• 생태와환경
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• 제46권4호
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• pp.507-512
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• 2013

Aquatic oligochaetes were investigated from a small amount of sediment sampled from the Jungnang Stream, an urban stream in Seoul, Korea, in November 2012. Sorted oligochaetes were observed under a light microscope in a drop of carbonated water, and then preserved in 70% ethanol. Some specimens were slide mounted using glycerin and Eupharal. As a result, the following 12 species were identified including 8 new Korean records, Bothrioneurum vejdoskyanum Stolc, Branchiodrilus hortensis (Stephenson), Chaetogaster cristalinus Vejdosky, Nais communis Piguet, Nais pardalis Piguet, Dero obtusa d'Udekem, Piguetiella denticulata Liang, and Haemonais waldvogeli Brescher and 4 additional known species, Limnodrilus hoffmeisteri Cleparede, Branchiura sowerbyi Beddard, Chaetogaster diastrophus (Gruithuisen), and Stylaria fossularis Leidy. This study shows how freshwater oligochaetes are diverse even in urban streams in Korea, if a proper sampling and examining method is employed.

• 자원환경지질
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• 제32권1호
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• pp.63-72
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• 1999

In order to examine the contamination levels of trace elements in stream sediments in the Chungnam coal mine area, stream sediment and water samples were collected and analyzed for trace elements. The pH of stream water was neutral or weak-alkaline and the mobility of metal in stream sediments was supposed to be low. From the result of cluster analysis, non-polluted sampling stations can be distinguished from polluted sampling stations influenced by mining activities. The trace element concentrations in sediments from non-polluted zone were considered to be the natural backround concentrations of this area. The trace element concentrations in sediment samples from the mining area were higher than those from non-polluted area, and contaminated area of enriched trace element levels need to be properly managed. From the results of discriminant and regression analyses, concentrations of Cd, Cu, Pb AND zN and predicted values of Be, Mo, and Ni in Chungnam coal mine area were found to be lower than those in metal mining areas in Korea.

• 농촌계획
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• 제9권2호
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• pp.1-6
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• 2003

This study was performed to investigate the degree of pollution of sediments of stream and reservoir in rural area. A series of field investigations were carried out for Kyongki-do area and chemical analysis were performed for sediment samples. It was found that some samples were heavily polluted with phenol and TPH and gave off a malodor. Soil Pollution Scores(SPSs) was determined for sediment samples. Some samples were classified to Soil Pollution Class(SPC) 2 and 3. For recycling and disposal of dredged sediments from stream and reservoirs, these polluted sediments should be carefully considered. In the environmental improvement operations of rural area, the degree of pollution of sediments of stream and reservoir are carefully investigated and suitable counterplan must be established.

• 한국습지학회지
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• 제9권1호
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• pp.107-114
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• 2007

This study aimed to investigate the hexachlorobenzene (HCB) dechlorinating ability of sediment microbes collected from a natural canal receiving secondary effluents from an industrial estate and nearby factories. Nine sites along the stream and one in the estuary in the Gulf of Thailand into which the canal spills were specified and sampling for sediment and water. Preliminary analysis of the sediments showed that the first four sites nearest to the discharging location were contaminated by HCB within the range of 0.18 to 1.25 ppm. Apart from that, 1,3,5-trichlorobenzene which has never been commercially produced or used in any manufacturing processes except for the transformation from higher chlorinated benzene was also identified in the range of 0.16 to 0.24 ppm. This suggested a possibility of sporadically HCB contamination in this stream. Of more important, people in the community along this canal earn their living by coastal fishery; hence, posing a risk of spreading HCB and its less chlorinated congeners via food chain from caught marine creatures to human. As a result, there is an urgent need to understand the behavior of HCB dechlorination in this stream sediment which can lead to a clean-up action in the future. Serum bottles with sediment slurries (sediment to water ratio of 1:1 (v/v) and filtered to remove particles larger than 0.7 mm) from each site were inoculated with 2 mg/l of HCB, kept anaerobically in the dark at room temperature without any nourishment, and analyzed for HCB and its less-chlorinated congeners every 6 days. Total chemical oxygen demand, suspended solids, and volatile suspended solids were in the range of 21,492-73,584, 158,100-518,100 and 6,000-32,700 mg/l, respectively. It was found that all sediment slurries began to dechlorinate HCB in 12 to 30 days and the HCB was completely removed within 42 to 60 days or so. On the other hand, there was no HCB dechlorination occurred in the controlled set which was sterilized by autoclaving prior to the addition of HCB. This implies that the HCB transformation was solely due to microorganisms' activities. HCB was dechlorinated principally via pentachlolobenzene to 1,2,3,5-tetrachlorobenzene and terminated at 1,3,5-trichlorobenzene which is the major pathway as reported by many researchers. Dichlorobenzene has not been detected in any samples within the dechlorination period of 60 days. The results indicate that the microbial matrix in the sediment of this stream has an outstanding capability to dechlorinate HCB. Existing substrates and nutrients which mainly sorbed onto the solid phase and the typical temperature in Thailand were sufficient and suitable to promote the activities of these HCB-dechlorinating microbes.

• Ecology and Resilient Infrastructure
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• 제2권2호
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• pp.167-176
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• 2015

본 연구대상지인 굴포천은 인천, 부천, 서울, 김포를 걸쳐 흐르는 도심하천으로서 수질오염이 심하고 지속적인 하천개수사업으로 인하여 하천의 자연성이 미비한 실정이다. 본 연구에서는 굴포천에서 하천수 및 하상 퇴적물의 이화학적 특성을 분석하였고, 퇴적물로부터 영양염 용출특성을 실내실험으로 호기와 혐기 조건에서 규명하고자 하였다. 굴포천의 수질은 영양염의 농도가 높을 뿐만 아니라 용존산소가 매우 낮아서 혐기화로 인한 다양한 수질문제를 야기할 우려가 있었다. 또한, 완만한 경사 및 느린 유속으로 인하여 유수가 정체되어 있기에 하상 내에 퇴적 오니가 쌓이게 되고, 이러한 퇴적오니는 다량의 유기물질과 영양염이 흡착하고 있어 재용출에 의한 내부오염의 가능성이 높았다. 결론적으로 굴포천 퇴적물은 혐기조건에서 오염물질이 용출될 가능성이 크고, 이로 인하여 하천 수질에 악영향을 미칠 수 있기에 준설 등의 주기적인 퇴적물 관리가 필요하다.

• 한국물환경학회지
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• 제27권1호
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• pp.19-29
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• 2011

In order to assess the influences of bottom sediment on water quality, following measurement were made. (1) Estimations of pollutant loads from the bottom sediment based on mass balance concept, (2) measurements of pollutant concentrations in the sediment to assess the pollution level and influence potential, (3) in situ and laboratory measurements of Sediment Oxygen Demants (SOD) and pollutant load (sediment release) from bottom sediment. Analyses of inflow and outflow loadings using simple mass balance show that there are some variations found according to the pollutants. However, there is no consistent evidence that the sediment can be a source of pollutants. Pollutant concentrations in the sediment range 16~724.8 mg/kg (COD), 1.68 ~12.64 mg/kg (T-P), 5.6~76.8 mg/kg (T-N), 0.32~21.6 mg/kg ($NH_3$-N), 0.092~0.544 mg/kg ($NO_2$-N), 4.8~18.4 mg/kg ($NO_3$-N), and 1.59~11.23 mg/kg ($PO_4$-P). Measured SOD ranges $0.190{\sim}0.802g{\cdot}m^{-2}{\cdot}d^{-1}$ and measured release rate ranges $-1618.42{\sim}10mg/m^2{\cdot}d$(COD), $-12{\sim}16mg/m^2{\cdot}d$(T-P), $-197.37{\sim}140mg/m^2{\cdot}d$(T-N), $0.4{\sim}74.32mg/m^2{\cdot}d$($NH_3$-N), $-2.04{\sim}0.8mg/m^2{\cdot}d$ ($NO_2$-N), $-70{\sim}40mg/m^2{\cdot}d$ ($NO_3$-N), and $-26.11{\sim}28.55mg/m^2{\cdot}d$($PO_4$-P). All study results indicate that bottom sediments in the Seoha weir show only limited effects on the water quality. It implies that sediment dredging is not an effective option or management measure to reduce pollutant loading.

• 환경생물
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• 제22권
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• pp.71-77
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• 2004

광양만 및 주변 하천에 존재하는 페놀류 화합물과 sterol 화합물의 분포특성을 알아보기 위하여 alkylphenols (8종), chlorophenols (2종), bisphenol A (1종), coprostanols (2종) 및 cholesterol (1종) 등 화합물들을 분석대상물질로 선정하여 표층수와 표층퇴적물 시료를 분석하였다. 모든 분석대상물질 중에서 nonylphenol과 dihydrocholesterol 화합물이 가장 높은 검출빈도를 보였으며 일부 하천퇴적물 시료에서 t-octylphenol, bisphenol A, coprostanols이 검출되었다. 분석대상물질은 하천시료에서 비교적 높게 검출되었으며, 또한 광양만 내해에서 외해보다 높게 검출되었다. 표층해수와 표층해양퇴적 물에서의 nonylphenol농도는 각각 4.0∼74.0 ng $l^{-1}$ 및 3.1∼74.3 ng $g^{-1}$ dry wt.이었다. 해양표층퇴적물에 의한 nonylphenol 평균 농축배수(Log $K_{oc}$ )는 4.8이었다. 하천표층퇴적물에서의 nonylphenol농도는 4.6∼808.6 ng $g^{-1}$ dry wt.이었으며 dihydrocholesterol 농도는 78.4∼1133.6 ng $g^{-1}$ dry wt.이었다 공단지 역을 경유하는 하천시료에서는 상대적으로 높게 nonylphenol이 검출되었으며 주민 거주지역을 경유하는 하천퇴적물에서는 dihydrocholesterol 화합물이 상대적으로 높은 노출농도를 보이였다. 섬진강 표층수에서의 nonylphenol 농도는 염분도의 증가에 따라 낮아지는 경향을 보였다.

• 자원환경지질
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• 제27권6호
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• pp.579-592
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• 1994

A case study is presented where a fluvial system is modeled in three dimensions and compared to data gathered from a study of the Arkansas River. The data is unique in that it documents changes that affected a straight channel that was excavated within the river by the U.S. Army Corps of Engineers. Excavation plan maps and sequential aerial photographs show that the channel underwent massive deposition and channel migration as it returned to a more natural, meandering path. These records illustrate that stability of fluvial system can be disrupted either by catastrophic events such as floods or by subtle events such as the altering of a stream's equilibrium base level or sediment load. SEDSIM, Stanford's Sedimentary Basin Simulation Model, is modified and used to model the Arkansas River and the geologic processes that changed in response to changing hydraulic and geologic parameters resulting from the excavation of the channel. Geologic parameters such as fluid and sediment discharge, velocity, transport capacity, and sediment load are input into the model. These parameters regulate the frequency distribution and sizes of sediment grains that are eroded, transported and deposited. The experiments compare favorably with field data, recreating similar patterns of fluid flow and sedimentation. Therefore, simulations provide insight for understanding and spatial distribution of sediment bodies in fluvial deposits and the internal sedimentary structure of fluvial reservoirs. These techniques of graphic simulation can be contributed to support the development of the new design criteria compatible with natural stream processes, espacially drainage problem to minimize environmental disruption.

• 한국산림과학회지
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• 제101권3호
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• pp.454-460
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• 2012

본 연구는 사방댐의 준설이 저서성 대형무척추동물 군집에 미치는 영향을 파악하기 위해 경북북부지역 예천, 영주, 봉화의 산간계류에 위치한 사방댐을 대상으로 준설 전 후로 조사하였다. 조사는 실험수계 3곳과 대조수계 2곳의 사방댐을 기준으로 상류와 하류로 설정하여 2011년 5월부터 8월까지 이루어졌다. 실험수계에서 준설 전 4문 6강 11목 31과 56종이 출현하였으나, 준설 후 4문 5강 10목 27과 51종으로 감소하였다. 이와 같이 사방댐 준설후 발생한 저서성 대형무척추동물의 미소서식처 파괴는 종수 및 개체수의 감소로 이어졌으며, 특히 실험수계의 상류지점에서는 종수가 평균 38% 감소하였다. 전반적으로 준설 후 실험수계에서 종풍부도지수와 종다양도지수가 감소했지만, 우점도지수는 증가하였다. 실험수계의 상류지점에서 미소서식처의 파괴와 정수역이 형성되었으며, 유속이 감소하고 하상구조는 모래나 실트로 단순해졌다. 그에 따라 상류지점의 섭식기능군과 서식기능군의 종조성은 단순해졌으며, 상 하류 군집의 차이가 커졌다. 또한 상류지점에서는 유속이 느리거나 정수역을 선호하는 깔따구류(Chironomidae spp.), 부채장수잠자리류(Gomphidae spp.), 하루살이류(Ephemeridae spp.)의 개체수 비율이 크게 증가하였으며, 군집의 균형성을 나타내는 EPT/C 지수가 감소하였다.

• 한국환경과학회지
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• 제17권3호
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• pp.287-296
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• 2008

A comprehensive quality survey for heavy metals, organophosphorous and organochlorine residual pesticides, and coplanar PCBs in samples such as water, sediments and soils as well as spiders has been implemented. The samples were undertaken at nine stream sites and their vicinity in August 2006, representing different surrounding environments. The levels of PCBs were expressed as concentrations and WHO-TEFs. Among 12 coplanar PCBs as target compounds in this study, 2,3', 4,4', 5-PentaCB (IUPAC # 118) was the congener with the highest concentration. The total concentrations and TEF values of coplanar PCBs in Siheung stream sediment (heavy industrial complex site located in Ansan city) were 3915.50 pg/g and 0.8366 pg-TEQ/g on a dry weight basis, respectively. Such levels were around 40 times higher compared to sediment from Gapyung stream (green site located in the upper of Myunggi mountain). It is probably due to the direct input of PCBs trom PCBs treatment materials. Organophosphorous (EPN, dementon-s-methyl, diazinon, parathion, and phenthoate) and organochlorine (alpha-BHC, aldrin, 4,4'-DDT, 4,4'-DDE, endosulfan alpha and etc.) pesticides were not detected above 5 ppb of detection limits. The concentrations of Cu and Cd in water and sediment samples from Siheung stream were 44.11 and $0.17ug/m\ell$ and $713.42{\mu}g/g$ and $3.73{\mu}g/g$, respectively, which contained $20\sim40$ times higher concentrations than those from Gapyung stream. In addition to the water and sediment samples, the levels of heavy metals in spider from designated sampling sites were also determined. Heavy metals in spider collected near Siheung stream was appeared to be equivalent and/or a little higher levels with respect to other spiders. Furthermore, the ratio of relative heavy metals (Cu, Cd, and Pb) in spider from each stream site showed a correlation as similar as that of heavy metals in soil samples.