scholarly journals Optimization of the Effect of Temperature and Bed Height on Cr (VI) Bioadsorption in Continuous System

2020 ◽  
Vol 29 (54) ◽  
pp. e10477
Author(s):  
Angel Villabona-Ortíz ◽  
Candelaria Tejada-Tovar ◽  
Erika Ruiz-Paternina ◽  
Jesús David Frías-González ◽  
Gerlyn David Blanco-García
Keyword(s):  
Electrostatic Interactions ◽  
Fixed Bed ◽  
Continuous System ◽  
Extraction Process ◽  
Operating Conditions ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Residual Concentration ◽  
Bed Height ◽  
Vis Spectroscopy

In the present paper, the residues of the plantain starch extraction process are proposed as an adsorbent to remove Cr (VI) in a continuous fixed bed-system, varying the temperature in 33, 40, 55, 70 y 76 °C and bed height in the range of 15.5, 30, 65, 100, 114.5 mm. The adsorbent material was characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-ray Diffraction Analysis (XRD). The Cr (VI) solution at 100 ppm had contact with the column by gravity, with a flow rate of 0.75 mL/s at the different working conditions. At the end of the process, the residual concentration of the metal was measured by UV-Vis spectroscopy using the standard method for the determination of Cr (VI) in water ASTM D1687-17. From the results, it was established that the bioadsorbent has the presence of hydroxyl, carboxyl and methyl functional groups and that the adsorption process is controlled by electrostatic interactions; the variables evaluated had a significant influence on the process because applying the RSM methodology it was observed that the optimal operating conditions are 81.49 mm of bed height and temperature of 68 ºC. Based on the behavior of the rupture curve, it was found that the bio-material has the potential to be used as a filler in an adsorption column with the purpose of remove Cr (VI).

scholarly journals Cr(VI) biosorption: Effect of temperature, particle size and bed height

2020 ◽  
pp. 78-86
Author(s):  
Candelaria Nahir Tejada-Tovar ◽  
Angel Villabona-Ortíz ◽  
Rodrigo Ortega Toro
Keyword(s):  
Particle Size ◽  
Fourier Transforms ◽  
Continuous System ◽  
Packed Bed ◽  
Effect Of Temperature ◽  
Infrared Spectrometry ◽  
Packed Bed Column ◽  
Chromium Vi ◽  
Bed Height ◽  
Vis Spectroscopy

The present work aimed to evaluate the effect of temperature, particle size and bed height of the chromium (VI) adsorption process using plantain peels in a continuous system. The experiment was carried out on a packed bed column, adjusting the feed temperature of the solution with a REX-C100 controller coupled to a type K thermocouple. The initial concentration of Cr (VI) was set at 100 ppm, the pH at 2 and the feed rate of 0.75 mL/s. The analyses were performed by UV-Vis spectroscopy using the colourimetric method of 1.5-diphenylcarbazide. The material was characterized by infrared spectrometry by Fourier Transforms (FTIR), from this analysis, it was determined that the OH and NH2 functional groups are the main responsible for the formation of complexes with the cations in solution. Also, it was established that only the particle size is statistically significant. According to the response surface analysis, the optimum conditions of the process were 353.15 K, a particle size of 0.819 mm and a bed height of 67.768 mm. From the thermodynamic study of the process, it is established that it is endothermic and the chemical adsorption prevails in it. The results obtained in the process modelling suggest that Dose-Response can be used reliably to scale the process.

scholarly journals Fixed-bed Column Dynamics of Ultrasound and Na-functionalized Diatomite to Remove Phosphate from Water

2021 ◽  
Author(s):  
Junxiu Ye ◽  
Min Yang ◽  
Xuemei Ding ◽  
Wei Tan ◽  
Guizhen Li ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Correlation Coefficients ◽  
Operating Conditions ◽  
Phosphate Adsorption ◽  
Breakthrough Time ◽  
Fixed Bed Column ◽  
Bed Height ◽  
Column Dynamics ◽  
Phosphorous Concentration ◽  
Column Process

Abstract A continuous fixed-bed column study has been used to evaluate phosphate adsorption performance of U-D-Na which was functionalized by the cheap NaCl reagent after simple ultrasonic purification of diatomite. Experimentally, various effect factors, the flow rate, the initial phosphate concentration, and the bed height on breakthrough time of fixed column were studied. Experimental results showed that the breakthrough time declined with the increase of inlet phosphorous concentration and feed rate, whereas the increase of bed height turned out to significantly prolong the breakthrough time. The dynamic adsorption data could better be fitted by the Thomas model, with the correlation coefficients obtained, R2 > 0.9000 at the majority of operating conditions (5/7). At least thrice loop of adsorption and desorption was achieved with 0.1 M hydrochloric acid eluent and deionized water. The results proved that U-D-Na could be used as a better alternative phosphate adsorbent from wastewater in a continuous column process.

Experimental Investigation on Flow Patterns of Cylindrical-Conical Spout-Fluidizing Bed

2011 ◽  
Vol 354-355 ◽  
pp. 338-343
Author(s):  
Qian Jun Li ◽  
Dong Ping Zhang
Keyword(s):  
Flow Pattern ◽  
Fluidized Bed ◽  
Fixed Bed ◽  
Ccd Camera ◽  
Flow Patterns ◽  
Operating Conditions ◽  
Hydrodynamic Characteristics ◽  
Experimental Investigations ◽  
Bed Height ◽  
Bed Materials

Experimental investigations on hydrodynamic characteristics of cylindrical pressurized spout-fluidizing bed were carried out. Two kinds of millet were used as bed materials. The operational pressure is 0.1MPa~0.4MPa (absolutely pressure). Five distinct flow patterns, i.e, fixed bed(FB), jet in fluidized bed with bubbles(JFB), jet in fluidized bed with slugging(JFS), spout with aeration(SA) and spout-fluidizing bed(SF) were identified. Effects of the static bed height and operational pressure on the flow pattern map were particularly studied. Typical flow pattern images obtained by a high- resolution digital CCD camera were presented for classifying these flow patterns. Typical flow pattern maps were plotted for describing the transitions between flow patterns with operating conditions

Synthesis, characterization and electrochemistry of bismuth porphyrins: X-ray crystal structure of (OEP)Bi(SO3CF3)

2000 ◽  
Vol 04 (03) ◽  
pp. 261-270 ◽  
Author(s):  
LYDIE MICHAUDET ◽  
DOMINIQUE FASSEUR ◽  
ROGER GUILARD ◽  
ZHONGPING OU ◽  
KARL M. KADISH ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Electrostatic Interactions ◽  
Free Base ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Bismuth Salts ◽  
Porphyrin Macrocycles

The metalation of several free base porphyrins by the bismuth salts Bi(NO3)3 and Bi(SO3CF3)3 in DMF or pyridine is described. The resulting stable Bi(III) porphyrin complexes are characterized by electrochemistry, 1H NMR and UV-vis spectroscopy. The structure of ( OEP ) Bi ( SO 3 CF 3) was also determined by single-crystal X-ray diffraction and shows that ( OEP ) Bi ( SO 3 CF 3) exists as a dimer which is stabilized by electrostatic interactions in which the two [(OEP)Bi]+ cations are linked via oxygen atoms of two symmetrically related [Formula: see text] anions, leading to a heptacoordinated bismuth center. Electrochemical oxidation of ( OEP ) Bi ( SO 3 CF 3) and ( T p TP ) Bi ( SO3CF3 ) shows that only the porphyrin macrocycles are oxidized.

Improving the Diffusion Controlled Cementation of Cadmium Ions Using Reciprocating Fixed Bed of Zinc Rings

2011 ◽  
Vol 312-315 ◽  
pp. 694-699 ◽  
Author(s):  
A.H. El-Shazly ◽  
Ashraf A. Mubarak ◽  
Hesham S. Bamufleh
Keyword(s):  
Arrhenius Equation ◽  
Fixed Bed ◽  
Effect Of Temperature ◽  
Vibration Velocity ◽  
Kcal Mole ◽  
Cadmium Ions ◽  
Bed Height ◽  
Diffusion Controlled ◽  
Ring Diameter ◽  
Kinetics Of

The aim of the present work is to investigate the effect of pulsation on improving the rate of the diffusion controlled cementation of cadmium ions using reciprocating fixed bed of zinc rings. The kinetics of the cementation reaction was investigated under different conditions of initial concentration of cadmium ions, frequency and amplitude of oscillation (vibration velocity), zinc ring diameter, bed diameter, bed height and temperature. The effect of temperature was found to fit the Arrhenius equation with an activation energy of 7.58 kcal/mole which confirms the diffusion controlled nature of the reaction. A dimensionless correlation in the form of Sh = 6.9 Re0.45 Sc0.33 (Bd/Bh)0.89 was deduced. The industrial application of the obtained results was discussed.

scholarly journals Desorption of Vitamin E from Silica-Packed Fixed-Bed Column by Isopropanol

2010 ◽  
Vol 6 (5) ◽  
Author(s):  
Boon-Seang Chu ◽  
Siew-Young Quek ◽  
Badlishah Sham Baharin ◽  
Yaakob Bin Che Man
Keyword(s):  
Vitamin E ◽  
Flow Rate ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Desorption Rate ◽  
Fixed Bed Column ◽  
Desorption Process ◽  
Column Temperature ◽  
Percentage Recovery ◽  
Bed Height

Desorption of vitamin E from silica-packed fixed-bed column was studied as functions of column bed height, column temperature and flow rate of isopropanol. Isopropanol was the desorbing solvent and it was eluted through the columns saturated with vitamin E. The desorption profiles of all systems showed that vitamin E might desorb at two distinct rates simultaneously. The slow desorbing step was the rate-controlling process for recovery of vitamin E. The desorption rate increased with the decrease of column bed height and flow rate, but increased with increasing column temperature. This indicated that the desorption process was an endothermic process. The percentage recovery of vitamin E upon completion of desorption was considered high for all systems, ranging from 94.8 to 98.8%, with vitamin E concentration in the extract of 18.5-21.5%. Although the bed height, column temperature and flow rate were functions of desorption rate, it appeared that percentage recovery and vitamin E concentration in the extract were rather unaffected by the operating conditions tested if the column was eluted by isopropanol for a sufficient time to desorb vitamin E. Nevertheless, the use of isopropanol would be more efficient if desorption was carried out at lower flow rate and higher column temperature.

Improving the Diffusion Controlled Cementation of Copper Ions on a Fixed Bed of Zinc Raschig Rings Using Flow Pulses in a Batch Reactor

2014 ◽  
Vol 353 ◽  
pp. 153-158 ◽  
Author(s):  
Ahmed H. El-Shazly ◽  
Ashraf A. Mubarak ◽  
Hesham S. Bamufleh
Keyword(s):  
Copper Ions ◽  
Batch Reactor ◽  
Fixed Bed ◽  
Effect Of Temperature ◽  
Vibration Velocity ◽  
Bed Height ◽  
Diffusion Controlled ◽  
Ring Diameter ◽  
Kinetics Of ◽  
Perforated Disc

This work investigates the possibility of improving the kinetics of the diffusion controlled cementation of copper on a fixed bed of zinc Raschig rings in a batch reactor by using flow pulses induced through the bed by a pulsating perforated disc. The kinetics of the cementation reaction was investigated under different conditions of initial concentration of copper ions, frequency and amplitude of oscillation (vibration velocity), zinc ring diameter, bed height and temperature. The effect of temperature was found to fit the Arrhenius equation with an activation energy of 5.5 kcal/mole which confirms the diffusion controlled nature of the reaction. A dimensionless correlation in the form that: Sh = 6.9 Re0.55 Sc0.33 (Pd/Bh)0.49 was deduced. Industrial application of the results obtained was discussed.

Synthesis of disodium phosphonate functionalized graphene oxide as an efficient heterogeneous nanocatalyst for mercaptan removal from the gas stream

2019 ◽  
Vol 12 (03) ◽  
pp. 1950027
Author(s):  
Masoumeh M. Mirzaeian ◽  
Ali Morad Rashidi ◽  
Masud Zare
Keyword(s):  
Graphene Oxide ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Effect Of Temperature ◽  
Functionalized Graphene ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Functionalized Graphene Oxide ◽  
Mercaptan Removal

Mercaptans are commonly present in natural gas. Their high corrosiveness make them the most undesirable sulfur compounds, so they should be removed because of harmful effects on the environment. Disodium phosphonate functionalized graphene oxide (GO-P(Na)2) nanocatalyst was synthesized and adsorption of mercaptan on nanocatalyst was studied in this work. The nanocatalyst was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy analysis. The experiments were carried out in a fixed-bed reactor and the effect of temperature and Gas Hour Space Velocity (GHSV) parameters on mercaptan removal under nanocatalyst were investigated, demonstrating that increasing the temperature and decreasing the GHSV improves the rate of the reaction. Moreover, the kinetic parameters relevant to catalytic reaction for mercaptan removal under nanocatalyst were reported. The experimental results displayed that the maximum of mercaptan removal was obtained under GO-P(Na)2 nanocatalyst at the temperature of 100∘C and GHSV of 1000[Formula: see text]h[Formula: see text]. The concentration of output mercaptan under nanocatalyst reduced from 16,800[Formula: see text]ppm to less than 25[Formula: see text]ppm.

scholarly journals Gasification of grapevine pruning waste in an entrained-flow reactor: gas products, energy efficiency and gas conditioning alternatives

2013 ◽  
Vol 12 (2) ◽  
pp. 215-227
Keyword(s):  
Flow Reactor ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Biomass Energy ◽  
Effect Of Temperature ◽  
Producer Gas ◽  
Heating Value ◽  
Entrained Flow ◽  
Entrained Flow Reactor ◽  
Cold Gas

Owing to its higher efficiency and versatility, gasification is seen as a necessary evolution in the development of biomass energy systems. This technology has been primarily tested in fixed bed (updraft and downdraft) and fluidised bed reaction systems, with less information available about the potential of entrained-flow reactors. This latter design benefits from a relatively simple mechanical structure, robustness against severe gasification conditions and also reduced investment and operating costs. This paper describes the development of a pilot scale entrained-flow reactor and evaluates its performance in the gasification of wood waste left over from the pruning of grapevine (Vitis vinifera). The original biomass was initially analysed for its chemical composition and thermal behaviour. A series of gasification trials were conducted to evaluate the effect of temperature and relative biomass/air ratio (Frg) on the yield, composition, heating value of the resulting syngas. The cold gas efficiency of the system was determined for different operating conditions from the heating value and yields of the resulting producer gas. The results showed that the use of higher temperatures caused a small increase in overall gas yields (from 1.76 Nm3 kg-1 at 750ºC to 1.96 Nm3 kg-1 at 1050ºC) and a notable rise in its heating value (from 3.65 MJ kg-1 at 750ºC to 4.95 MJ kg-1 at 1050ºC), primarily derived from an increase in the concentration of hydrogen. The experimental results show a reduction in the fuel properties of the producer gas when using biomass/air ratios (Frg) below 2.5, which was attributed to the partial combustion of the producer gas. However, this effect was largely counteracted by the production of higher gas yields (3.39 Nm3 kg-1 for Frg = 2.16 compared to 1.96 Nm3 kg-1 for Frg = 4.05), owing to the higher conversion of the fuel at low biomass/air ratios. Optimum gasification conditions (cold gas efficiency up to 83.06 %) were reached when using high reaction temperatures (1050ºC) and low Frg (2.19). This paper also provides a final review about the formation of unwanted tars and particulates in gasification processes, its effect in energy applications, and the use of alternative technologies (thermocatalytic cracking, reforming, water-gas shift) for the conditioning and upgrading of the resulting gas stream.

Dimethyldisulphide Hydrodesulphurization on NiCoMo / Al2O3 Catalyst

2017 ◽  
Vol 68 (7) ◽  
pp. 1496-1500
Author(s):  
Rami Doukeh ◽  
Mihaela Bombos ◽  
Ancuta Trifoi ◽  
Minodora Pasare ◽  
Ionut Banu ◽  
...  
Keyword(s):  
Good Accuracy ◽  
Fixed Bed ◽  
Continuous System ◽  
Space Velocity ◽  
Molar Ratio ◽  
Catalytic Reactor ◽  
Liquid Hourly Space Velocity ◽  
Hydrodesulfurization Process ◽  
Al2o3 Catalyst ◽  
Simplified Kinetic Model

Hydrodesulphurization of dimethyldisulphide was performed on Ni-Co-Mo /�-Al2O3 catalyst. The catalyst was characterized by determining the adsorption isotherms, the pore size distribution and the acid strength. Experiments were carried out on a laboratory echipament in continuous system using a fixed bed catalytic reactor at 50-100�C, pressure from 10 barr to 50 barr, the liquid hourly space velocity from 1h-1 to 4h-1 and the molar ratio H2 / dimethyldisulphide 60/1. A simplified kinetic model based on the Langmuir�Hinshelwood theory, for the dimethyldisulphide hydrodesulfurization process of dimethyldisulphide has been proposed. The results show the good accuracy of the model.

Sign in / Sign up

Export Citation Format

Share Document