• Environmental Analysis Health and Toxicology
• /
• 제11권1_2호
• /
• pp.31-39
• /
• 1996

Leachate from municipal solid waste (MSW) landfill, effluent from leachate treatment plant, and ground water sample from a monitoring well near landfill site were tested for an acute toxicity. Microtox toxicity test was used for testing the acute toxicity of leachate and other samples. EC$_{50}$ values which a concentration of pollutant for reducing 50% light output from luminescent bacteria, Photobacterium phosphoreum were determined to assess the toxicity of pollutants as well as the relative toxicity. In addition, characteristics of leachate were studied and compared to those of phenol and pentachlorophenol (PCP) which are typical aquatic toxic pollutants. For leachate, EC$_{50}$ for 30 min incubation was 10.8%, while for phenol and PCP, 46 ppm and 1.2 ppm, respectively. the relative toxicity of treated leachate by in situ aeration with activated sludge was reduced to more than 75% of toxicity of the untreated leachate. Microtox toxicity test was failed to figure out EC$_{50}$ values for groundwater from a monitoring well since the relative toxicity of the unconcentrated sample was too low to estimate EC$_{50}$. Addition of activated carbon to leachate was reduced the relative toxicity. The reduction Pattern of the relative toxicity of leachate by mechanical aeration was similar to that of PCP, but different from that of phenol. These findings suggest that the toxicity of leachate may come from PCP-like toxic compounds rather than phenol-like one. In conclusion, the process of aeration with activated sludge might be very important to reduce the environmental toxicity of leachate. And Microtox test could be a reasonable bioassay for screening and monitoring the environmental toxicity of leachate from municipal solid waste landfill as well as for determining the reduction efficiency of the leachate toxicity by various treatment processes in leachate treatment plant.

• 한국습지학회지
• /
• 제10권2호
• /
• pp.23-37
• /
• 2008

The vertical distribution of dioxins and hexachlorobenzene(HCB) in a sediment core was investigated to elucidate historical trends of dioxins and HCB deposited into Upo wetland. The total concentration of dioxin ranged from 8.7 to 66.27 pg/g-dw in Upo sediments deposited, and from 17.64 to 97.03 pg/g-dw in Mokpo. Dioxin fluxes increased from the first-1990s and then reached a maximum in the mid-1990s. The major source of dioxin by comparing the congeners pattern was pentachlorophenol(PCP) used of agrochemicals. The HCB concentration in most of samples was detected below the MDL(Method Detection Limit of 0.5ng/g), except a few samples.

• 분석과학
• /
• 제18권4호
• /
• pp.320-328
• /
• 2005

산업폐수 중 염화폐놀류 5종 (4-chloro-3-methylphenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol)의 잔류량을 GC/MS를 사용하여 측정하였다. 산업폐수 시료는 석유화학, 섬유염색, 가죽피혁 분야의 공장에서 방류되는 원수 및 방류수를 채취하여 분석하였다. 본 논문에서는 USEPA 3510 방법을 변형하여 새로운 방법을 확립하였다. 각 시료들은 pH 2와 5~6조건에서 디클로로메탄을 사용하여 액체-액체 추출법으로 추출한 다음 GC/MS에 주입하여 SIM방법으로 분석하였다. 그 결과 0.1 ng/mL~10.0 ng/mL과 0.5 ng/mL~10.0 ng/mL 정량구간내에서 $R^2=0.9943$ 이상의 좋은 직선성을 나타내었으며, 검출한계는 0.1 ng/mL~0.5 ng/mL이었다. 실제 시료측정에 앞서서 1, 5, 10 ng/mL 농도에서 회수율을 측정하였는데, PCP의 경우를 제외하고는 71.6-98.9%의 양호한 절대회수율을 나타내었다. 상대표준편차(RSD)는 1.2~14.3% 범위의 좋은 재현성을 나타내었고, 정밀도를 나타내는 bias는 낮은 농도(1 ng/mL)에서 약간 높은 값(11.3~22.l%)을 나타내었지만 그 이상의 농도에서는 좋은 정밀도를 나타내었다.

• Journal of Applied Biological Chemistry
• /
• 제42권3호
• /
• pp.107-112
• /
• 1999

A carboxymethyl-cellulase (CMCase) was purified from the culture supernatant of Bacillus sp. KD1014 by ultrafiltration, ammonium sulfate precipitation, and a series of chromatography on QAE-Sephadex A-50, hydroxylapatite and Sephadex G-75. The purified CMCase was a single protein of 32 kDa, showed an optimum activity at $60^{\circ}C$ and pH 6.0, and had a half-life of 23 min at $70^{\circ}C$. The enzyme activity was not influenced by metal ions such as $Mg^{2+},\;Fe^{3+},\;K^+,\;Zn^{2+}$, and $Cu^{2+}$ at a concentration of 1.0 mM, partially inhibited by $Mn^{2+}$ and $Ag^+$, and significantly inhibited by pentachlorophenol (PCP). The purified enzyme showed a 3.9-times higher activity on lichenan than on CMC, but hardly cleaved xylan, starch, avicel, laminarin, filter paper and levan. The results of activity staining of the purified enzyme separated by native and denaturing gel electrophoresis suggested that the CMCase might exist in dimeric, oligomeric or aggregated form as well as in monomeric form. The enzymatic cleavage products from cellotetraose indicated that the CMCase possessed transglycosylation activity.

• 멤브레인
• /
• 제15권4호
• /
• pp.297-309
• /
• 2005

다수의 잠재적인 내분비계장애물질이 환경에 방출됨으로써 새로운 환경문제로 세계적 관심이 모아지고 있다. 이러한 물질들을 측정하고 감시하기 위한 고감도이며 신뢰성 있는 분석방법의 개발이 필수적이다. 이 연구에서는 기체크 로마토그래피 질량분석법과 액체크로마토그래피 질량분석법이 내분비계장애물질들의 분석을 위해 이용되었으며 두 가지 분석방법들이 DEHP, BBP, PCP, BPA에 대해 비교 및 평가되었다 그 결과 액체크로마토그래피 질량분석법이 더 낮은 검출 한계를 나타내는 것으로 조사되었다. 또한 액체크로마토그래피 질량분석법은 대부분의 순수한 분자들로서 내분비계장애물질들을 측정 가능함이 판명되었다. 이 연구에서는 음용수에서 내분비계장애물질들을 제거하는 방법으로 유기막과 세라믹막을 제시하였으며 십자류 나노여과 방식이 내분비계장애물질들을 $100\%$ 제거하는 것으로 조사되었고 분획분자량 250 나노여과는 내분비계장애물질을 제거함에 있어 효과적인 것으로 판명되었다. 나노여과, 고속한외여과, 저속한외여과의 투과플럭스와 물질전달계수와의 비는 0.67, 3.4, 그리고 0.44였으며 나노여과와 저속한외여과는 확산이 주요한 조건에서 운전되며 고속한외여과는 대류가 주요한 조건에서 운전된다. 더욱이, 확산이 주요한 나노여과와 저속한외여과에서 내분비계장애물질의 제거율이 높은 것으로 측정되었다. 한외여과에 의한 제거는 내분비계장애물질들의 분자량에 의존하는 것으로 조사되었으며 내분비계장애물질들은 확산이 주요한 수리동역학적 조건에서 제거됨이 판명되었다.