罗非鱼鱼鳞对染料废水中亚甲基蓝的吸附研究北大核心

通过吸附实验,考察鱼鳞用量、亚甲基蓝初始质量浓度和溶液pH等因素对罗非鱼鱼鳞吸附水中亚甲基蓝性能的影响,通过红外光谱、BET、SEM、吸附动力学和吸附等温线分析吸附机理。结果表明:当溶液pH为7、温度为30℃,吸附剂用量为3 g/L、吸附时间为30 min,亚甲基蓝初始质量浓度为40 mg/L时,吸附效果最好;罗非鱼鱼鳞对亚甲基蓝的吸附过程符合Lagergren准二级动力学模型,吸附过程属于物理吸附;吸附等温线符合Langmuir吸附等温式;傅里叶红外光谱分析表明罗非鱼鱼鳞中的胶原蛋白和羟基鳞灰石均参与了亚甲基蓝染料的吸附。     

罗非鱼鱼鳞对染料废水中亚甲基蓝的吸附研究

通过吸附实验,考察鱼鳞用量、亚甲基蓝初始质量浓度和溶液pH等因素对罗非鱼鱼鳞吸附水中亚甲基蓝性能的影响,通过红外光谱、BET、SEM、吸附动力学和吸附等温线分析吸附机理。结果表明:当溶液pH为7、温度为30℃,吸附剂用量为3 g/L、吸附时间为30 min,亚甲基蓝初始质量浓度为40 mg/L时,吸附效果最好;罗非鱼鱼鳞对亚甲基蓝的吸附过程符合Lagergren准二级动力学模型,吸附过程属于物理吸附;吸附等温线符合Langmuir吸附等温式;傅里叶红外光谱分析表明罗非鱼鱼鳞中的胶原蛋白和羟基鳞灰石均参与了亚甲基蓝染料的吸附。     

交联羧甲基玉米淀粉对水溶液中亚甲基蓝吸附特性的研究

采用交联羧甲基玉米淀粉吸附剂对模拟废水中的亚甲基蓝进行吸附性能研究.考察了吸附剂用量、pH、吸附时间以及染料初始浓度等因素对亚甲基蓝吸附效果的影响,并进行交联羧甲基玉米淀粉去除亚甲基蓝染料的吸附等温线拟合及吸附动力学研究.结果表明,当亚甲基蓝初始浓度100mg/L、pH6.0、交联羧甲基玉米淀粉用量0.2g、吸附温度25℃以及吸附时间60min时,亚甲基蓝吸附率可达95.66％;25℃下交联羧甲基玉米淀粉理论饱和吸附量为80mg/g;染料吸附等温线符合Langmuir模式(R2＞0.99);吸附过程符合准一级和二级反应动力学方程(R2＞0.99).     

废弃干果壳粉吸附亚甲基蓝模拟印染废水试验研究

采用巴旦杏、核桃、杏壳粉对亚甲基蓝质量浓度为10mg/L的模拟废水进行了静态吸附试验.结果表明,在吸附剂种类、吸附剂用量和吸附时间3个因素中,吸附剂种类对亚甲基蓝吸附量影响最大,巴旦杏壳粉对亚甲基蓝吸附量最佳,亚甲基蓝去除率可达90.49%.二级动力学模型能较好地描述巴旦杏壳粉对模拟染料废水中亚甲基蓝大分子的吸附动力学过程.随着温度的升高,巴旦杏壳粉对亚甲基蓝的吸附量增加.对吸附等温线相关系数进行拟合,表明Freundlich吸附等温线方程能较好地反映吸附过程.     

绿茶微粉对染料亚甲基蓝和孔雀石绿的吸附研究

亚甲基蓝和孔雀石绿是造成水体污染的偶氨工业染料.本文研究在不同的颗粒、pH、吸附剂量、吸附时间条件下绿茶微粉对亚甲基蓝和孔雀石绿的吸附效果,并分析其吸附速率曲线和吸附等温线.结果表明,常温下绿茶微粉能够较好地吸附亚甲基蓝和孔雀石绿,且颗粒越小吸附效果越佳;亚甲基蓝和孔雀石绿最佳吸附pH分别是7和5,吸附饱和量分别是19.37 mg/g和16.50 mg/g.在初始染料质量浓度20 mg/L条件下,240 min左右可达到吸附平衡.吸附动力学分析表明,绿茶微粉对亚甲基蓝和孔雀石绿的生物吸附平衡数据均与拟二级速率方程拟合度较好,吸附规律分别符合Langmuir和Freundlich等温式.     

榴莲壳和龙眼壳活性炭的制备、表征及其吸附性能研究

本文以废弃榴莲壳、龙眼壳为原料,采用KOH化学活化法制备了榴莲壳、龙眼壳生物质活性炭,并探究了其对水中亚甲基蓝的吸附性能。采用比表面积测试(BET)、傅立叶红外光谱(FT-IR)、电子扫描电镜(SEM)、X-射线衍射(XRD)对制备的榴莲壳、龙眼壳生物质活性炭进行了表征,并重点研究了活性炭添加量、亚甲基蓝溶液初始浓度、反应时间、温度和pH对其吸附亚甲基蓝(MB)的影响。结果表明：200 mg/L MB水溶液在最佳反应条件(炭投入量为30 mg、pH8.0、120 min)下,榴莲壳(龙眼壳)活性炭最大吸附量为363 mg/g;榴莲壳和龙眼壳活性炭的比表面积分别为999.63 m²/g和1377.95 m²/g,平均孔径分别为2.13 nm和2.20 nm,另外榴莲壳、龙眼壳活性炭表面均有大量孔洞且具有一定的层状结构,这些孔洞的存在为活性炭吸附提供了丰富的吸附位点,与市售商用活性炭相比,具有更加密集的孔状结构,并且对亚甲基蓝的吸附能力更强。     

改性方法对辣木籽壳生物炭吸附亚甲基蓝的影响

目的：探究不同工艺条件所制备的辣木籽壳生物炭对亚甲基蓝的吸附性能。方法：以辣木籽壳为原料,采用超声辅助碳酸钾—Fe₃O₄共浸渍热解和KOH浸渍—1 000 ℃高温热解两种方法分别制备磁性辣木籽壳生物炭（Fe₃O₄-MOS）和改性辣木籽壳生物炭（KOH-MOS）,并用XRD、SEM和FTIR对样品表面物化性质进行表征。在此基础上,通过平衡吸附法测定两种生物炭对溶液中亚甲基蓝（MB）的吸附特性,并用动力学、热力学和等温吸附模型分析对MB的吸附机理。结果：在试验所探究的条件下,Fe₃O₄-MOS和KOH-MOS对MB的吸附效率接近100%,且由Langmuir模型所得到最大吸附量分别为116.83,99.37 mg/g。结论：两种材料对MB的吸附是一个自发吸热熵增、化学吸附为主的过程。Fe₃O₄-MOS和KOH-MOS分别展现出了良好的磁分离能力和吸附能力。     

活性炭-高岭土混合吸附剂对亚甲基蓝吸附性能研究

以亚甲基蓝为模拟污染物,采用混合吸附剂处理废液,考察投加量、pH值、温度、时间等因素对亚甲基蓝去除率和吸附量的影响。结果表明:活性炭与高岭土的质量比为2∶1,吸附剂投加量为0.2 g/150 m L,温度为35℃,时间为60 min,此时亚甲基蓝的去除率可达95%,pH变化对此吸附行为的影响不大;吸附等温线及动力学研究表明,此吸附满足Freundlich等温线模型,吸附符合准二级动力学模型,为化学吸附。     

角蛋白/酚磺酸缩合物复合材料对亚甲基蓝的吸附研究

在皮革的生产加工过程中,角蛋白未能得到充分利用便被处置,造成了一定的资源浪费.通过溶液共混法制备了角蛋白/酚磺酸缩合物复合材料,并考察其对亚甲基蓝的吸附性能.研究结果表明:复合材料对亚甲基蓝的吸附量随pH值的上升而上升,对400 mg/L的亚甲基蓝最佳吸附条件是pH值为10,复合材料使用量为2.0 g/L,吸附温度50...     

Cu-BTC-SiO_2材料的制备及其对亚甲基蓝的吸附性能

利用原位合成法,将Cu-BTC负载到介孔/大孔二氧化硅孔道中,获得介孔Cu-BTC-SiO_2材料.研究在不同温度、亚甲基蓝浓度、pH值下Cu-BTC-SiO_2对亚甲基蓝吸附效果的影响,并对其吸附动力学及其吸附热力学数据进行分析.结果表明,该样品对亚甲基蓝的吸附符合Langmuir吸附等温模型和准一级动力学模型,其最佳条件为反应温度25℃,染料质量浓度为5mg/L,pH值为5.热力学研究发现,在25~45℃内,亚甲基蓝在Cu-BTC-SiO_2上的吸附行为是放热过程而且是自发进行的.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.