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Zeitschriftendaten
Format
Zeitschrift
eISSN
1899-4741
Erstveröffentlichung
03 Jul 2007
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

Volumen 17 (2015): Heft 1 (March 2015)

Zeitschriftendaten
Format
Zeitschrift
eISSN
1899-4741
Erstveröffentlichung
03 Jul 2007
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

20 Artikel
Uneingeschränkter Zugang

Numerical modeling of batch formation in waste incineration plants

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 1 - 6

Zusammenfassung

Abstract

The aim of this paper is a mathematical description of algorithm for controlled assembly of incinerated batch of waste. The basis for formation of batch is selected parameters of incinerated waste as its calorific value or content of pollutants or the combination of both. The numerical model will allow, based on selected criteria, to compile batch of wastes which continuously follows the previous batch, which is a prerequisite for optimized operation of incinerator. The model was prepared as for waste storage in containers, as well as for waste storage in continuously refilled boxes. The mathematical model was developed into the computer program and its functionality was verified either by practical measurements or by numerical simulations. The proposed model can be used in incinerators for hazardous and municipal waste.

Keywords

  • waste incineration
  • waste to energy
  • waste storage in containers
  • waste storage in boxes
  • algorithm for batch formation
Uneingeschränkter Zugang

Reactivity of nano zero-valent iron in permeable reactive barriers

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 7 - 10

Zusammenfassung

Abstract

In this paper, the ability of nZVI to remove heavy metals (Cd, Cu, Ni, Pb, Zn) from multicomponent aqueous solutions was investigated through batch experiments. The experimental data were fitted to a second-order kinetic model based on solid capacity. The data for copper and lead fitted well into the second-order kinetic model, thus suggesting that the adsorption had a physical character. The values of the removal ratio and the second-order rate constant indicated that the order of adsorption priority of nZVI was as follows: Pb>Cu>Zn>Cd>Ni. The adsorption isotherm data were described by the most conventional models (Henry, Freundlich, and Langmuir). Equilibrium tests showed that copper and zinc were removed from the solution by adsorption processes, i.e., complexation and competitive adsorption. The test results suggested that the removal processes using nZVI are more kinetic than equilibrium. The study demonstrated that nZVI is favorable reactive material; however, comprehensive investigation should be performed for further in situ applications in PRB technology.

Keywords

  • contaminated groundwater
  • permeable reactive barrier
  • nano zero-valent iron
  • reactivity
Uneingeschränkter Zugang

The effect of preparation method on the performance of PtSn/Al2O3 catalysts for acetic acid hydrogenation

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 11 - 17

Zusammenfassung

Abstract

PtSn/Al2O3 catalysts with a given loading of 1 wt% Pt and 1 wt% Sn were prepared by co-impregnation or successive impregnation with aqueous solutions of Pt, Sn precursors and a commercial alumina. The catalysts were characterized by N2 adsorption, H2-TPR (H2 temperature-programmed reduction), H2-pulse chemisorption, XPS (X-ray photoelectron spectroscopy) and CO-FTIR (Fourier transform infrared spectroscopy), and tested in the hydrogenation of acetic acid. The results showed that the preparation method affected both the chemical properties and their performance in the hydrogenation of acetic acid. Sn enrichment on the catalysts surface was observed on the co-impregnated catalyst and catalyst in which the Pt precursor had been loaded first. It was found that the modification of Pt was a function of the sequence of Sn addition as revealed by CO-FTIR. Co-impregnated catalyst showed the highest activity and ethanol selectivity.

Keywords

  • PtSn catalysts
  • preparation method
  • acetic acid hydrogenation
  • XPS
  • CO-FTIR
Uneingeschränkter Zugang

Hydrogen evolution reaction at Ru-modified nickel-coated carbon fibre in 0.1 M NaOH

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 18 - 22

Zusammenfassung

Abstract

The electrochemical activity towards hydrogen evolution reaction (HER) was studied on commercially available (Toho-Tenax) and Ru-modified nickel-coated carbon fibre (NiCCF) materials. Quality and extent of Ru electrodeposition on NiCCF tows were examined by means of scanning electron microscopy (SEM). Kinetics of the hydrogen evolution reaction were investigated at room temperature, as well as over the temperature range: 20-50°C in 0.1 M NaOH solution for the cathodic overpotential range: -100 to -300 mV vs. RHE. Corresponding values of charge-transfer resistance, exchange current-density for the HER and other electrochemical parameters for the examined fibre tow composites were recorded.

Keywords

  • NiCCF
  • Ru-modification
  • hydrogen evolution reaction
  • HER
  • impedance spectroscopy
Uneingeschränkter Zugang

Removal of chlorophenols from aqueous solutions by sorption onto walnut, pistachio and hazelnut shells

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 23 - 31

Zusammenfassung

Abstract

The efficiency of walnut, pistachio and hazelnut shells to remove three monochlorophenols (2-CP, 3-CP and 4-CP) from aqueous solutions has been investigated. To describe the kinetic data pseudo-first and pseudo-second order models were used. The kinetics data were fitted better into the pseudo-second order model with the coefficient of determination values greater than 0.99. The k2 values increased in the order 4-CP < 3-CP < 2-CP. Sorption was also analyzed as a function of solution concentration at equilibrium. The experimental data received were found to be well described by the Freundlich isotherm equation. Effectiveness of chlorophenols removal from water on the walnut, pistachio and hazelnut shells was comparable. Individual differences in sorption of monochlorophenols were also negligible.

Keywords

  • nut shells
  • walnut
  • pistachio
  • hazelnut
  • chlorophenols
  • sorption
Uneingeschränkter Zugang

Effect of TiO2-ZnO/GAC on by-product distribution of CVOCs decomposition in a NTP-assisted catalysis system

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 32 - 40

Zusammenfassung

Abstract

In this study, the catalytic effect of TiO2-ZnO/GAC coupled with non-thermal plasma was investigated on the byproducts distribution of decomposition of chlorinated VOCs in gas streams. The effect of specific input energy, and initial gas composition was examined in a corona discharge reactor energized by a high frequency pulsed power supply. Detected by-products for catalytic NTP at 750 J L-1 included CO, CO2, Cl2, trichloroacetaldehyde, as well as trichlorobenzaldehyde with chloroform feeding, while they were dominated by CO, CO2, and lower abundance of trichlorobenzaldehyde and Cl2 with chlorobenzene introduction. Some of the by-products such as O3, NO, NO2, and COCl2 disappeared totally over TiO2-ZnO/GAC. Furthermore, the amount of heavy products such as trichlorobenzaldehyde decreased significantly in favor of small molecules such as CO, CO2, and Cl2 with the hybrid process. The selectivity towards COx soared up to 77% over the catalyst at 750 J L-1 and 100 ppm of chlorobenzene.

Keywords

  • non-thermal plasma
  • catalyst
  • CVOCs
  • TiO2-ZnO
  • granular activated carbon
Uneingeschränkter Zugang

Effect of waste rubber powder as filler for plywood application

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 41 - 47

Zusammenfassung

Abstract

The study investigated the suitability of waste rubber powder (WRP) use as filler in adhesive formulation for plywood application. Melamine Urea Formaldehyde (MUF) was employed as resin for formulating the wood adhesive. To improve chemical properties and bonding quality of adhesive, WRP was treated by different chemicals like 20% nitric acid, 30% hydrogen peroxide and acetone solution. The treated WRP were analysed by XRD and it showed that inorganic compounds were removed and carbon was remained as major component under the treatment of 20% HNO3. The treatment improved the mechanical properties like shear strength and formaldehyde emission of plywood (high shear strength and low formaldehyde emission). The physico-chemical interaction between the wood, resin and filler was investigated using fourier transform infrared spectroscopic (FTIR) technique and the interactions among N-H of MUF and C=O of wood and WRP were identified. The morphology of wood-adhesive interface was studied by field emission scanning electron microscope (FESEM) and light microscope (LM). It showed that the penetration of adhesives and fillers through the wood pores was responsible for mechanical interlocking. Therefore, chemically treated WRP proved its potential use as filler in MUF based adhesive for making plywood.

Keywords

  • waste rubber powder
  • melamine urea formaldehyde resin
  • filler
  • wood adhesive
  • plywood
Uneingeschränkter Zugang

A novel approach for calculating packed column height based on new correlation of mass transfer coefficient

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 48 - 54

Zusammenfassung

Abstract

The calculation of column’s height plays an important role in packed columns precise design. This research is based on experimentally measurement of mass transfer coefficients in different heights of packed column to predict its height. The objective of presented work is to introduce a novel conceptual method to predict column height via new correlation for mass transfer coefficient. As the mass transfer coefficient is decreased with increase of column height, the HTU’s are not constant figures along the column so this new approach is called increasing HTU’s. The results of the proposed idea were compared with other correlations and the conventional method i.e. constant HTU’s. Since the results are in very good agreement with experimental data comparing to conventional method, it seems this approach can be a turning point in design of all differential columns like packed columns. Making use of this method is suggested for design of differential columns.

Keywords

  • separation
  • liquid-liquid extraction
  • packed column
  • mass transfer
  • column design
  • diffusion
Uneingeschränkter Zugang

Potencial management of waste phosphogypsum with particular focus on recovery of rare earth metals

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 55 - 61

Zusammenfassung

Abstract

Phosphogypsum is a noxious industrial waste contributing to global environmental and economic problems. This publication focuses above all on phosphogypsum resulting from the processing of apatite as a phosphorus bearing compound, since it contains considerable amounts of lanthanides due to its magma origin. The possibilities of its waste-free processing are large, however they require the application of suitable technologies, frequently expensive ones, and allowing for the individual characteristics of the given waste. The research works conducted so far confirm the possibility of applying phosphogypsum for the recovery of lanthanides, and the process enhances the removal of remaining impurities, thanks to which the purified calcium sulphate (gypsum) may find application for the production of construction materials.

Keywords

  • phosphogypsum waste
  • phosphogypsum conversion
  • rare earth elements
  • environmental threats
Uneingeschränkter Zugang

Direct synthesis of dimethyl carbonate and propylene glycol using potassium bicarbonate as catalyst in supercritical CO2

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 62 - 65

Zusammenfassung

Abstract

The improved one-pot synthesis of dimethyl carbonate and propylene glycol from propylene oxide, supercritical carbon dioxide, and methanol with potassium bicarbonate as the catalyst has been reported in this paper. As far as we know, it is the first time to use potassium bicarbonate only as the catalyst in the production process which is simple and cheap. Satisfactory conversion rate of propylene oxide and yield of the products could be achieved at the optimized conditions with quite a small amount of by-products. Our new method offers an attractive choice for the production of dimethyl carbonate in large-scale industry efficiently and environmental friendly.

Keywords

  • direct synthesis
  • dimethyl carbonate
  • carbon dioxide
  • potassium bicarbonate
  • supercritical fluids
Uneingeschränkter Zugang

Simulation of circulating fluidized bed gasification for characteristic study of pakistani coal

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 66 - 78

Zusammenfassung

Abstract

A process model for turbulent pressurized circulating fluidized-bed coal gasifier is created using ASPEN PLUS software. Both hydrodynamic and reaction kinetics parameter are taken into account, whose expressions for fluidized bed are adopted from the literature. Various reactor models available in ASPEN PLUS with calculator as External Block are nested to solve hydrodynamics and kinetics. Multiple operational parameters for a pilot-plant circulating fluidized-bed coal gasifier are used to demonstrate the effects on coal gasification characteristics. This paper presents detailed information regarding the simulation model, including robust analysis of the effect of stoichiometric ratio, steam to coal ratio, gasification temperature and gasification agent temperature. It is observed that, with the increase in the flow rate of air, the components hydrogen, carbon monoxide, carbon dioxide and methane reduce, which causes the Lower Heating Value (LHV) of synthesis gas (Syn. Gas) to decrease by about 29.3%, while increment in the steam flow rate shows a minute increase in heating value of only 0.8%. Stoichiometric ratio has a direct relationship to carbon conversion efficiency and carbon dioxide production. Increasing the steam to coal ratio boosts the production of hydrogen and carbon monoxide, and causes a drop in both carbon dioxide concentration and the conversion efficiency of carbon. High gasifying agent temperature is desired because of high concentration of CO and H2, increasing carbon conversion and LHV. A high gasifying agent temperature is the major factor that affects the coal gasification to enhance H2 and CO production rapidly along with other gasification characteristics.

Keywords

  • ASPEN PLUS
  • circulating fluidized bed
  • coal
  • gasification
  • simulation
Uneingeschränkter Zugang

Biosorption of lead(II), zinc(II) and nickel(II) from industrial wastewater by Stenotrophomonas maltophilia and Bacillus subtilis

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 79 - 87

Zusammenfassung

Abstract

The biosorption of Pb(II), Zn(II) and Ni(II) from industrial wastewater using Stenotrophomonas maltophilia and Bacillus subtilis was investigated under various experimental conditions regarding pH, metal concentration and contact time. The optimum pH values for the biosorption of the three metals were in the range 5.0-6.0, while the optimal contact time for the two bacterial species was 30 min. Experimental data was analyzed using Langmuir and Freundlich isotherms; the former had a better fit for the biosorption of Pb(II), Zn(II) and Ni(II). The maximum adsorption uptakes (qmax) of the three metals calculated from the Langmuir biosorption equation for S. maltophilia were 133.3, 47.8 and 54.3 for Pb(II), Zn(II) and Ni(II), respectively, and for B. subtilis were 166.7, 49.7 and 57.8 mg/g, respectively. B. subtilis biomass was more favorable for the biosorption of Pb (II) and Ni (II), while S. maltophilia was more useful for the biosorption of Zn (II).

Keywords

  • heavy metals
  • biosorption
  • Bacillus subtilis
  • Stenotrophomonas maltophilia
Uneingeschränkter Zugang

Super phosphoric acid catalyzed esterification of Palm Fatty Acid Distillate for biodiesel production: physicochemical parameters and kinetics

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 88 - 96

Zusammenfassung

Abstract

In the present study the esterification of palm fatty acid distillate (PFAD), a by-product from palm oil industry, in the presence of super phosphoric acid (SPA) catalyst was studied. The effects of various physico-chemical parameters such as temperature, PFAD to methanol molar ratio and amount of catalyst on the conversion of biodiesel were investigated. The percent conversion of FFA and properties of the biodiesel were determined following standard methodologies. Percent conversion of biodiesel was found to increase with the increase in PFAD to methanol molar ratio and at 1:12 molar ratio and 70°C temperature 95% conversion was achieved. Thermodynamic parameters were also evaluated in terms of Gibbs free energy, enthalpy and entropy at different molar ratio and temperatures. Both pseudo first and second order irreversible kinetics were applied to a wide range of experimental data. However, according to regression coefficient (R2) the second order described better experimental behavior of kinetic data.

Keywords

  • Biodiesel
  • palm fatty acids distillate
  • Super Phosphoric Acid
Uneingeschränkter Zugang

Studies on the effect of coal particle size on biodepyritization of high sulfur coal in batch bioreactor

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 97 - 102

Zusammenfassung

Abstract

The moderate thermophilic mix culture bacteria were used to depyritize the Illinois coal of varying particle sizes (-100 μm, 100-200 μm, +200 μm). Mineral libration analysis showed the presence of pyrite along with other minerals in coal. Microbial depyritization of coal was carried out in stirred tank batch reactors in presence of an iron-free 9K medium. The results indicate that microbial depyritization of coal using moderate thermophiles is an efficient process. Moreover, particle size of coal is an important parameter which affects the efficiency of microbial depyritization process. At the end of the experiment, a maximum of 75% pyrite and 66% of pyritic sulphur were removed from the median particle size. The XRD analysis showed the absence of pyrite mineral in the treated coal sample. A good mass balance was also obtained with net loss of mass ranging from 5-9% showing the feasibility of the process for large scale applications.

Keywords

  • biodepyritization
  • coal
  • pyrite
  • stirred tank bioreactor
Uneingeschränkter Zugang

One-dimensional isothermal multicomponent diffusion-reaction model and its application to methanol synthesis over commercial Cu-based catalyst

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 103 - 109

Zusammenfassung

Abstract

The present work was a study on global reaction rate of methanol synthesis. We measured experimentally the global reaction rate in the internal recycle gradientless reactor over catalyst SC309. The diffusion-reaction model of methanol synthesis was suggested. For model we chose the hydrogenation of CO and CO2 as key reaction. CO and CO2 were key components in our model. The internal diffusion effectiveness factors of CO and CO2 in the catalyst were calculated by the numerical integration. A comparison with the experiment showed that all the absolute values of the relative error were less than 10%. The simulation results showed that decreasing reaction temperature and catalyst diameter were conducive to reduce the influence of the internal diffusion on the methanol synthesis.

Keywords

  • global kinetics
  • internal effectiveness factor
  • diffusion-reaction model
  • methanol synthesis
Uneingeschränkter Zugang

Effect of magnetic field and silver nanoparticles on yield and water use efficiency of Carum copticum under water stress conditions

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 110 - 114

Zusammenfassung

Abstract

Normally the productivity of cropping systems in arid and semi- arid regions is very low. The sustainable agricultural systems try to find out environmental friendly technologies based on physical and biological treatments to increase crop production. In this study two irrigation treatments (control and water stress) and six methods of fertilizer treatment (control, NPK-F, using magnetic band- M, using silver nano particles- N, M+N and M+N+50% F) on performance of ajowan were compared. Results showed that treatments with magnetic field or base fertilizer had more yield compared to the control and silver nanoparticles (N) treatments. Application of silver nanoparticles had no positive effect on yield. The highest seed and biomass WUE achieved in base fertilizer or magnetic field treatments. Under water stress treatment, seed WUE significantly increased. In conclusion magnetic field exposure, probably by encourage nutrient uptake efficiency could be applied to reduce fertilizer requirement. On the other hand the cultivation of plants under low MF could be an alternative way of WUE improving.

Keywords

  • biomass
  • harvest index
  • yield components
Uneingeschränkter Zugang

Monitoring and remediation technologies of organochlorine pesticides in drainage water

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 115 - 122

Zusammenfassung

Abstract

This study was carried out to monitor the presence of organochlorine in drainage water in Kafr-El-Sheikh Governorate, Egypt. Furthermore, to evaluate the efficiencies of different remediation techniques (advanced oxidation processes [AOPs] and bioremediation) for removing the most frequently detected compound (lindane) in drainage water. The results showed the presence of several organochlorine pesticides in all sampling sites. Lindane was detected with high frequency relative to other detected organochlorine in drainage water. Nano photo-Fenton like reagent was the most effective treatment for lindane removal in drainage water. Bioremediation of lindane by effective microorganisms (EMs) removed 100% of the lindane initial concentration. There is no remaining toxicity in lindane contaminated-water after remediation on treated rats relative to control with respect to histopathological changes in liver and kidney. Advanced oxidation processes especially with nanomaterials and bioremediation using effective microorganisms can be regarded as safe and effective remediation technologies of lindane in water.

Keywords

  • lindane
  • remediation
  • toxicity
  • degradation
  • water
Uneingeschränkter Zugang

Flame resistant cellulosic substrate using banana pseudostem sap

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 123 - 133

Zusammenfassung

Abstract

Flame retardancy was imparted in cellulosic cotton textile using banana pseudostem sap (BPS), an eco-friendly natural product. The extracted sap was made alkaline and applied in pre-mordanted bleached and mercerized cotton fabrics. Flame retardant properties of both the control and the treated fabrics were analysed in terms of limiting oxygen index (LOI), horizontal and vertical flammability. Fabrics treated with the non-diluted BPS were found to have good flame retardant property with LOI of 30 compared to the control fabric with LOI of 18, i.e., an increase of 1.6 times. In the vertical flammability test, the BPS treated fabric showed flame for a few seconds and then, got extinguished. In the horizontal flammability test, the treated fabric showed no flame, but was burning only with an afterglow with a propagation rate of 7.5 mm/min, which was almost 10 times lower than that noted with the control fabric. The thermal degradation and the pyrolysis of the fabric samples were studied using a thermogravimetric analysis (TGA), and the chemical composition by FTIR, SEM and EDX, besides the pure BPS being characterized by EDX and mass spectroscopy. The fabric after the treatment was found to produce stable natural khaki colour, and there was no significant degradation in mechanical strengths. Based on the results, the mechanism of imparting flame retardancy to cellulosic textile and the formation of natural colour on it using the proposed BPS treatment have been postulated.

Keywords

  • banana pseudostem sap
  • cellulose
  • cotton fabric
  • flame retardant
  • thermogravimetry
Uneingeschränkter Zugang

Chemical composition and properties of spray-dried sugar beet concentrate obtained after ultrafiltration of diffusion juice

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 134 - 137

Zusammenfassung

Abstract

Ultrafiltration of diffusion juice is a method that can reduce environmental pollution during the production of sugar. A by-product (concentrate) of ultrafiltration contains a large amount of sucrose, but due to its properties, it is difficult to manage. The aim of this study was to determine the effects of the temperature used during drying of diffusion juice concentrates on the content of certain components and characteristics of resultant preparations. Diffusion juice obtained from one of the Polish sugar plants was subjected to ultrafiltration and the obtained concentrates were dried in a spray dryer. In the dried samples, the following parameters were analyzed: dry mass, sucrose, total ash, protein, crude fiber and color. It has been declared that the degree of concentration and drying temperature influenced the chemical composition and the properties of the dehydrated diffusion juice concentrates. An increase in drying temperature was accompanied by the increased content of dry mass, protein, ash and fiber content in the preparations. The greater the degree of juice concentration, the greater was the content of dry mass, ash, and fiber. Inversely, the greater the degree of juice concentration, the lower the content of sucrose. The brightest color of the dehydrated product was observed at the drying temperature of 200°C. Spray-drying may be used for waste management after the diffusion juice membrane filtration, and the resultant preparations might be used in the production of feedstuff or food industry in general e.g. as sucrose source, in fermentation processes or in microorganisms propagation.

Keywords

  • ceramic membrane
  • ultrafiltration
  • diffusion juice
  • concentrate
  • spray drying
Uneingeschränkter Zugang

Properties and activity of the cobalt catalysts for NH3 synthesis obtained by co-precipitation – the effect of lanthanum addition

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 138 - 143

Zusammenfassung

Abstract

In modern research on catalysts for NH3 synthesis a lot of attention is paid to cobalt. In this work the new catalytic systems based on cobalt are presented. Unsupported cobalt catalysts singly promoted (La or Ba) and doubly promoted (La and Ba) were prepared and tested in NH3 synthesis reaction under commercial synthesis conditions. Characterization studies revealed that lanthanum plays a role of a structural promoter, which improves the surface of catalyst precursors and prevents from sintering during calcination. However, lanthanum has a negative effect on the reduction of cobalt oxide, but the addition of barium promoter (Co/La/Ba catalyst) diminishes the negative impact of La. The co-promotion of cobalt with lanthanum and barium results in the increasing of the active phase surface and improvement of its activity in NH3 synthesis.

Keywords

  • ammonia synthesis
  • cobalt catalyst
  • promoter
  • lanthanum
  • co-precipitation
20 Artikel
Uneingeschränkter Zugang

Numerical modeling of batch formation in waste incineration plants

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 1 - 6

Zusammenfassung

Abstract

The aim of this paper is a mathematical description of algorithm for controlled assembly of incinerated batch of waste. The basis for formation of batch is selected parameters of incinerated waste as its calorific value or content of pollutants or the combination of both. The numerical model will allow, based on selected criteria, to compile batch of wastes which continuously follows the previous batch, which is a prerequisite for optimized operation of incinerator. The model was prepared as for waste storage in containers, as well as for waste storage in continuously refilled boxes. The mathematical model was developed into the computer program and its functionality was verified either by practical measurements or by numerical simulations. The proposed model can be used in incinerators for hazardous and municipal waste.

Keywords

  • waste incineration
  • waste to energy
  • waste storage in containers
  • waste storage in boxes
  • algorithm for batch formation
Uneingeschränkter Zugang

Reactivity of nano zero-valent iron in permeable reactive barriers

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 7 - 10

Zusammenfassung

Abstract

In this paper, the ability of nZVI to remove heavy metals (Cd, Cu, Ni, Pb, Zn) from multicomponent aqueous solutions was investigated through batch experiments. The experimental data were fitted to a second-order kinetic model based on solid capacity. The data for copper and lead fitted well into the second-order kinetic model, thus suggesting that the adsorption had a physical character. The values of the removal ratio and the second-order rate constant indicated that the order of adsorption priority of nZVI was as follows: Pb>Cu>Zn>Cd>Ni. The adsorption isotherm data were described by the most conventional models (Henry, Freundlich, and Langmuir). Equilibrium tests showed that copper and zinc were removed from the solution by adsorption processes, i.e., complexation and competitive adsorption. The test results suggested that the removal processes using nZVI are more kinetic than equilibrium. The study demonstrated that nZVI is favorable reactive material; however, comprehensive investigation should be performed for further in situ applications in PRB technology.

Keywords

  • contaminated groundwater
  • permeable reactive barrier
  • nano zero-valent iron
  • reactivity
Uneingeschränkter Zugang

The effect of preparation method on the performance of PtSn/Al2O3 catalysts for acetic acid hydrogenation

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 11 - 17

Zusammenfassung

Abstract

PtSn/Al2O3 catalysts with a given loading of 1 wt% Pt and 1 wt% Sn were prepared by co-impregnation or successive impregnation with aqueous solutions of Pt, Sn precursors and a commercial alumina. The catalysts were characterized by N2 adsorption, H2-TPR (H2 temperature-programmed reduction), H2-pulse chemisorption, XPS (X-ray photoelectron spectroscopy) and CO-FTIR (Fourier transform infrared spectroscopy), and tested in the hydrogenation of acetic acid. The results showed that the preparation method affected both the chemical properties and their performance in the hydrogenation of acetic acid. Sn enrichment on the catalysts surface was observed on the co-impregnated catalyst and catalyst in which the Pt precursor had been loaded first. It was found that the modification of Pt was a function of the sequence of Sn addition as revealed by CO-FTIR. Co-impregnated catalyst showed the highest activity and ethanol selectivity.

Keywords

  • PtSn catalysts
  • preparation method
  • acetic acid hydrogenation
  • XPS
  • CO-FTIR
Uneingeschränkter Zugang

Hydrogen evolution reaction at Ru-modified nickel-coated carbon fibre in 0.1 M NaOH

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 18 - 22

Zusammenfassung

Abstract

The electrochemical activity towards hydrogen evolution reaction (HER) was studied on commercially available (Toho-Tenax) and Ru-modified nickel-coated carbon fibre (NiCCF) materials. Quality and extent of Ru electrodeposition on NiCCF tows were examined by means of scanning electron microscopy (SEM). Kinetics of the hydrogen evolution reaction were investigated at room temperature, as well as over the temperature range: 20-50°C in 0.1 M NaOH solution for the cathodic overpotential range: -100 to -300 mV vs. RHE. Corresponding values of charge-transfer resistance, exchange current-density for the HER and other electrochemical parameters for the examined fibre tow composites were recorded.

Keywords

  • NiCCF
  • Ru-modification
  • hydrogen evolution reaction
  • HER
  • impedance spectroscopy
Uneingeschränkter Zugang

Removal of chlorophenols from aqueous solutions by sorption onto walnut, pistachio and hazelnut shells

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 23 - 31

Zusammenfassung

Abstract

The efficiency of walnut, pistachio and hazelnut shells to remove three monochlorophenols (2-CP, 3-CP and 4-CP) from aqueous solutions has been investigated. To describe the kinetic data pseudo-first and pseudo-second order models were used. The kinetics data were fitted better into the pseudo-second order model with the coefficient of determination values greater than 0.99. The k2 values increased in the order 4-CP < 3-CP < 2-CP. Sorption was also analyzed as a function of solution concentration at equilibrium. The experimental data received were found to be well described by the Freundlich isotherm equation. Effectiveness of chlorophenols removal from water on the walnut, pistachio and hazelnut shells was comparable. Individual differences in sorption of monochlorophenols were also negligible.

Keywords

  • nut shells
  • walnut
  • pistachio
  • hazelnut
  • chlorophenols
  • sorption
Uneingeschränkter Zugang

Effect of TiO2-ZnO/GAC on by-product distribution of CVOCs decomposition in a NTP-assisted catalysis system

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 32 - 40

Zusammenfassung

Abstract

In this study, the catalytic effect of TiO2-ZnO/GAC coupled with non-thermal plasma was investigated on the byproducts distribution of decomposition of chlorinated VOCs in gas streams. The effect of specific input energy, and initial gas composition was examined in a corona discharge reactor energized by a high frequency pulsed power supply. Detected by-products for catalytic NTP at 750 J L-1 included CO, CO2, Cl2, trichloroacetaldehyde, as well as trichlorobenzaldehyde with chloroform feeding, while they were dominated by CO, CO2, and lower abundance of trichlorobenzaldehyde and Cl2 with chlorobenzene introduction. Some of the by-products such as O3, NO, NO2, and COCl2 disappeared totally over TiO2-ZnO/GAC. Furthermore, the amount of heavy products such as trichlorobenzaldehyde decreased significantly in favor of small molecules such as CO, CO2, and Cl2 with the hybrid process. The selectivity towards COx soared up to 77% over the catalyst at 750 J L-1 and 100 ppm of chlorobenzene.

Keywords

  • non-thermal plasma
  • catalyst
  • CVOCs
  • TiO2-ZnO
  • granular activated carbon
Uneingeschränkter Zugang

Effect of waste rubber powder as filler for plywood application

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 41 - 47

Zusammenfassung

Abstract

The study investigated the suitability of waste rubber powder (WRP) use as filler in adhesive formulation for plywood application. Melamine Urea Formaldehyde (MUF) was employed as resin for formulating the wood adhesive. To improve chemical properties and bonding quality of adhesive, WRP was treated by different chemicals like 20% nitric acid, 30% hydrogen peroxide and acetone solution. The treated WRP were analysed by XRD and it showed that inorganic compounds were removed and carbon was remained as major component under the treatment of 20% HNO3. The treatment improved the mechanical properties like shear strength and formaldehyde emission of plywood (high shear strength and low formaldehyde emission). The physico-chemical interaction between the wood, resin and filler was investigated using fourier transform infrared spectroscopic (FTIR) technique and the interactions among N-H of MUF and C=O of wood and WRP were identified. The morphology of wood-adhesive interface was studied by field emission scanning electron microscope (FESEM) and light microscope (LM). It showed that the penetration of adhesives and fillers through the wood pores was responsible for mechanical interlocking. Therefore, chemically treated WRP proved its potential use as filler in MUF based adhesive for making plywood.

Keywords

  • waste rubber powder
  • melamine urea formaldehyde resin
  • filler
  • wood adhesive
  • plywood
Uneingeschränkter Zugang

A novel approach for calculating packed column height based on new correlation of mass transfer coefficient

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 48 - 54

Zusammenfassung

Abstract

The calculation of column’s height plays an important role in packed columns precise design. This research is based on experimentally measurement of mass transfer coefficients in different heights of packed column to predict its height. The objective of presented work is to introduce a novel conceptual method to predict column height via new correlation for mass transfer coefficient. As the mass transfer coefficient is decreased with increase of column height, the HTU’s are not constant figures along the column so this new approach is called increasing HTU’s. The results of the proposed idea were compared with other correlations and the conventional method i.e. constant HTU’s. Since the results are in very good agreement with experimental data comparing to conventional method, it seems this approach can be a turning point in design of all differential columns like packed columns. Making use of this method is suggested for design of differential columns.

Keywords

  • separation
  • liquid-liquid extraction
  • packed column
  • mass transfer
  • column design
  • diffusion
Uneingeschränkter Zugang

Potencial management of waste phosphogypsum with particular focus on recovery of rare earth metals

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 55 - 61

Zusammenfassung

Abstract

Phosphogypsum is a noxious industrial waste contributing to global environmental and economic problems. This publication focuses above all on phosphogypsum resulting from the processing of apatite as a phosphorus bearing compound, since it contains considerable amounts of lanthanides due to its magma origin. The possibilities of its waste-free processing are large, however they require the application of suitable technologies, frequently expensive ones, and allowing for the individual characteristics of the given waste. The research works conducted so far confirm the possibility of applying phosphogypsum for the recovery of lanthanides, and the process enhances the removal of remaining impurities, thanks to which the purified calcium sulphate (gypsum) may find application for the production of construction materials.

Keywords

  • phosphogypsum waste
  • phosphogypsum conversion
  • rare earth elements
  • environmental threats
Uneingeschränkter Zugang

Direct synthesis of dimethyl carbonate and propylene glycol using potassium bicarbonate as catalyst in supercritical CO2

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 62 - 65

Zusammenfassung

Abstract

The improved one-pot synthesis of dimethyl carbonate and propylene glycol from propylene oxide, supercritical carbon dioxide, and methanol with potassium bicarbonate as the catalyst has been reported in this paper. As far as we know, it is the first time to use potassium bicarbonate only as the catalyst in the production process which is simple and cheap. Satisfactory conversion rate of propylene oxide and yield of the products could be achieved at the optimized conditions with quite a small amount of by-products. Our new method offers an attractive choice for the production of dimethyl carbonate in large-scale industry efficiently and environmental friendly.

Keywords

  • direct synthesis
  • dimethyl carbonate
  • carbon dioxide
  • potassium bicarbonate
  • supercritical fluids
Uneingeschränkter Zugang

Simulation of circulating fluidized bed gasification for characteristic study of pakistani coal

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 66 - 78

Zusammenfassung

Abstract

A process model for turbulent pressurized circulating fluidized-bed coal gasifier is created using ASPEN PLUS software. Both hydrodynamic and reaction kinetics parameter are taken into account, whose expressions for fluidized bed are adopted from the literature. Various reactor models available in ASPEN PLUS with calculator as External Block are nested to solve hydrodynamics and kinetics. Multiple operational parameters for a pilot-plant circulating fluidized-bed coal gasifier are used to demonstrate the effects on coal gasification characteristics. This paper presents detailed information regarding the simulation model, including robust analysis of the effect of stoichiometric ratio, steam to coal ratio, gasification temperature and gasification agent temperature. It is observed that, with the increase in the flow rate of air, the components hydrogen, carbon monoxide, carbon dioxide and methane reduce, which causes the Lower Heating Value (LHV) of synthesis gas (Syn. Gas) to decrease by about 29.3%, while increment in the steam flow rate shows a minute increase in heating value of only 0.8%. Stoichiometric ratio has a direct relationship to carbon conversion efficiency and carbon dioxide production. Increasing the steam to coal ratio boosts the production of hydrogen and carbon monoxide, and causes a drop in both carbon dioxide concentration and the conversion efficiency of carbon. High gasifying agent temperature is desired because of high concentration of CO and H2, increasing carbon conversion and LHV. A high gasifying agent temperature is the major factor that affects the coal gasification to enhance H2 and CO production rapidly along with other gasification characteristics.

Keywords

  • ASPEN PLUS
  • circulating fluidized bed
  • coal
  • gasification
  • simulation
Uneingeschränkter Zugang

Biosorption of lead(II), zinc(II) and nickel(II) from industrial wastewater by Stenotrophomonas maltophilia and Bacillus subtilis

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 79 - 87

Zusammenfassung

Abstract

The biosorption of Pb(II), Zn(II) and Ni(II) from industrial wastewater using Stenotrophomonas maltophilia and Bacillus subtilis was investigated under various experimental conditions regarding pH, metal concentration and contact time. The optimum pH values for the biosorption of the three metals were in the range 5.0-6.0, while the optimal contact time for the two bacterial species was 30 min. Experimental data was analyzed using Langmuir and Freundlich isotherms; the former had a better fit for the biosorption of Pb(II), Zn(II) and Ni(II). The maximum adsorption uptakes (qmax) of the three metals calculated from the Langmuir biosorption equation for S. maltophilia were 133.3, 47.8 and 54.3 for Pb(II), Zn(II) and Ni(II), respectively, and for B. subtilis were 166.7, 49.7 and 57.8 mg/g, respectively. B. subtilis biomass was more favorable for the biosorption of Pb (II) and Ni (II), while S. maltophilia was more useful for the biosorption of Zn (II).

Keywords

  • heavy metals
  • biosorption
  • Bacillus subtilis
  • Stenotrophomonas maltophilia
Uneingeschränkter Zugang

Super phosphoric acid catalyzed esterification of Palm Fatty Acid Distillate for biodiesel production: physicochemical parameters and kinetics

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 88 - 96

Zusammenfassung

Abstract

In the present study the esterification of palm fatty acid distillate (PFAD), a by-product from palm oil industry, in the presence of super phosphoric acid (SPA) catalyst was studied. The effects of various physico-chemical parameters such as temperature, PFAD to methanol molar ratio and amount of catalyst on the conversion of biodiesel were investigated. The percent conversion of FFA and properties of the biodiesel were determined following standard methodologies. Percent conversion of biodiesel was found to increase with the increase in PFAD to methanol molar ratio and at 1:12 molar ratio and 70°C temperature 95% conversion was achieved. Thermodynamic parameters were also evaluated in terms of Gibbs free energy, enthalpy and entropy at different molar ratio and temperatures. Both pseudo first and second order irreversible kinetics were applied to a wide range of experimental data. However, according to regression coefficient (R2) the second order described better experimental behavior of kinetic data.

Keywords

  • Biodiesel
  • palm fatty acids distillate
  • Super Phosphoric Acid
Uneingeschränkter Zugang

Studies on the effect of coal particle size on biodepyritization of high sulfur coal in batch bioreactor

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 97 - 102

Zusammenfassung

Abstract

The moderate thermophilic mix culture bacteria were used to depyritize the Illinois coal of varying particle sizes (-100 μm, 100-200 μm, +200 μm). Mineral libration analysis showed the presence of pyrite along with other minerals in coal. Microbial depyritization of coal was carried out in stirred tank batch reactors in presence of an iron-free 9K medium. The results indicate that microbial depyritization of coal using moderate thermophiles is an efficient process. Moreover, particle size of coal is an important parameter which affects the efficiency of microbial depyritization process. At the end of the experiment, a maximum of 75% pyrite and 66% of pyritic sulphur were removed from the median particle size. The XRD analysis showed the absence of pyrite mineral in the treated coal sample. A good mass balance was also obtained with net loss of mass ranging from 5-9% showing the feasibility of the process for large scale applications.

Keywords

  • biodepyritization
  • coal
  • pyrite
  • stirred tank bioreactor
Uneingeschränkter Zugang

One-dimensional isothermal multicomponent diffusion-reaction model and its application to methanol synthesis over commercial Cu-based catalyst

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 103 - 109

Zusammenfassung

Abstract

The present work was a study on global reaction rate of methanol synthesis. We measured experimentally the global reaction rate in the internal recycle gradientless reactor over catalyst SC309. The diffusion-reaction model of methanol synthesis was suggested. For model we chose the hydrogenation of CO and CO2 as key reaction. CO and CO2 were key components in our model. The internal diffusion effectiveness factors of CO and CO2 in the catalyst were calculated by the numerical integration. A comparison with the experiment showed that all the absolute values of the relative error were less than 10%. The simulation results showed that decreasing reaction temperature and catalyst diameter were conducive to reduce the influence of the internal diffusion on the methanol synthesis.

Keywords

  • global kinetics
  • internal effectiveness factor
  • diffusion-reaction model
  • methanol synthesis
Uneingeschränkter Zugang

Effect of magnetic field and silver nanoparticles on yield and water use efficiency of Carum copticum under water stress conditions

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 110 - 114

Zusammenfassung

Abstract

Normally the productivity of cropping systems in arid and semi- arid regions is very low. The sustainable agricultural systems try to find out environmental friendly technologies based on physical and biological treatments to increase crop production. In this study two irrigation treatments (control and water stress) and six methods of fertilizer treatment (control, NPK-F, using magnetic band- M, using silver nano particles- N, M+N and M+N+50% F) on performance of ajowan were compared. Results showed that treatments with magnetic field or base fertilizer had more yield compared to the control and silver nanoparticles (N) treatments. Application of silver nanoparticles had no positive effect on yield. The highest seed and biomass WUE achieved in base fertilizer or magnetic field treatments. Under water stress treatment, seed WUE significantly increased. In conclusion magnetic field exposure, probably by encourage nutrient uptake efficiency could be applied to reduce fertilizer requirement. On the other hand the cultivation of plants under low MF could be an alternative way of WUE improving.

Keywords

  • biomass
  • harvest index
  • yield components
Uneingeschränkter Zugang

Monitoring and remediation technologies of organochlorine pesticides in drainage water

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 115 - 122

Zusammenfassung

Abstract

This study was carried out to monitor the presence of organochlorine in drainage water in Kafr-El-Sheikh Governorate, Egypt. Furthermore, to evaluate the efficiencies of different remediation techniques (advanced oxidation processes [AOPs] and bioremediation) for removing the most frequently detected compound (lindane) in drainage water. The results showed the presence of several organochlorine pesticides in all sampling sites. Lindane was detected with high frequency relative to other detected organochlorine in drainage water. Nano photo-Fenton like reagent was the most effective treatment for lindane removal in drainage water. Bioremediation of lindane by effective microorganisms (EMs) removed 100% of the lindane initial concentration. There is no remaining toxicity in lindane contaminated-water after remediation on treated rats relative to control with respect to histopathological changes in liver and kidney. Advanced oxidation processes especially with nanomaterials and bioremediation using effective microorganisms can be regarded as safe and effective remediation technologies of lindane in water.

Keywords

  • lindane
  • remediation
  • toxicity
  • degradation
  • water
Uneingeschränkter Zugang

Flame resistant cellulosic substrate using banana pseudostem sap

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 123 - 133

Zusammenfassung

Abstract

Flame retardancy was imparted in cellulosic cotton textile using banana pseudostem sap (BPS), an eco-friendly natural product. The extracted sap was made alkaline and applied in pre-mordanted bleached and mercerized cotton fabrics. Flame retardant properties of both the control and the treated fabrics were analysed in terms of limiting oxygen index (LOI), horizontal and vertical flammability. Fabrics treated with the non-diluted BPS were found to have good flame retardant property with LOI of 30 compared to the control fabric with LOI of 18, i.e., an increase of 1.6 times. In the vertical flammability test, the BPS treated fabric showed flame for a few seconds and then, got extinguished. In the horizontal flammability test, the treated fabric showed no flame, but was burning only with an afterglow with a propagation rate of 7.5 mm/min, which was almost 10 times lower than that noted with the control fabric. The thermal degradation and the pyrolysis of the fabric samples were studied using a thermogravimetric analysis (TGA), and the chemical composition by FTIR, SEM and EDX, besides the pure BPS being characterized by EDX and mass spectroscopy. The fabric after the treatment was found to produce stable natural khaki colour, and there was no significant degradation in mechanical strengths. Based on the results, the mechanism of imparting flame retardancy to cellulosic textile and the formation of natural colour on it using the proposed BPS treatment have been postulated.

Keywords

  • banana pseudostem sap
  • cellulose
  • cotton fabric
  • flame retardant
  • thermogravimetry
Uneingeschränkter Zugang

Chemical composition and properties of spray-dried sugar beet concentrate obtained after ultrafiltration of diffusion juice

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 134 - 137

Zusammenfassung

Abstract

Ultrafiltration of diffusion juice is a method that can reduce environmental pollution during the production of sugar. A by-product (concentrate) of ultrafiltration contains a large amount of sucrose, but due to its properties, it is difficult to manage. The aim of this study was to determine the effects of the temperature used during drying of diffusion juice concentrates on the content of certain components and characteristics of resultant preparations. Diffusion juice obtained from one of the Polish sugar plants was subjected to ultrafiltration and the obtained concentrates were dried in a spray dryer. In the dried samples, the following parameters were analyzed: dry mass, sucrose, total ash, protein, crude fiber and color. It has been declared that the degree of concentration and drying temperature influenced the chemical composition and the properties of the dehydrated diffusion juice concentrates. An increase in drying temperature was accompanied by the increased content of dry mass, protein, ash and fiber content in the preparations. The greater the degree of juice concentration, the greater was the content of dry mass, ash, and fiber. Inversely, the greater the degree of juice concentration, the lower the content of sucrose. The brightest color of the dehydrated product was observed at the drying temperature of 200°C. Spray-drying may be used for waste management after the diffusion juice membrane filtration, and the resultant preparations might be used in the production of feedstuff or food industry in general e.g. as sucrose source, in fermentation processes or in microorganisms propagation.

Keywords

  • ceramic membrane
  • ultrafiltration
  • diffusion juice
  • concentrate
  • spray drying
Uneingeschränkter Zugang

Properties and activity of the cobalt catalysts for NH3 synthesis obtained by co-precipitation – the effect of lanthanum addition

Online veröffentlicht: 25 Mar 2015
Seitenbereich: 138 - 143

Zusammenfassung

Abstract

In modern research on catalysts for NH3 synthesis a lot of attention is paid to cobalt. In this work the new catalytic systems based on cobalt are presented. Unsupported cobalt catalysts singly promoted (La or Ba) and doubly promoted (La and Ba) were prepared and tested in NH3 synthesis reaction under commercial synthesis conditions. Characterization studies revealed that lanthanum plays a role of a structural promoter, which improves the surface of catalyst precursors and prevents from sintering during calcination. However, lanthanum has a negative effect on the reduction of cobalt oxide, but the addition of barium promoter (Co/La/Ba catalyst) diminishes the negative impact of La. The co-promotion of cobalt with lanthanum and barium results in the increasing of the active phase surface and improvement of its activity in NH3 synthesis.

Keywords

  • ammonia synthesis
  • cobalt catalyst
  • promoter
  • lanthanum
  • co-precipitation

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