• Title/Summary/Keyword: electrochemical treatment

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Effect of electrochemical treatment on consolidation of soft clay

  • Li, Xiaobing;Yuan, Guohui;Fu, Hongtao;Wang, Jun;Cai, Yuanqiang
    • Geomechanics and Engineering
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    • v.15 no.4
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    • pp.957-964
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    • 2018
  • In this study, a method of electrochemical consolidation is applied. This method utilizes electro-osmosis, which is an effective ground improvement technique for soft clays, and soil treatment using lime, which is the oldest traditional soil stabilizer. The mechanism of lime treatment for soil involves cation exchange, which leads to the flocculation and agglomeration. Five representative laboratory tests-an electro-osmotic test and four electrochemical tests with various proportions of lime-were performed on dredged marine clay. The objectives of this study are to investigate the effect of electrochemical treatment and to determine the optimum dose for optimal consolidation performance of dredged marine clay. The results show that a better consolidation effect was achieved in terms of current, temperature, and vane shear strength by using electrochemical treatment. The best results were observed for the electrochemical test using 4% lime content.

Electrochemical oxidation of sodium dodecylbenzenesulfonate in Pt anodes with Y2O3 particles

  • Jung-Hoon Choi;Byeonggwan Lee;Ki-Rak Lee;Hyun Woo Kang;Hyeon Jin Eom;Seong-Sik Shin;Ga-Yeong Kim;Geun-Il Park;Hwan-Seo Park
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4441-4448
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    • 2022
  • The electrochemical oxidation process has been widely studied in the field of wastewater treatment for the decomposition of organic materials through oxidation using ·OH generated on the anode. Pt anode electrodes with high durability and long-term operability have a low oxygen evolution potential, making them unsuitable for electrochemical oxidation processes. Therefore, to apply Pt electrodes that are suitable for long-term operation and large-scale processes, it is necessary to develop a new method for improving the decomposition rate of organic materials. This study introduces a method to improve the decomposition rate of organic materials when using a Pt anode electrode in the electrochemical oxidation process for the treatment of organic decontamination liquid waste. Electrochemical decomposition tests were performed using sodium dodecylbenzenesulfonate (SDBS) as a representative organic material and a Pt mesh as the anode electrode. Y2O3 particles were introduced into the electrolytic cell to improve the decomposition rate. The decomposition rate significantly improved from 21% to 99%, and the current efficiency also improved. These results can be applied to the electrochemical oxidation process without additional system modification to enhance the decomposition rate and current efficiency.

Surface Treatment with CO2 to Improve Electrochemical Characteristics of Carbon Felt Electrode for VRFB

  • Yechan Park;Sunhoe Kim
    • Journal of Electrochemical Science and Technology
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    • v.14 no.2
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    • pp.131-138
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    • 2023
  • The carbon felt is usually hired as electrodes for vanadium redox flow battery (VRFB). In the study, surface modification of carbon felt under CO2 atmosphere with variables of operating various temperature ranges between 700℃ and 900℃. The qualitative and quantitative analysis were carried out such as scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) to observe degree of surface modification. Result of XPS analysis confirmed increase of carbon and oxidation functional group on the surface with increase of temperature. SEM image was discovered similar phenomena. Electrochemical characteristics such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) revealed the improved electrode performance with increase of temperature. However, the electrochemical performance under treatments temperature of 900℃ was less than that of under treatment temperature of 850℃ due to weight loss at the treatment temperature of 900℃. From the CV and EIS results, the best electrochemical characteristics was at the temperature of 850℃. That of at the temperature of 900℃ was decreased due to weight loss. The energy efficiencies (EE) obtained from full cell test were 69.37, 80.76, 82.45, and 75.47%, at the temperature of 700, 800, 850, and 900℃, respectively.

Study of Electrochemical Cs Uptake Into a Nickel Hexacyanoferrate/Graphene Oxide Composite Film

  • Choi, Dongchul;Cho, Youngjin;Bae, Sang-Eun;Park, Tae-Hong
    • Journal of Electrochemical Science and Technology
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    • v.10 no.2
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    • pp.123-130
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    • 2019
  • We investigated the electrochemical behavior of an electrode coated with a nickel hexacyanoferrate/graphene oxide (NiPB/GO) composite to evaluate its potential use for the electrochemical separation of radioactive Cs as a promising approach for reducing secondary Cs waste after decontamination. The NiPB/GO-modified electrode showed electrochemically switched ion exchange capability with excellent selectivity for Cs over other alkali metals. Furthermore, the repetitive ion insertion and desertion test for assessing the electrode stability showed that the electrochemical ion exchange capacity of the NiPB/GO-modified electrode increased further with potential cycling in 1 M of $NaNO_3$. In particular, this electrochemical treatment enhanced Cs uptake by nearly two times compared to that of NiPB/GO and still retained the ion selectivity of NiPB, suggesting that the electrochemically treated NiPB/GO composite shows promise for nuclear wastewater treatment.

A Study on Inorganic Chemical Treatment Method of Animal Wastes Using by Electroflotation for Recycle (전해부상 장치를 이용한 축산폐수의 유기질비료와 용수 재활용에 관한 연구)

  • Sung Ki-chun;Kim Yong-Ryul;Kim Ki-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.5 no.6
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    • pp.588-591
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    • 2004
  • There is an increasing interest in the use of electrochemical methods for the animal waste treatment The technologies using the electrochemical method provide ideal tools for approaching industrial and animal wastes problems. Unlike other chemical treatments, the electrochemical systems do not make the volume of the secondary waste increase. The electrochemical methods can be operated with electrochemical apparatus and inorganic agent allow selective separation and recovery and even quieter than others. This study concerns design factors, electrode construction and wastewater treatment process of the electrochemical apparatus. The experiment of color, COD and BOD removal is much effective in using electrochemical method with ultrasonication and ozonation.

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Electrochemical Properties of EDLC Electrodes Prepared by Acid and Heat Treatment of Commercial Activated Carbons

  • Wu, Jin-Gyu;Hong, Ik-Pyo;Park, Sei-Min;Lee, Seong-Young;Kim, Myung-Soo
    • Carbon letters
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    • v.9 no.2
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    • pp.137-144
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    • 2008
  • The commercial activated carbons are typically prepared by activation from coconut shell char or coal char containing lots of inorganic impurities. They also have pore structure and pore size distribution depending on nanostructure of precursor materials. In this study, two types of commercial activated carbons were applied for EDLC electrode by removing impurities with acid treatments, and controlling pore size distribution and contents of functional group with heat treatment. The effect of the surface functional groups on electrochemical performance of the activated carbon electrodes was investigated. The initial gravimetric and volumetric capacitance of coconut based activated carbon electrode which was acid treated by $HNO_3$ and then heat treated at $800^{\circ}C$ were 90 F/g and 42 F/cc respectively showing 94% of charge-discharge efficiency. Such a good electrochemical performance can be possibly applied to the medium capacitance of EDLC.

Basic study and patent analysis of electrochemical denitrification from industrial wastewater (산업폐수(産業廢水)로부터 전해처리(電解處理)에 의한 탈질(脫窒) 연구(硏究) 및 특허(特許) 분석(分析))

  • Lee, Churl-Kyoung
    • Resources Recycling
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    • v.16 no.6
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    • pp.52-60
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    • 2007
  • Denitrification from aqueous solution was investigated through patent analysis and electrochemical denitrification experiment. Among several candidates, biological treatment and oxidation/reduction method are mainly discussed. Recently, patent pending concerning to electrochemical treatment is increasing. Based on basic electrochemical study, total nitrogen was removed up 47% by 1-hour galvanostatic electrolysis with Fe cathode and Pt anode. More applicable technique to industry could be mentioned combination of two or more technologies suitable to waste water characteristics. In the case of small and concentrate effluent, combination of chemical and electrochemical treatment would be recommendable because nitrate could be easily converted to nitrite by chemical treatment, and in that case denitrification by electrolysis becomes more efficient and metal ions from chemical treatment can be recovered during electrolysis.

The Effect of Electrochemical Treatment in Lowering Alkali Leaching from Cement Paste to an Aquatic Environment: Part 2- Microscopic Observation (전기화학적 기법을 통한 시멘트페이스트의 수중노출에 따른 알칼리이온 침출저감 효과: Part 2- 미세구조 분석)

  • Bum-Hee Youn;Ki-Yong Ann
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.2
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    • pp.145-152
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    • 2023
  • In this study, microscopic observation was made on the surface of cement paste immersed in an aquatic environment for 100 days at electrochemical treatment to mitigate the leaching of alkali ions. To quantitatively rank the hydration products, unhydrated grains and porosity in the interfacial region, the backscattered electron(BSE) images were obtained by scanninng electron microscopy. As a result, it was found that the porosity on the surface was significantly reduced by the electrochemical treatment, while unhydrated grains were more or less increased presumably limited hydration reaction under electric charge. At electrochemical treatment, Ca2+ ions present in C-S-H gel could be precipitated with OH- to form Ca(OH)2 then to lower C-S-H gel and simultaneously to enhance Ca(OH)2. Substantially, the risk of alkali leaching could be lowered by the limited ionized matrix under electrochemical treatment.

Photo and Electrocatalytic Treatment of Textile Wastewater and Its Comparison

  • Singaravadivel, C.;Vanitha, M.;Balasubramanian, N.
    • Journal of Electrochemical Science and Technology
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    • v.3 no.1
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    • pp.44-49
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    • 2012
  • Electrochemical and photochemical techniques have been proved to be effective for the removal of organic pollutants in textile wastewater. The present study deals with degradation of synthetic textile effluents containing reactive dyes and assisting chemicals, using electro oxidation and photo catalytic treatment. The influence of various operating parameters such as dye concentration, current density, supporting electrolyte concentration and lamp intensity on TOC removal has been determined. From the present investigation it has been observed that nearly 70% of TOC removal has been recorded for electrooxidation treatment with current density 5 mA/$dm^2$, supporting electrolyte concentration of 3 g/L and in photocatalytic treatment with 250 V as optimum lamp intensity nearly 67% of TOC removal was observed. The result indicates that electro oxidation treatment is more efficient than photocatalytic treatment for dye degradation.

A Study on Recycle of Concreted Organic Waste water by Electroflotation Apparatus for Resource Recycle of Non-Metal (비금속 자원 재활용을 위한 전해부상 장치를 이용한 고농도 유기질 폐수의 재활용에 관한 연구)

  • Kim, Ki-Jun;Nam, Sang-Sung
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.4
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    • pp.653-658
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    • 2012
  • There is an increasing interest in the use of electrochemical methods for the food waste treatment. The technologies using the electrochemical method provide ideal tools for approaching industrial and food wastes problems. Unlike other chemical treatments, the electrochemical systems do not make the volume of the secondary waste increase. The electrochemical methods can be operated with electrochemical apparatus and inorganic agent allow selective separation and recovery and even quieter than others. This study concerns design factors, electrode construction and wastewater treatment process of the electrochemical apparatus. The experiment of color, COD and BOD removal is much effective in using electrochemical method with ultrasonication and ozonation.