CO 내성을 갖는 Clostridium sp. AWRP 돌연변이주의 분리 및 이를 이용한 합성가스로부터의 에탄올 생산 연구

권수재,이종민,이현숙 한국미생물·생명공학회 2019 한국미생물·생명공학회지 Vol.47 No.4

In this study, the carbon monoxide (CO)-fermenting acetogen, Clostridium sp. AWRP was subjected to chemical mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine (NTG) to generate a CO-resistant mutant. Among the 26 colonies obtained, the highest alcohol production was observed in one isolate, named C1. Compared to the wild-type strain, the C1 strain exhibited 1.5- and 3.4-fold higher CO consumption rate and alcohol selectivity, respectively. The total CO consumption of strain C1 could be further enhanced by increasing the content of metal ions, such as nickel and iron. The highest ethanol titer (5.7 g/l) was achieved by 5-fold increase in the iron concentration.

A Glove Box for the Subsampling of Suboxic and Cold Core Sediment

정회수,권수재,김종근,JUNG, HOI-SOO,KWEON, SOO-JAE,KIM, CHONG-KUN The Korean Society of Oceanography 1990 韓國海洋學會誌 Vol.25 No.4

To solve two problems, temperature shock to the man and difficulty in exchanging the air in the glove box into N2 gas, during the subsampling of Suboxic and cold core sediments, a portable glove box with a refrigerating machine and a gas exchanging bag was constructed for subsampling of sediment cores on board. The refrigerator of the glove box can cool down 200 litter air at 30$^{\circ}C$ to 2$^{\circ}C$${\pm}$2$^{\circ}C$ within 5 minutes. The box was successfully operated during the second KORDI's deep sea research cruise of 1989 in the North equatorial Pacific. Pore water data obtained from the cruise show no evidence for artifacts caused by warming up or oxidation of sediments during subsampling.

오염 원단위 자료를 이용한 아산시 주요 저수지들의 수질오염 부하량 산정

장봉기,양예람,권수재,김주희,강동혁,오유림,임지현,김윤재 순천향대학교 기초과학연구소 2020 순천향자연과학연구 논문집 Vol.26 No.2

The pollution source data of the major reservoirs in Asan city, Chungcheongnam-do were used to calculate the water pollution load and the pollution contribution rate of living sewage, livestock wastewater, and outflow of land using them, and to find the main pollution source and suggest a plan to reduce it. Five of Asan's representative reservoirs were selected, including reservoirs of Songak, Yeomchi, Masan, Seongnae, Dogo and the average of population, livestock head, and land use statistics over four years from 2015 to 2018, using the load calculation by the Ministry of Environment. The water quality of each reservoir has used chemical oxygen demand(COD), total phosphorus(T-P), total nitrogen(T-N), suspended solids(SS), and chlorophyll(Chl-a) data over the last five years. The biochemical oxygen demand(BOD), T-N, and T-P pollution loads for each reservoir were the lowest in Songak and Yeomchi reservoir, with the largest amount of reservoirs in the Seongnae reservoir. In addition, the water quality of each reservoir was relatively low in Songak and Yeomchi reservoir, with the highest level of pollution in the Seongnae reservoir. The contribution rate of pollutant load from the inflow of livestock wastewater from each basin of all reservoirs was very high at 79.4% for BOD, 63.6% for T-N, and 86.9% for T-P. As a result of calculating the load amount of livestock wastewater by separating it into dung and urine, the load amount of urine was less than half of the total. As a result, it was found that measures against livestock wastewater with the highest contribution rate to water pollution in reservoirs calculated by using the pollution unit are needed. When the load amount of livestock wastewater by reservoir is only seen, the pollution contribution rate of dung is much higher than that of urine, so it is necessary to improve the water quality of the reservoir through the policy that can transfer all the dung of livestock that can be collected to the livestock manure treatment plant. In addition, it is necessary to develop a technology that can be recycled by using livestock dung as soil improvement materials or eco-friendly fertilizers.

강화 동검도 동부 갯벌의 퇴적 특성 변화

우한준,장석,권수재 한국습지학회 2012 한국습지학회지 Vol.14 No.3

강화 갯벌의 퇴적작용은 주변의 대규모 건설로 인하여 지난 20여년 동안 변화되어 왔다. 강화 갯벌 동부 와 염하수로 하류에 위치한 동검 갯벌의 퇴적환경은 조류와 하구 순환의 변화에 의하여 영향을 받았다. 그 결과 동검 갯벌에 급격한 퇴적이 일어났다. 두 개의 코어 퇴적물 상부에 나타나는 실트-점토 호층 엽리 실트 퇴적상은 동검 갯벌에서 상대적으로 많은 퇴적이 있었음을 나타냈다. 210Pb 분석에 의한 두 개 코어 시료의 퇴적률은 정점 3에서 3.25cm/year와 정점 5에서 3.47cm/year 였다. 그러나 2010년부터 2012년까지의 단기 퇴적률은 대부분 1cm/year 미만으로 상대적으로 낮은 비율의 퇴적을 나타내고 있었다. 결과적으로, 동검 갯벌의 퇴적물은 2000년 대에 인공구조물 건설에 의하여 급격히 퇴적되었다. 현재 동검 갯벌의 고도 증가는 계절 변화를 가진 상대적으로 낮은 퇴적률을 보여 주고 있다.

중금속 원소와 유공충을 이용한 마산만 퇴적물의 오염 역사에 관한 연구

우한준,조진형,정갑식,정창수,권수재,박성민 한국지구과학회 2003 한국지구과학회지 Vol.24 No.7

황해 가로림만 조간대 표층퇴적물의 이동경로

신동혁,이희일,한상준,오재경,권수재,Shin, Dong-Hyeok,Yi, Hi-Il,Han, Sang-Joon,Oh, Jae-Kyung,Kwon, Su-Jae 한국해양학회 1998 바다 Vol.3 No.2

Two-dimensional trend-vector model of sediment transport is first tested in the tidal flat of Garolim Bay, mid-western coast of the Korean Peninsula. Three major parameters of surface sediment, i.e., mean grain size, sorting and skewness, are used for defining the best-fitting transport trend-vector on the sand ridge and muddy sand flat. These trend vectors are compared with the real transport directions determined from morphology, field observation and bedforms. The 15 possible cases of trend vectors are calculated from total sediments. In order to find the role of coarse sediments, trend vectors from sediments coarser than < 4.5 ${\phi}$, (sand size) are separately calculated from those of total sediments. As compared with the real directions, the best-fitting transport-vector model is the "case M" of coarse sediments which is the combined trend vectors of two cases: (1) finer, better sorted and more negatively skewed and (2) coarser, better sorted and more positively skewed. This indicates sand-size grains are formed by simpler hydrodynamic processes than total sediments. Transported sediment grains are better sorted than the source sediment grains. This indicates that consistent hydrodynamic energy can make sediment grains better sorted, regardless of complicated mechanisms of sediment transport. Consequently, both transported vector model and real transported direction show that the source of sediments are located outside of bay (offshore Yellow Sea) and in the baymouth. These source sediments are transported through the East Main Tidal Channel adjacent the baymouth. Some are transported from the subtidal zone to the upper tidal flat, but others are transported farther to the south, reaching the south tidal channel in the study area. Also, coarse sediment grains on the sand ridge are originally from the baymouth, and transported through the subtidal zone to the south tidal channel. These coarse sediments are moved to the northeast, but could not pass the small north tidal channel. It is interpreted that the great amount of coarse sediments is returned back to the outside of the bay (Yellow Sea) again through the baymouth during the ebb tide. The distribution of muddy sand in the northeastern part of study area may result from the mixing of two sediment transport mechanisms, i.e., suspension and bedload processes. The landward movement of sand ridge and the formation of the north tidal channel are formed either by the supply of coarse sediments originating from the baymouth and outside of the bay (subaqueous sand ridges including Jang-An-Tae) or by the recent relative sea-level rise.

부유물질의 응접작용 및 침전특성에 관한 실험적 연구

추용식,박용안,이희준,박광순,권수재,Chu, Yong-Shik,Park, Yong-Ahn,Lee, Hee-Jun,Park, Kwang-Soon,Kweon, Su-Jae 한국해양학회 1999 바다 Vol.4 No.1

A laboratory flume experiment, using turbulence-generating acryl tank and natural sediments, was conducted to investigate the effects of salinity, concentration of suspended sediment, turbulence and clay minerals on the flocculation and settling of fine-grained suspended sediments. While experiments were run, a sequence of water samples were taken near the bottom of the tank to analyze the variations of size distribution and relative contents of clay minerals. The results of the salinity experiment indicate that median settling velocity ($W_{50}$) increases linearly with salinity. Different settling processes of suspended sediments under variable concentrations appear to be predictable, depending upon the range of the suspension concentration. At concentrations less than 200 mg/l, $W_{50}$ is rarely varied with concentration probably because of the individual--grain settling mode. In the range of 200 to 13,000 mg/l show $W_{50}$ and concentration a good relationship following an empirical formula: $W_{50}=0.45C^{0.44}$. This relationship, however, no longer holds in concentrations exceeding 13,000 mg/l; instead, a more or less reverse one is shown. This result suggests an effect of hindered settling. The turbulence effect is somewhat different from that of concentration. Turbulence accelerates the flocculation and settling susepended sediments at low concentration (200 mg/l), whereas at high concentration turbulence breaks floes down and impedes the settling. Size distribution of suspended sediments sampled near the bottom of the tank tend to be more negatively skewed and leptokurtic in turbulent conditions compared to those in static conditions. The clay mineral analysis from the sequential water samples shows that over time the content of smectite decreases most rapidly with illite remaining concentrated in suspension. This means that smectite, among other clay minerals, plays the most effective role in the flocculation of fine-grained sediment in saline water.

새만금 갯벌의 퇴적환경 변화

우한준,안순모,구본주,최재웅,권수재 한국해양과학기술원 2006 Ocean and Polar Research Vol.28 No.4

The Saemangeum tidal flat with an area of approximately 233 km2 is one of the biggest estuarine tidal flats on the west coast of Korea. Because of its location in the estuary of Mangyeong and Dongjin Rivers, the tidal flat receives large amount of sediments. A 33-km long sea dyke, enclosing a coastal zone of 401 km2, was constructed to reclaim tidal flat in the Saemangeum area. The dyke construction radically changes the local tidal current regime and estuarine circulation. These have an effect on sedimentary environments in the tidal flat. On the tidal flats of the study area net deposition occurred, but net erosion occurred near tidal channel in 2004. The comparison of topography and surface sediments in summer 2004 with those in summer 1988 before the dyke construction showed that elevation increased with maximum 80cm and mean grain sizes were fining at Gwanghwal tidal flats. Sedimentary facies of two cores fromGwanghwal tidal flat revealed homogeneous layers in the upper part, suggesting rapid deposition after the dyke construction. The sedimentation rate in Gwanghwal tidal flat(GW 6) using 210Pb analysis was about 5.4 cm/yr, which is well matched with the sedimentation pattern revealed by change in topography.

대산 유화학단지 주변의 저서성 유공충 분포 특성

우한준(Han Jun Woo),정갑식(Kap Sik Jeong),권수재(Su Jae Kwon),추용식(Yong Shik Chu),김효영(Hyo Young Kim),박성민(Sung Min Park) 한국고생물학회 2000 고생물학회지 Vol.16 No.2