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윤우현(Woo-Hyun Yoon),김현갑(Hyun-Kab Kim),이태진(Tae-Jin Lee) 유기성자원학회 2006 유기물자원화 Vol.14 No.1
본 연구는 혐기성 발효를 이용한 수소생산과정에서 pH를 일정하게 유지한 상태에서 안정적인 수소를 생산하기 위한 최적 pH를 찾고자 하였다. 실험결과 pH 6이었을 때 최적의 조건이었으며 이때 수소생산량은 1175.87 mL/L 이고, 이론적 수소 전환율은 22.51 %였다. pH 5는 901.77 mL/L의 수소가 발생되었으며, 수소 전환율은 17.48 %, pH 7은 454.26 mL/L의 수소생산량과 8.74 %의 수소 전환율을 나타내었다. 그리고 pH 7과 8에서는 각각 452.08 mL/L와 82.25 mL/L의 저조한 수소 생산량을 나타내었다. 자당의 혐기성 발효를 통한 유기산 생성에 있어서 pH가 7과 8에서는 propionate가 주로 관찰되었으나 pH가 5와 6인 영역 에서는 butyrate의 생성이 두드러지는 결과가 나타났다. In this study, the optimum condition of pH was investigated on the hydrogen gas production under anaerobic fermentation process. The results of the experiment showed that the optimum condition was observed at pH 6, resulting in 1175.87 mL/L of hydrogen gas production rate and 22.51% theoretical hydrogen conversion ratio. Hydrogen gas production rate and theoretical hydrogen conversion ratio were 901.77 mL/L and 17.48 % respectively at pH 5. At pH 7 and 8, the production rate of hydrogen gas was little low as 82.15 mL/L. Among the organic acids from the sucrose fermentation, propionate was observed as the dominant acid at pH 7 and 8 but butyrate was the dominant at pH 5 and 6.
GC-MS/MS를 이용한 한강수계 및 상수도계통에서 N-nitrosamines 조사
윤우현 ( Woo-hyun Yoon ),이준호 ( Jun-ho Lee ),이현주 ( Hyun-ju Lee ),이수원 ( Su-won Lee ),안재찬 ( Jae-chan Ahn ),김복순 ( Bog-soon Kim ) 한국물환경학회 2016 한국물환경학회지 Vol.32 No.5
This study was conducted to improve the analysis method used for N-nitrosamines and to investigate the occurrences of N-nitrosamines in tributaries of the Han-river, intake stations, water treatment plants and tap water used within the city of Seoul. The samples were pretreated through a solid phase extraction and analyzed using a gas chromatography tandem mass spectrometer (GC-MS/MS). The GC-MS/MS in CI mode was compared with the GC-MS/MS in EI mode by the method detection limits (MDLs). MDLs by GC-CI/MS/MS and GC-EI/MS/MS were 0.2 ~ 1.1 ng/L and 0.2 ~ 1.4 ng/L, respectively. Samples were collected from ten tributaries of the Han-river (T1 ~ T10), six intake stations (II ~ 16), six water treatment plants (P1 ~ P6) and 25 taps in Seoul city. The maximum levels of N-nitrosodimethylamine (NDMA) were 0.013 ㎍/L, 0.008 ㎍/L, 0.006 ㎍/L and 0.002 ㎍/L in tributary water, raw water, finished water and tap water samples, respectively. Detected levels were much lower than 0.1 ㎍/L corresponding to the guideline value of WHO.