scholarly journals Adsorption optimized of the coal-based material and application for cyanide wastewater treatment

2019 ◽  
Vol 8 (1) ◽  
pp. 391-398 ◽  
Author(s):  
Ting Su ◽  
Yonghui Song ◽  
Xinzhe Lan ◽  
Wenwen Gao

Abstract Custom design of JMP software was used to optimize the iodine number of coal-based electrode materials. Taking the additive ratio (A), heating rate (B) and final pyrolysis temperature (C) into account and the significance sequence was C>B>A. Set the additive ratio as 0.2, the heating rate as 5°C/min and the final temperature as 900°C, the iodine number was improved to 403.14 mg·g-1, and the compressive strength was 2.01 MPa. Surface morphology of the coal-based electrode materials were characterized by scanning electron microscopy (SEM). The functional group species were explored by Fourier infrared spectrophotometer (FTIR). Then applied the voltage of 4 V, coal-based adsorption materials were set as cathodes and anodes in a 3-dimensional electrode system with the commercial activated carbon as a particle electrode. After 5 h treatment for cyanide wastewater, the removal rate of most ions was achieved to 72% or more. It was the collaborative effect in the combined action of electro-adsorption and electrodeposition.

2021 ◽  
Vol 10 (1) ◽  
pp. 756-767
Author(s):  
Ting Su ◽  
Wenwen Gao ◽  
Xiangdong Xing ◽  
Xinzhe Lan ◽  
Yonghui Song

Abstract The present work demonstrated preparation of coal-based electrode materials (CEM)-derived low-rank coal for simultaneous removal of ammonia nitrogen (NH3-N) and chemical oxygen demand (COD) from coking wastewater by a three-dimensional electrode system (3DES). The influence of important parameters in 3DES such as processing time, applied voltage, electrode plate spacing, mass of commercially activated carbon (CAC), and initial pH were investigated. Based on the central composite design, the response surface method (RSM) was employed in order to optimize the variable parameters in removal process of pollutants. From the analysis of RSM, the optimum conditions for 3DES were 4.5 h of processing time, 5.5 V of applied voltage, 17 mm electrode plate spacing, 4.5 g CAC, and pH of 3 with higher simultaneous removal rate of COD (74.20%) and NH3-N (51.48%). Besides, the content of N element (4.9%) and N containing groups were traced by SEM-EDS and FTIR analysis in order to verify the removal effect. The experiment results showed the capability of CEM for electrode system removal of pollutants from coking wastewater and obtained considerable simultaneous removal rate of NH3-N and COD.


2009 ◽  
Vol 60 (5) ◽  
pp. 1341-1346 ◽  
Author(s):  
W. H. Kuan ◽  
C. Y. Hu ◽  
M. C. Chiang

A batch electrocoagulation (EC) process with bipolar electrode and potentiodynamic polarization tests with monopolar systems were investigated as methods to explore the effects of electrode materials and initial solution pH on the As(V) and As(III) removal. The results displayed that the system with Al electrode has higher reaction rate during the initial period from 0 to 25 minutes than that of Fe electrode for alkaline condition. The pH increased with the EC time because the As(V) and As(III) removal by either co-precipitation or adsorption resulted in that the OH positions in Al-hydroxide or Fe-hydroxide were substituted by As(V) and As(III). The pH in Fe electrode system elevate higher than that in Al electrode because the As(V) removal substitutes more OH position in Fe-hydroxide than that in Al-hydroxide. EC system with Fe electrode can successfully remove the As(III) but system with Al electrode cannot because As(III) can strongly bind to the surface of Fe-hydroxide with forming inner-sphere species but weakly adsorb to the Al-hydroxide surface with forming outer-sphere species. The acidic solution can destroy the deposited hydroxide passive film then allow the metallic ions liberate into the solution, therefore, the acidic initial solution can enhance the As(V) and As(III) removal. The over potential calculation and potentiodynamic polarization tests reveal that the Fe electrode systems possess higher over potential and pitting potential than that of Al electrode system due to the fast hydrolysis of and the occurrence of Fe-hydroxide passive film.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pengfei Hao ◽  
Yanjie Yi ◽  
Youming Li ◽  
Yi Hou

Abstract A green and economically viable route without any additional activation agents and templates has been developed to synthesize biomass-derived nanoporous carbon for superior electric double-layer capacitors via direct pyrolysis of dried black liquor powders, which is the main waste in pulping and paper-making industry. The resulting carbon materials present hierarchical porosity and moderate specific surface area of 1134  m 2 g − 1 {\text{m}^{2}}\hspace{0.1667em}{\text{g}^{-1}} , as well as multi-heteroatoms co-doping such as N, S, Na and K, which exist originally in black liquor. When evaluated as electrode materials for supercapacitors in 6 M KOH aqueous electrolyte, the-prepared carbon samples deliver a significantly high gravimetric capacitance of 331  F g − 1 \text{F}\hspace{0.1667em}{\text{g}^{-1}} at 0.5  A g − 1 \text{A}\hspace{0.1667em}{\text{g}^{-1}} in a three-electrode system. Moreover, the fabricated symmetric supercapacitor also possesses a gravimetric capacitance of 211  F g − 1 \text{F}\hspace{0.1667em}{\text{g}^{-1}} at 0.5  A g − 1 \text{A}\hspace{0.1667em}{\text{g}^{-1}} , with an impressive long-term cycling stability of 92 % capacitance retention after 3000 cycles. This work explores a suitable and scalable approach for mass production of high-performance electrode materials with industrial wastes on the base of cost-efficiency and environment-friendship.


2015 ◽  
Vol 8 (3) ◽  
pp. 702-730 ◽  
Author(s):  
Zenan Yu ◽  
Laurene Tetard ◽  
Lei Zhai ◽  
Jayan Thomas

A review of supercapacitor electrode materials with 0, 1, 2, and 3 dimensional nanostructures.


2012 ◽  
Vol 488-489 ◽  
pp. 876-880 ◽  
Author(s):  
Manoj Kumar Kuttuboina ◽  
A. Uthirapathi ◽  
Singaravelu D. Lenin

The effect of process parameters namely peak current, pulse on time and flushing pressure on electrical discharge machining (EDM) of titanium alloy (Ti–6Al–4V) were investigated by using three different tool electrode materials namely copper, brass, and aluminium. Kerosene is used as dielectric. The process parameters for machining Ti6Al4V are varied at three levels by using Taguchi's orthogonal array table. The responses such as Metal Removal Rate (MRR), Tool Wear Rate (TWR), and Surface Roughness (SR) are measured and the most significant parameter was confirmed by ANOVA (Analysis Of Variance). The test result shows that copper electrode material possesses higher MRR, less TWR as compared to brass and aluminium. Brass and copper tools has good surface finish as compared with aluminium. The finest electrode material for machining of Ti6Al4V alpha beta alloy in EDM process was in the order of copper, brass and aluminium.


Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1077
Author(s):  
Islam Md. Rashedul ◽  
Yan Zhang ◽  
Kebing Zhou ◽  
Guoqian Wang ◽  
Tianpeng Xi ◽  
...  

Electrochemical discharge machining (ECDM) is an emerging method for developing micro-channels in conductive or non-conductive materials. In order to machine the materials, it uses a combination of chemical and thermal energy. The tool electrode’s arrangement is crucial for channeling these energies from the tool electrode to the work material. As a consequence, tool electrode optimization and analysis are crucial for efficiently utilizing energies during ECDM and ensuring machining accuracy. The main motive of this study is to experimentally investigate the influence of different electrode materials, namely titanium alloy (TC4), stainless steel (SS304), brass, and copper–tungsten (CuW) alloys (W70Cu30, W80Cu20, W90Cu10), on electrodes’ electrical properties, and to select an appropriate electrode in the ECDM process. The material removal rate (MRR), electrode wear ratio (EWR), overcut (OC), and surface defects are the measurements considered. The electrical conductivity and thermal conductivity of electrodes have been identified as analytical issues for optimal machining efficiency. Moreover, electrical conductivity has been shown to influence the MRR, whereas thermal conductivity has a greater impact on the EWR, as characterized by TC4, SS304, brass, and W80Cu20 electrodes. After that, comparison experiments with three CuW electrodes (W70Cu30, W80Cu20, and W90Cu10) are carried out, with the W70Cu30 electrode appearing to be the best in terms of the ECDM process. After reviewing the research outcomes, it was determined that the W70Cu30 electrode fits best in the ECDM process, with a 70 μg/s MRR, 8.1% EWR, and 0.05 mm OC. Therefore, the W70Cu30 electrode is discovered to have the best operational efficiency and productivity with performance measures in ECDM out of the six electrodes.


2020 ◽  
Vol 20 (6) ◽  
pp. 3785-3794 ◽  
Author(s):  
Manohar D. Mehare ◽  
Abhay D. Deshmukh ◽  
S. J. Dhoble

A sucrose derived carbon quantum dots/polyaniline (S-CQD/PANI) nanocomposite was synthesized as electrode materials by electrodeposition method to achieve excellent electrocapacitive performance for supercapacitor application. The morphology reveals that CQD were distributed uniformly over the surface of PANI. The highest specific capacitance obtained to be 1512.4 Fg−1 at current density 1 Ag−1 for S-CQD/PANI-25 composite in three electrode system with 1 M H2SO4 aqueous electrolyte within the potential range of −0.2 to 0.8 V. In addition asymmetric supercapacitor device was fabricated reveals highest specific capacitance of 295 Fg−1 at 1 Ag−1 with excellent stability over 1000 cycle at 3 Ag−1. Remarkably, the device delivers energy density of 40.86 Whkg−1 at power density 2000 Wkg−1.


2011 ◽  
Vol 347-353 ◽  
pp. 3260-3263
Author(s):  
Bin Yang ◽  
Tao Xu ◽  
Neng Huang

In order to reduce production cost of making H2, one of the key points was to reduce Pt loading in Pt/C catalytic electrode. In our study, a new type of Pt/C membrane electrodes -- PtCu/C (abbr. P), PtCuLaOx/C (abbr. PL), PtCu-LaOx/C (abbr. P-L), LaOx-PtCu/C (abbr. L-P), LaOx-PtCu-LaOx/C (abbr. L-P-L) and PtCu-LaOx-PtCu/C (abbr. P-L-P) composite multi-layer membrane electrodes -- would be raised, in which with developing different membranouslayer form and different La content homogeneously dispersed on the surface of carbonaceous substrates was manufactured by Ion Beam Sputtering (IBS) technology. The hydrogen evolution polarization curves of these electrodes were tested by tri-electrode system, and were calculated results of their exchange current density (i0) and decomposition voltage (Ed). It was found that PtCu-LaOxcomposite multi-layer membrane with Pt loading less than 0.05mg/cm2(the electrode area) whose Ed and i0 was -0.227(V vs SCE) and 4.717mA/cm2respectively in balanced condition.


2014 ◽  
Vol 984-985 ◽  
pp. 73-82 ◽  
Author(s):  
A. Kadirvel ◽  
P. Hariharan ◽  
M. Mudhukrishnan

Micro-EDM is an extensively used machining process for the fabrication of micro-holes with various advantages resulting from its characteristics of non-contact and thermal process. In this micro-fabrication technique, processing parameters greatly affect processing efficiency and stability. An experimental investigation on die-sinking Micro-EDM of EN-24 die steel using various electrodes such as tungsten, copper, copper tungsten and silver tungsten has been carried out. The present study aims to assess the quality and accuracy of the produced micro-holes, machining stability, material removal rate (MRR), tool wear ratio (TWR), surface roughness (Ra), Heat affected zone (HAZ) and overcut (OC). In addition, the influence of gap voltage, capacitance and discharge energy on the performance of the process has also been investigated. Experimental results proved that the overall performance of the copper electrode is found to be optimum with high MRR, thin HAZ though copper shows higher TWR, surface roughness and overcut.


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