• Title/Summary/Keyword: Shihwa Industrial Complex

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Heavy Metal Contamination and Spatial Differences in Redox Condition of the Artificial Shihwa lake, Korea (시화호의 중금속 오염과 산화-환원 상태의 공간적 차이)

  • Hyeon, Sang-Min;Kim, Eun-Su;Paeng, U-Hyeon
    • Journal of Environmental Science International
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    • v.13 no.5
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    • pp.479-488
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    • 2004
  • Five sediment cores from the tidal flat of artificial Lake Shihwa are analyzed in terms of sedimentology and geochemistry to evaluate the heavy metal contamination and redox condition of surficial sediment following the Shihwa seawall construction. The variability of concentrations of various elements depends on the depositional environment, and reflects the various redox conditions and sediment provenances. The amounts of Ti and Al and their ratio of Ti/ Al with respect to Li clearly indicate that there is an anthropogenic contribution to the surficial sediment. The high concentrations of heavy metals suggest an anthropogenic contribution at ST. 34 and ST. 22. Concentrations of most elements (Cr, Cu, Zn and Pb) are higher near the Shihwa-Banwol industrial complex than in the central part of Lake Shihwa. Concentrations of heavy metal in surficial sediment near the Shihwa-Banwol industrial complex are two to eight times higher than in the center of Lake Shihwa. Enrichment factors (EF), which are normalized by the unpolluted shale, suggests a significant metallic contamination near the Shihwa-Banwol industrial complex (SBIC). The redox condition is divided into two anoxic and mixed oxi $c_oxic zones based on the carbon:sulfur (C/S) ratios of organic matter and elemental relationships. Correlations among geochemical elements Mn, U and Mo are significantly different from site to site, and may therefore be an indicator of the spatial redox condition. Controlling factors for switching anoxic/oxic conditions are thought to be water depth and the differences in industrial effluent supply. The variations of the Cu/Mn ratio in the sediments confirms above mentioned spatial differences of a redox condition in part, and therefore shows a location-dependence redox condition in sediments at four other sites. The redox condition of the surficial sediment characteristics of the Shihwa Lake are controlled by its geographic location and water depth.th.

Assessment of Organic Matter Sources in the Singil Stream Flowing into Lake Shihwa, South Korea

  • Kim, Dahae;Kim, Jung-Hyun;Kang, Sujin;Kim, Min-Seob;Shin, Kyung-Hoon
    • Korean Journal of Ecology and Environment
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    • v.53 no.2
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    • pp.138-147
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    • 2020
  • The Singil Stream, flowing into an artificial lake, Lake Shihwa (South Korea), experiences a strong anthropogenic pressure with continuous organic matter (OM) inputs from rural, urban, and industrial areas. In this study, we investigated suspended particulate matter (SPM) and streambed sediments collected along the Singil Stream in 2014 and 2016, by applying a dual element approach (δ13C and δ15N) to identify OM sources. The SPM and streambed sediment samples from the indusrial area showed higher organic carbon and nitrogen concentrations (or contents) than those from the other areas, with distinctively lower δ15N values. Accordingly, our dual element approach indicates that the industrial area was the predominant OM source influencing OM quality and thus water quality of the Singil Stream flowing into Lake Shihwa during the study periods. However, further studies are necessary to better constrain OM sources in the Singil Stream since OM sources from the industrial area appear to be complex.

From L-Ascorbic Acid to Protease Inhibitors: Practical Synthesis of Key Chiral Epoxide Intermediates for Aspartyl Proteases

  • Chang, Sun-Ki;So, Soon-Mog;Lee, Sang-Min;Kim, Min-Kyu;Seol, Kyoung-Mee;Kim, Sung-Min;Kang, Jae-Sung;Choo, Dong-Joon;Lee, Jae-Yeol;Kim, B.-Moon
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2213-2218
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    • 2012
  • Efficient synthetic routes were developed to prepare a sizable amount (4-15 grams) of the chiral epoxides 4-6 as versatile intermediates for the synthesis of aspartyl protease inhibitors of therapeutic interest such as HIV protease and ${\beta}$-secretase. Oxidative cleavage of the C(2)-C(3) double bond of L-ascorbic acid followed by functional group manipulation led to the preparation of the epoxide 10, which was opened with an azide to yield a common aziridine intermediate 12. Through opening of the aziridine ring of 12 with either a carbon or a sulfur nucleophile, chiral epoxide precursors 4-6 could be prepared for various HIV protease inhibitors. Except for the final low melting epoxides 5 and 6, all intermediates were obtained as crystalline solids, thus the synthetic pathway can be easily applied to a large-scale synthesis of the chiral epoxides.

Local R&D Networking of SMEs in the Shihwa Industrial Complex (시화산업단지내 중소기업의 R&D 네트워크 형성)

  • Kim, Ho-Yeon
    • Journal of the Economic Geographical Society of Korea
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    • v.13 no.1
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    • pp.147-158
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    • 2010
  • Knowledge spillover among firms is a crucial ingredient in realizing the benefits of agglomeration. This paper provides an overview and critical assessment of the Shihwa Industrial Complex (SIC) in Korea. In order to identify the relationships and interplay among different agents in the area, a survey was conducted on business networking of industry-academia-government collaboration in research and development. Unlike the closely knit input-output relationship, the findings suggest that the technological linkages in the SIC still have room for improvement. As the role of small and medium enterprises as catalysts of regional economic development in Korea is expected to grow in importance, more effort should be made to nurture clustering and R&D networking among them.

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Assessing Water Quality of Siheung Stream in Shihwa Industrial Complex Using Both Principal Component Analysis and Multi-Dimensional Scaling Analysis of Korean Water Quality Index and Microbial Community Data (Principal Component Analysis와 Multi-Dimensional Scaling 분석을 이용한 시화공단 시흥천의 수질지표 및 미생물 군집 분포 연구)

  • Seo, Kyeong-Jin;Kim, Ju-Mi;Kim, Min-Jung;Kim, Seong-Keun;Lee, Ji-Eun;Kim, In-Young;Zoh, Kyung-Duk;Ko, Gwang-Pyo
    • Journal of Environmental Health Sciences
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    • v.35 no.6
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    • pp.517-525
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    • 2009
  • The water quality of Lake Shihwa had been rapidly deteriorating since 1994 due to wastewater input from the watersheds, limited water circulation and the lack of a wastewater treatment policy. In 2000, the government decided to open the tidal embankment and make a comprehensive management plan to improve the water quality, especially inflowing stream water around Shihwa and Banwol industrial complex. However, the water quality and microbial community have not as yet been fully evaluated. The purpose of this study is to investigate the influent water quality around the industrial area based on chemical and biological analysis, and collected surface water sample from the Siheung Stream, up-stream to down-stream through the industrial complex, Samples were collected in July 2009. The results show that the downstream site near the industrial complex had higher concentrations of heavy metals (Cu, Mn, Fe, Mg, and Zn) and organic matter than upstream sites. A combination of DGGE (Denaturing Gradient Gel Electrophoresis) gels, lists of K-WQI (Korean Water Quality Index), cluster analysis, MDS (Multi-Dimensional Scaling) and PCA (Principal Component Analysis) has demonstrated clear clustering between Siheung stream 3 and 4 and with a high similarity and detected metal reducing bacteria (Shewanella spp.) and biodegrading bacteria (Acinetobacter spp.). These results suggest that use of both chemical and microbiological marker would be useful to fully evaluate the water quality.

Sedimentary Environments and Heavy Metallic Pollution at Shihwa Lake (시화호의 퇴적환경과 중금속오염)

  • Hyun, Sang-Min;Chun, Jong-Hwa;Yi, Hi-Il
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.4 no.3
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    • pp.198-207
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    • 1999
  • Five core sediments acquired from the Lake Shihwa are analyzed for variations of sedimentary environment and heavy metal pollution after the Shihwa seawall construction. The depositional environment of the study area is divided into anoxic, oxic and mixed suboxic conditions based on the C/N ratio and C/S ratios of organic matters. Controlling factors for redox condition are the water depth and the difference in industrial effluents supply. Correlations among geochemical elements (Mn, U, Mo) show a distinctive difference and thus can be used as an indicator of redox condition. The content of Al, Ti are dependent on the sediment characteristics, and the contents of heavy metals (Cr, Ni, Cu, Zn, and Pb) indicate heavy metal pollution. The concentrations of heavy metals are higher near Shiswa-Banwol industrial complexies than the central part of Lake Shihwa. Especially, the accumulation of the heavy metal at the surface sediments near Shihwa-Banwol industrial complex are two to eight times higher than in the center of Lake Shihwa.

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Distribution of TOC and metals in the surface sediments of the Lake Shihwa (시화호 표층 퇴적물의 유기탄소와 금속의 분포)

  • Kim, Kyung-Tae;Kim, Eun-Soo;Cho, Sung-Rok;Park, Jun-Kun;Kim, Jong-Kun;Lee, Jeong-Moo
    • Proceedings of KOSOMES biannual meeting
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    • 2008.05a
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    • pp.159-164
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    • 2008
  • In order to understand the spatio-temporal distribution of geochemical parametrs in surface sediments of the artificial Lake Shihwa in the vicinity of Kyunggi Hay in Korea, surface sediments were sampled at 14 sites in July 2007 and analyzed by CHN analyzer and ICP/MS. Metal concentrations in the sediments tended to be decreasing from the head to the mouth of the Lake Shihwa because of extreme pollutant discharge from various kinds of anthropogenic sources such as the Banweol and Shihwa Industrial Complex and cities. With the deposition of fine-grained sediments, high metal concentrations were also observed in the central part of lake. Although various programs(improvement of wastewater collection and treatment system, sea-lake water exchange etc) to improve the environmental conditions around the Lake Shihwa after dike construction were carried out, it was not dear to reach a good environmental quality. Therefore, further environmental programs should be conducted continuously for environmental improvement.

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The Study on the Phytoplankton Bloom and Primary Productivity in Lake Shihwa and Adajcent Coastal Areas (시화호와 시화호 주변 해역 식물플랑크톤의 대증식과 일차 생산력에 관한 연구)

  • Choi, Joong-Ki;Lee, Eun-Hee;Noh, Jae-Hoon;Huh, Sung-Hoi
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.2 no.2
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    • pp.78-86
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    • 1997
  • To clarify the phytoplankton blooms in Lake Shihwa after the construction of a dyke, a study on the environmental factors, the distribution of chlorophyll-a, phytoplankton standing stocks, dominant species and primary productivity was carried out in Lake Shihwa and adjacent coastal areas from October, 1995 to August, 1996. Lake Shihwa is brackish water with mixing of freshwater from tributaries and the remaining salt water at the bottom. The dense phytoplankton bloom of average value of 168.6 ${\mu}gChl-a\;l^{-1}$ have occurred throughout the year in Lake Shihwa which is eutrophicated by the large input of nutrients from inflowing 5 tributaries and Shihwa Industrial Complex. The major organisms of algal bloom in Lake Shihwa were diatoms, Cyclotella atomus, Nitzschia sp. and Chaetoceros sp. in autumn and winter, and dinoflagellate Prorocentrum minimum and Chrysophyceae in spring and summer. The autumn and winter diatom blooms were limited by the depletion of silicate in the lake. Diatom blooms have occurred in the coastal areas adjacent to Shihwa lake from winter to summer due to the inflow of nutrient rich-water from Lake Shihwa. The primary productivities in the Lake Shihwa ranged from 2,653 mgC $m^{-2}\;day^{-1}$ to 9,505 mgC $m^{-2}\;day^{-1}$ with an average of 3,972 mgC $m^{-2}\;day^{-1}$. However, most of the high primary production was limited to the shallow euphotic zone due to the inhibition of light penetration. The primary productivities during autumn and winter were limited by the depletion of silicate. Lack of photosynthesis and the decomposition of falling organic matter under the middle of water column accelerated the depletion of dissolved oxygen in the bottom layer.

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Patterns of Offensive Odor Compounds According to Blocks in Shiwha Industrial Complex (시화산업단지의 블록 별 악취유발물질 특성)

  • Byeon, Sang-Hoon;Lee, Jung-Geun;Kim, Jung-Keun
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.12
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    • pp.1161-1168
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    • 2009
  • This research was conducted on characteristic of offensive odors in Shihwa industrial complex. Result of blocks distribution of TVOC indicates that mechanic block, site D, was the highest concentration (74 ppb). Chemistry block, site A, was the second highest concentration (50 ppb). Also, mixed blocks, metal blocks and park etc. were measured almost similar concentration about 30 ppb, but mixed block, site F, was the place where concentrations were the smallest. Average of TVOC was shown about 35 ppb concentration. Aldehydes including acetaldehyde, butyraldehyde and hydrogen sulfide concentrations were prevalent among offensive odors in Shihwa industrial complex. Comparing the offensive odor intensity mostly about acetaldehyde, butyraldehyde and hydrogen sulfide which contain high offensive odor intensity showed results that sites A, B (chemistry block) and site D, I (mechanic block) site H (metal block) have showed the intensity over 1. In the case of acetaldehyde, relatively the high odor intensities over '2' were able to obtain in many cases. The correlation coefficient (r) for hydrogen sulfide was 0.91, so that high positive correlation exists between offensive odor intensity and the hydrogen sulfide element. Butyraldehyde also showed high positive correlation coefficient, as 0.82. Correlation coefficient of acetaldehyde that had the highest value as offensive odor substance was 0.62, had somewhat correlation with offensive odor intensity.