Extraction Of Organic Components Research Articles

Optimization of the Efficient Extraction of Organic Components in Atmospheric Particulate Matter by Accelerated Solvent Extraction Technique and Its Application

Organic components in atmospheric fine particulate matter have attracted much attention and several scientific studies have been performed, although most of the sample extraction methods are time consuming and laborious. Accelerated solvent extraction (ASE) is a new sample extraction method offering number of advantages, such as low extraction cost, reduced solvent and time consumption, and simplified extraction protocols. In order to optimize ASE methods to determine the concentrations of organic compounds in atmospheric fine particulate matter, different parameters were set out for the experiment, and the optimal method was selected according to the recoveries of the standard (i.e., n−alkanes and polycyclic aromatic hydrocarbons (PAHs)). This study also involves a comparison of the optimal method with the traditional method of ultrasonic extraction (USE). In addition, the optimized method was applied to measure the mass concentrations of organic compounds (n−alkanes and PAHs) in fine particulate matter samples collected in Beijing. The findings showed that the average recovery of target compounds using ASE was 96%, with the majority of compounds falling within the confidence levels, and the ASE recoveries and precision were consistent with the USE method tested. Furthermore, ASE combines the advantages of high extraction efficiency, automation, and reduced solvent use. In conclusion, the optimal ASE methods can be used to extract organic components in atmospheric particulate matter and serve as a point of reference for the development of analytical methodologies for assessing organic compounds in atmospheric particulate matter in China.

Improving the efficiency of technological processes for the treatment of highly concentrated wastewater to ensure environmental safety

The complexity of biochemical wastewater treatment is most often due to the presence of a large number of organic impurities, causing the death of the biological community of activated sludge microorganisms. Application of the method of lowering the pH of industrial effluents to minimum value reduces the solubility of organic substances in water, separating them into a separate layer of emulsified wastewater. In this case, the process of removing organic impurities from treated wastewater becomes the most accessible, but also requires solving the problems of technological and environmental safety. Dissolution of wastewater organic impurities separated into a separate layer a solvent – the extractant followed by the extraction of organic components extracted from it, reduces the level of wastewater pollution with organic substances according to the oxidation index (COD) to an acceptable level. The technology of the applied method allows for the final treatment using biological methods; and practically constructively mounts and build a new modernized technological line.

Evaluation of the bovine tendon decellularization method in the development of a cruciate ligament prosthesis

Introduction. Ligaments play a critical role in the body, linking bones together. Ligament ruptures are the most common manifestations of serious musculoskeletal injuries. This is especially true for the anterior cruciate ligament of the knee joint. In trauma surgery, orthopedics, the ligament functional recovery can be achieved by using tissue autografting, synthetic and biological prostheses. Of great interest to surgeons is the use of prostheses made of biological tissues of animal origin, since they are easily available and, when high-quality processing is achieved, they are safe, retaining their natural structure and strength. Purpose of the study. To decellularize the bovine tendon according to our originally developed technique and to investigate its efficacy in terms of the presence of cellular elements and physical and mechanical parameters of the material. Material and methods. To manufacture the prototype of the ligament prosthesis product, we developed the technique for processing the bovine tendon, as the most similar material by structure, including its mechanical processing, chemical and physical processing methods and a special treatment with supercritical carbon dioxide fluid containing nonionic surfactant Tween-80 for decellularization and extraction of organic components in addition to collagen framework, while maintaining strength properties. Histological studies were performed to check for the residues of cellular elements, and the measurements of the physical and mechanical properties of the material were made. Results. Histological examination of the material showed that after processing, 0–2 cells in the field of view were found in the material. The strength properties of the material were 503 kgf/mm2 before processing and 605 kgf/mm2 after processing. Conclusion. The data obtained in the study confirmed that the processing performed qualitatively affected the elimination of cells, did not worsen but even increased the mechanical strength of the material. Further study of the biocompatible properties of the material is required.

Waste Management in Propylene Epoxidation Process with the Use of Supercritical Fluid Media

Experimental results on solubility of the styrene, phenol, methylphenylcarbinol, acetophenone, ethyl benzene, propylene glycol and molybdenum as a complex with Trilon B in supercritical CO2 obtained using a dynamic (flow) method are presented. The obtained data are described in the framework of Peng-Robinson equation. The results of the experients on the extraction of organic components from waste formed in the olefin epoxidation process at Nizhnekam-skneftekhim Inc., on the analysis of extract composition, and on the testing of the extract as an epoxidation catalyst are presented. The supercritical water oxidation (SCWO) process of epoxidation process waste was conducted in periodical and continuous mode. The analysis results of reaction product are given. Pilot experiments on dry sediment formation were conducted using Radio Frequency (RF) Inductively Coupled Plasma (ICP) of low pressure.

Extraction of organic components from wastewater by pervaporation

In the run of the last decades the coming up of new technologies as well as new needs has increased the interest in wastewater treatment. This study concerns the synthetic membrane development; synthesis of polymers for membrane preparation and the extraction of volatile organic components in aqueous media by pervaporation through polydimethylsiloxane, which is the most frequently used polymer material for the active layer of pervaporation for the extraction of organic compounds from wastewater. This elastomer has some special characteristics: high hydrophobicity, high permeability, good thermal and mechanical resistance and easy manufacture of the active layer on asymmetric substrate. The elastomer is a cross-linked material in which the degree of cross-linking and the structure of the network theoretically depends uniquely on the chemical structure. In this work we study the influence of some parameters of the preparation procedure on the membrane properties. Sorption of ethyl acetate, an aroma model, in pure state and in aqueous solution of different concentrating was performed and analysed. The curing was also carried out at different temperatures. The membrane physical properties (density, shore hardness and elasticity) were determined. Finally, in order to predict quantitatively the solvent contents in the membrane at the upstream face in pervaporation flux, we used floury, Huggins approach which appears to be valid in its simplified form.

Extraction of organic components from aqueous streams by vacuum membrane distillation

The removal of volatile organic compounds from aqueous streams by vacuum membrane distillation (VMD) has been analyzed. VMD is an evaporation process which takes place through microporous hydrophobic membranes; at low pressure the mass transfer through the membrane is generally dominated by the Knudsen mechanism, while the process selectivity is essentially determined by the liquid-vapor equilibrium conditions existing at the interface. Dilute aqueous mixtures containing ethanol or methylterbutyl ether have been experimentally investigated, in a wide range of operating conditions. The role of concentration-polarization phenomena on the separation factor was also investigated. A detailed model of the transport phenomena involved in the process is developed and compared with the experimental data. A VMD system is finally designed for the purification of waste waters and the related treatment costs are evaluated.

Separation efficiency in vacuum membrane distillation

Vacuum membrane distillation has been analyzed as a separation process for aqueous mixtures. The total permeate flux obtained is affected by two simultaneous resistances, those due to the heat and mass transfer processes which take place through the liquid phase and through the membrane respectively. On the other hand, the separation factor is highly sensitive to the mass transfer resistance existing within the liquid phase. Different applications have been considered such as extraction of organic components, degassing of water and evaporation of pure water. In all cases appropriate design equations for shell and tube equipment have been obtained and solved. In parallel, appropriate criteria for a priori recognition of the principal resistances have been formulated.

A high pressure liquid chromatographic method for the quantitation of sub-microgram amounts of zearalenone (F-2) in agricultural products.

A highly sensitive and reliable method for the quantitation of sub-microgram quantitaties of zearalenone (F-2) residues in corn, corn oil and mixed feed is described. The isolation of this mycotoxin from a mixed solvent extract involves partitioning of the alkali soluble components from a chloroform solution, followed by acidification and extraction of organic components into chloroform, a silica gel column clean-up and analysis by high pressure liquid chromatography using a ultraviolet (UV) detector at 280 nm. The limit of detection of the instrument is shown to be 2.5 ng and that of the method is 100 ppb. The percent recoveries of zearalenone in corn is found to be 72.1 +/- 6.0 at the levels between 0.1 and 1.0 ppm, in corn oil 72.6 +/- 8.8 at levels 0.25 and 1.0 ppm and in pig starter 67.3 +/- 4.5 at 1.0 ppm level. In the case of two field samples, the reproducibility of analysis is very good and the mycotoxin contents are shown to be 11.5 +/- 0.26 and 0.61 +/- 0.07 ppm.

STUDIES IN THE TRANSPLANTATION OF BONE

1. The present study is an attempt to analyse and apportion significance to the role of inductive mechanisms in bone transplantation. 2. The experimental model used in the present work is that of the composite homograftautograft of cancellous bone previously described (Burwell 1964a). 3. Iliac bone was removed from hooded rats and washed free from its marrow. The bone was then treated by various physical and chemical methods (some of which have been used by other workers to prepare bank bone), namely freezing (-20 degrees Centigrade, -79 degrees Centigrade, -196 degrees Centigrade); freeze-drying (without sterilisation, sterilisation with high energy radiation, sterilisation with ß-propiolactone); decalcification (with E.D.T.A.); irradiation (in the frozen state at a dose of 4 million rads); boiling in water; immersion in merthiolate solution; extraction of organic components with ethylenediamine: and calcining at 660 degrees Centigrade. The treated bone was then impregnated with fresh autologous marrow procured from the femoral shaft of the Wistar rat into which the treated composite graft was to be implanted. The grafts were inserted intramuscularly and removed for study after two, six and twelve weeks. 4. After fixation, serial sectioning and staining, each graft was examined microscopically, and the proportion of new bone/grafted bone scored using an arbitrary scale (0-4). The mean score (and the standard error of the mean score) was then plotted for each treated composite graft and also for several types of fresh cancellous bone grafts. 5. It was found (Fig. 2) that the various treated composite grafts formed a spectrum of bone-forming capacities–the maximum scores being attained by the frozen and freeze-dried composite grafts, the lowest scores by the "deproteinised" composite grafts. 6. The reasons for these differences are discussed. It is concluded that cancellous bone, after transplantation, has the property to induce and promote osteogenesis in marrow; moreover, that this property is contained in the organic components of bone. 7. From the standpoint of inductive mechanisms, cancellous bone treated by freezing or freeze-drying seems to be the most suitable devitalised bone for grafting purposes; bone which has been boiled or merthiolated less suitable; and "deproteinised" bone the least suitable. 8. Freeze-dried bone sterilised physically (by high energy radiation) or chemically (by ß-propiolactone) did not form significantly less new bone than did freeze-dried bone which had not been sterilised. 9. Remodelling mechanisms in bone transplantation are briefly discussed and attention drawn to the deficiencies of present knowledge. The quantitative studies of other workers have indicated that freeze-dried bone may be more rapidly remodelled than is frozen bone. 10. The importance of fresh red marrow in promoting osteogenesis in bone transplantation and in the healing of certain fractures, is emphasised. It seems likely that the interrelationship of bone and marrow revealed by experiment has wider significance not only in health and in response to injury but also in causation of certain idiopathic bone disorders.