Comparative between different Natural Sources of Activated Carbon for the Removal Reactive Green Dye from Aqueous Solution

Water pollution is one of the biggest problems facing us, so it requires the need to develop a very high-efficiency and inexpensive absorbent material from natural surfaces and compare it with expensive commercial sorbents. Where in this study an absorbent substance was prepared from the natural surfaces of Syzgium Aromaticum Flower Bud (SAFB), Nigella Sativa (NS) Converted to activated carbon to activated carbon Activated (SAFB), and Activated (NS), as these surfaces are characterized by high porosity, cheap price and very high efficiency in removing dye. The composite was illustrated via different analysis apparatus included FTIR, and FE-SEM, The adsorption result were fitted with Freundlich isotherms. The experimental kinetic result at different primary reactive green dye concentrations, were also analyzed through first model, second model and Elovich model. The obtained data appear that the model pseudo-first model fits the adsorption kinetic result through R2 0.96028, R2 0.9486, R2 0.9016 and R2 0.9620 of SAFB and ACTIVE-SAFB and Nigella Sativa (NS) and Activated (NS) in the same order.

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Phenol Removal from Contaminated Wastewater Using Activated Carbon/Zeolite Composite Coated with Titanium Dioxide

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.690.103 ◽

2016 ◽

Vol 690 ◽

pp. 103-108

Author(s):

Khemmakorn Gomonsirisuk ◽

Thanakorn Wasanapiarnpong ◽

Charusporn Mongkolkachit

Keyword(s):

Titanium Dioxide ◽

Activated Carbon ◽

High Efficiency ◽

Adsorption Property ◽

Phenol Concentration ◽

Study Phase ◽

Phenol Removal ◽

High Porosity ◽

Good Efficiency ◽

Composite Substrate

Phenol and phenolic compounds in wastewater from various industries were toxic to water livings and human even in ppm concentration. A number of photocatalysts and adsorbents were applied for the low cost and good efficiency wastewater management to reduce phenol concentration in water. In this work titanium dioxide, one of high efficiency photocatalysts which is widely used in water treatement, was coated on the fabricated adsorbent composite substrate. The composite substrate composed of activated carbon and NaA zeolite presents high phenol adsorption because of high porosity and good ion exchange properties resulting in good adsorption property. Accordingly, the absorption could promote the photocatalytic activity of TiO2 catalyst. As the specimens were easily disposed after water treatment process, therefore, it was a good choice for lower energy consumption. The composite substrate was easily fabricated by simple extrusion and fired under non oxidation atmosphere at 650°C for 3 hours. Then polyurethane foam was inserted into the composite substrate to make it be able to float and be swirled by wind near water surface to get more UV excitation than deeper water. Phenol concentration was investigated by the UV absorbance at 270 nm using UV-Vis spectrophotometer. The XRD and SEM were used to study phase crystal structure and morphology of the composite.

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Textural Development of Activated Carbon Prepared from Recycled PET with Different Chemical Activation Agents

Materials Science Forum ◽

10.4028/www.scientific.net/msf.587-588.753 ◽

2008 ◽

Vol 587-588 ◽

pp. 753-757 ◽

Cited By ~ 5

Author(s):

Isabel P.P. Cansado ◽

Manuela M.L. Ribeiro Carrott ◽

Peter J.M. Carrott ◽

Paulo A.M. Mourão

Keyword(s):

Activated Carbon ◽

Pore Size ◽

Potassium Hydroxide ◽

Activated Carbons ◽

Chemical Activation ◽

High Porosity ◽

N2 Adsorption ◽

Recycled Pet ◽

Textural Development ◽

Very High

Activated carbons (AC) were prepared from waste granulated Polyethyleneterephthalate (PET) by chemical activation with phosphoric acid, sodium hydroxide and potassium hydroxide. All AC were characterised by N2 adsorption at 77 K, and those prepared with H3PO4 had a narrow pore size around 0.8 nm, those prepared with NaOH had a larger pore size higher than 1.52 nm and those prepared with KOH presented a pore size varying between 0.66 and 1.58 nm. The results suggest that H3PO4 and NaOH are not the most suitable activating agents for preparing AC with a high pore volume from waste PET. The AC produced with KOH presented a very high porosity, which passed through a maximum of 0.75 cm3g-1, due to an enlargement of the small micropores with an increase of the carbonisation temperature.

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Use of activated carbon to remove undesirable residual amylase from refinery streams

Sugar Industry ◽

10.36961/si18170 ◽

2017 ◽

pp. 96-103 ◽

Cited By ~ 1

Author(s):

Gillian Eggleston ◽

Isabel Lima ◽

Emmanuel Sarir ◽

Jack Thompson ◽

John Zatlokovicz ◽

...

Keyword(s):

Activated Carbon ◽

High Temperature ◽

High Performance ◽

Activated Carbons ◽

Amylase Activity ◽

Sugar Industry ◽

End User ◽

Customer Complaints ◽

Carry Over ◽

Very High

In recent years, there has been increased world-wide concern over residual (carry-over) activity of mostly high temperature (HT) and very high temperature (VHT) stable amylases in white, refined sugars from refineries to various food and end-user industries. HT and VHT stable amylases were developed for much larger markets than the sugar industry with harsher processing conditions. There is an urgent need in the sugar industry to be able to remove or inactivate residual, active amylases either in factory or refinery streams or both. A survey of refineries that used amylase and had activated carbon systems for decolorizing, revealed they did not have any customer complaints for residual amylase. The use of high performance activated carbons to remove residual amylase activity was investigated using a Phadebas® method created for the sugar industry to measure residual amylase in syrups. Ability to remove residual amylase protein was dependent on the surface area of the powdered activated carbons as well as mixing (retention) time. The activated carbon also had the additional benefit of removing color and insoluble starch.

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Near quantitative synthesis of urea macrocycles enabled by bulky N-substituent

Nature Communications ◽

10.1038/s41467-021-21678-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yingfeng Yang ◽

Hanze Ying ◽

Zhixia Li ◽

Jiang Wang ◽

Yingying Chen ◽

...

Keyword(s):

High Efficiency ◽

Molecular Structures ◽

High Yield ◽

Kinetic Control ◽

High Concentration ◽

Weak Association ◽

Quantitative Synthesis ◽

Thermodynamic Stabilization ◽

Discrete Structures ◽

Very High

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.

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Large Optical Nonlinearity of the Activated Carbon Nanoparticles Prepared by Laser Ablation

Nanomaterials ◽

10.3390/nano11030737 ◽

2021 ◽

Vol 11 (3) ◽

pp. 737

Author(s):

Yasin Orooji ◽

Hamed Ghanbari Gol ◽

Babak Jaleh ◽

Mohammad Reza Rashidian Vaziri ◽

Mahtab Eslamipanah

Keyword(s):

Electron Microscopy ◽

Activated Carbon ◽

Laser Ablation ◽

Carbon Nanoparticles ◽

Morphological Properties ◽

Excitation Wavelength ◽

Saturable Absorption ◽

Reverse Saturable Absorption ◽

High Porosity ◽

Nlo Properties

Carbon nanoparticles (CNPs) with high porosity and great optical features can be used as a luminescent material. One year later, the same group investigated the NLO properties CNPs and boron-doped CNPs by 532 nm and 1064 nm laser excitations to uncover the underlying physical mechanisms in their NLO response. Hence, a facile approach, laser ablation technique, was employed for carbon nanoparticles (CNPs) synthesis from suspended activated carbon (AC). Morphological properties of the prepared CNPs were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). UV-Vis and fluorescence (FL) spectra were used to optical properties investigation of CNPs. The size distribution of nanoparticles was evaluated using dynamic light scattering (DLS). The nonlinear optical (NLO) coefficients of the synthesized CNPs were determined by the Z-scan method. As a result, strong reverse saturable absorption and self-defocusing effects were observed at the excitation wavelength of 442 nm laser irradiation. These effects were ascribed to the presence of delocalized π-electrons in AC CNPs. To the best of our knowledge, this is the first study investigating the NLO properties of the AC CNPs.

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Design and Analysis of a High Pitch to Chord Ratio Cascade Representative of Ducted Propfans

Volume 1: Turbomachinery ◽

10.1115/91-gt-335 ◽

1991 ◽

Author(s):

A. Weber ◽

W. Steinert ◽

H. Starken

Keyword(s):

Boundary Layer ◽

Mach Number ◽

High Efficiency ◽

Pressure Ratio ◽

Flow Analysis ◽

High Pitch ◽

Integral Boundary ◽

Pressure Loss Coefficient ◽

Distribution Boundary ◽

Very High

Efforts to reduce the specific fuel consumption of a modern aero engine focus in particular on increasing the by-pass ratio beyond the current level of around 5. One concept is the counterrotating shrouded propfan operating at low overall pressure ratio and having only very few fan blades of extremely high pitch/chord ratios. The relative inlet Mach numbers cover a range from 0.7 at the hub to 1.1 at the tip section of the first rotor. A propfan cascade was designed by taking into account two characteristic features of a propfan blade-blade section: • a very high pitch/chord ratio of s/c = 2.25 • an inlet Mach number of M1 = 0.90 which leads to transonic flow conditions inside the blade passage In the design process a profile generator and a quasi-3D Euler solver were used iteratively to optimize the profile Mach number distribution. Boundary layer behavior was checked with an integral boundary layer code. The cascade design was verified experimentally in the transonic cascade wind tunnel of DLR at Cologne. The extensive experimental results confirm the design goal of roughly 5 degree flow turning. A total pressure loss coefficient of less than 1.5% was measured at design conditions. This validates the very high efficiency level the propfan concept is calling for. A 2D Navier-Stokes flow analysis code yields good results in comparison to the experimental ones.

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Instantaneous Electromagnetic Torque Components in Synchronous Motors Fed by Load-Commutated Inverters

Energies ◽

10.3390/en14113223 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3223

Author(s):

Gabriel Ekemb ◽

Fouad Slaoui-Hasnaoui ◽

Joseph Song-Manguelle ◽

P. M. Lingom ◽

Issouf Fofana

Keyword(s):

High Efficiency ◽

Air Gap ◽

International Standards ◽

Synchronous Motors ◽

Gas Compression ◽

Variable Frequency Drives ◽

Torsional Analysis ◽

Analytical Expressions ◽

Very High ◽

Excitation Circuit

This paper proposes time-domain analytical expressions of the instantaneous pulsating torque components in a synchronous machine air gap when supplied by a load-commutated-inverter (LCI) system. The LCI technology is one of the most used variable frequency drives when very high power and low speed are required in applications such as pipeline recompression and decompression, as well as liquefied natural gas compression. In such applications, synchronous motors are used because of their high efficiency resulting from a separated supply of the current to their rotor through the excitation circuit. These applications usually have long and flexible shafts, which are very sensitive to torsional vibration excitation when their natural frequencies interact with any external torque applied to the shaft. A torsional analysis is required by international standards to assess the survivability of the shaft through the overall speed range of the motor. Therefore, the magnitude and frequencies of the motor air-gap torque are needed for such evaluation. The proposed developments are supported by numerical simulations of LCI systems in a large range of operation range. From the simulation results, torque harmonic families are derived and expressed in a parametric form, which confirm the accuracy of the proposed relationships.

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