枇杷多酚的工艺条件为：进样浓度1.50 mg/mL,样液体积5 BV,进样流速1.5 BV/h,洗脱剂乙醇体积分数为70％,洗脱流速1.5 BV/h,洗脱体积1.2 BV,此工艺下枇杷果皮多酚纯度可达76.52％,回收率为56.44％。     

甘蔗皮生物炭对苯酚的吸附特性研究

为使甘蔗皮得到资源化利用,本研究采用慢速热解技术于400、500、600℃条件下制备生物炭吸附剂(BC400、BC500、BC600),以去除废水中的苯酚。吸附试验结果表明,废水中苯酚的初始浓度、生物炭的制备温度、吸附温度和时间等因素均能影响甘蔗皮生物炭对苯酚的吸附效果。3种温度制备的生物炭对苯酚的吸附能力表现为BC600>BC500>BC400。35℃下苯酚初始浓度为50 mg/L,生物炭BC600吸附300 min后苯酚的去除率可高达96%,生物炭对苯酚的等温吸附线符合Langmuir模式和Freundlich模式。      

桑叶中1-脱氧野尻霉素提取的工艺研究

利用单因素试验和正交试验研究酸水提取法桑叶中DNJ的提取工艺。确定最佳工艺条件为:桑叶粉末粒度60目、提取温度55℃、pH3盐酸溶液、料液比为1:20(g/m L)、提取时间为60 min。     

棉铃壳生物炭对尼泊金乙酯吸附特性研究

为促进棉铃壳的资源化利用,以棉铃壳为材料,采用慢速热解技术于300 ℃、400 ℃、500 ℃条件下制备生物炭吸附剂（BC300、BC400、BC500）,检测其去除废水中尼泊金乙酯（Ethyl paraben,EP）的效果。吸附试验结果表明,生物炭的制备温度显著影响其对EP的吸附效果,3个温度制备的生物炭对EP的吸附能力表现为BC500＞BC400＞BC300。此外,废水中EP的初始质量浓度、吸附温度和时间等均能影响吸附效果。45 ℃下EP初始质量浓度为40 mg·L^－1时,BC500对EP去除率最高,达89.4%。生物炭对EP的吸附等温线符合Langmuir模式和Freundlich模式。研究结果探明了在3个温度下制备的棉铃壳生物炭去除废水中EP的最适条件,可为棉铃壳应用于EP等有机污染物的去除提供依据。     

亚麻粕生物炭对苯酚的吸附特性研究

为促进亚麻粕的资源化利用,以亚麻粕为材料,采用慢速热解技术于300、400、500℃条件下制备生物炭吸附剂(BC300、BC400、BC500),检测其去除水中苯酚的效果。结果表明,生物炭的制备温度显著影响其对苯酚的吸附效果,3种温度制备的生物炭对苯酚的吸附能力表现为BC500 BC400 BC300。此外,苯酚的初始浓度、吸附温度和时间等因素均能影响吸附效果。25℃下苯酚初始浓度为20 mg/L时,BC500对苯酚的去除率最高,达98%,生物炭对苯酚的等温吸附线符合Langmuir模式和Freundlich模式。研究结果探明了亚麻粕制备生物炭吸附剂去除苯酚的最适条件,可为亚麻粕应用于苯酚等有机污染物的去除提供理论依据。     

槟榔红色素提取工艺的研究

探讨了槟榔中制备红色素的最佳工艺条件,结果表明,槟榔色素最佳的提取溶剂为含0.1mol/L盐酸的50%乙醇,最佳的工艺条件为提取温度50℃、料液比1:30、提取时间90min。     

S-8大孔吸附树脂纯化大豆异黄酮工艺条件的研究

对S-8大孔吸附树脂在大豆糖蜜中对大豆异黄酮的吸附与洗脱性能进行研究.测定其静态吸附率为86.5%,静态解吸率为92.5%,吸附量为16.1mg/g,通过对树脂的静态吸附、解析及实际吸附效果实验,绘制出静态吸附动力学曲线、静态解吸动力学曲线、静态吸附等温线、动态吸附透过曲线、动态解析曲线,确定出S-8大孔树脂吸附纯化大豆异黄酮的最佳工艺条件.     

大豆秸秆生物炭对苯酚的吸附特性研究

为促进大豆秸秆的资源化利用,以大豆秸秆为材料,采用慢速热解技术于400,500,600℃条件下制备生物炭吸附剂(BC400、BC500、BC600),检测其去除废水中苯酚的效果。结果表明:生物炭的制备温度显著影响其对苯酚的吸附效果,3种温度制备的生物炭对苯酚的吸附能力表现为BC500BC600BC400。此外,废水中苯酚的初始浓度、吸附温度和时间等因素均能影响吸附效果。45℃下苯酚初始浓度为40 mg·L~(-1)时,BC500对苯酚的去除率最高,达86%,生物炭对苯酚的等温吸附线符合Langmuir模式和Freundlich模型。研究结果探明了大豆秸秆制备生物炭吸附剂去除苯酚的最适条件,可为大豆秸秆应用于苯酚等有机污染物的去除提供理论依据。     

Preparation of high surface area activated carbons from tobacco stems with K2CO3 activation using microwave radiation

In this paper, activated carbons with high surface area from carbonized tobacco stems with K₂CO₃ activation by microwave radiation were investigated. Effects of microwave radiation time and K₂CO₃/C ratio on the yield and adsorption capacities of activated carbons were evaluated. Experimental results indicated that the optimum conditions were as follow: microwave power 700 W; microwave radiation time 30 min; K₂CO₃/C ratio 1.5:1. Iodine number, amount of methylene blue adsorption and the yield of activated carbon prepared under optimum conditions were 1834 mg/g, 517.5 mg/g and 16.65%, respectively. Surface area, micropore volume and pore size distribution (PSD) of the carbons were determined by the BET, H-K and DFT methods. Results showed that activated carbons had a micropore content about 59.98% and a small number of mesopores and macropores; BET specific surface area and total pore volume were 2557 m²/g and 1.647 cm³/g, respectively.     

Applicability of Industrial Sisal Fiber Waste Derived Activated Carbon for the Adsorption of Volatile Organic Compounds (VOCs)

Agricultural waste produced by the industry is a huge threat for the global environment. Utilization of agricultural waste is necessary and there is an urgent need to develop new techniques to solve this important problem. The main objective of this research was to evaluate the applicability of the activated carbon (AC) derived from industrial sisal fiber waste as passive samplers in monitoring toluene by comparing them to industry standard wafer and granular activated carbon (GAC). Carbonization time and ball milling effect on sisal fiber derived AC sample adsorption properties were investigated. Toluene adsorption isotherms were used to predict toluene adsorption capacities. Surface characteristics including surface area and pore volume were used to determine the relationships between them and adsorption capacity. Even though prepared AC samples have mesoporous structure, commercial samples have microporous structure. Surface area from 1245 m²/g to 1297 m²/g and toluene adsorption capacity from 21.4 % to 26.6 % was improved by increasing carbonization time from 1 h to 3 h at 650 °C carbonization temperature and 94.4 ml/min flow rate. Conversely, ball milling technique had negative effect by decreasing the surface area (674 m²/g) and the adsorption capacity of toluene (12.27 %). It is concluded that industrial sisal fiber waste have great potential as a precursor of AC for application in passive monitoring against toluene, particularly the produced mesoporous AC with 3 h carbonization time performs higher adsorption capacity (26.6 %) than commercially available microporous passive sampler (24.1 %) and GAC (22.8 %).     

Effects of carbonization temperatures on characteristics of porosity in coconut shell chars and activated carbons derived from carbonized coconut shell chars

A series of experiments have been conducted to study the effects of different carbonization temperatures (400, 600, 800 and 1000 °C) on characteristics of porosity in carbonized coconut shell char and activated carbon derived from carbonized coconut shell char with different activation times (30, 60, 90 and 120 min) at activation temperature of 900 °C. The results showed that high temperature carbonized coconut shell char and activated carbon samples derived from high temperature carbonized coconut shell chars had higher BET surface area, total volume, micropore volume and yield as compared to those of low temperature carbonized coconut shell char and activated carbon derived from low temperature carbonized coconut shell char. The BET surface area, total volume and micropore volume of activated carbon prepared from char obtained at 1000 °C with activation time of 120 min were 1926 m²/g, 1.26 cm³/g and 0.931 cm³/g, respectively. From the results, it was concluded that we could produce high surface area activated carbons from coconut shells using physical activation (steam activation) by proper selections of carbonization temperature and activation time.     

Optimum manufacturing conditions of activated carbon fiber absorbents. II. Effect of carbonization and activation conditions

In this paper, viscose rayon-based knitted fabrics were utilized as the precursor to produce activated carbon fiber absorbents (ACFA). The effects of carbonization and activation conditions on characteristics (ACFA) were examined. Experimental results revealed that increasing the flow rate of environmental gas N₂ and steam activator used in conjunction and decreasing the production rate of ACFA can obtain better pore properties. However, higher flow rate of steam activator and lower production rate of ACFA reduced the weight yield. According to our findings, to maintain good absorption property of ACFA, the optimum manufacturing conditions are flow rate of gas N₂ at 80 cc/min, flow rate of steam activator at 60 ml/min, and production rate of ACFA at 30 cm/min, with flame retardant reagent concentration maintained at 30%. Under these conditions, the weight yield can be up to 40.85% and the BET surface area can exceed 1500 g/m².     

PAN-based carbon nanofiber absorbents prepared using electrospinning

This study takes polyacrylonitrile (PAN) as a raw material for PAN-based nanofiber nonwoven prepared using electrospinning. First we construct a thermal-stable process for the fabrication of oxidized nanofiber nonwovens as the precursor. A semi-open high-temperature erect furnace is then used with steam as the activator, through carbonization and activation processes to prepare carbon nanofiber absorbents continuously. The experiment varies the production rate and activator flow rate to prepare carbon nanofiber absorbents. Experimental results show that carbon nanofiber adsorbents are primarily made up of micropores and mesopores, averaging under 20 Å. Given a production rate of 10–20 cm/min with a matching activator feed rate of 120 ml/min, the specific surface area can reach about 1000 m²/g, producing an adsorption ratio of carbon tetrachloride over 200 %.     

大豆异黄酮的提取优化与测定

试验优化了大豆异黄酮的提取方法,建立了一套适用于实验室提取、测定异黄酮含量的高效液相色谱法(HPLC)标准体系。优化后建立的提取条件为:脱脂大豆样品粉末,加入体积浓度为80%的色谱级甲醇10 mL,室温下放置2 h,置于超声功率200 W条件下80℃水浴12 h,12 000 r·min~(-1)离心15 min,取上清液经0.45μm微孔滤膜过滤,待测液4℃保存。优化后的HPLC法:流动相选择甲醇-水(体积比30∶70),柱温设置40℃,波长为254 nm,流速为1 mL·min~(-1),进样体积10μL,进样时间26 min,采用峰面积法计算。结果表明:优化的HPLC法提取大豆异黄酮的效率高、精度高,可为实验室内高效提取大豆异黄酮提供技术参考。     

Optimum manufacturing conditions of activated carbon fiber absorbents. I. Effect of flame retardant reagent concentration

In this paper, viscose rayon-based knitted fabrics were utilized as the precursor to produce activated carbon fiber absorbents (ACFA). To obtain better pore characteristics and higher weight yield of ACFA, the effect of flame retardant reagent concentration was studied. Experimental results revealed that both BET surface area and micropore volume increased with increasing flame retardant reagent concentration. On the other hand, both weight yield and micropore volume ratio (V_mic/V_tot) decreased as the flame retardant reagent concentration increased. It was therefore concluded that controlling the flame retardant reagent concentration at 30% not only could obtain better absorption property of ACFA but also helped maintain its production efficiency.     

Development of Activated carbon from Windmill palm sheath fiber by KOH activation

In this study, activated carbon was prepared from windmill palm sheath fiber (WPF) powder by KOH activation for full utilization of the bioresource. First, the optimal parameters of the activation technology, such as impregnation ratio, temperature, and time, were determined. The pyrolysis process and activation mechanism of KOH were investigated by thermogravimetric analysis (TGA). WPF powder-based activated carbons were then prepared under the optimized condition and characterized by SEM, FTIR, XRD, and nitrogen adsorption techniques. The reaction mechanisms were deduced in two phases. The reaction mechanisms in the first carbonization process were mainly related to substitution, scission, and oxidization reactions of methylene. In the second activation process, KOH and carbon began to react at 350 °C, producing potassium compounds, which further reacted with carbon. Results show that the optimal process for preparing an excellent adsorbent from WPF employs an impregnation ratio of 4:1 at 850 °C for 2.5 h, which can result in a good adsorption property for methylene blue, high BET surface area of 1734.34 m²/g, and total pore volume of 0.96 cm³/g. WPF-based activated carbon demonstrates a remarkable adsorption capacity, and thus WPF has great potential value as a new agricultural resource.     

复合酶法制备早籼米多孔淀粉的工艺条件

以早籼米淀粉为原料,探讨了复合酶法制备多孔淀粉的工艺条件。在适宜条件下用一定比例的α 淀粉酶与糖化酶复合酶水解早籼米淀粉,以形成多孔淀粉。主要考查了温度、ｐＨ值、时间、酶用量和复合酶比对多孔淀粉得率、吸水率和吸附色素能力的影响。研究表明,针对多孔淀粉的得率、吸水率和对胭脂红吸附量3个指标,其最佳工艺条件不一致,以吸水率最佳为标准,最佳制备条件为温度55℃,pH 4.0,时间16 h,α 淀粉酶与糖化酶体积比1∶3,酶活分别为14.00 KNU/g和90.00 AGU/g。在此条件下经两次验证,多孔淀粉的得率分别为41.07％和43.37％,吸水率分别为148.03％和15561％,对胭脂红的吸附量分别为9.37 mg/g和9.38 mg/g。     

Macroporous cellulose-based cryogels with tunable porous structure and surface functional groups

In this work, cellulose-based macroporous cryogels were fabricated by grafting with acrylic acid and acrylamide, which provided the carboxyl and amino functional groups, respectively. The effects of crosslinker, extra water, acrylic acid/ (acrylic acid+acrylamide) feeding ratio on the structure and swelling performance of the resultant cryogels were experimentally investigated. Cellulose-based cryogels with different pore size were prepared by adjusting the reaction parameters. The pore size and functional group contents influenced the swelling behavior of the cryogels. The fabricated cryogels were also investigated as an adsorbent for the removal of toxic methyl blue (MB) from aqueous solution. The interconnected macroporous structure as well as large number of functional groups of the cryogels led to the high adsorption capacity of MB. The maximum adsorption capacity was around 990.1 mg per 1 g dye gel within 60 min. The investigation of the adsorption kinetics revealed that the adsorption process of MB from aqueous solution was well described by pseudosecond order kinetic model. Large-scale preparation of cryogel adsorbents with tunable porous structure and surface functional groups are possible. Therefore, the macroporous cellulose-based cryogels can be used as an adsorbent for the removal of chemical toxic products from aqueous solution.