Regeneration of Granular Activated Carbon Using Dual-Frequency Ultrasound

2012 ◽  
Vol 616-618 ◽  
pp. 1707-1710
Author(s):  
Jiong Yuan Lu ◽  
San Fan Wang ◽  
Jin Feng Zhu
Keyword(s):  
Activated Carbon ◽  
Granular Activated Carbon ◽  
Experimental Results ◽  
Single Frequency ◽  
Dual Frequency ◽  
Thermal Regeneration ◽  
Regeneration Efficiency ◽  
The Individual ◽  
Better Than ◽  
Frequency Ultrasound

The saturate granular activated carbon(GAC) which adsorbed Ni2+ is regenerated using dual-frequency ultrasound. The individual frequency is 45KHz, 80KHz and 100KHz respectively. The experimental results show that the regeneration efficiency using dual-frequency ultrasound is better than that using single- frequency ultrasound under the same experimental condition. When the two ultrasound’s frequency is 45KHz, the regeneration efficiency is 81.03%, comparing single- frequency ultrasound it increase by 40% and it is the best in six group dual-frequency ultrasound. In conclusion, the dual-frequency ultrasound regeneration showed a possibility as an alternative to chemical and thermal regeneration of GAC.

Dual-Frequency Ultrasonic Desorption of Pb2+ from Coconut Shell Activated Carbon

2013 ◽  
Vol 777 ◽  
pp. 38-42
Author(s):  
Jian Zhou ◽  
San Fan Wang
Keyword(s):  
Activated Carbon ◽  
Metal Ion ◽  
Coconut Shell ◽  
Single Frequency ◽  
Dual Frequency ◽  
Cavitation Effect ◽  
Desorption Efficiency ◽  
The Stability ◽  
Coconut Shell Activated Carbon ◽  
Frequency Ultrasound

Desorption experiments of coconut shell activated carbon (CSAC) saturated with Pb2+had been conducted in presence of dual-frequency and single-frequency (30 kHz,500 kHz,1200 kHz) ultrasound. The desorption efficiency was better at dual-frequency ultrasound than at single-frequency ultrasound. The best of desorption efficiency of Pb2+was 65.5% at 500×500 kHz. The desorption efficiency of Pb2+increased by increasing temperature, but when the temperature was more than 50°C, the desorption efficiency decreased initially. The stability of CSAC was not affected with cavitation effect produced by ultrasound of frequency of 500×500 kHz. The carbon loss was less. The rate of loss was only 0.6%. In conclusion, ultrasound was used as alternative method to regenerate activated carbon adsorbing with heavy metal ion.

Devanagari Text Detection From Natural Scene Images

2020 ◽  
Vol 10 (3) ◽  
pp. 44-59
Author(s):  
Sankirti Sandeep Shiravale ◽  
R. Jayadevan ◽  
Sanjeev S. Sannakki
Keyword(s):  
Edge Detection ◽  
Image Understanding ◽  
Text Detection ◽  
Experimental Results ◽  
Combined Approach ◽  
Natural Scene ◽  
Light Conditions ◽  
The Individual ◽  
Natural Scene Images ◽  
Better Than

Text present in a camera captured scene images is semantically rich and can be used for image understanding. Automatic detection, extraction, and recognition of text are crucial in image understanding applications. Text detection from natural scene images is a tedious task due to complex background, uneven light conditions, multi-coloured and multi-sized font. Two techniques, namely ‘edge detection' and ‘colour-based clustering', are combined in this paper to detect text in scene images. Region properties are used for elimination of falsely generated annotations. A dataset of 1250 images is created and used for experimentation. Experimental results show that the combined approach performs better than the individual approaches.

scholarly journals Safe drinking water: effect of granular activated carbon bed characteristics on iron removal from water

2016 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
Md Golam Rasul ◽  
Imtiaz Ahmed ◽  
Md Iqbal Hossain
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Chemical Engineering ◽  
Fixed Bed ◽  
Granular Activated Carbon ◽  
Water Effect ◽  
Engineering Research ◽  
Household Water ◽  
The Individual ◽  
Water Filters

<p>Tuning the characteristics of granular activated carbon bed (GAC-bed) in household water-filters would be a technique to maintain iron at the required-level in drinking water. In the present study the individual effects of the depth of GAC-bed and the size and porosity of GAC particles on the iron removing capacity are investigated experimentally. A spectrophotometer is used to measure iron-content in water. It is observed that iron removing capacity increases monotonically with the increase in bed-depth regardless of the size of GAC particles. It is also observed that the iron removing capacity decreases drastically with the increase in the size of GAC particles for any fixed bed-depth. Finally the porosity of GAC particles is found to affect the iron removing capacity. The higher the GAC porosity the higher is the iron removing capacity over the considered porosity-range. It is believed that the observations of present study would be useful in adjusting GAC-bed characteristics at the time of designing household water-filters to maintain iron at the required-level.</p><p>Chemical Engineering Research Bulletin 18(2015) 1-5</p>

Improvement of thermal regeneration of spent granular activated carbon using air agent : Application of sintering and deoxygenation

2014 ◽  
Vol 31 (9) ◽  
pp. 1641-1650 ◽  
Author(s):  
Joon-Hyung Cho ◽  
Yoon-Su Kim ◽  
Soo-Bin Jeon ◽  
Jong-Beom Seo ◽  
Jong-Hyeon Jung ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Granular Activated Carbon ◽  
Thermal Regeneration

scholarly journals Ionosphere-Constrained Single-Frequency PPP with an Android Smartphone and Assessment of GNSS Observations

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5917
Author(s):  
Guangxing Wang ◽  
Yadong Bo ◽  
Qiang Yu ◽  
Min Li ◽  
Zhihao Yin ◽  
...  
Keyword(s):  
Single Point ◽  
Application Programming Interface ◽  
Satellite System ◽  
Single Frequency ◽  
Dual Frequency ◽  
Application Programming ◽  
Point Positioning ◽  
Global Navigation Satellite ◽  
Gnss Observations ◽  
Better Than

With the development of Global Navigation Satellite System (GNSS) and the opening of Application Programming Interface (API) of Android terminals, the positioning research of Android terminals has attracted the attention of GNSS community. In this paper, three static experiments were conducted to analyze the raw GNSS observations quality and positioning performances of the smartphones. For the two experimental smartphones, the numbers of visible satellites with dual-frequency signals are unstable and not enough for dual-frequency Precise Point Positioning (PPP) processing all through the day. Therefore, the ionosphere-constrained single-frequency PPP model was employed to improve the positioning with the smartphones, and its performance was evaluated and compared with those of the Single Point Positioning (SPP) and the traditional PPP models. The results show that horizontal positioning accuracies of the smartphones with the improved PPP model are better than 1 m, while those with the SPP and the traditional PPP models are about 2 m.

Reaction mechanism of calcium-catalyzed thermal regeneration of spent granular activated carbon

Carbon ◽  
1994 ◽  
Vol 32 (7) ◽  
pp. 1285-1301 ◽  
Author(s):  
Fred S. Cannon ◽  
Vernon L. Snoeyink ◽  
Ramon G. Lee ◽  
Gerard Dagois
Keyword(s):  
Activated Carbon ◽  
Reaction Mechanism ◽  
Granular Activated Carbon ◽  
Thermal Regeneration

Effect of Dual Frequency Ultrasound on the Bubble Formation in a Capillary Tube

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Benwei Fu ◽  
Nannan Zhao ◽  
Guoyou Wang ◽  
Hongbin Ma
Keyword(s):  
Bubble Growth ◽  
High Speed ◽  
Capillary Tube ◽  
Bubble Formation ◽  
Single Frequency ◽  
Quartz Tube ◽  
Outer Diameter ◽  
Dual Frequency ◽  
Heating Section ◽  
Frequency Ultrasound

A visual experimental investigation was conducted to determine the effect of dual frequency ultrasound on the bubble formation and growth in a capillary quartz tube. Two piezoelectric ceramics were used in this experiment. They were made of Pb-based lanthanum-doped zirconate titanates (PLZTs). The PLZTs were placed on a quartz tube with an inner diameter of 2 mm and an outer diameter of 3 mm. The capillary tube was vacuumed first and then charged with water using a filling ratio of 70%. The ultrasonic sound was applied to the heating section of a capillary tube. The bubble formation and growth were recorded by a high speed camera. As shown in figures, when the ultrasound with a single frequency of either 154 kHz or 474 kHz was applied, only one bubble was generated. When the dual frequencies of 154 kHz and 474 kHz were applied, more bubbles were generated. The speed of the bubble growth with dual frequency ultrasound was much higher than that with a single frequency. When a dual frequency ultrasound (154 kHz and 474 kHz) was used, the nucleation sites for bubble formation were significantly increased and the bubble growth rate enhanced.

scholarly journals Hydrochlorofluorocarbon Adsorption by Granular and Extruded Activated Carbons

1996 ◽  
Vol 13 (3) ◽  
pp. 187-195 ◽  
Author(s):  
S.H. Lin ◽  
Y.W. Chen ◽  
J.K. Huang
Keyword(s):  
Activated Carbon ◽  
Polyurethane Foam ◽  
Activated Carbons ◽  
Granular Activated Carbon ◽  
Experimental Results ◽  
Rigid Polyurethane Foam ◽  
Foaming Agent ◽  
Adsorption And Desorption ◽  
Desorption Efficiency ◽  
Adsorption Desorption

Experiments have been conducted to examine the adsorption/desorption characteristics of 1,1-dichloro-1-fluoroethane (HCFC-141b) by granular activated carbon (GAC) and extruded activated carbon. HCFC-141b is currently deemed an excellent replacement for CFC-11, a foaming agent widely used in the rigid polyurethane foam industries. Experimental results of adsorption and desorption were analyzed in terms of the equilibrium capacity, time to reach equilibrium and desorption efficiency of the adsorbent, and with the aim of assessing the viability of using both adsorbents for possible HCFC-141b recovery. The results have clearly revealed great potential for both adsorbents for this purpose.

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