• 제목/요약/키워드: Naphthalenes

검색결과 14건 처리시간 0.016초

Activated Carbon Performance for the Treatment of Diesel-Derived Polycyclic Aromatic Hydrocarbons

  • Choi, Yongju;Luthy, Richard G.
    • Ecology and Resilient Infrastructure
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    • 제2권2호
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    • pp.177-184
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    • 2015
  • This study assessed the performance of activated carbon (AC) amendment to treat polycyclic aromatic hydrocarbons (PAHs) including both parent- and alkylated-moieties in sediment impacted by diesel. A field-collected, diesel-impacted sediment with a NAPL content of 1% was used for the study. No. 2 diesel fuel is weathered by heating at $70^{\circ}C$ for 4 days to obtain a weathered diesel sample having C3-naphthalenes to C2-phenanthrenes/anthracenes (N2/P3) ratio similar to the original sediment. The sediment samples spiked with the weathered diesel to obtain non-aqueous phase liquid (NAPL) contents of 1, 5 and 10% were contacted with AC with a dose of 5% as sediment dry weight for 1 month. By the AC-sediment contact, the freely-dissolved equilibrium concentrations were substantially reduced. Even for sediment with 10% NAPL content, the reductions in the freely-dissolved concentrations were 92% and 75% for total parent-and alkylated-PAHs, respectively. The effect of NAPL contents on the performance of AC was negligible for parent-PAHs, while for alkylated-PAHs, a slightly reduced AC performance was observed. The results suggest that the AC amendment can be an effective option for the treatment of petroleum-impacted sediment with relatively high NAPL contents.

Recent Progress in Luminescent Lanthanide Complexes for Advanced Photonics Applications

  • Kim, Hwan-Kyu;Oh, Jae-Buem;Baek, Nam-Seob;Roh, Soo-Gyun;Nah, Min-Kook;Kim, Yong-Hee
    • Bulletin of the Korean Chemical Society
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    • 제26권2호
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    • pp.201-214
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    • 2005
  • We have designed and developed novel luminescent lanthanide complexes for advanced photonics applications. Lanthanide(III) ions (Ln$^{3+}$) were encapsulated by the luminescent ligands such as metalloporphyrins and naphthalenes. The energy levels of the luminescent ligands were tailored to maintain the effective energy transfer process from luminescent ligands to Ln$^{3+}$ ions for getting a higher optical amplification gain. Also, key parameters for emission enhancement and efficient energy transfer pathways for the sensitization of Ln$^{3+}$ ions by luminescent ligands were investigated. Furthermore, to enhance the optophysical properties of novel luminescent Ln$^{3+}$ complexes, aryl ether-functionalized dendrons as photon antennas have been incorporated into luminescent Ln$^{3+}$ complexes, yielding novel Ln(III)-cored dendrimer complex. The novel Ln(III)-cored dendrimer complex has much higher PL intensity than the corresponding simple complex, due to the efficient site-isolation effect. In this article, we will deal with recent progress in the synthesis and photophysical studies of inert and stable luminescent Ln$^{3+}$ complexes for advanced photonics applications. Also, our review will include the exploratory investigation of the key parameters for emission enhancement and the effective energy transfer pathways from luminescent ligands to Ln$^{3+}$ ions with Ln(III)-chelated prototype complexes.

Releasing a Genetically Engineered Microorganism for Bioremediation

  • Sayler, Gary;Burlage, Robert;Cox, Chris;Nivens, David;Ripp, Steven;Ahn, Yeonghee;Easter, Jim;Wrner, Claudia;Jarrell, John
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2000년도 추계학술대회
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    • pp.153-162
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    • 2000
  • A field study was performed to test effectiveness of a bloluminescent genetically engineered microorganism (GEM) for bioremediation process monitoring and control. The study employed Pseudomonas fluorescens HK44 that was the first strain approved for field application in the U.S. for bioremediation purposes. HK44 contains lux gene fused within a naphthalene degradative pathway, allowing this GEM to bioluminesce as it degrades naphthalene as well as substituted naphthalenes and other polycyclic aromatic hydrocarbons (PAHs) , Results showed that HK44 was maintained in both PAH-contarninated and uncontaminated soils even 660 days after inoculation. HK44 was able to produce bioluminescence in response to PAHs in soil. Although effectiveness of chemical remediation was not assessed due to heterogeneous distribution of contaminants, decreased concentration of naphthalene was shown in the soils, Taken together, HK44 was useful for in situ bioremediation process monitoring and control. This work is so far the only field release of a GEM for bioremediation purposes.

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Bioaccumulation of polycyclic aromatic hydrocarbons in Manila clam (Ruditapes philippinarum) exposed to crude oil-contaminated sediments

  • Lee, Chang-Hoon;Lee, Ji-Hye;Sung, Chan-Gyoung;Moon, Seong-Dae;Kang, Sin-Kil;Lee, Jong-Hyeon;Yim, Un Hyuk;Shim, Won Joon;Ha, Sung Yong
    • 한국패류학회지
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    • 제30권4호
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    • pp.371-381
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    • 2014
  • The bioaccumulation of 16 United States Environmental Protection Agency (USEPA) priority polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs in the Manila clam, Ruditapes philippinarum exposed to sediments artificially contaminated by Iranian Heavy Crude Oil was measured and the biota-sediment accumulation factor (BSAF) was estimated through laboratory experiments. The proportion of 16 PAHs accumulated in the tissue of R. philippinarum was only from 3 to 7% of total PAHs. Among 16 PAHs, the concentration of naphthalene was highest in the tissue. Alkylated PAHs were highly accumulated more than 93% of total PAHs. The C3 dibenzothiophene was most highly accumulated. The relative composition of alkylated naphthalenes in the tissue of R. philippinarum was lower than in the sediments. In contrast, those of alkylated compounds of fluorenes, phenanthrenes, dibenzothiophenes were higher in the tissue than the sediments. The BSAF for sum of 16 PAHs was 0.11 to 0.13 g carbon/g lipid and that for alkylated PAHs was 0.05 to 0.06 g carbon/g lipid. Naphthalene showed the highest BSAF value. Alkylated PAHs with the same parent compound, BSAF tended to increase with the number of alkylated branch increased, except for alkylated chrysenes. BSAF of total PAHs lies between that of field-based values, and are also similar to those of other persistent organic pollutants (PCBs, DDTs, HCHs). This study provides the BSAF values of individual alkylated PAHs accumulated in R. philippinarum for the first time and will be used as a basis for further understanding the bioaccumulation of organic contaminants in the marine benthic organisms.