钻井废水处理工艺技术和设备现状

目前我国大多数钻井废水经处理后直接排放。随着钻井技术的发展及环境保护要求的提高,相应地对外排废水的CODcr指标提出了更高的要求。利用现有设施处理钻井废水难以使废水处理后达到国家排放标准。本文介绍了国内主要的钻井废水处理技术及工艺,结合钻井废水的特点提出采用混凝离心法连续处理钻井废水的简化工艺。     

Atomically Thin 2D‐Arsenene by Liquid‐Phased Exfoliation: Toward Selective Vapor Sensing

Phosphorene and antimonene, single‐ or few‐layered (FL) semiconductor materials, have recently attracted enormous attention due to their unique properties, provided by their extreme thinness. Here, a liquid‐phase exfoliation (LPE) procedure to prepare FL arsenene, another member of pnictogens, assisted by sonication and without any additional surfactant is reported. The exfoliation process is performed in various solvents. Among those, N‐methylpyrrolidone is found to provide the highest concentration of stable arsenene sheets. Spectroscopic and microscopic analyses confirm the formation of high‐quality few‐layer arsenene nanosheets with large lateral dimensions. An application of this material for construction of vapor sensor based on electrochemical impedance spectroscopy is demonstrated. The device detects selectively methanol or acetone vapors depending on the selected resonance frequency. The results are highly reproducible, and the vapor sensor has long‐term stability.     

溶剂-离心法脱除煤焦油沥青中的喹啉不溶物

以洗油和烷烃的混合物为溶剂,采用溶剂-离心法对煤焦油沥青中的喹啉不溶物（QI）进行分离,考察混合溶剂芳烷比、溶剂用量、溶解温度、离心转速以及离心时间等因素对精制沥青QI含量和收率的影响。结果表明,随着芳烷比的增加,精制沥青的收率逐渐增加,QI含量先降低后增加;随着溶剂比的增大,精制沥青的QI含量逐渐减小,收率逐渐增大;溶解温度升高有利于QI的脱除和精制沥青收率的提高;离心转速越快,离心时间越长,所得精制沥青的QI含量和收率均越低;当芳烷比为1.2、溶剂比为2、溶解温度为80℃、离心转速为3000r/min、离心时间为8min时,精制沥青收率可达79.8%,其QI含量低达0.18%。     

High-resolution density variations of coal macerals

A number of coals have been separated into their maceral components by density gradient centrifugation. Each maceral group exhibits a distribution of densities. In general, exinite distributions do not overlap with those of vitrinite. However, vitrinite density distributions overlap significantly with inertinite distributions. This behaviour places inherent limits on the ability to completely separate macerais using density measurements alone. The density distribution of vitrinites and probably exinites has been found to narrow as rank increases.     

脂质体包裹胶原蛋白的制备及其透皮性能

为提高胶原蛋白体外透皮吸收性能,以卵磷脂和胆固醇为成膜材料,采用薄膜分散法制备了鱼皮水解胶原蛋白脂质体。以模拟Franze扩散池进行小鼠离体皮肤渗透扩散实验,采用高效液相色谱法(high performance liquid chromatography,HPLC)测定胶原蛋白含量,考察胶原蛋白脂质体的透皮吸收量与吸收率。实验结果表明,相对分子质量(简称分子量,下同)3 500的鱼皮水解胶原蛋白经脂质体包封后,透皮吸收量在24 h内达到21.9%,较直接涂抹胶原蛋白的透皮吸收率提高一倍。证明小分子胶原蛋白经脂质体包封能够改善其体外透皮吸收性能。     

活性炭出水中炭附细菌解吸附机制及工况优化

针对活性炭出水生物安全性中炭附细菌所致的难点问题,分析了细小炭粒特性对水中细菌的吸附影响和微生物吸附炭粒的微生物学及化学机制,探讨了炭附细菌的解吸附原理;并通过正交试验和对比组合实验,研发出高速离心协同解吸附剂的新方法,能够破坏炭附细菌和炭粒间的多种作用力,提高炭附细菌解吸附的效率;进一步优化了高速离心与解吸附剂组合适宜的工况.结果表明:离心工作条件为转速18×103r/min,时间5 min,温度4℃,解吸附剂组合为焦磷酸钠(质量分数为0.01%)、Tris Buffer(浓度为0.01 mol/L,pH7.0)、蛋白胨(质量分数为0.01%)、表面活性剂(浓度为1μmol/L)和乙二醇双(2-氨乙基醚)四乙酸(EGTA)(浓度为1mmol/L)时,活性炭粒的解吸附倍数达到15.1.解吸附效率提高了75.6%,基本实现炭附细菌的分离,为活性炭出水中生物颗粒控制的研究提供理论和方法.     

Water Addition During Oil Extraction Affects on Virgin Olive Oil Ethanol Content,Quality and Composition

Ethanol is the alcoholic precursor of fatty acid ethyl esters (FAEEs) in virgin olive oil (VOO). Because of its miscibility, water addition during oil extraction may affect oil ethanol content and then, the FAEEs synthesis during oil storage. In this work, the effect of water addition on VOO ethanol content and composition is studied. Water addition at two extraction systems (two and three phases) is compared and for vertical centrifuge, water addition at different temperatures is assayed. Ethanol content, quality parameters, and healthy components are determined in the oils. Results indicate three phase system gives oils with a 25% lower ethanol content than two phases. Ethanol reduction because of water addition is more important for three phases system (≈14%). For vertical centrifugation, ethanol is lowered as water dose and temperature increase. In general, water addition for any of the extraction steps analyzed reduces the oil ethanol concentration but other aspects such as fruity intensity and phenol content are also lowered. Practical applications: Virgin olive oil final ethanol content, and then its FAEEs concentration, does not only depend on the health and conservation status of olives, but also on the extraction system used and the amount of water added to the extraction process. The knowledge of the impact on ethanol content of water addition during oil extraction can be useful for olive oil legislators in order to keep the approved limits of FAEEs or to modify them. For oil producers, results can help to reduce the oil ethanol content and then FAEEs synthesis during virgin olive oil storage.     

Reduction of Mycobacterium avium ssp. paratuberculosis in colostrum: Development and validation of 2 methods,one based on curdling and one based on centrifugation

The aim of this study was to develop and validate 2 protocols (for use on-farm and at a central location) for the reduction of Mycobacterium avium ssp. paratuberculosis (MAP) in colostrum while preserving beneficial immunoglobulins (IgG). The on-farm protocol was based on curdling of the colostrum, where the IgG remain in the whey and the MAP bacteria are trapped in the curd. First, the colostrum was diluted with water (2 volumes colostrum to 1 volume water) and 2% rennet was added. After incubation (1 h at 32°C), the curd was cut and incubated again, after which whey and curd were separated using a cheesecloth. The curd was removed and milk powder was added to the whey. Approximately 1 log reduction in MAP counts was achieved. A reduction in total proteins and IgG was observed due to initial dilution of the colostrum. After curd formation, more than 95% of the immunoglobulins remained in the whey fraction. The semi-industrial protocol was based on centrifugation, which causes MAP to precipitate, while the IgG remain in the supernatant. This protocol was first developed in the laboratory. The colostrum was diluted with skimmed colostrum (2 volumes colostrum to 1 volume skimmed colostrum), then skimmed and centrifuged (at 15,600 × g for 30 min at room temperature). We observed on average 1.5 log reduction in the MAP counts and a limited reduction in proteins and IgG in the supernatant. To obtain a semi-industrial protocol, dairy pilot appliances were evaluated and the following changes were applied to the protocol: after 2:1 dilution as above, the colostrum was skimmed and subsequently clarified, after which the cream was heat treated and added to the supernatant. To investigate the effect of the colostrum treatment on the nutritional value and palatability of the colostrum and the IgG transfer, an animal experiment was conducted with 24 calves. Six received the dam's colostrum, 6 were given untreated purchased colostrum (control), and 2 groups of 6 calves received colostrum treated according to both of the above-mentioned methods. No significant differences were found between the test groups and the dam's colostrum group in terms of animal health, IgG uptake in the blood serum, milk, or forage uptake. Two protocols to reduce MAP in colostrum (for use on-farm or at a central location) were developed. Both methods preserve the vital IgG.     

Development and optimization of a new processing approach for manufacturing topical liposomes-in-hydrogel drug formulations by dual asymmetric centrifugation

Objective: The objective of the present study was to utilize dual asymmetric centrifugation (DAC) as a novel processing approach for the production of liposomes-in-hydrogel formulations.

Materials and methods: Lipid films of phosphatidylcholine, with and without chloramphenicol (CAM), were hydrated and homogenized by DAC to produce liposomes in the form of vesicular phospholipid gels with a diameter in the size range of 200?300?nm suitable for drug delivery to the skin. Different homogenization processing parameters were investigated along with the effect of adding propylene glycol (PG) to the formulations prior to homogenization. The produced liposomes were incorporated into a hydrogel made of 2.5% (v/v) soluble β-1,3/1,6-glucan (SBG) and mixed by DAC to achieve a homogenous liposomes-in-hydrogel-formulation suitable for topical application.

Results and discussion: CAM-containing liposomes with a vesicle diameter of 282?±?30?nm and polydispersity index (PI) of 0.13?±?0.02 were successfully produced by DAC after 50?min centrifugation at 3500?rpm, and homogenously (centrifugation time to 2?min and 55?s, producing liposomes of 230?±?51?nm and PI of 0.25?±?0.04. All formulations had an entrapment efficiency of approximately 50%.

Conclusion: We managed to develop a relatively fast and reproducible new method for the production of liposomes-in-hydrogel formulations by DAC.     

Use of Neural Network for the Simulation of a Gas Centrifuge

The prediction by a mathematical model of the separation of uranium isotopes using a gas centrifuge process is a hard task. The gas motion can be described by analytical or numerical solutions of the system of equations defined by the equation of continuity, the Navier-Stokes equation and the equation of energy. However, these calculations cannot be performed for actual centrifuges.

Neural networks are an alternative for modelling complex problems that show too many difficulties to be solved by phenomenological models.

The authors propose the use of neural networks for the simulation and prevision of the separative and operational parameters of a gas centrifuge separating uranium isotopes. The results from the uranium separation experiments (Zippe data) are compiled and presented to the neural network in the learning and testing processes. The prediction using the neural network model shows good agreement with the experimental data.