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Modeling and Simulation
Hajar seyfi; Sirous shafiei; Reza Dehghanzadeh; Parya Amirabedi
Abstract
Removal of Acrylonitrile (AN) from waste gas streams using biological methods has recently gained more attraction due to their better performance. The purpose of this research is modeling of the AN removal by a bio-filter. The model validation is done using the experimental data of a bench-scale bio-filter ...
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Removal of Acrylonitrile (AN) from waste gas streams using biological methods has recently gained more attraction due to their better performance. The purpose of this research is modeling of the AN removal by a bio-filter. The model validation is done using the experimental data of a bench-scale bio-filter bed column including yard waste compost and shredded hard plastics and thickened municipal activated sludge. In this work the kinetics of the biodegradation of Acrylonitrile is first investigated. Then equations of the biofilm and air are obtained at steady state and constant temperature. The unknown parameters of the model are determined by the least square optimization method along with solving the model equations using MATLAB. For inlet concentrations less than 1 g/m3 the model results show reasonable similarity to the experimental data. The effect of various parameters on bio-filter performance is evaluated. Peclet number, biofilm thickness and biomass concentration are the most important parameters respectively. The proposed model can be useful for design aims.
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Separation Technology,
Saeed Ovaysi
Abstract
A new approach is proposed to evaluate various designs for gas-solid cyclone separators. This approach uses single-phase flow simulation results to find a quantitative measure of flow symmetry in a given cyclone. Flow symmetry is computed by averaging imbalances of non-axial velocities throughout the ...
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A new approach is proposed to evaluate various designs for gas-solid cyclone separators. This approach uses single-phase flow simulation results to find a quantitative measure of flow symmetry in a given cyclone. Flow symmetry is computed by averaging imbalances of non-axial velocities throughout the cyclone. Using this approach, two standard design methods, namely Shepherd and Stairmand design methods, are evaluated and the cyclone with a more symmetric flow pattern is chosen as a starting point for further design improvements by reducing the diameter of its vortex finder. Two-phase computational fluid dynamics simulations computes 90.2% collection efficiency for the improved design. Computational fluid dynamics simulations reveal using a cascade of four cyclones results in an overall 99.98% collection efficiency. Once installed in the actual industrial setting, the cyclone cascade achieves a 98.56% collection efficiency and a particle size distribution which is in good agreement with those computed using Computational fluid dynamics.
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Environmental Engineering,
Adel Panahadeh; Arsalan Parvareh; Mostafa Moraveji
Abstract
Central composite design (CCD) was employed to investigate the adsorption of Pb(II) and Zn(II) metal ions as well as methylene blue (MB) as an aromatic anion by a new EDTA/MnO2/CS/Fe3O4 synthesized nanocomposite. The effect of possible affective factors including contaminant concentration (20-200 mg/L), ...
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Central composite design (CCD) was employed to investigate the adsorption of Pb(II) and Zn(II) metal ions as well as methylene blue (MB) as an aromatic anion by a new EDTA/MnO2/CS/Fe3O4 synthesized nanocomposite. The effect of possible affective factors including contaminant concentration (20-200 mg/L), pH (2-8), adsorbent content (0.1-0.9 g/L), and contact time (10-110 min) were studied on the adsorption of the metal ions using response surface methodology (RSM). The highest removal percentages predicted by the model were 100.776% and 87.069%, respectively, for the removal of Pb(II) and Zn(II), that the value of more than 100% in the case of Pb(II) was due to the model error. The effect of the simultaneous presence of methyl blue (MB) and the metal ions in the aqueous solution on the adsorption rate of each metal ion was investigated. The study of adsorption isotherms in the single-component adsorption showed the dominance of Langmuir isotherm over the adsorption process of each pollutants (R2>0.99). The maximum adsorption capacities according to the Langmuir model were 310.4 and 136 mg/g for lead and zinc ions, respectively, and 421.1 mg/g for methyl blue. The results showed that the studied nanocomposite still has high efficiency after five consecutive adsorption-desorption cycles.