extraction

摘要： Lithium is considered to be the most important energy metal of the 21st century.Because of the development trend of global electrification,the consumption of lithium has increased significantly over the last decade,and it is foreseeable that its demand will continue to increase for a long time.Limited by the total amount of lithium on the market,lithium extraction from natural resources is still the first choice for the rapid development of emerging industries.This paper reviews the recent technological developments in the extraction of lithium from natural resources.Existing methods are summarized by the main resources,such as spodumene,lepidolite,and brine.The advantages and disadvantages of each method are compared.Finally,reasonable suggestions are proposed for the development of lithium extraction from natural resources based on the understanding of existing methods.This review provides a reference for the research,development,optimization,and industrial application of future processes.

摘要： PIMs(Polymer Inclusion Membranes)are popular in molecular transport in different solutions.Most often they are used in the transport and removal of ionic compounds,for example metal ions or organic ionic compounds.In this work,membranes were used as extraction devices for isolation of pharmaceuticals from water samples.PIMs were composed of CTA(Cellulose Triacetate)as polymeric matrix,2-NPOE(2-Nitrophenylo Octyl Ether)as plasticizer,and alkyl quaternary ammonium salt(Aliquat 336)was used as the carrier.The influence of the carrier and plasticizer presence on PIM’s extraction efficiency was described.This extraction deice was used for isolation of ibuprofen,ascorbic acid and paracetamol form water samples.The best retention percentage on polymer membranes was achieved between 80%-100%for three components membranes.The extraction ability of polymeric membranes was described and confirmed using HSP(Hansen Solubility Parameter)determined for each analyte and membrane components.Determination of these parameters allows describing the interaction between the analytes and membrane and concludes which membrane composition gives the best properties.All qualitative and quantitative analysis was done using HPLC(High Performance Liquid Chromatography).

摘要： The Hyperbaric and Diving Medicine Centre of Singapore provides regular treatment for various UHMS indications for hyperbaric treatment in our dual multi-place connected chambers. When any single patient requires evacuation during the treatment, a connected dual chamber facility is advantageous to avoid disruption for the remaining patients. We share our experience and procedures to facilitate repeated unexpected evacuation with minimal disruption to other patients undergoing treatment, in an elderly semiactivity dependent patient who had gastrointestinal symptoms during treatment.

摘要： More and more attention has been paid to the polysaccharide components of Dendrobium officinale (D. officinale). They are rich in active components and have extensive pharmacological effects. This paper systematically summarized the extraction, separation, purification process, content determination, chemical compositions and pharmacological activities of D. officinale polysaccharides, which provided the basis for the preparation, quality control and further development and utilization of the medicinal materials.

摘要： N-alkyl imidazolium carbonate ionic liquids were employed to separate and recover naphthenic acid from model oils.The effects of the cationic and anionic structures of ionic liquids and operating conditions on the deacidification performance were investigated.The deacidification performance of traditional organic solvents was also investigated for comparison.The results indicated that the naphthenic acid could be completely removed from the model oil with a small mass ratio of ionic liquid to oil.The extracted naphthenic acid was regenerated with a recovery of up to 92%.In addition,imidazolium carbonate ionic liquids could be successfully regenerated and recycled.The mechanism of interaction between imidazole ionic liquids and the naphthenic acid molecules were explained by Gauss calculation.

摘要： In this study, the influence of provenance and extraction methods on the physicochemical properties and the antioxidant potential of M. charantia seeds oil were evaluated. The oil is obtained on the one hand by cold extraction with hexane and on the other hand by hot extraction with soxhlet. The results obtained show that the extraction yield is significantly impacted by the extraction methods and the origin of the seeds. In addition, the soxhlet extraction gives a higher oil yield (32.07 ± 0.01). Cold extraction has made it possible to obtain oils with less attenuated physicochemical characteristics. Indeed, the acid numbers are high in the oils extracted by soxhlet (5.92 ± 0.25;4.25 ± 0.62 and 13.86 ± 0.83) than in those cold extracted with very low peroxide for all the oils obtained. On the other hand, the iodine and refractive indices are high in oils obtained cold (91.58 ± 0.85;100.74 ± 0.03 and 102.08 ± 0.28) (1.53 ± 0.01;1.52 ± 0.01 and 1.52 ± 0.01) with low saponification indices. The polyphenol concentrations and the anti-free radical activity are higher with the oils obtained cold (0.086 ± 0.001;0.08 ± 0.000 and 0.09 ± 0.01 mgEAG/g of oil) and (DPPH) (55.75% ± 1.16%;55.03% ± 0.72% and 56.35% ± 0.45%). The color parameters (L*, a* and b*) of the different oils extracted also vary depending on the extraction method used. Principal Component Analysis (PCA) and correlation analysis were performed on the physicochemical properties and the antioxidant potential of the extracted oils. Therefore, the results suggest cold extraction to obtain a good quality and oxidation resistant oil.

摘要： Due to their interesting properties, bamboo fibers are more and more used as reinforcements in polymer matrices as a substitute for synthetic fibers. For their future service life, it is important to understand their physical and mechanical behavior over time in order to control the aging phenomenon within this fiber. The paper analyzed the influence of the age of the bamboo thatch and the vertical position of the Bambusa vulgaris species cultivated in Cameroon on the physicomechanical properties of the fibers extracted from the thatch. Fibers were mechanically extracted from three bamboo culms aged respectively 3 years (BV3), 4 years (BV4) and 5 years (BV5). The culms were thus identified according to their number of ramifications, and were felled no abated for a total of three culms. A section of about one meter on each of the parts (lower part, middle part, upper part) of these three culms was made for the opposite technological studies. Each age was therefore represented by three portions of thatch, one from the upper part, one from the middle part and the last from the lower part of the thatch, all giving a total number of nine samples taken and marked BV3inf, BV3moy, BV3sup, BV4inf, BV4moy, BV4sup, BV5inf, BV5moy, BV5sup before handling in the laboratory. Physical (density, moisture absorption rate) and mechanical (tensile tests according to DIN EN ISO 13934-1, natural durability) characterizations were used to better understand the mechanisms of this influence. In view of all the results obtained, the fiber from the upper part of the 3-year-old thatch (BV3sup) is the one with the best characteristics and is recommended for a better elaboration of bamboo fiber composites: (Density: 0.83;Absorption rate 11.7%;Young’s modulus: 7.4 GPa;Maximal stress: 64.3 MPa;Elongation at rupture: 1.1;Loss of mass natural durability: 7.63%).

摘要： Polyphenol is an important secondary metabolite with unique physiological functions and biological activity.The polyphenols in different plants and biomass have different chemical structures,which needs various extraction methods to obtain them.Recently,plant polyphenols and their application research in food and medicine have become a research hotspot,which is mainly focused on preparation,purification,structural identification,and biological activity assays.Among these researches,extraction and separation are the key sections to investigate the structure and activity of polyphenol.Hence,this review summarized the recent extraction and separation techniques of polyphenol,including solvent extraction,supercritical fluid extraction,ultrasonic extraction,enzymatic extraction,resin adsorption extraction,and electric field method,etc.In addition,this review also reveals the current problems and proposes future extraction research of polyphenol.It is hoped that this review will provide a guide for the researchers who are actively committed to promoting progress in the field of polyphenolics.

摘要： Xylooligosaccharides(XOS)are mainly derived from lignocellulosic materials,such as rice husk,corn cobs,straw,wheat bran,wheat straw and other grain by-products.XOS have become one of the functional oligosaccharides of great concern at home and abroad due to their beneficial functional properties,such as low calorie,high stability,poor digestibility and high performance in proliferating probiotics.At present,the XOS extraction methods from grain byproducts mainly include autohydrolysis,acidolysis and enzymolysis.Among them,autohydrolysis has high requirements for equipment for achieving higher extraction rate and higher purity of products;and acidolysis can cause environmental pollution due to the usage of harmful reagents.Enzymolysis is the most common method for the production of XOS because of its high convenience,high efficiency and no pollution;and the widely used enzyme is the xylanase from Aspergillus niger.Current researches have showed that XOS can be utilized by probiotics such as Bifidobacteria and Lactobacillus to exert prebiotic effects,such as optimizing intestinal flora,promoting intestinal health,improving intestinal barrier,enhancing immune function,improving antioxidant capacity and so on.However,XOS extracted from the grain byproducts contain a large amount of impurities,which limits their industrial application and makes it dif-ficult to control the product quality.Therefore,XOS refining,separation and purification has become the key to their subsequent industrial application.This paper reviewed the current status of XOS extraction technologies from various grain by-products,and also summarized the prebiotic effect of XOS to provide reference for industrial production of XOS and its wide application in prebiotics market,thereby facilitating utilization and development of grain byproducts.

摘要： Recently,there has been considerable interest in the use of microchannel reactors for hydrometallurgy of rare earths(REs).Here,a novel integrated microchannel reactor based on the hollow-strut SiC foam material is presented and demonstrated to extract Ce^(3+)and Pr^(3+)using 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester(P507)as the extractant.The typical three-dimensional reticulated structure of the hollow-strut SiC foam was characterized by scanning electron microscopy and X-ray micro computed tomography.Since the reactor’s structure plays a key role in fluid mixing and mass diffusion during the extraction process,the structure-performance relationship of the foam was studied by extraction experiments combined with numerical simulations.Using the foam with the optimal structure,the influence of the flow rate Q_(0) of the two liquid phases on the extraction efficiency η and overall volume mass transfer coefficient KLa was discussed.For both RE ions,with increasing Q_(0),η decreases while KLa increases.For the total flow rate of the two phases of 4 ml·min^(-1),the η values of Pr^(3+)and Ce^(3+)reached 98.7%and 97.0%,respectively.For the total flow rate of 36 ml·min^(-1) which was much higher than that of many other microchannel reactors reported in the literatures,the η values of Pr^(3+)and Ce^(3+)still reached 92.2%and 86.9%,respectively,and the KLa values of Pr^(3+)and Ce^(3+)were 0.198 and 0.161 s^(-1),respectively,similar to the high values reported for other microchannel reactors studied in previous work.These findings indicate that the hollow-strut SiC foam microchannel reactor is suitable for use in REs extraction.