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Journal Details
Format
Journal
eISSN
1899-4741
First Published
03 Jul 2007
Publication timeframe
4 times per year
Languages
English

Search

Volume 16 (2014): Issue 2 (June 2014)

Journal Details
Format
Journal
eISSN
1899-4741
First Published
03 Jul 2007
Publication timeframe
4 times per year
Languages
English

Search

20 Articles
Open Access

Separation and Concentration of Succinic Adic from Multicomponent Aqueous Solutions by Nanofiltration Technique

Published Online: 26 Jun 2014
Page range: 1 - 4

Abstract

Abstract

This paper applies the determined suitability of nanofiltration (NF) membrane separation for selective isolation and concentration of succinic acid from aqueous solutions which are post-fermentation multicomponent fluids. The study analyzed the influence of concentration and the pH of the separated solutions on the efficiency and selectivity of NF process that runs in a module equipped with a ceramic membrane. Moreover, the effect of applied trans-membrane pressure on the retention of succinic acid and sodium succinate has been studied. The investigations have shown that in the used NF module the retention of succinic acid salt is equal almost 50% in the case of a three-component model solution, although the degree of retention depends on both the transmembrane pressure and the initial concentration of separated salt.

Keywords

  • glycerol bioconversion
  • fermentation broth
  • succinic acid
  • nanofiltration
  • ceramic membrane
Open Access

Morphological Evaluation of Variously Intercalated Pre-baked Clay

Published Online: 26 Jun 2014
Page range: 5 - 11

Abstract

Abstract

The use of porous materials is enjoying tremendous popularity and attention of the advance scientific communities due to their excellent adsorptive and catalytic activities. Clays are one of the most important candidates in the porous community which shows the above mentioned activities after modifing with a different intercalating agent. The paper is focused on the infiuence of some inorganic intercalating agents (NaOH) on the morphology of the variously intercalated clay samples. The alkali metal was used as the inorganic intercalating agent. The effect of intercalation temperature, intercalation agent concentration and intercalation time on the pre-baked clay morphology were also part of the study. Scanning electron microscopy (SEM) study was performed to evaluate the morphological changes of the resultant intercalates. Different morphological properties were improved significantly in the case of the inorganically modified clay samples. Thus, such intercalations are suggested to be effective if the clays under study are to be used for different industrial process at elevated conditions.

Keywords

  • clay
  • alkali metal intercalation
  • inorganic modifier
  • scanning electron microscopy
Open Access

Binding of Industrial Deposits of Heavy Metals and Arsenic in the Soil by 3-Aminopropyltrimethoxysilane

Published Online: 26 Jun 2014
Page range: 12 - 15

Abstract

Abstract

The results of the research studies concerning binding of heavy metals and arsenic (HM+As), occurring in soils affected by emissions from Głogów Copper Smelter and Refinery, by silane nanomaterial have been described. The content of heavy metals and arsenic was determined by AAS and the effectiveness of heavy metals and arsenic binding by 3-Aminopropyltrimethoxysilane was examined. The total leaching level of impurities in those fractions was 73.26% Cu, 74.7% – Pb, 79.5% Zn, 65.81% – Cd and 55.55% As. The studies demonstrated that the total binding of heavy metals and arsenic with nanomaterial in all fractions was about as follows: 20.5% Cu, 9.5% Pb, 7.1% Zn, 25.3% Cd and 10.89% As. The results presented how the safety of food can be cultivated around industrial area, as the currently used soil stabilization technique of HM by soil pH does not guarantee their stable blocking in a sorptive complex.

Keywords

  • nanotechnology
  • heavy metals
  • soil stabilization
Open Access

Comparison of Hydrolytic Resistance of Polyurethanes and Poly(Urethanemethacrylate) Copolymers in Terms of their Use as Polymer Coatings in Contact with the Physiological Liquid

Published Online: 26 Jun 2014
Page range: 16 - 26

Abstract

Abstract

PU elastomers were synthesized using MDI, PTMO, butane-1,4-diol or 2,2,3,3-tetrafiuorobutane-1,4-diol. Using the same diisocyanate and polyether reagents urethane segments were prepared, to be inserted in the poly(urethane-methacrylate) copolymers. Bromourethane or tetraphenylethane-urethane macroinitiators were used as transitional products reacting with MMA according to the ARGET ATRP. 1H and 13C NMR spectral methods, as well as DSC and TGA thermal methods, were employed to confirm chemical structures of synthesised elastomers and copolymers. To investigate the possibility of using synthesized polymers as biomaterials a research on keeping them in physiological liquid at 37°C was performed. A loss in weight and ability to sorption of water was determined and by using GPC the molecular weight changes were compared. Additionally, changes in the thermal properties of the samples after exposure in physiological liquid were documented using both the TGA and DSC methods. The studies of surface properties (confocal microscopy and SFE) of the obtained polymers were performed. The structure of the polymer chains was defined by NMR. Possible reasons of hydrolysis were discussed, stating that new copolymers are more resistant and polar biomaterials can be less interesting than elastomers.

Keywords

    Open Access

    Removal of Organic Dyes from Aqueous Solutions with Surfactant-Modified Magnetic Nanoparticles

    Published Online: 26 Jun 2014
    Page range: 27 - 30

    Abstract

    Abstract

    The paper presents the results of studies on the possibility of using magnetic nanoparticles modified with selected hydrophobic surfactants for model post-production water purification. Colloidal solutions of iron hydroxide (III) and iron oxide (II and III) were obtained and their particles were subjected to surface modification using surfactants. Thus obtained magnetic fluids were used as active agents in the process of removing selected organic dyes from their aqueous solutions. The effectiveness of the modified compounds was analysed using spectrophotometric methods. It has been shown that the effectiveness of the process depends on the type of surfactant used to modify selected magnetic nanoparticles.

    Keywords

    • organic dyes
    • iron compounds
    • magnetic fluids
    • surfactants
    • ecology
    Open Access

    Application of Response Surface Methodology for Optimization of Permeabilization Process of Baker’s Yeast

    Published Online: 26 Jun 2014
    Page range: 31 - 35

    Abstract

    Abstract

    Permeabilization was used for the purpose of transforming the cells of microorganisms into biocatalysts with an enhanced enzyme activity. Baker’s yeast cells were permeabilized with various organic solvents. A high degree of catalase activity was observed upon permeabilization with acetone, chloroform, isopropyl alcohol and ethyl acetate. Response surface methodology was used to model the effect of concentration of isopropyl alcohol, temperature and treatment time on the permeabilization of baker’s yeast cells to maximize the decomposition of H2O2. The optimum operating conditions for permeabilization were observed at 53.7% concentration of isopropyl alcohol, treatment time of 40 min and temperature of 15.6oC. A maximum value of catalase activity was found to be 6.188 U/g wet wt. and was ca. 60 times higher than the catalytic activity of yeast not treated by the permeabilization process.

    Keywords

    • permeabilization
    • baker’s yeast
    • response surface methodology
    • isopropyl alcohol
    Open Access

    Use of MgO to Promote the Oxyethylation Reaction of Lauryl Alcohol

    Published Online: 26 Jun 2014
    Page range: 36 - 42

    Abstract

    Abstract

    Synthesis of magnesium hydroxide was performed by the precipitation method with the use of magnesium sulfate and sodium hydroxide. The infiuence of temperature and ratio of reagents was studied. Magnesium hydroxides, and the magnesium oxides obtained from them by thermal decomposition, were analyzed to determine their bulk density, polydispersity and particle size. The magnesium oxide with the largest surface area was tested as a catalyst in the oxyethylation of lauryl alcohol, and shown to be selective but poorly reactive in comparison with commercially available catalysts. Further studies are needed to improve its reactivity.

    Keywords

    • magnesium hydroxide and oxide
    • precipitation
    • dispersive and structural properties
    • oxyethylation
    • catalytic activity
    Open Access

    Comparative Studies of Electrospinning and Solution Blow Spinning Processes for the Production of Nanofibrous Poly(L-Lactic Acid) Materials for Biomedical Engineering

    Published Online: 26 Jun 2014
    Page range: 43 - 50

    Abstract

    Abstract

    Comparative statistical analysis of the infiuence of processing parameters, for electrospinning (ES) and solution blow spinning (SBS) processes, on nanofibrous poly(L-lactic acid) (PLLA) material morphology and average fiber diameter was conducted in order to identify the key processing parameter for tailoring the product properties. Further, a comparative preliminary biocompatibility evaluation was performed. Based on Design of Experiment (DOE) principles, analysis of standard effects of voltage, air pressure, solution feed rate and concentration, on nanofibers average diameter was performed with the Pareto’s charts and the best fitted surface charts. Nanofibers were analyzed by scanning electron microscopy (SEM). The preliminary biocompatibility comparative tests were performed based on SEM microphotographs of CP5 cells cultured on materials derived from ES and SBS. Polymer solution concentration was identified as the key parameter infiuencing morphology and dimensions of nanofibrous mat produced from both techniques. In both cases, when polymer concentration increases the average fiber diameter increase. The preliminary biocompatibility test suggests that nanofibers produced by ES as well as SBS are suitable as the biomedical engineering scaffold material.

    Keywords

    • electrospinning
    • solution blow spinning
    • nanofibers
    • biomedical engineering
    • design of experiments
    • biocompatibility
    Open Access

    Quantification of the Radiative and Convective Heat Transfer Processes and their Effect on mSOFC by CFD Modelling

    Published Online: 26 Jun 2014
    Page range: 51 - 55

    Abstract

    Abstract

    The CFD modelling of heat transfer in a microtubular Solid Oxide Fuel Cell (mSOFC) stack has been presented. Stack performance predictions were based on a 16 anode-supported microtubular SOFCs sub-stack, which is a component of the overall stack containing 64 fuel cells. Both radiative and convective heat transfer were taken into account in the modelling. The heat flux value corresponded to the cell voltage of 0.7 [V]. Two different cases of the inlet air velocity of 2.0 and 8.5 [ms–1] were considered. It was found that radiation accounted for about 20–30 [%] of the total heat flux from the active tube surface, which means that the convective heat transfer predominated over the radiative one.

    Keywords

    • microtubular Solid Oxide Fuel Cell stack
    • heat transfer
    • Computational Fluid Dynamics
    • temperature distributions
    Open Access

    Pilot Study of Generation and Disposal of Municipal Solid Wastes in Selected Household in Rural Areas in the South-Western Poland

    Published Online: 26 Jun 2014
    Page range: 56 - 62

    Abstract

    Abstract

    Pilot study of the composition of wastes was carried out in 15 rural family households engaged in agricultural activity. In the study group the average resident of rural areas generates about 166 kg of municipal wastes annually. The conducted studies showed that the composition of municipal wastes coming from rural households changes seasonally. During the periods of summer and autumn, the quantity of bio-wastes increased distinctly. The average mass of wastes transferred to the companies engaged in the collection of wastes in the analyzed rural households is almost 50 kg · M–1. year–1. The studies showed that over 80% of organic wastes (kitchen and garden) is utilized in the place where they are generated. In the studies, organic wastes were collected selectively (in separate bags), which undoubtedly had infiuence on their humidity (70–90%). Laboratory analysis of these wastes showed that the ratio C:N in it was from 7 to 19, whereas pH lay within the limits from 5.8 to 6.9 indicating its very good properties for the composting process. Therefore composting of organic waste from rural household should be recommended as the best way for its disposal and the weight reduction of biodegradable waste going to landfills. Comparison of the analyzed variants showed that some waste other than kitchen and garden does not leave the holding (it is re-used or burned in home hearths).

    Keywords

    • waste management
    • rural areas
    Open Access

    Nanocolloidal Ru/MgF2 Catalyst for Hydrogenation of Chloronitrobenzene and Toluene

    Published Online: 26 Jun 2014
    Page range: 63 - 68

    Abstract

    Abstract

    The use of magnesium fluoride support for ruthenium active phase allowed obtaining new catalysts of high activities in the hydrogenation of toluene and ortho-chloronitrobenzene. Ruthenium colloid catalysts (1 wt.% of Ru) were prepared by impregnation of the support with the earlier produced polyvinylpyrrolidone (PVP)-stabilized ruthenium colloids. The performances of the colloidal catalysts and those obtained by traditional impregnation were tested in the reactions of toluene hydrogenation to methylcyclohexane and selective hydrogenation of ortho-chloronitrobenzene (o-CNB) to ortho-chloroaniline (o-CAN). It was shown that the use of chemical reduction method allows obtaining highly monodisperse ruthenium nanoparticles of 1.6–2.6 nm in size. After reduction in hydrogen at 400oC, the colloidal ruthenium nanoparticles were found to strongly interact with MgF2 surface (SMSI), which decreased the catalyst ability to hydrogen chemisorption, but despite this, the colloid catalysts showed higher activity in o-CNB hydrogenation and higher selectivity to o-CAN than the traditional ones. It is supposed that their higher activity can be a result of high dispersion of Ru in colloid catalysts and the higher selectivity can be a consequence of the lower availability of hydrogen on the surface.

    Keywords

    • ruthenium nanocolloidal catalyst
    • magnesium fluoride
    • toluene hydrogenation
    • reduction of chloronitrobenzene
    Open Access

    The Use of Ion Exchange in the Recovery of Vanadium from the Mass of a Spent Catalyst Used in the Oxidation of SO2 to SO3

    Published Online: 26 Jun 2014
    Page range: 69 - 73

    Abstract

    Abstract

    In the studies on the recovery of vanadium from vanadium catalyst extracts, three types of polymer strongly acidic ion exchangers were used. The ion exchange resins differed in terms of granularity and their ion exchange capacity. As a result, breakthrough curves were made for three main components of the test extract, i.e.: ions of vanadium, iron and potassium. On this basis the optimum conditions for the removal of iron ions from the solution were defined and the technological concept of the process in the semi-technical scale was proposed.

    Keywords

    • spent vanadium catalyst
    • recovery of vanadium
    • ion exchange
    • solid waste utilization
    Open Access

    Carbon Shale Combustion in the Fluidized Bed Reactor

    Published Online: 26 Jun 2014
    Page range: 74 - 76

    Abstract

    Abstract

    The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm) and VOC (30 mg/m3) have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the combustion of high quality hard coal, 600 ppm and 500 ppm, respectively. Optional reduction of SO2 and NOx emission may require the installation of flue gas desulphurization and de-NOx systems.

    Keywords

    • shale coal
    • combustion
    • fluidized bed technology
    Open Access

    Infiuence of Hydrogen on the Properties of Nanostructured C-Pd Films for Sensing Applications

    Published Online: 26 Jun 2014
    Page range: 77 - 81

    Abstract

    Abstract

    In this paper we present the results of the investigations of nanostructured C-Pd films for hydrogen sensing applications. These C-Pd films were prepared by physical vapor deposition and then annealed in an argon flow at the temperature of 500°C. The structure and morphology of the prepared C-Pd films were investigated using transmission electron microscopy and energy dispersive X-ray spectroscopy. We studied the infiuence of hydrogen on the electrical properties and crystal structure of C-Pd films. It was shown that film resistance changes depended on hydrogen concentration. At lower hydrogen concentration (up to 2 vol.%), the films response increased proportionally to [H2], while above 2 vol.% H2, it was almost constant. This is connected with the formation of a solid solution of hydrogen in palladium at lower H2 concentration and the creation of palladium hydride at higher H2 concentration. X-ray diffraction was used to confirm the formation of Pd-H solid solution and palladium hydride.

    Keywords

    • C-Pd films
    • hydrogen sensor
    • GIXD measurements
    • resistance changes
    Open Access

    Separation of 1,3-Propanediol from Aqueous Solutions by Ion Exchange Chromatography

    Published Online: 26 Jun 2014
    Page range: 82 - 86

    Abstract

    Abstract

    1,3-propanediol is a promising monomer with many applications and can be produced by bioconversion of renewable resources. The separation of this product from fermentation broth is a difficult task. In this work, the application of cation exchange resin for the separation of 1,3-propanediol from model aqueous solution was examined. The best effect of separation of 1,3-propanediol from glycerol using sorption method was obtained for H+ resin form, although the observed partition coefficient of 1,3-propanediol was low. On the basis of the results of the sorption of 1,3-propanediol, the ionic forms of the resin were selected and used in the next experiments (H+, Ca2+, Ag+, Na+, Pb2+, Zn2+). The best results in ion exchange chromatography were obtained for cation exchange resin in H+ and Ca2+ form. The use of smaller particle size of resin and a longer length of the column allows to obtain better separation of mixtures.

    Keywords

    • 1,3-propanediol
    • glycerol
    • fermentation
    • sorption
    • ion exchange chromatography
    Open Access

    Removal of Ni2+ from Aqueous Solutions by Adsorption Onto Magnetic Multiwalled Carbon Nanotube Nanocomposite

    Published Online: 26 Jun 2014
    Page range: 87 - 94

    Abstract

    Abstract

    The removal of Ni2+ from aqueous solution by magnetic multiwalled carbon nanotube nanocomposite (MMWCNTs-C) was investigated. MMWCNTs-C was characterized by X-ray Diffraction method (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), surface area (BET), and Fourier Transform-Infrared Spectroscopy (FTIR). The effects of initial concentration, contact time, solution pH, and temperature on the Ni2+ adsorption onto MMWCNTs-C were studied. The Langmuir and Freundlich isotherm models were applied to fit the adsorption data. The results showed that the adsorption isotherm data were fitted well to the Langmuir isotherm model with the maximum monolayer adsorption capacity of 2.11 mg g–1. The adsorption kinetics was best described by the pseudo-second-order model. The thermodynamic parameters, such as ΔHo, ΔGo and ΔSo, were also determined and evaluated. The adsorption of Ni2+ is generally spontaneous and thermodynamically favorable. The values of ΔHo and ΔGo indicate that the adsorption of Ni2+ onto MMWCNTs-C was a physisorption process.

    Keywords

    • magnetic nanocomposite
    • multiwalled carbon nanotubes
    • nickel
    • adsorption
    Open Access

    Precipitation of Calcium Carbonate in the Presence of Urea at 293 K and 343 K

    Published Online: 26 Jun 2014
    Page range: 95 - 98

    Abstract

    Abstract

    The results of the precipitation of calcium carbonate from a waste post-distillation liquid (DS) and a sodium bicarbonate saturated solution – both from the Solvay method – in the presence of urea are presented. The investigation was carried out at 293 K and 343 K. Reagent dosage times of 1, 5, 10, 20 and 30 min, and urea concentrations of 5, 6 and 10 mol/dm3 were applied. The granulometric composition, the values of bulk and packing densities and the absorptiveness sorption of water and paraffin oil from the obtained calcium carbonate were investigated.

    Keywords

    • calcium carbonate
    • precipitation
    • sodium bicarbonate
    • urea
    • utilization
    Open Access

    High Pressure Synthesis versus Calcination – Different Approaches to Crystallization of Zirconium Dioxide

    Published Online: 26 Jun 2014
    Page range: 99 - 105

    Abstract

    Abstract

    Calcination and microwave-assisted hydrothermal processing of precipitated zirconium dioxide are compared. Characterization of synthesized products of these two technologies is presented. The infiuence of thermal treatment up to 1200oC on the structural and spectroscopic properties of the so-obtained zirconium dioxide is examined. It was found that initial crystallization of material inhibits the crystal growth up to the 800oC (by means of XRD and TEM techniques), while the material crystallized from amorphous hydroxide precursor at 400oC, exhibits 26 nm sized crystallites already. It was found using the TG technique that the temperature range 100–200oC during the calcination process is equivalent to a microwave hydrothermal process by means of water content. Mass loss is estimated to be about 18%. Based on X-ray investigations it was found that the initial hydroxide precursor is amorphous, however, its luminescence activity suggests the close range ordering in a material.

    Keywords

    • microwave
    • hydrothermal technology
    • zirconium dioxide
    • calcination
    Open Access

    Flame Retardant and Antimicrobial Jute Textile Using Sodium Metasilicate Nonahydrate

    Published Online: 26 Jun 2014
    Page range: 106 - 113

    Abstract

    Abstract

    Flame retardant and antimicrobial functionalities were imparted in jute textile using sodium metasilicate nonahydrate (SMSN), commonly known as “water glass”. Sodium metasilicate nonahydrate (SMSN) was applied in jute fabric in different concentration by padding method followed by drying. Flame retardancy of the fabric was evaluated by Limiting Oxygen Index (LOI) and burning behaviour under vertical flammability tester including the char length. Burning rate was found to decrease by almost 10 times after an application of 2% SMSN compared to the control sample. Thermogravimetry (TG) and differential scanning calorimetry (DSC) analysis of both the control and treated jute fabrics were utilized to understand the mechanism of developed flame retardance in jute fabric. It was observed that the SMSN treated samples showed excellent antimicrobial property against both gram positive and gram negative bacteria. Antimicrobial properties of both the control and treated jute fabrics were also measured quantitatively.

    Keywords

    • flame retardant
    • sodium metasilicate nonahydrate
    • jute
    • LOI
    • antimicrobial
    Open Access

    Foams Stabilized with Nanoparticles for Gas Well Deliquification

    Published Online: 26 Jun 2014
    Page range: 114 - 117

    Abstract

    Abstract

    This study examined the interaction of solid nanoparticles and anionic and non-ionic surfactant at an air–water interface. Aqueous foams stabilized by silica nanoparticles in water with different levels of salinity were studied in detail. The stability of solid/surfactant dispersion was evaluated visually. Nanoparticles content impact and concentration of surfactant on the foamability, deliquification of foams and structure of wet foams were studied. It was found that the foamability of dispersion depends either on the surfactant concentration or on the nanoparticles concentration. The adsorption of hydrophobically modified silica particles and surfactants reduces the air/water interface tension. The results of the examinations showed that the use of nanoparticles allows to increase the efficiency of brine unloading even up to 20%. Surfactant particle and nanosilica present synergistic action, use of 4 wt% of nanoparticles allows to reduce surfactant consumption up to half. The cost of the preparation of the proposed dispersion is slightly higher, about 5%, compared to the sole surfactant.

    Keywords

    • Foam
    • foamability
    • solid nanoparticles
    • surfactant
    20 Articles
    Open Access

    Separation and Concentration of Succinic Adic from Multicomponent Aqueous Solutions by Nanofiltration Technique

    Published Online: 26 Jun 2014
    Page range: 1 - 4

    Abstract

    Abstract

    This paper applies the determined suitability of nanofiltration (NF) membrane separation for selective isolation and concentration of succinic acid from aqueous solutions which are post-fermentation multicomponent fluids. The study analyzed the influence of concentration and the pH of the separated solutions on the efficiency and selectivity of NF process that runs in a module equipped with a ceramic membrane. Moreover, the effect of applied trans-membrane pressure on the retention of succinic acid and sodium succinate has been studied. The investigations have shown that in the used NF module the retention of succinic acid salt is equal almost 50% in the case of a three-component model solution, although the degree of retention depends on both the transmembrane pressure and the initial concentration of separated salt.

    Keywords

    • glycerol bioconversion
    • fermentation broth
    • succinic acid
    • nanofiltration
    • ceramic membrane
    Open Access

    Morphological Evaluation of Variously Intercalated Pre-baked Clay

    Published Online: 26 Jun 2014
    Page range: 5 - 11

    Abstract

    Abstract

    The use of porous materials is enjoying tremendous popularity and attention of the advance scientific communities due to their excellent adsorptive and catalytic activities. Clays are one of the most important candidates in the porous community which shows the above mentioned activities after modifing with a different intercalating agent. The paper is focused on the infiuence of some inorganic intercalating agents (NaOH) on the morphology of the variously intercalated clay samples. The alkali metal was used as the inorganic intercalating agent. The effect of intercalation temperature, intercalation agent concentration and intercalation time on the pre-baked clay morphology were also part of the study. Scanning electron microscopy (SEM) study was performed to evaluate the morphological changes of the resultant intercalates. Different morphological properties were improved significantly in the case of the inorganically modified clay samples. Thus, such intercalations are suggested to be effective if the clays under study are to be used for different industrial process at elevated conditions.

    Keywords

    • clay
    • alkali metal intercalation
    • inorganic modifier
    • scanning electron microscopy
    Open Access

    Binding of Industrial Deposits of Heavy Metals and Arsenic in the Soil by 3-Aminopropyltrimethoxysilane

    Published Online: 26 Jun 2014
    Page range: 12 - 15

    Abstract

    Abstract

    The results of the research studies concerning binding of heavy metals and arsenic (HM+As), occurring in soils affected by emissions from Głogów Copper Smelter and Refinery, by silane nanomaterial have been described. The content of heavy metals and arsenic was determined by AAS and the effectiveness of heavy metals and arsenic binding by 3-Aminopropyltrimethoxysilane was examined. The total leaching level of impurities in those fractions was 73.26% Cu, 74.7% – Pb, 79.5% Zn, 65.81% – Cd and 55.55% As. The studies demonstrated that the total binding of heavy metals and arsenic with nanomaterial in all fractions was about as follows: 20.5% Cu, 9.5% Pb, 7.1% Zn, 25.3% Cd and 10.89% As. The results presented how the safety of food can be cultivated around industrial area, as the currently used soil stabilization technique of HM by soil pH does not guarantee their stable blocking in a sorptive complex.

    Keywords

    • nanotechnology
    • heavy metals
    • soil stabilization
    Open Access

    Comparison of Hydrolytic Resistance of Polyurethanes and Poly(Urethanemethacrylate) Copolymers in Terms of their Use as Polymer Coatings in Contact with the Physiological Liquid

    Published Online: 26 Jun 2014
    Page range: 16 - 26

    Abstract

    Abstract

    PU elastomers were synthesized using MDI, PTMO, butane-1,4-diol or 2,2,3,3-tetrafiuorobutane-1,4-diol. Using the same diisocyanate and polyether reagents urethane segments were prepared, to be inserted in the poly(urethane-methacrylate) copolymers. Bromourethane or tetraphenylethane-urethane macroinitiators were used as transitional products reacting with MMA according to the ARGET ATRP. 1H and 13C NMR spectral methods, as well as DSC and TGA thermal methods, were employed to confirm chemical structures of synthesised elastomers and copolymers. To investigate the possibility of using synthesized polymers as biomaterials a research on keeping them in physiological liquid at 37°C was performed. A loss in weight and ability to sorption of water was determined and by using GPC the molecular weight changes were compared. Additionally, changes in the thermal properties of the samples after exposure in physiological liquid were documented using both the TGA and DSC methods. The studies of surface properties (confocal microscopy and SFE) of the obtained polymers were performed. The structure of the polymer chains was defined by NMR. Possible reasons of hydrolysis were discussed, stating that new copolymers are more resistant and polar biomaterials can be less interesting than elastomers.

    Keywords

      Open Access

      Removal of Organic Dyes from Aqueous Solutions with Surfactant-Modified Magnetic Nanoparticles

      Published Online: 26 Jun 2014
      Page range: 27 - 30

      Abstract

      Abstract

      The paper presents the results of studies on the possibility of using magnetic nanoparticles modified with selected hydrophobic surfactants for model post-production water purification. Colloidal solutions of iron hydroxide (III) and iron oxide (II and III) were obtained and their particles were subjected to surface modification using surfactants. Thus obtained magnetic fluids were used as active agents in the process of removing selected organic dyes from their aqueous solutions. The effectiveness of the modified compounds was analysed using spectrophotometric methods. It has been shown that the effectiveness of the process depends on the type of surfactant used to modify selected magnetic nanoparticles.

      Keywords

      • organic dyes
      • iron compounds
      • magnetic fluids
      • surfactants
      • ecology
      Open Access

      Application of Response Surface Methodology for Optimization of Permeabilization Process of Baker’s Yeast

      Published Online: 26 Jun 2014
      Page range: 31 - 35

      Abstract

      Abstract

      Permeabilization was used for the purpose of transforming the cells of microorganisms into biocatalysts with an enhanced enzyme activity. Baker’s yeast cells were permeabilized with various organic solvents. A high degree of catalase activity was observed upon permeabilization with acetone, chloroform, isopropyl alcohol and ethyl acetate. Response surface methodology was used to model the effect of concentration of isopropyl alcohol, temperature and treatment time on the permeabilization of baker’s yeast cells to maximize the decomposition of H2O2. The optimum operating conditions for permeabilization were observed at 53.7% concentration of isopropyl alcohol, treatment time of 40 min and temperature of 15.6oC. A maximum value of catalase activity was found to be 6.188 U/g wet wt. and was ca. 60 times higher than the catalytic activity of yeast not treated by the permeabilization process.

      Keywords

      • permeabilization
      • baker’s yeast
      • response surface methodology
      • isopropyl alcohol
      Open Access

      Use of MgO to Promote the Oxyethylation Reaction of Lauryl Alcohol

      Published Online: 26 Jun 2014
      Page range: 36 - 42

      Abstract

      Abstract

      Synthesis of magnesium hydroxide was performed by the precipitation method with the use of magnesium sulfate and sodium hydroxide. The infiuence of temperature and ratio of reagents was studied. Magnesium hydroxides, and the magnesium oxides obtained from them by thermal decomposition, were analyzed to determine their bulk density, polydispersity and particle size. The magnesium oxide with the largest surface area was tested as a catalyst in the oxyethylation of lauryl alcohol, and shown to be selective but poorly reactive in comparison with commercially available catalysts. Further studies are needed to improve its reactivity.

      Keywords

      • magnesium hydroxide and oxide
      • precipitation
      • dispersive and structural properties
      • oxyethylation
      • catalytic activity
      Open Access

      Comparative Studies of Electrospinning and Solution Blow Spinning Processes for the Production of Nanofibrous Poly(L-Lactic Acid) Materials for Biomedical Engineering

      Published Online: 26 Jun 2014
      Page range: 43 - 50

      Abstract

      Abstract

      Comparative statistical analysis of the infiuence of processing parameters, for electrospinning (ES) and solution blow spinning (SBS) processes, on nanofibrous poly(L-lactic acid) (PLLA) material morphology and average fiber diameter was conducted in order to identify the key processing parameter for tailoring the product properties. Further, a comparative preliminary biocompatibility evaluation was performed. Based on Design of Experiment (DOE) principles, analysis of standard effects of voltage, air pressure, solution feed rate and concentration, on nanofibers average diameter was performed with the Pareto’s charts and the best fitted surface charts. Nanofibers were analyzed by scanning electron microscopy (SEM). The preliminary biocompatibility comparative tests were performed based on SEM microphotographs of CP5 cells cultured on materials derived from ES and SBS. Polymer solution concentration was identified as the key parameter infiuencing morphology and dimensions of nanofibrous mat produced from both techniques. In both cases, when polymer concentration increases the average fiber diameter increase. The preliminary biocompatibility test suggests that nanofibers produced by ES as well as SBS are suitable as the biomedical engineering scaffold material.

      Keywords

      • electrospinning
      • solution blow spinning
      • nanofibers
      • biomedical engineering
      • design of experiments
      • biocompatibility
      Open Access

      Quantification of the Radiative and Convective Heat Transfer Processes and their Effect on mSOFC by CFD Modelling

      Published Online: 26 Jun 2014
      Page range: 51 - 55

      Abstract

      Abstract

      The CFD modelling of heat transfer in a microtubular Solid Oxide Fuel Cell (mSOFC) stack has been presented. Stack performance predictions were based on a 16 anode-supported microtubular SOFCs sub-stack, which is a component of the overall stack containing 64 fuel cells. Both radiative and convective heat transfer were taken into account in the modelling. The heat flux value corresponded to the cell voltage of 0.7 [V]. Two different cases of the inlet air velocity of 2.0 and 8.5 [ms–1] were considered. It was found that radiation accounted for about 20–30 [%] of the total heat flux from the active tube surface, which means that the convective heat transfer predominated over the radiative one.

      Keywords

      • microtubular Solid Oxide Fuel Cell stack
      • heat transfer
      • Computational Fluid Dynamics
      • temperature distributions
      Open Access

      Pilot Study of Generation and Disposal of Municipal Solid Wastes in Selected Household in Rural Areas in the South-Western Poland

      Published Online: 26 Jun 2014
      Page range: 56 - 62

      Abstract

      Abstract

      Pilot study of the composition of wastes was carried out in 15 rural family households engaged in agricultural activity. In the study group the average resident of rural areas generates about 166 kg of municipal wastes annually. The conducted studies showed that the composition of municipal wastes coming from rural households changes seasonally. During the periods of summer and autumn, the quantity of bio-wastes increased distinctly. The average mass of wastes transferred to the companies engaged in the collection of wastes in the analyzed rural households is almost 50 kg · M–1. year–1. The studies showed that over 80% of organic wastes (kitchen and garden) is utilized in the place where they are generated. In the studies, organic wastes were collected selectively (in separate bags), which undoubtedly had infiuence on their humidity (70–90%). Laboratory analysis of these wastes showed that the ratio C:N in it was from 7 to 19, whereas pH lay within the limits from 5.8 to 6.9 indicating its very good properties for the composting process. Therefore composting of organic waste from rural household should be recommended as the best way for its disposal and the weight reduction of biodegradable waste going to landfills. Comparison of the analyzed variants showed that some waste other than kitchen and garden does not leave the holding (it is re-used or burned in home hearths).

      Keywords

      • waste management
      • rural areas
      Open Access

      Nanocolloidal Ru/MgF2 Catalyst for Hydrogenation of Chloronitrobenzene and Toluene

      Published Online: 26 Jun 2014
      Page range: 63 - 68

      Abstract

      Abstract

      The use of magnesium fluoride support for ruthenium active phase allowed obtaining new catalysts of high activities in the hydrogenation of toluene and ortho-chloronitrobenzene. Ruthenium colloid catalysts (1 wt.% of Ru) were prepared by impregnation of the support with the earlier produced polyvinylpyrrolidone (PVP)-stabilized ruthenium colloids. The performances of the colloidal catalysts and those obtained by traditional impregnation were tested in the reactions of toluene hydrogenation to methylcyclohexane and selective hydrogenation of ortho-chloronitrobenzene (o-CNB) to ortho-chloroaniline (o-CAN). It was shown that the use of chemical reduction method allows obtaining highly monodisperse ruthenium nanoparticles of 1.6–2.6 nm in size. After reduction in hydrogen at 400oC, the colloidal ruthenium nanoparticles were found to strongly interact with MgF2 surface (SMSI), which decreased the catalyst ability to hydrogen chemisorption, but despite this, the colloid catalysts showed higher activity in o-CNB hydrogenation and higher selectivity to o-CAN than the traditional ones. It is supposed that their higher activity can be a result of high dispersion of Ru in colloid catalysts and the higher selectivity can be a consequence of the lower availability of hydrogen on the surface.

      Keywords

      • ruthenium nanocolloidal catalyst
      • magnesium fluoride
      • toluene hydrogenation
      • reduction of chloronitrobenzene
      Open Access

      The Use of Ion Exchange in the Recovery of Vanadium from the Mass of a Spent Catalyst Used in the Oxidation of SO2 to SO3

      Published Online: 26 Jun 2014
      Page range: 69 - 73

      Abstract

      Abstract

      In the studies on the recovery of vanadium from vanadium catalyst extracts, three types of polymer strongly acidic ion exchangers were used. The ion exchange resins differed in terms of granularity and their ion exchange capacity. As a result, breakthrough curves were made for three main components of the test extract, i.e.: ions of vanadium, iron and potassium. On this basis the optimum conditions for the removal of iron ions from the solution were defined and the technological concept of the process in the semi-technical scale was proposed.

      Keywords

      • spent vanadium catalyst
      • recovery of vanadium
      • ion exchange
      • solid waste utilization
      Open Access

      Carbon Shale Combustion in the Fluidized Bed Reactor

      Published Online: 26 Jun 2014
      Page range: 74 - 76

      Abstract

      Abstract

      The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm) and VOC (30 mg/m3) have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the combustion of high quality hard coal, 600 ppm and 500 ppm, respectively. Optional reduction of SO2 and NOx emission may require the installation of flue gas desulphurization and de-NOx systems.

      Keywords

      • shale coal
      • combustion
      • fluidized bed technology
      Open Access

      Infiuence of Hydrogen on the Properties of Nanostructured C-Pd Films for Sensing Applications

      Published Online: 26 Jun 2014
      Page range: 77 - 81

      Abstract

      Abstract

      In this paper we present the results of the investigations of nanostructured C-Pd films for hydrogen sensing applications. These C-Pd films were prepared by physical vapor deposition and then annealed in an argon flow at the temperature of 500°C. The structure and morphology of the prepared C-Pd films were investigated using transmission electron microscopy and energy dispersive X-ray spectroscopy. We studied the infiuence of hydrogen on the electrical properties and crystal structure of C-Pd films. It was shown that film resistance changes depended on hydrogen concentration. At lower hydrogen concentration (up to 2 vol.%), the films response increased proportionally to [H2], while above 2 vol.% H2, it was almost constant. This is connected with the formation of a solid solution of hydrogen in palladium at lower H2 concentration and the creation of palladium hydride at higher H2 concentration. X-ray diffraction was used to confirm the formation of Pd-H solid solution and palladium hydride.

      Keywords

      • C-Pd films
      • hydrogen sensor
      • GIXD measurements
      • resistance changes
      Open Access

      Separation of 1,3-Propanediol from Aqueous Solutions by Ion Exchange Chromatography

      Published Online: 26 Jun 2014
      Page range: 82 - 86

      Abstract

      Abstract

      1,3-propanediol is a promising monomer with many applications and can be produced by bioconversion of renewable resources. The separation of this product from fermentation broth is a difficult task. In this work, the application of cation exchange resin for the separation of 1,3-propanediol from model aqueous solution was examined. The best effect of separation of 1,3-propanediol from glycerol using sorption method was obtained for H+ resin form, although the observed partition coefficient of 1,3-propanediol was low. On the basis of the results of the sorption of 1,3-propanediol, the ionic forms of the resin were selected and used in the next experiments (H+, Ca2+, Ag+, Na+, Pb2+, Zn2+). The best results in ion exchange chromatography were obtained for cation exchange resin in H+ and Ca2+ form. The use of smaller particle size of resin and a longer length of the column allows to obtain better separation of mixtures.

      Keywords

      • 1,3-propanediol
      • glycerol
      • fermentation
      • sorption
      • ion exchange chromatography
      Open Access

      Removal of Ni2+ from Aqueous Solutions by Adsorption Onto Magnetic Multiwalled Carbon Nanotube Nanocomposite

      Published Online: 26 Jun 2014
      Page range: 87 - 94

      Abstract

      Abstract

      The removal of Ni2+ from aqueous solution by magnetic multiwalled carbon nanotube nanocomposite (MMWCNTs-C) was investigated. MMWCNTs-C was characterized by X-ray Diffraction method (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), surface area (BET), and Fourier Transform-Infrared Spectroscopy (FTIR). The effects of initial concentration, contact time, solution pH, and temperature on the Ni2+ adsorption onto MMWCNTs-C were studied. The Langmuir and Freundlich isotherm models were applied to fit the adsorption data. The results showed that the adsorption isotherm data were fitted well to the Langmuir isotherm model with the maximum monolayer adsorption capacity of 2.11 mg g–1. The adsorption kinetics was best described by the pseudo-second-order model. The thermodynamic parameters, such as ΔHo, ΔGo and ΔSo, were also determined and evaluated. The adsorption of Ni2+ is generally spontaneous and thermodynamically favorable. The values of ΔHo and ΔGo indicate that the adsorption of Ni2+ onto MMWCNTs-C was a physisorption process.

      Keywords

      • magnetic nanocomposite
      • multiwalled carbon nanotubes
      • nickel
      • adsorption
      Open Access

      Precipitation of Calcium Carbonate in the Presence of Urea at 293 K and 343 K

      Published Online: 26 Jun 2014
      Page range: 95 - 98

      Abstract

      Abstract

      The results of the precipitation of calcium carbonate from a waste post-distillation liquid (DS) and a sodium bicarbonate saturated solution – both from the Solvay method – in the presence of urea are presented. The investigation was carried out at 293 K and 343 K. Reagent dosage times of 1, 5, 10, 20 and 30 min, and urea concentrations of 5, 6 and 10 mol/dm3 were applied. The granulometric composition, the values of bulk and packing densities and the absorptiveness sorption of water and paraffin oil from the obtained calcium carbonate were investigated.

      Keywords

      • calcium carbonate
      • precipitation
      • sodium bicarbonate
      • urea
      • utilization
      Open Access

      High Pressure Synthesis versus Calcination – Different Approaches to Crystallization of Zirconium Dioxide

      Published Online: 26 Jun 2014
      Page range: 99 - 105

      Abstract

      Abstract

      Calcination and microwave-assisted hydrothermal processing of precipitated zirconium dioxide are compared. Characterization of synthesized products of these two technologies is presented. The infiuence of thermal treatment up to 1200oC on the structural and spectroscopic properties of the so-obtained zirconium dioxide is examined. It was found that initial crystallization of material inhibits the crystal growth up to the 800oC (by means of XRD and TEM techniques), while the material crystallized from amorphous hydroxide precursor at 400oC, exhibits 26 nm sized crystallites already. It was found using the TG technique that the temperature range 100–200oC during the calcination process is equivalent to a microwave hydrothermal process by means of water content. Mass loss is estimated to be about 18%. Based on X-ray investigations it was found that the initial hydroxide precursor is amorphous, however, its luminescence activity suggests the close range ordering in a material.

      Keywords

      • microwave
      • hydrothermal technology
      • zirconium dioxide
      • calcination
      Open Access

      Flame Retardant and Antimicrobial Jute Textile Using Sodium Metasilicate Nonahydrate

      Published Online: 26 Jun 2014
      Page range: 106 - 113

      Abstract

      Abstract

      Flame retardant and antimicrobial functionalities were imparted in jute textile using sodium metasilicate nonahydrate (SMSN), commonly known as “water glass”. Sodium metasilicate nonahydrate (SMSN) was applied in jute fabric in different concentration by padding method followed by drying. Flame retardancy of the fabric was evaluated by Limiting Oxygen Index (LOI) and burning behaviour under vertical flammability tester including the char length. Burning rate was found to decrease by almost 10 times after an application of 2% SMSN compared to the control sample. Thermogravimetry (TG) and differential scanning calorimetry (DSC) analysis of both the control and treated jute fabrics were utilized to understand the mechanism of developed flame retardance in jute fabric. It was observed that the SMSN treated samples showed excellent antimicrobial property against both gram positive and gram negative bacteria. Antimicrobial properties of both the control and treated jute fabrics were also measured quantitatively.

      Keywords

      • flame retardant
      • sodium metasilicate nonahydrate
      • jute
      • LOI
      • antimicrobial
      Open Access

      Foams Stabilized with Nanoparticles for Gas Well Deliquification

      Published Online: 26 Jun 2014
      Page range: 114 - 117

      Abstract

      Abstract

      This study examined the interaction of solid nanoparticles and anionic and non-ionic surfactant at an air–water interface. Aqueous foams stabilized by silica nanoparticles in water with different levels of salinity were studied in detail. The stability of solid/surfactant dispersion was evaluated visually. Nanoparticles content impact and concentration of surfactant on the foamability, deliquification of foams and structure of wet foams were studied. It was found that the foamability of dispersion depends either on the surfactant concentration or on the nanoparticles concentration. The adsorption of hydrophobically modified silica particles and surfactants reduces the air/water interface tension. The results of the examinations showed that the use of nanoparticles allows to increase the efficiency of brine unloading even up to 20%. Surfactant particle and nanosilica present synergistic action, use of 4 wt% of nanoparticles allows to reduce surfactant consumption up to half. The cost of the preparation of the proposed dispersion is slightly higher, about 5%, compared to the sole surfactant.

      Keywords

      • Foam
      • foamability
      • solid nanoparticles
      • surfactant

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