电Fenton技术深度处理造纸废水

采用电Fenton技术深度处理二级生化后的造纸废水,以色度去除率和COD去除率为主要考察指标,研究不同因素对造纸废水深度处理效果的影响。反应的最佳条件为：反应时间120 min、初始pH值=3、电压12 V、Fe²⁺浓度0.8 mmol/L、H₂O₂浓度0.8 mmol/L、极板间距10 cm、电解质Na₂SO₄浓度6 g/L。最佳反应条件下,电Fenton法对造纸废水的色度去除率和COD_Cr去除率分别达到89.5%和68.4%。动力学分析表明,电Fenton技术对造纸废水COD的降解符合一级反应动力学规律,一级反应速率常数为k=0.2072 min^-1。     

碳泡沫阴极电-Fenton深度处理造纸废水研究

本研究通过蔗糖发泡-碳化工艺制备了碳泡沫阴极材料并应用于电-Fenton深度处理造纸废水。采用扫描电子显微镜（SEM）、X射线光电子能谱仪（XPS）对碳泡沫阴极表面形貌和化学结构进行表征。以COD_Cr去除率为评价指标,考察了阴极材料、反应时间、初始pH值、Fe²⁺投加量和电流密度对造纸废水深度处理效果的影响。结果表明,碳泡沫由大量孔洞结构堆叠而成,表面存在含氧官能团。反应时间180 min、pH值3、Fe²⁺投加量0.5 mmol/L、电流密度200 mA/cm²时,以碳泡沫为阴极的电-Fenton深度处理造纸废水的COD_Cr去除率最高,达到88.4%,相比常规碳毡阴极提高了1.3倍。以碳泡沫为阴极的电-Fenton深度处理造纸废水法具有良好的稳定性,10次循环的COD_Cr去除率均超过85%,效率降低率不超过5%。     

石墨烯促进Fenton氧化处理制浆中段废水的研究

以制浆中段废水为研究对象,首先采用正交实验研究了石墨烯促进Fenton氧化的各影响因素间的显著程度,然后通过单因素实验研究了废水pH值、石墨烯加入量以及H₂O₂加入量对废水处理效果的影响。结果表明,石墨烯促进Fenton氧化的各影响因素间的显著程度为废水pH值>石墨烯加入量>H₂O₂加入量>n（Fe²⁺）∶n（H₂O₂）;加入石墨烯后,Fenton反应的最佳pH值由4提高至6;石墨烯最佳加入量为3 mg/L;随着H₂O₂的不断加入,制浆中段废水降解效果先不断升高而后趋于平稳,H₂O₂的最佳加入量为7 mL/L。Fenton反应体系符合一级反应动力学方程,加入石墨烯的Fenton反应速率常数k为0.0632 min-1,比传统Fenton反应速率常数大,表明制浆中段废水的降解速率明显加快。     

高级氧化集成技术深度处理造纸废水工艺研究

本课题介绍一种活性炭吸附+芬顿氧化+臭氧催化氧化的高级氧化集成技术,并将其应用于造纸废水处理。结果表明,最佳处理条件为：活性炭添加量为0.5 g/L,吸附时间30 min,COD_Cr去除率达60%;芬顿氧化工艺处理活性炭吸附出水时,H₂O₂添加量为0.25 g/L,n(Fe²⁺):n(H₂O₂)=1:4、反应时间为1 h,COD_Cr去除率最高可达到32%;臭氧催化氧化处理芬顿氧化出水时,臭氧浓度为10%,H₂O₂加入量为0.1 g/L,气液比为2:1,反应时间为1.0 h,去除效果最佳。该高级氧化集成技术可将废水COD_Cr从180 mg/L降至25 mg/L,去除率为86.1%;达到地表水准Ⅳ类,综合运行成本为8.9元/t。     

Fenton氧化对制浆废水中难降解有机污染物的去除效果研究

与传统Fenton氧化法相比流化床Fenton氧化法可以有效降低氧化剂的消耗量,同时可以使COD_Cr的去除效率有所提高。由于制浆废水的复杂特性,Fenton氧化反应存在一定的矿化能力极限,处理后废水很难稳定达标。进一步研究确定了最佳反应条件为：H₂O₂用量为1/2Qth、Fe²⁺与H₂O₂摩尔比为1∶5时,一沉池出水进行氧化处理后COD_Cr由1004 mg/L降至235 mg/L,BOD₅/COD_Cr提高到0.59,并通过AOX值和二氯甲烷萃取物GC-MS分析对比,判断废水可生化性显著提高。在此基础上采用流化床Fenton氧化与废水生物处理组合工艺进行处理,可以满足达标排放要求。     

响应面法优化O3/H2O2组合工艺处理制浆中段废水的研究

本研究为提高臭氧（O₃）氧化处理制浆中段废水的COD去除率,以广西某造纸厂制浆中段废水为研究对象,采用O₃/H₂O₂组合工艺对其进行高级氧化处理。分别探究了废水初始pH值、O₃用量、H₂O₂用量、反应时间和搅拌速度等影响因素对废水色度和COD去除效果的影响。为提高最优工艺参数的精确度,对O₃/H₂O₂组合工艺参数进行响应面优化法分析。结果表明,在废水初始pH值=8、H₂O₂用量为1.0 mL/L、O₃用量为480 mg/L的工艺条件下,废水色度为85.7倍,色度去除率为99.3%;COD_Cr达208.2 mg/L,COD_Cr去除率为84.5%。     

均相Fenton氧化降解对木素模型物对羟基苯丙酸去除效果的研究

以木素类模型物对羟基苯丙酸（HL）为研究对象,研究了均相Fenton试剂对HL的降解,探讨了体系pH值、H₂O₂用量、Fe²⁺用量、HL溶液初始质量浓度、反应时间、紫外光照射等因素对HL降解的影响。结果表明,在室温条件下,当体系原始pH值4.0时,加入2倍理论用量的H₂O₂,Fe²⁺与H₂O₂摩尔比为1∶100,反应60 min后,初始质量浓度为60 mg/L的HL溶液,其去除率可达79.2%;体系在紫外光照射下可形成协同效应,降解速度显著加快,同样条件下反应20 min,溶液中HL和TOC去除率分别可达到98.3%和79.6%。     

铁改性膨润土光催化剂的制备、表征及应用

以膨润土作为载体,制备了铁改性膨润土光催化剂,采用多种手段对其结构进行表征,将制备的铁改性膨润土光催化剂用于非均相Fenton法深度处理造纸法烟草薄片废水,考察了铁改性膨润土光催化剂的催化活性及稳定性。结果表明,膨润土经铁改性后X射线衍射（XRD）峰强度略有减弱,基本骨架未产生太大变化,层状结构变得疏松,比表面积也增大,膨润土经铁改性后Fe₂O₃的含量增加。对于COD_Cr值为365 mg/L的造纸法烟草薄片废水,当反应初始pH值为3.0、H₂O₂用量为3.0 mL/L、铁改性膨润土光催化剂用量为1700 mg/L时,采用光催化非均相Fenton法处理3 h时,废水COD_Cr的去除率达到80.2%。另外,铁改性膨润土催化剂具有较高的稳定性和较好的可重复使用性,催化剂的重复使用并不会改变原来的骨架及微观形貌。     

Fenton法深度处理造纸废水

利用 Fenton 法对造纸废水生化出水进行深度处理,考察了废水 pH 值、反应时间、Fe-SO4投加量和 H2O2投加量对废水中色度和 CODcr去除率的影响,结果表明:在 pH 值为 5.00、FeSO4投量为 400mg/L、30%H2O2投量为 200mg/L,反应时间为 30min,出水 CODcr降至 60...     

微波强化Fenton氧化处理弱酸艳红B染色废水的研究

采用微波强化Fenton氧化法处理含阴离子表面活性剂十二烷基磺酸钠(SDS)的弱酸艳红B染色废水,探讨初始pH值、H2O2投加量、FeSO4投加量、微波功率、反应时间对废水色度和COD去除率的影响。结果表明:在pH值为2.5、30%H2O2投加量为4 mL/L、FeSO4投加量为100 mg/L、微波功率为539 W、反应时间为10 min条件下,废水色度去除率达到99.1%,COD去除率达到81.9%。微波辐射、Fenton氧化、水浴强化Fenton氧化、微波强化Fenton氧化4种方法的对比实验表明,微波、Fenton氧化对染色废水的降解起协同作用,微波强化Fenton氧化法处理染色废水能显著缩短处理时间、降低Fenton试剂用量、提高COD去除率。     

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.     

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.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

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

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status