混凝强化微电解工艺深度处理造纸中段废水

采用混凝强化微电解工艺深度处理造纸中段废水,通过考察废水CODCr、色度的去除效果,得到其最佳工艺条件:常温下,pH值4.0,用铁量40g·L-1,活性炭用量8g·L-1,反应时间60min,PAC用量120mg·L-1,PAM用量1mg·L-1。结果表明:出水色度36倍,去除率90%;CODCr96mg·L-1,去除率66%,达到造纸行业废水排放标准。     

生物法脱墨废水污染负荷及其混凝处理

研究了生物法脱墨废水污染负荷,分别用不同的混凝剂Al2(SO4)3、PAC与PAM配合对该废水进行处理,确定处理该废水的最佳工艺条件,并在相同条件下与化学法脱墨废水的处理效果作比较.结果表明,生物法脱墨废水比化学法脱墨废水污染负荷低且易处理;PAC与PAM配合使用处理效果优于Al2(SO4)3与PAM配合使用处理效果,其对生物法脱墨废水CODCr去除率最高可达79.1%,处理后CODCr为81 mg/L,其浊度接近普通自来水.     

高铁酸钾和聚合硫酸铁对造纸综合废水的净化效果

使用高铁酸钾和聚合硫酸铁联合处理造纸综合废水,当废水pH值7·53,色度80倍,浊度800NTU,BOD4863mg·L-1,CODCr2825mg·L-1时,高铁酸钾用量15mg·L-1,聚合硫酸铁使用量50mg·L-1具有较好的效果,色度去除率为94·3%,浊度去除率为95·2%,BOD去除率为91·14%,CODCr去除率为92·01%,处理后的废水达到国家排放标准。     

絮凝法深度处理造纸废水

采用新型废水处理剂Fe2+配合物,预处理二沉池出水,然后分别用聚丙烯酰胺(PAM)、Al2(SO4)3、聚合氯化铝(PAC)三种絮凝剂进行絮凝处理。通过检测废水的COD和色度等指标,结果发现聚合氯化铝效果最佳。确定最优条件为:废水pH值6~7,聚合氯化铝的投放量为200mg·L-1,沉降时间3h。最终出水COD可降至85mg·L-1,色度为32倍。达到了《制浆造纸工业水污染物排放标准》(GB3544-2008)的排放要求。聚合氯化铝用于造纸废水深度处理效率高、成本低、绿色环保,具有很好的应用前景。     

粉煤灰联合混凝剂处理废纸造纸废水的试验

以PAC为混凝剂、PAM为助凝剂联合处理经过粉煤灰预处理后的造纸废水,探讨粉煤灰协同PAC、PAM处理造纸废水的工艺。研究结果表明:在中性条件下,粉煤灰用量150g·L-1,搅拌1h,对造纸废水处理效果最为明显,上清液再用含铝量10%的PAC和1g·L-1的PAM处理,投加量分别为1mL·L-1和1.5mg·L-1,出水CODCr小于100mg·L-1,达到造纸行业排放标准。     

混凝沉淀法处理脱墨废水的研究

用混凝沉淀法处理脱墨废水,通过正交实验研究了混凝剂种类、混凝剂用量、助凝剂用量、pH值4因素对混凝法处理脱墨废水效果的影响.结果表明,混凝剂种类和用量、助凝剂均为影响脱墨废水混凝效果的关键因素,其中混凝剂聚合氯化铝(PAC)去除效果最好,确定脱墨废水的适宜处理条件为:选用PAC为混凝剂,用量200 mg/L;助凝剂PAM用量3 mg/L;pH值7 2,该条件下脱墨废水的CODCr去除率可达30％以上.     

混凝-絮凝工艺处理水性油墨废水

采用混凝-絮凝工艺处理水性油墨废水,探讨了油墨废水初始pH值、PAC用量和CPAM用量对CODCr去除率、色度去除率和浊度去除率的影响。采用中心组合设计(CCD)和响应曲面法(RSM)设计多因素实验并优化混凝-絮凝过程中的3个影响因素。单因素实验结果表明,混凝-絮凝工艺处理废水主要是通过电荷中和以及架桥作用完成的,降低废水初始pH值可以提高去除率。多因素实验结果表明,废水初始pH值为6.56,PAC最佳用量为126.5 mg/L,CPAM最佳用量为4.6 mg/L,CODCr去除率达到96.5%;废水初始pH值为6.78,PAC最佳用量为107.7 mg/L,CPAM最佳用量为3.0 mg/L,色度去除率接近100%;废水初始pH值为6.5,PAC最佳用量为107.8 mg/L,CPAM最佳用量为5.8 mg/L,浊度去除率达到99.97%。整合以上3个响应面的最佳条件,油墨废水的初始pH值为6.51,PAC最佳用量为128.7 mg/L,CPAM最佳用量为4.9 mg/L,处理效果最好。     

化学絮凝法在造纸白水处理中的应用

造纸白水用絮凝剂处理后CODCr、浊度去除明显,通过对比聚合碱式氯化铝(PAC)、聚合硫酸亚铁(PFS)、聚硅硫酸铝(PASS)3种不同的絮凝剂与助凝剂阳离子聚丙烯酰胺(PAM)配合处理造纸白水的结果发现,PASS絮凝效果最佳.研究表明,PASS与PAM配合处理白水的最佳条件:PASS用量100 mg/L,PAM用量2 mg/L,pH值7.0,在最佳絮凝条件下,CODCr、浊度的去除率分别为93%、98.2%.     

造纸法烟草薄片废水混凝预处理研究

以聚合氯化铝(PAC)和聚合硫酸铁(PFS)为混凝剂,4种不同类型的聚丙烯酰胺(PAM)为助凝剂,对造纸法烟草薄片废水进行混凝处理,分别考察了 pH值、混凝剂用量、助凝剂用量对混凝效果的影响.结果表明,PAC与PFS对COD、氨氮和悬浮物(SS)去除率效果相当,但PAC的脱色效果更佳.相对分子质量700万、离子化度为15％的阳离子聚丙烯酰胺(PAM4)与PAC的复配体系具有最佳的混凝效果,在pH值为6 5、PAC用量为500mg/L、PAM4用量为5mg/L的优化工艺条件下,COD、氨氮、色度和SS去除率分别为70.8％、84.8％、72.3％和98.5％.废水的铝含量分析表明,该体系非但没有产生残留铝,而目大幅去除了原水中的铝.处理后废水的紫外吸收光谱表明,有机物含量降低.     

PAM-Al(OH)_3-PDMDAAC杂化絮凝剂的制备与应用

以原位聚合法制备了有机-无机杂化高分子絮凝剂PAM-Al(OH)3-PDMDAAC,并考察了该杂化高分子絮凝剂对印染废水的处理效果。结果表明,优化的制备条件为:单体配比AM∶Al(OH)3∶DM=70∶2∶28、反应温度40℃、反应时间6 h、引发剂0.2%;将制备的杂化高分子絮凝剂用于处理分散染料的废水脱色,脱色率达98%,COD去除率达83%;与纯PAM和复配型PAM/Al(OH)3/PDMDAAC相比,杂化型高分子絮凝剂表现出优良的絮凝效果。     

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.     

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.     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

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.