• Title, Summary, Keyword: 1,4-dioxane

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Treatment Characteristics of 1,4-Dioxane by Advanced Oxidation Process System (AOP에 의한 1,4-다이옥산의 처리 특성에 관한 연구)

  • Lee, Soo;Kang, Hak-Su;Choi, Jae-Hyuk
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.1
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    • pp.32-40
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    • 2008
  • 1,4-Dioxane is an EPA priority pollutant often found in contaminated ground waters and industrial effluents. Conventional water treatment techniques are limited to decompose this compound effectively. Therefore, an advanced oxidation process system (AOP) was used for the degradation of 1,4-dioxane. This research investigates the effect of adding oxidants, such as ozone, air, and $H_2O_2$ during the UV irradiation of 1,4-dioxane solution. In order to analyze 1,4-dioxane, a modified 8270 method, which is an improved method of U.S EPA 8720, was used. Degradation efficiencies of 1,4-dioxane by only UV irradiation at various temperatures were not significant. However, The addition of oxidants and air bubbling in the UV irradiation system for 1,4-dioxane decomposition showed the higher 1,4-dioxane degradation rate. And, during AOP treatment the tendency of TOC changes was similar to that of 1,4-dioxane decomposition rate.

Photo-Fenton Oxidation Treatment of Pilot Scale for the Decomposition of 1,4-dioxane Generated in a Polyester Manufacturing Process (폴리에스테르 중합 공정에서 발생되는 1,4-dioxane의 분해를 위한 파일럿 규모의 광펜톤산화처리)

  • So, Myung-Ho;Han, Ji-Sun;Han, Thi-Hiep;Seo, Jang-Won;Kim, Chang-Gyun
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.1
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    • pp.9-14
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    • 2009
  • In this research, a polyester manufacturing company (i.e. K Co.) in Gumi, South Korea was investigated regarding the release of high concentrations of 1,4-dioxane(about 600 mg/L) and whether treatment prior to release should occur to meet with the level of the regulation standard (e.g., 5 mg/L in 2011). The pilot-scale (reactor volume, 10 $m^3$) treatment system using Photo-Fenton Oxidation was able to remove approximately 90% of 1,4-dioxane under the conditions that concentrations of 2,800 ppm $H_2O_2$ and 1,400 ppm $FeSO_4$ were maintained along with 10 UV-C lamps (240 ${\mu}W/cm^2$) illuminated during aeration. However, the effluent concentration of 1,4-dioxane was still high at about 60 mg/L. Thus, further investigation is needed to see whether the bench scale (reactor volume, 8.9 L) of activated sludge could facilitate the decomposition of 1,4-dioxane. As a result, 1,4-dioxane in the effluent has been decreased as low as about 2~3 mg/L. Consequently, Photo-Fenton Oxidation coupled with activated sludge process can make it possible to efficiently decompose 1,4-dioxane to keep up with that of the regulation standard.

A Study on the Degradation Characteristics of 1,4-dioxane at Different Initial pHs with Advanced Oxidation Process Using $O_3/H_2O_2$ ($O_3/H_2O_2$ 고급산화공정에서 초기 pH 변화에 따른 1,4-dioxane의 제거 특성 연구)

  • Park, Jin-Do;Suh, Jung-Ho;Lee, Hak-Sung
    • Journal of Environmental Health Sciences
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    • v.31 no.5
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    • pp.404-410
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    • 2005
  • The pH efforts on the removal of 1,4-dioxane and the biodegradobility enhancement of dioxane contaminated water were investigated using $O_3/H_2O_2$ baled advanced oxidation process. Experiments were conducted using a bubble column reactor under different initial pH. The $O_3/H_2O_2$ process effectively converted 1,4-dioxane to more biodegradable intermediates which had a maximum $BOD_5$ enhancement at pH 11 within the experimental range, precisely, when the initial pH increased, $BOD_5$ enhanced. However, in case of removal efficiencies of 1,4-dioxane during $O_3/H_2O_2$ oxidation the optimum condition was shown at pH 9 compared with pH 6 and 11. TOC and COD values were not largely changed for all reaction time. From the results of 1,4-dioxane removal efficiency, TOC, COD, and $BOD_5$ enhancement with reaction time, it was surely observed that 1,4-dioxane was just converted to biodegradable materials, not completely oxidized to carbon dioxide.

The Study of Statistical Optimization of 1,4-dioxane Treatment Using E-beam Process (전자빔 공정을 이용한 1,4-Dioxane 처리의 통계적 최적화 연구)

  • Hwang, Haeyoung;Chang, Soonwoong
    • Journal of the Korean Geoenvironmental Society
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    • v.12 no.4
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    • pp.25-31
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    • 2011
  • In this study, the experimental design methodology was applied to optimize 1,4-dioxane treatment in E-beam process. Main factor was mathematically described as a function of parameters 1,4-dioxane removal efficiencies(%), TOC removal efficiencies(%) modeled by the use of the central composite design(CCD) method among the response surface methodology(RSM). Concentration of 1,4-dioxane is designated as "$x_1$" and Irradiation intensity is designated as "$x_2$". The regression equation in coded unit between the 1,4-dioxane concentration and removal efficiencies(%) was $y=71.00-10.85x_1+20.67x_2+{1.53x_1}^2-{7.92x_2}^2-1.23x_1x_2$. The regression equation in coded unit between the 1,4-dioxane concentration and TOC removal efficiencies(%) was $y=44.48-13.25x_1+9.54x_2+{5.43x_1}^2-{1.35x_2}^2+4.45x_1x_2$. The model predictions agreed well with the experimentally observed results $R^2$(Adj) over 90%. Toxicity test using algae Pseudokirchneriella Subcapitata showed that the inhibition was reduced according to increasing an E-beam irradiation.

Structural and Kinetic Characteristics of 1,4-Dioxane-Degrading Bacterial Consortia Containing the Phylum TM7

  • Nam, Ji-Hyun;Ventura, Jey-R S.;Yeom, Ick Tae;Lee, Yongwoo;Jahng, Deokjin
    • Journal of Microbiology and Biotechnology
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    • v.26 no.11
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    • pp.1951-1964
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    • 2016
  • 1,4-Dioxane-degrading bacterial consortia were enriched from forest soil (FS) and activated sludge (AS) using a defined medium containing 1,4-dioxane as the sole carbon source. These two enrichments cultures appeared to have inducible tetrahydrofuran/dioxane and propane degradation enzymes. According to qPCR results on the 16S rRNA and soluble di-iron monooxygenase genes, the relative abundances of 1,4-dioxane-degrading bacteria to total bacteria in FS and AS were 29.4% and 57.8%, respectively. For FS, the cell growth yields (Y), maximum specific degradation rate ($V_{max}$), and half-saturation concentration ($K_m$) were 0.58 mg-protein/mg-dioxane, $0.037mg-dioxane/mg-protein{\cdot}h$, and 93.9 mg/l, respectively. For AS, Y, $V_{max}$, and $K_m$ were 0.34 mg-protein/mg-dioxane, $0.078mg-dioxane/mg-protein{\cdot}h$, and 181.3 mg/l, respectively. These kinetics data of FS and AS were similar to previously reported values. Based on bacterial community analysis on 16S rRNA gene sequences of the two enrichment cultures, the FS consortium was identified to contain 38.3% of Mycobacterium and 10.6% of Afipia, similar to previously reported literature. Meanwhile, 49.5% of the AS consortium belonged to the candidate division TM7, which has never been reported to be involved in 1,4-dioxane biodegradation. However, recent studies suggested that TM7 bacteria were associated with degradation of non-biodegradable and hazardous materials. Therefore, our results showed that previously unknown 1,4-dioxane-degrading bacteria might play an important role in enriched AS. Although the metabolic capability and ecophysiological significance of the predominant TM7 bacteria in AS enrichment culture remain unclear, our data reveal hidden characteristics of the TM7 phylum and provide a perspective for studying this previously uncultured phylotype.

Degradation of 1,4-Dioxane using $O_3$/$H_2O_2$

  • Suh, Jung-Ho;Mohseni, Madjld
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • pp.139-144
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    • 2003
  • 1, 4-dioxane is a recalcitrant pollutant found in contaminated ground waters and industrial effluents. Conventional water treatment techniques are limited to treat this compound effectively. In this study, $O_3$$H_2O_2$ oxidation process was used to eliminate 1, 4-dioxane in water and to enhance the biodegradability. Several factors affecting biodegradability enhancement were investigated. The relationship between initial oxidation rate of 1 A-dioxane and BOD enhancement rate has been determined, a kinetic model has been proposed. $H_2O_2$ concentration and pH had a proportional relation with biodegradability of 1, 4-dioxane, but in case of ozone, there was no relationship with biodegradability. 1, 4-Dioxane removal efficiencies had good agreement with the biodegradability.

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The Analysis of 1,4-Dioxane in Water Sample by Gas Chromatograph/Mass Spectrometer and Risk Assessment (기체크로마토그래프/질량분석계에 의한 물시료 중 1,4-dioxane의 분석 및 위해성 평가)

  • 홍지은;표희수;박송자
    • Environmental health and toxicology
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    • v.18 no.3
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    • pp.219-224
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    • 2003
  • 1,4-Dioxane is used as a solvent for lacquers, paints, varnish removers, dye baths and printing compositions. And it is also used for detergent preparations, cosmetics, deodorants and fumigants. A method is described for the determination of 1,4-dioxane in water samples by GC/MS. The extraction recoveries were studied for some solvents and solvent volume ratio were investigated using r-butyl methyl ether (MTBE). Optimum condition was obtained by the liquid-liquid extraction using the 10 mL of MTBE for 10 mL of water. Method detection limit of 1,4-dioxane in the 20 mL of water samples was 0.05 ng/mL. It could be determined in the range of 0.24∼240 ng/mL in treated water, and in the range of 0.69∼81.9 ng/mL in raw water, respectively. Risk assessments with 1,4-dioxane exposure by drinking water ingestion were carried out. Based on the results of analysis, chronic daily intake of 1,4-dioxane was 2.22${\times}$10$\^$-4/ mg/kg/day and excess cancer risk was calcu-lated to be 2.44${\times}$10$\^$-6/.

A Study on the Degradation Characteristics of 1,4-dioxane at Different Initial $H_2O_2$ Concentration with Advanced Oxidation Process using Ozone and Hydrogen Peroxide ($O_3/H_2O_2$를 이용한 고급산화공정에서 초기 $H_2O_2$ 농도에 따른 1,4-dioxane의 제거 특성 연구)

  • Park, Jin-Do;Suh, Jung-Ho;Lee, Hak-Sung
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.10
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    • pp.1108-1113
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    • 2005
  • Advanced oxidation process involving $O_3/H_2O_2$ was used to eliminate 1,4-dioxane and to enhance the biodegradability of dioxane-contaminated water. Oxidation process was carried out in a bubble column reactor under different pH and $H_2O_2$ concentrations. The removal efficiencies of 1,4-dioxane were investigated at hydrogen peroxide concentration between 40 and 120 mg/L. At the same pH, removal efficiencies of 1,4-dioxane increased with increasing initial $H_2O_2$ concentration. There was a linear relationship between initial concentration of $H_2O_2$ and the amount of consumed $O_3$. It was observed that the high $H_2O_2$ concentration accelerated the generation of hydroperoxy ions(${HO_2}^-$) and hydroxyl radicals($OH{\cdot}$). Hydrogen peroxide enhanced the decomposition of 1,4-dioxane and the biodegradability of the solution.

Decomposition Characteristics of 1,4-dioxane in an E-beam Process and Toxicity Assessment (전자빔 공정을 적용한 1,4-dioxane의 제거특성 및 독성평가)

  • Hwang, Haeyoung;Chang, Soonwoong
    • Journal of the Korean Geoenvironmental Society
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    • v.12 no.2
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    • pp.63-68
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    • 2011
  • The aim of this study was 1,4-dioxane's degradation efficiency and toxicity test applying E-beam. The experiments were shows that the degradation efficiency in the initial concentration of 1,4-dioxane and the irradiation capacity of E-beam and the degree of mineralization based on a change of scavenger gas. The biological toxicity test by using on of green algae, Pseudokirchneriella Subcapitata was conducted to lead the reducing toxicity. Degradation efficiency of 1,4-dioxane was improved when E-beam irradiation intensity was higher and the efficiency of TOC removal using Radical scavenger gas was increased by $N_2O$, $O_2$ and $N_2$ in order. In 4 days(96hrs), toxicity test results indicated that toxicity effect was decreased by increase of E-beam irradiation intensity.

A study on removal of 1,4-dioxane in drinking water by multi filtration system (다단계 필터시스템에서의 음용수 중 1,4-Dioxane 제거)

  • Lee, Kang Jin;Pyo, Heesoo;Yoo, Je Kang;Lee, Dae Woon
    • Analytical Science and Technology
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    • v.18 no.2
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    • pp.154-162
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    • 2005
  • Recently, 1,4-Dioxane is known as the contaminant in water plants in Korea. Owing to its toxicity and potential health effect, 1,4-Dioxane must be determined at very low levels in drinking water. Studies on the removal of 1,4-Dioxane in drinking water were performed by using multi filtration system with activated carbons and membrane filter. For extraction of 1,4-Dioxane, methyl-t-butyl ether (MTBE) was used and then analyzed using gas chromatography-mass selective detection (GC/MSD). Removal experiment was proceeded for 300 L with a sample volume of 30 L. At first. The removal was 70%, 95% and 100% after using activated carbon, membrane and second activated carbon respectively. At larger accumulated water fluxes, the removal rate decreased at each filter. After the flow volume was 300 L, the removal rate was 30%, 88% and 99% through the first activated carbon, membrane and second activated carbon respectively.