• Title/Summary/Keyword: Oxidized environment

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Drug adsorption and anti-microbial activity of functionalized multiwalled carbon nanotubes

  • Saxena, Megha;Mittal, Disha;Boudh, Richa;Kumar, Kapinder;Verma, Anita K.;Saxena, Reena
    • Advances in nano research
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    • v.11 no.6
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    • pp.667-678
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    • 2021
  • Multiwalled carbon nanotubes (MWCNTs) were first oxidized (O-CNTs) to introduce carboxylic group and then further functionalized (F-CNTs) with m-phenylenediamine, which was confirmed by FTIR and SEM. It was used as an effective adsorbent for the adsorptive removal of diclofenac drug from water. Under optimum conditions of pH 6, stirring speed 600 rpm, the maximum adsorption capacity obtained was 532 mg g-1 which is superior to the values reported in literature. The adsorption was quite rapid as 25 mg L-1 drug solution was adsorbed in only 3 minutes of contact time with 10 mg of adsorbent dose. The adsorption kinetics and isotherms were studied using various models to evaluate the adsorption process. The results showed that the data best fit in kinetics pseudo-second order and Langmuir isotherm model. Furthermore, the oxidized and functionalized MWCNTs were applied on gram-negative Escherichia coli and gram-positive Staphylococcus aureus using agar disc diffusion assay to validate their anti-microbial activity. Results were unique as both oxidized and functionalized MWCNTs were equally active against both E. coli and S. aureus. The newly synthesized F-CNTs have great potential in water treatment, with their dual action of removing drug and pathogens from water, makes it potential applicant to save environment.

A Study on Heavy Metal Concentrations of Oxidized Hair Coloring Products in Korea Market (한국에서 유통 중인 산화형 염모제의 중금속 농도에 관한 연구)

  • Choi, Chae Man;Hong, Mi Sun;Lee, Yun Jung;Kim, Hwa Soon;Kim, Hyun Jung;Kim, Jung Hun;Chae, Young Zoo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.3
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    • pp.241-249
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    • 2013
  • This study was aimed to provide the fundamental data about oxidized hair color products. For this reason, we collected 125 oxidized hair color products, which were distributed in domestic market from January to October, 2012, and measured the heavy metal concentrations of lead, arsenic, cadmium, chromium, manganese, nickel, copper in the samples. Results were compared by domestic, foreign, henna, type and color. The average metal concentrations were as follows; 0.211 ${\mu}g/g$ for lead, 0.008 ${\mu}g/g$ for cadmium, 0.051 ${\mu}g/g$ for arsenic, 0.954 ${\mu}g/g$ for chromium, 6.250 ${\mu}g/g$ for manganese, 0.591 ${\mu}g/g$ for nickel and 0.544 ${\mu}g/g$ for copper. In case of lead and arsenic, the concentrations were much less than the regulated amount (20 ${\mu}g/g$ and 10 ${\mu}g/g$, respectively) suggested by MFDS (Ministry of Food and Drug Safety). In henna (p < 0.05), the concentrations were significantly higher than those of other domestic and foreign oxidized hair color products as follows; 1.264 ${\mu}g/g$ for lead, 0.267 ${\mu}g/g$ for arsenic, 0.025 ${\mu}g/g$ for cadmium, 4.055 ${\mu}g/g$ for chromium, 72.044 ${\mu}g/g$ for manganese, 3.076 ${\mu}g/g$ for nickel and 4.640 ${\mu}g/g$ for copper. Statistically, it showed that the heavy metal concentrations were quite different for the different types of hair color products. The cream and liquid type products had the highest average concentration in chromium (0.708 ${\mu}g/g$, 0.478 ${\mu}g/g$, respectively). On the other hand, powder type products showed the highest concentration in manganese (60.041 ${\mu}g/g$). In addition, the concentrations of heavy metals and the color of products are not quite correlated. It was shown that average concentrations of lead and chromium were higher for yellow, chromium for red and pink, manganese for brown and black, and nickel for green.

Feasibility Study on Stabilization Technique of Cr(VI)-contaminated Site (Cr(VI)으로 오염된 부지의 안정화 기술에 의한 정화 타당성 연구)

  • Yoon, Geun Seok;Yoo, Jong Chan;Ko, Sung-Hwan;Shim, Myung-Ho;Cho, Myung-Hyun;Baek, Kitae
    • Journal of Soil and Groundwater Environment
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    • v.22 no.4
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    • pp.27-32
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    • 2017
  • In this study, a remedial investigation using reductive stabilization was conducted to treat Cr(VI)-contaminated soil. The influences of various operational parameters, including reaction time and the mass of ferrous iron, were also evaluated. The study site was contaminated with a large amount of Cr(III) and Cr(VI), and the selected treatment method was to stabilize Cr(VI) with ferrous iron, which reduced Cr(VI) to Cr(III) and stabilized the chromium, although a greater mass of ferrous iron than the stoichiometric amount was required to stabilize the Cr(VI). However, some Cr(III) re-oxidized to Cr(VI) during the drying process, and addition of a strong reducing agent was required to maintain reducing conditions. With this reducing agent, the treated soil met the required regulatory standard, and the mass of Cr(III) re-oxidized to Cr(VI) was significantly reduced, compared to the use of only Fe(II) as a reducing agent.

Study on the Decomposition of Some Volatile Organic Compounds by Photocatalyst Plasma Reaction (광촉매 플라즈마 반응에 의한 몇가지 VOCs의 제거에 관한 연구)

  • 허경욱
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.4
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    • pp.373-380
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    • 2000
  • A new type of photocatalyst plasma air purification filter for decomposition of some VOCs has been developed. The photocatalyst plasma air purification filter employs the pulsed discharge plasma as an energy source of TiO2. photocatalyst instead of UV light. In closed room(2m3) test removal efficiency of some VOCs was 80∼100% in 15∼24 hours. In the initial step of phptocatalyst plasma reaction. Acetone and Nitromethane etc were detected. But they were completely oxidized to CO2 and H2O.

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Cometabolism of MTBE by pure culture isolated from gasoline contaminated aquifer

  • 장순웅;이시진
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.364-367
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    • 2003
  • In this paper, we have examined the MTBE cometabolic degradation by pure culture, which is isolated gasoline contaminated aquifer. Propane was more effectively utilized as a growth substrate to oxidize MTBE. Specific substrate degradation rate was Increased with increasing initial propane amount. Respiking propane was enhanced and continued MTBE degradation and TBA observation was supported MTBE degradation. The mass balance of MTBE and TBA indicated that MTBE was oxidized to TBA as well as further oxidation of TBA.

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Removal of Humic Acid Using Titania Film with Oxygen Plasma and Rapid Thermal Annealing (산소플라즈마와 급속열처리에 의해 제조된 티타니아 박막의 휴믹산 제거)

  • Jang, Jun-Won;Park, Jae-Woo
    • Journal of Soil and Groundwater Environment
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    • v.12 no.3
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    • pp.29-35
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    • 2007
  • Titanium was oxidized with oxygen plasma and calcinated with rapid thermal annealing for degradation of humic acid dissolved in water. Titania photocatalytic plate was produced by titanium surface oxidized with oxygen plasma by Plasma Enhanced Chemical Vapor Deposition (PECVD). RF-power and deposition condition is controlled under 100 W, 150 W, 300 W and 500 W. Treatment time was controlled by 5 min and 10 min. The film properties were evaluated by the X-ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD). From the experimental results, we found the optimal condition of titania film which exhibited good performance. Moreover photocatalytic capacity was about twice better than thermal spray titania film, and also as good as titania powder.

Estimation of Nitrogen and Sulfur Deposition over the Yellow Sea Region (황해 지역의 질소와 황 침적 추정)

  • 김진영;김영성;이승복;문길주
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.2
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    • pp.217-229
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    • 2003
  • The amounts of nitrogen and sulfur deposited in the region of the Yellow Sea in both dry and wet forms were estimated by using the measurement data published in tile literature during tile past 10 years. In the estimation of dry deposition, concentrations at ground stations including those at a station on the Chinese side and concentrations from shipboard and aircraft measurements were used as well as deposition velocities. Wet deposition flux was determined at ground stations on the Korean side either by taking the flux data themselves or by calculating them from precipitation data in the literature. The dry deposition flux over the Yellow Sea was much greater than those China was confirmed from the fact that the total amount summing wet and dry depositions exceeded the emission amount from Korea. Dry deposition was principally made in the gaseous form due to a larger deposition velocity. Nevertheless, since the deposition velocity over water was smaller than that over the ground, dry deposition of oxidized nitrogen was smaller than wet deposition. As a whole, wet depositions of nitrogen and sulfur were 2.3 and 1.9 times 1arger than corresponding dry depositions, respectively.

Surface Composition Change of UV/Ozone Modified Polypropylene (UV/오존에 의해 개질된 폴리프로필렌의 표면 조성 변화)

  • Kim, J.I.;Ryu, S.H.
    • Elastomers and Composites
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    • v.37 no.1
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    • pp.49-56
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    • 2002
  • Polypropylene is oxidized with UV/ozone as a function of UV treatment time and ozone flow rate and its surface characteristics are investigated using contart angle measurements and XPS. The aging behavior of oxidized surface is investigated under air, water and ethylene glycol as the aging media. Adhesion strength is also investigated using a lap shear test. Polar surface energy increases with increasing UV/ozone treatment time as well as ozone flow rate. No polar surface energy change is observed under water aging, while under air aging it decreases significantly within 2-3 days and reaches the close value as that of the untreated PP. Adhesion strength increases with increasing UV/ozone treatment time as well as ozone flow rate.

Study on Photodegradable Water-Soluble Compounds of Expanded Polystyrene

  • Lee, Seulgidaun;Kim, Sunghwan
    • Mass Spectrometry Letters
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    • v.12 no.3
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    • pp.118-124
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    • 2021
  • Many previous studies have focused on revealing the harmfulness of microplastic particles, whereas very few studies have focused on the effects of chemicals, particularly photooxidation product. In this study, products of photodegradation from expanded polystyrene (EPS), compounds produced by photolysis by ultraviolet (UV) light, were investigated. EPS was directly irradiated and photolyzed using a UV lamp, and then the extracted sample was analyzed using high-resolution mass spectrometry (HRMS). Multiple ionization techniques, including electrospray ionization, atmospheric pressure chemical ionization, and atmospheric pressure photoionization, were used. In total, >300 compounds were observed, among which polystyrene monomer, dimer, and oxidized products were observed. In this work, the data presented clearly demonstrate that it is necessary to identify and monitor oxidized plastic compounds and assess their effect on the environment.

A Study on Fractions and Leaching Potential of Heavy Metals in Abandoned Mine Wastes (휴ㆍ폐광산지역에서 폐재내 중금속의 존재형태 및 용출특성에 관한 연구)

  • 김휘중;양재의;이재영;전상호
    • Journal of Soil and Groundwater Environment
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    • v.8 no.3
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    • pp.45-55
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    • 2003
  • This study investigates the fractional composition and the leaching characteristics of heavy metals in polluted soils due to mining activities. The fractionated composition of heavy metals is classified into five fractions; adsorbed, carbonate, reducible, organic and residual fraction. The status of humic substances in mine wastes of most sites are polyhumic except tailing from Sangdong mine. According to the sequential extraction procedures (SEPs), leaching probabilities of Cd in coal wastes and tailing are relatively low due to high percentage of residual fraction. 46.4% of Ni in tailings from Sangdong mine is probably leached under oxidized environment, and 39.4% of Cu in these tailings is readily extracted under strongly oxidized environment by organic fraction. According to leaching condition of pH 3.0 and pH 5.6, the amount of heavy metals leached out of coal wastes and tailing increases to 1/2 hours. At pH 3.0 and pH 5.6, concentration of Ni in tailing increases up three times of the initial value. Heavy metals released from coal wastes and tailing were not influenced significantly by leaching time.