scholarly journals Determination of the structural and chemisorption characteristics of granulated active charcoal on the basis of coconut shell

2004 ◽  
Vol 58 (9) ◽  
pp. 416-422
Author(s):  
Dragan Milenkovic ◽  
Stanisa Stoiljkovic ◽  
D.R. Ilic
Keyword(s):  
Mathematical Model ◽  
Aqueous Solution ◽  
Structural Characteristics ◽  
Active Charcoal ◽  
Wastewater Purification ◽  
Industrial Plants ◽  
Coconut Shells ◽  
Kinetics Of ◽  
Regression Correlation

Wastewater purification and the acquirement of drinking water from water streams that are in most cases recipients of various industrial plants, present a significant problem nowadays. The structural characteristics of granulated active charcoal (GAC) obtained by the carbonization of coconut shells and activated by steam are presented in this paper. The established kinetics of suspending cyanide from aqueous solution using GAC impregnated with copper(II) acetate were studied and a mathematical model estabkusged by a regression - correlation analysis.

Enhancement of carboxylic acid degradation with sulfate radical generated by persulfate activation

2010 ◽  
Vol 61 (5) ◽  
pp. 1221-1226 ◽  
Author(s):  
J. Criquet ◽  
P. Nebout ◽  
N. Karpel Vel Leitner
Keyword(s):  
Aqueous Solution ◽  
Citric Acid ◽  
Carboxylic Acids ◽  
Sulfate Radical ◽  
Acid Degradation ◽  
Competitive Reactions ◽  
Radical Production ◽  
Persulfate Activation ◽  
Kinetics Of

The aim of this work was to investigate the generation of sulfate radical for the removal of two carboxylic acids in aqueous solution: acetic and citric acids. From photochemical and radiolytic processes, kinetics of the degradation of these two carboxylic acids was studied as a function of the pH of the solution. It was shown that the maximum of acetic acid degradation occurred at pH 5. Above this pH, competitive reactions with the carbon mineralized inhibit the reaction of with the solute. In the case of citric acid, pH has only a little effect on the kinetic of citric acid degradation. The determination of mineralization yields shows several differences depending on carboxylic acids and pH. The degradation of both carboxylic acids was also studied in the radiolysis process whether with or without persulfate addition. A comparison of the processes of sulfate radical production is presented.

Determination of the intensity of polychromatic radiation in the reaction compartment as a function of wavenumber

1991 ◽  
Vol 56 (6) ◽  
pp. 1173-1179 ◽  
Author(s):  
Radim Hrdina ◽  
Igor Čepčiansky ◽  
Hana Bittová
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
High Pressure ◽  
Emission Spectrum ◽  
Photochemical Reactions ◽  
Tabular Form ◽  
Mercury Lamp ◽  
Kinetics Of ◽  
Polychromatic Radiation

A procedure is suggested for studying the kinetics of photochemical reactions using excitation with polychromatic radiation, where the wavenumber dependence of the intensity of the polychromatic radiation entering the reaction compartment must be known. The observed relative intensities of the polychromatic source are calibrated by ferrioxalate actinometry, selected parts of the emission spectrum being eliminated by insertion of filters. The relative intensities of an HBO 200 high-pressure mercury lamp were measured. For the sake of brevity, the experimental data were fitted by a mathematical model (a polynominal), and only the parameters of the polynomial are presented in a tabular form.

Capillary Scanning of a Porous Matrix. Experimental Techniques and Processing of its Results

2019 ◽  
Vol 7 (4) ◽  
pp. 29-42
Author(s):  
А. Синцов ◽  
A. Sintsov ◽  
Владимир Девисилов ◽  
Vladimir Devisilov
Keyword(s):  
Mathematical Model ◽  
Porous Structure ◽  
Structural Characteristics ◽  
Experimental Methods ◽  
Porous Matrix ◽  
Experimental Setup ◽  
Porous Structures ◽  
Porous Sample ◽  
Starting Position

The article presents an analysis of the possibilities of the previously unused method for the experimental study of porous permeable materials and the determination of their structural characteristics. The purpose of the experiment is to determine the geometric parameters of the porous matrix, which integrates the characteristics of the porous material. An example of analytical scanning of a porous structure is considered. A review of existing experimental methods is given. A scheme of the experimental setup, methods for conducting a capillary experiment and processing the data obtained are proposed. As an example, a mathematical model of the experiment is used, illustrating the possible results of the study of a porous sample. It is shown how the results of experiments are transformed into a porous matrix and are interpreted as its capillary scanning. It is proved that this model of porous structure can be used as a starting position in the mathematical calculations of the processes occurring in porous structures.

scholarly journals Determination of Hydration Kinetics of Sulfaguanidine Anhydrate in Aqueous Solution by Calorimetry.

2000 ◽  
Vol 48 (2) ◽  
pp. 208-210
Author(s):  
Yasuo YOSHIHASHI ◽  
Etsuo YONEMOCHI ◽  
Midori MAKITA ◽  
Shigeo YAMAMURA ◽  
Eihei FUKUOKA ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydration Kinetics ◽  
Kinetics Of

Modified factor analysis of the circular dichroism spectra, applied to a series of cyclodipeptides containing L-proline

1979 ◽  
Vol 44 (4) ◽  
pp. 1296-1311 ◽  
Author(s):  
Petr Pančoška ◽  
Ivo Frič ◽  
Karel Bláha
Keyword(s):  
Mathematical Model ◽  
Factor Analysis ◽  
Hilbert Spaces ◽  
Principal Components ◽  
Structural Characteristics ◽  
Cd Spectra ◽  
Modified Method ◽  
Minimum Number ◽  
Related Compounds

A mathematical model has been developed which uses the theory of Hilbert spaces and the modified method of the principal components of the factor analysis to the determination of the minimum number of subspectra sufficient to describe a set of experimental CD curves of a series of structurally related compounds. The use of this method has been demonstrated on the CD spectra of nine cyclodipeptides containing (besides L-proline) glycine, L or D alanine, L or D valine, L or D leucine, and L or D tert-leucine, measured in acetonitrile and 2,2,2-trifluoroethanol. Relation is discussed between the calculated subspectra and the structural characteristics of the measured systems.

scholarly journals KINETICS OF A BINARY MIXTURE DECOMPOSITION IN RELATIONTO THE EFFECTS ON OIL RESERVOIR

2017 ◽  
pp. 67-72
Author(s):  
A. I. Varavva ◽  
V. E. Vershinin ◽  
R. A. Idiatullin
Keyword(s):  
Mathematical Model ◽  
Aqueous Solution ◽  
Binary Mixture ◽  
Decomposition Reaction ◽  
Oil Reservoir ◽  
Thermal Pressure ◽  
Temperature Growth ◽  
Mixture Decomposition ◽  
Kinetics Of ◽  
Stimulation Of

The kinetic constants of the decomposition reaction of an aqueous solution of a binary mixture used for thermal-pressure induced impact on the bottomhole zone during stimulation of oil inflow are determined. The obtained constants allow predicting the effects of pressure and temperature growth in the reaction zone. A mathematical model is proposed that makes it possible to describe the kinetics of the reaction taking into account the escape of gas.

Practices for modeling oil shale pyrolysis and kinetics

2017 ◽  
Vol 34 (1) ◽  
Author(s):  
Muhammad Afzal Raja ◽  
Yongsheng Zhao ◽  
Xiangping Zhang ◽  
Chunshan Li ◽  
Suojiang Zhang
Keyword(s):  
Oil Shale ◽  
Structural Characteristics ◽  
Pyrolysis Gas ◽  
Multiple Reactions ◽  
Oil Shale Pyrolysis ◽  
Structural Skeleton ◽  
Gas Chromatography Mass Spectroscopy ◽  
Kerogen Pyrolysis ◽  
Kinetics Of

AbstractOil shale is one of the largest, relatively undeveloped natural fossil fuel resources in the world and so an important potential source of energy. The organic matter of oil shale is present as a complex combination of carbon, hydrogen, sulfur and oxygen named kerogen. Pyrolysis-gas chromatography-mass spectroscopy affords the opportunity to chemically characterize the main structural skeleton in this kerogen and is a favorable method to study the structural characteristics of kerogen at a molecular level. The thermal degradation of oil shale kerogen is a complex chemical process, accompanied by the wide variety of products obtained, which poses difficulties in the determination of the kinetics and mechanism of pyrolysis. Understanding the kinetics of kerogen decomposition to oil is critical to design a viable retorting process. Comprehensive kinetic data are also essential for accurate mathematical modeling of various oil shale processes. Classic graphical methods cannot unambiguously measure and estimate kinetic parameters due to the mathematical complexity. Advanced isoconversion methods would be appropriate for the calculation of the distribution of activation energies for multiple reactions involved in the decomposition of complex material such as kerogen to products. The range of variability in the principal activation energy is from about 200 to 242 kJ mol

scholarly journals Continuous assay for acid phosphatase using 1-naphthyl phosphate as a substrate.

1997 ◽  
Vol 44 (4) ◽  
pp. 853-860 ◽  
Author(s):  
E Luchter-Wasylewska
Keyword(s):  
Aqueous Solution ◽  
Steady State ◽  
Acid Phosphatase ◽  
Reverse Micelles ◽  
Prostatic Acid Phosphatase ◽  
Precise Determination ◽  
Ph Range ◽  
Phosphatase Assay ◽  
Kinetics Of

The described continuous acid phosphatase assay is based on kinetics of the release of 1-naphthol in the course of the enzyme-catalyzed hydrolysis of 1-naphthyl phosphate, measured at 320 nm in aqueous solution and at 322 nm in sodium-bis(2-ethylhexyl)sulfosuccinate isooctane-water reverse micelles in a broad pH range (1.0-8.2). The method allows precise determination of the initial rate of the reaction and therefore may be used in the steady-state and pre-steady-state studies on the phosphatase-catalyzed reaction. The kinetic parameters (Km and kcat) for human prostatic acid phosphatase in aqueous solution and in reverse micelles, at pH 3.8, 4.5 and 5.7, by the proposed 1-naphthyl phosphate assay have been determined.

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