• Title/Summary/Keyword: 과황산염

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Sludge solubilization using sono-activated persulfate (활성 과황산염을 이용한 슬러지 가용화)

  • Moon, Sang-Jae;Nam, Se-Yong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.29 no.3
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    • pp.35-40
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    • 2021
  • In order to investigate the degree of solubilization of sewage sludge using sono-activated persulfate(UV/PP), VSS reduction rate, solubilization rate and extracellular polymeric substances were measured. Ultrasonic(US) and alkali·ultrasonic method using sodium hydroxide(US/SH) were compared. Under the persulfate·ultrasonic conditions, the VSS reduction rate and the solubilization rate increased to 27.6% and 58.9%, respectively. TB-EPS as Carbohydrate and Protein were extracted by 770 mg/L and 2,162 mg/L. Compared to the other methods, US and US/SH, the VSS reduction rate and solubilization rate were higher. And also, according to the TB-EPS values, cell wall destruction was more efficient.

Electrochemical Oxidation of Phenol using Persulfate and Nanosized Zero-valent Iron (과황산염과 나노영가철을 이용한 페놀의 전기화학적 산화)

  • Kim, Cheolyong;Ahn, Jun-Young;Kim, Tae Yoo;Hwang, Inseong
    • Journal of Soil and Groundwater Environment
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    • v.22 no.2
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    • pp.17-25
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    • 2017
  • The efficiency and mechanism of electrochemical phenol oxidation using persulfate (PS) and nanosized zero-valent iron (NZVI) were investigated. The pseudo-first-order rate constant for phenol removal by the electrochemical/PS/NZVI ($1mA^*cm^{-2}/12$ mM/6 mM) process was $0.81h^{-1}$, which was higher than those of the electrochemical/PS and PS/NZVI processes. The electrochemical/PS/NZVI system removed 1.5 mM phenol while consuming 6.6 mM PS, giving the highest stoichiometric efficiency (0.23) among the tested systems. The enhanced phenol removal rates and efficiencies observed for the electrochemical/PS/NZVI process were attributed to the interactions involving the three components, in which the electric current stimulated PS activation, NZVI depassivation, phenol oxidation, and PS regeneration by anodic or cathodic reactions. The electrochemical/PS/NZVI process effectively removed phenol oxidation products such as hydroquinone and 1,4-benzoquinone. Since the electric current enhances the reactivities of PS and NZVI, process performance can be optimized by effectively manipulating the current.

Fabrication of Metal-biochar Composite through CO2 Assisted Co-pyrolysis of Chlorella and Red Mud and Its Application for Persulfate Activation (녹조류와 적니의 이산화탄소환경 공동열분해를 통한 탄소-철 복합체 생성 및 과황산염 활성화를 통한 수중 염료 제거)

  • Jang, Hee-Jin;Kwon, Gihoon;Yoon, Kwangsuk;Song, Hocheol
    • Journal of Soil and Groundwater Environment
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    • v.27 no.1
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    • pp.31-38
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    • 2022
  • The common algae and industrial waste, chlorella and red mud, were co-pyrolyzed in carbon dioxide condition to fabricate iron-biochar composite. In order to investigate the direct effect of chlorella and red mud in the syngas generation and the property of biochar, experiments were performed using mixture samples of chlorella and red mud. The evolution of flammable gasses (H2, CH4, CO) was monitored during pyrolysis. The produced biochar composite was employed as a catalyst for persulfate activation for methylene blue removal. BET analysis indicated that the iron-biochar composite mainly possessed meso- and macropores. The XRD analysis revealed that hematite (Fe2O3) contained in red mud was transformed to Fe3O4 during co-pyrolysis. The composite effectively activated persulfate and removed methylene blue. Among the composite samples, the composite fabricated from the mixture composed of 1:2 chlorella:red mud showed the best performance in syngas generation and methylene blue removal.

Effects of Adsorption and Decomposition on the Removal of Total Organic Carbon (TOC) in Oil Wastewater by Cellulose-based Pseudo Graphene and Persulfate (셀룰로오스 기반 유사-그래핀과 과황산염에 의한 압연류 폐수내 총유기탄소(TOC) 흡착 및 분해효과 연구)

  • Song-I Kim;Ji-Young Shin;Kyung-Chul Park;Jae-Kyu Yang;Dong-Su Kim
    • Journal of the Korea Organic Resources Recycling Association
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    • v.32 no.3
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    • pp.5-18
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    • 2024
  • Chemical oxygen demand (COD), an organic material measurement index, has a limit to the management of the total amount of all organic materials including non-degradable organic materials due to low oxidation rate. So total organic carbon (TOC) that can measure organic materials more accurately is introduced and used as a measurement index. Several environmental companies including company A in Gyeonggi-do dilute raw wastewater first and then treats it with chemicals. And an activated carbon is used at the rear stage to treat total organic carbon even though various treatment processes can be applied to reduce TOC in wastewater. There are some problems such as use of a lot of diluting water and generation of an excessive amount of sludge, so it is urgent to come up with an alternative plan. Therefore, in this study, an application experiment was conducted on two different methods for improving the TOC reduction efficiency of waste water from Company A. The first method is the evaluation of the substitution potential of powered activated carbon(PAC), an adsorbent currently used, by manufacturing cellulose-based graphene like carbon (CGLC). This first study showed that CGLC had about 10% higher TOC adsorption efficiency than commercial PAC, showing the possibility of being applied as an alternative adsorbent for PAC in water treatment sites. The second method relates to the removal of TOC by sulfate radials produced by persulfate (PS) activation. Two activation methods were applied: using CGLC and PAC as carbon-based catalyst and using the high temperature of wastewater for PS activation. As a result of using PAC and CGLC as PS activation materials, the TOC removal rate was lower than the adsorption amount of TOC by CGLC and PAC due to excessive chlorine ions present in the real wastewater. However, as a result of using the high water temperature (55~60℃) of the field wastewater for PS activation, it showed a much greater TOC removal efficiency than PAC alone, CGLC alone, and using a carbon-based catalyst for PS activation. When PS was injected more than 0.5%, it showed a TOC removal efficiency of 95% or more within 24 hr. In addition, when PS was injected more than 0.3%, the TOC concentration could be lowered to less than 75 ppm, which is the wastewater discharge standard applied to company A. When these results were summarized, raw wastewater of high temperature can be treated with a simple process of only adding of PS and discharged by treating TOC below the wastewater discharge standard applied to company A.

Solar Photochemical Degradation and Toxicity Reduction of Trichloroethlylene (TCE) (Trichloroethlylene (TCE)의 광화학적 분해 및 독성 저감)

  • Park, Jae-Hong;Kwon, Soo Youl
    • Clean Technology
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    • v.12 no.4
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    • pp.244-249
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    • 2006
  • The photocatalytic degradation of trichloroethlylene (TCE), has been investigated over $TiO_2$ photocatalysts irradiated with solar light. The effect of operational parameters, i.e., initial TCE concentration, $TiO_2$ concentration, pH and additives ($H_2O_2$, persulphate($S_2O{_8}^-$)) on the degradation rate of aqueous solution of TCE has been examined. The results presented in this work demonstrated that degradation of the TCE with $TiO_2/solar$ light was enhanced by augumentation in $TiO_2$ loading, pH, and adding additives but was inhibited by increase in initial TCE concentration. Also individual use of $H_2O_2$ was far more effective than using persulphate in TCE removal efficiency. Furthermore, the relative toxicity with a $solar/TiO_2/H_2O_2$ system was about 15% lower than with a $solar/TiO_2/persulphate$ system and about 35% lower than with a $solar/TiO_2$ system within a reaction time of 150 min, respectively.

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