Elimination of organic matter present in wastewaters from the cork industry by membrane filtration

BACKGROUND: The first stage of the cork industrial process generates great volumes of wastewater with moderate to high organic pollutant content that must be purified using different procedures, such as filtration by membranes. RESULTS: The tangential filtration of these wastewaters was studied using two different laboratory equipments. In the first one, three ultrafiltration (UF) membranes were tested, with molecular weight cut‐off (MWCO) 100 kDa and 30 kDa, and two operating modes were used: total recycling of permeate and retentate streams, and in continuous mode, without recycling both streams. In the total recycling UF experiments, the influence of the operating variables on the permeate flux was first established. The effectiveness of the different membranes was determined by evaluating the rejection coefficients for several parameters that measure the global pollutant content of the effluent. The values found for these rejection coefficients were in the following order: ellagic acid and color > absorbance at 254 nm > tannic content > COD (chemical oxygen demand). In the continuous mode experiments, the fouling mechanism for each membrane was established by fitting the experimental data to various filtration fouling models given in the literature. The operating mode in the second equipment was batch concentration, and additional experiments were carried out with an UF membrane (2 kDa), and with a NF membrane (with MWCO in the range 150–300 Da). CONCLUSIONS: The three operating modes tested provided different rejection levels of organic matter; among them, the most effective procedure tested was batch concentration mode using a NF membrane. Copyright © 2007 Society of Chemical Industry     

Spouted bed drying of cork stoppers

The spouted bed is commonly used to dry granular particles as it displays some special characteristics which render it capable of performing cyclic operations, with particles that are very difficult to fluidize under a different type of bed.Information on the characteristic drying rates of cork stoppers is still very limited in the technical and scientific literature, and until now no published data was found on the spouted bed drying of cork stoppers.The characterization of the drying performance of Port wine cork stoppers was carried out in a laboratory scale spouted bed. Characteristic drying curves were determined with 29 mm × 21 mm cork stoppers under several operating conditions. Values for the effective diffusivity were obtained in the range of 1.36 × 10⁻⁹ to 4.44 × 10⁻⁹ m²/s, with the temperature dependence represented by an Arrhenius-type relationship. The activation energy obtained was 28.72 kJ/mol.     

Urethanes and polyurethanes based on oxypropylated cork: 1. Appraisal and reactivity of products

The reaction of various polyols derived from the oxypropylation of cork with aliphatic and aromatic mono‐ and diisocyanates was studied in solution at room temperature. In all instances, good second‐order kinetics were observed and the corresponding rate constant determined. The reactivity of the aromatic isocyanate was found to be much higher than that of aliphatic counterparts. The ensuing urethanes and polyurethanes were characterised by FTIR and ¹H NMR spectroscopy, DSC and sol/gel distribution. © 2001 Society of Chemical Industry     

几种不同结构塑料封口塞适用性分析

文章通过对几种塑料塞进行实验分析,提出在原工艺尺寸基础上加长塞体和塞内掐印部分改用不捻合平行导线的设计思路,在解决毫秒延期电雷管断电阻问题上取得了良好效果.     

Lightweight screed containing cork granules: Mechanical and hygrothermal characterization

This paper presents the results of an experimental study on the use of expanded cork granule waste with cement-based mixtures to produce lightweight screeds as an overlay of a structural concrete slab. Lightweight screeds (LWSs) were made with Portland cement, sand, expanded cork granules (ECG) and water. These cork particles are industrial waste and are still a completely natural material even after industrial processing. The experiments were carried out on 3 cement dosages of 150 kg/m³, 250 kg/m³ and 400 kg/m³, incorporating expanded cork granules as replacement of part of the sand. Three additional mixtures without cork were prepared and used as reference. They had the same cement content as the lightweight ones. Hardened density, compressive strength, thermal conductivity, water vapor permeability, adsorption isotherms and water absorption by partial immersion of the mixtures were determined. Results show that the addition of expanded cork granules affects the screeds by decreasing their density, compressive strength and thermal conductivity while increasing their water vapor permeability.     

燃气爆炸对砖混住宅安全影响分析

随着燃气应用的普及,住宅燃气爆炸事故时有发生,文章通过某住宅楼发生燃气爆炸后的现状调查,分析了燃气爆炸的特点及对砖混结构住宅安全的影响,并提出了减少爆炸影响的防护措施,探索性提出燃气爆炸下一步研究的重点。     

Oxygen permeability of macrocrystalline paraffin wax and relevance to wax coatings on natural corks used as wine bottle closures

The oxygen permeability of a commercial macrocrystalline paraffin wax was determined. This permeability figure and diffusion theory were used to calculate the theoretical ingress of oxygen through the paraffin coating of a cork used as a bottle closure. We wanted to ascertain whether macrocrystalline paraffin wax coatings used on corks could be permeable enough to allow oxidation of wine. We also employed electron microscopy to show the spread of coatings on waxed corks before and after insertion inside a bottle. Our calculations indicated that oxygen permeation along the length of paraffin coating on a cork closure would not allow ingress of sufficient oxygen to cause oxidation of wine during storage.     

不同透氧率的瓶塞对瓶储两年葡萄酒感官品质的影响

该研究采用三种不同透氧率瓶塞（经典、至尊500和至尊300）对赤霞珠干红和贵人香干白葡萄酒进行两年的瓶内储存,通过测定不同瓶塞葡萄酒溶解氧（DO）、顶端空间游离氧（HSO）含量、单体花色苷总含量、CIELab颜色参数、挥发性香气成分及感官评价,分析不同瓶塞对葡萄酒感官品质的影响。结果表明,不同瓶塞葡萄酒中DO和HSO含量下降幅度为经典>至尊500>至尊300。a*值、b*值、色度（Cab值）和色调（hab值）与单体花色苷总含量呈极显著正相关（P<0.01）,而L*值与之呈极显著负相关（P<0.01）。不同瓶塞赤霞珠干红葡萄酒中共检测出30种挥发性香气成分,包括4种醇类,11种酯类,8种有机酸类,1种萜烯类和6种酚类。至尊瓶塞感官品质优于经典瓶塞,至尊500与至尊300之间无明显差异。     

室内单立管排水系统若干问题的探讨

肯定了单立管排水系统的优越性及其广泛发展前途。通过流态分析和计算，指出了影响管道内压力波动的关键问题。对系统中关键配件的结构形式提出了改进意见和设想。指出在高层建筑中推广采用塑料管材的必要性。