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.

Thirty sediment samples of the <63㎛ fraction collected from the southwestern coast of Korea were analysed for their heavy metal (Fe, Mn, Cr, Co, Cu, Ni, Zn and Pb) concentration. The results show that sediment texture plays a controlling role on the total metal concentrations and their spatial distribution. A single 1M HCl extraction procedure was used in order to assess the environmental risk of heavy metals in bottom sediments. The non-residual fraction was the most abundant pool for Mn and Pb in most samples, which means that this metals are highly avaliable in these sediments. Cr, Ni, Fe, Co, Zn and Cu were mainly associated with the residual fraction, suggesting that their concentrations are controlled significantly by transport processes with the fine particles as carriers from diffuse pollution source. Concentration enrichment ratios(CER) were calculated from the non-residual contents and their values allowed us to classify the sediments according to their environmental risk.

To utilize coastal aquaculture ground bottom sediment in which concentrations of harmful pollutants are low and organic content is high as an organic fertilizer alkaline stabilizers such as CaO, Oyster shell, Mg(OH)2 were added to the bottom sediment organic additives of livestock or food wastes. Nutritive qualities of crude fertilizers were measured to examine effects of alkaline stabilizers and organic waste additions. The Mg(OH)2-added crude fertilizer had significantly lower total carbon(T-C) and nitrogen(T-N) content, reflecting the dilution effect due to great amount of Mg(OH)2 addition. However, the addition of oyster shell had no significant effect on the T-C and T-N content of the fertilizer. P2O5 and K2O content was considerably higher in the mixed sample of aquaculture ground bottom sediments and livestock wastes than in the mixture of the sediments and food wastes, resulting from higher P2O5 and K2O content in livestock wastes. Addition of Mg(OH)2 increased the content of MgO in the crude fertilizer but significantly reduced the content of other nutritive elements such as P2O5, K2O and CaO. Addition of oyster shell as an alkaline stabilizer seemed to have the advantage of saving time and expenses for dryness due to its role as a modulator of water content. Moreover, additions of effect Mg(OH)2 decreased the concentrations of heavy metals in the fertilizer by the dilution while additions of oyster shell had no influence on heavy metal concentrations in the fertilizer.

새만금 미세점착성 퇴적물의 침강특성을 퇴적물 자체의 물리ㆍ화학적 기본특성과 연계 해석하기 위하여, 퇴적물의 입경분포, 광물질 구성 및 유기물 함량 조사로 구성되는 새만금 퇴적물에 대한 물리ㆍ화학적 특성 조사가 수행되었다. 새만금 퇴적물의 물리ㆍ화학적 특성에 대한 분석 결과, 새만금 퇴적물은 평균입경(52)이 비교적 크고 유기물 함량(2%)이 매우 작으며, 점착력이 비교적 자은 석영이 주된 광물질 구성성분으로 점착력에 의한 침강효과 보다는 중력에 의한 침

Sediments and river waters from the channel of Hwasun-cheon were studied in sedimentological size and geochemical analyses of metallic elements for the purposes of identification of depositional environments and geochemical characteristics. The sizes of sediments are assigned to pebble to coarse sand in mean size and polymodal in distribution. And the sediments are poorly to very poorly sorted and positively skewed. According to the grain size distributions of the sediments, the Hwasun-cheon belongs to gravel-bed river on the basis of the grain size distribution of the sediments. The behaviors of metallic elements in the sediments mainly depend on not grain size distribution but the geology connected with geomorphological reliefs near the stream. Contamination indices(CI) of Zn, Cu and Pb are 2.83 to 6.96 with average 4.31 in the sediments. Hwasun-cheon is assigned to general stream type in accordance with water quality of physical factors and chemical characteristics by Piper's diagram. Though meaningful values of BOD, T-N, T-P were locally depicted near Masan-ri, Hwasun-eup and Jiseok-cheon areas, artificial metal concentration do not represent in the most area of the stream. Sediments and river water are considered that the relatively more or less high metallic contents in the stream are originated from coal mine and urban area.

A comparison of Daphnia magna, Ceriodaphnia dubia and Simocephalus mixtus toxicity test was performed to study the relative sensitivities and discrimination abilities with both pore and elutriate water of Woopo wetland sediments. Sediment risk assessment has been done by standardized preparation method of pore and elutriate water described in the joint US EPA-US Army Crops of Engineers manual. Simocephalus mixtus which was obtained from Woopo wetlands in Korea was cultured and applied to sediment toxicity test. Water quality in Woopo wetland had great site and seasonal variations. S. mixtus was more sensitive than D. magna in heavy metal toxicity test. The toxicity results with S. mixtus reflected the water quality of elutriate and pore water. The results also suggested that S. mixtus could be used as a test organism in estimating potential risk of contaminated sediments.

In order to evaluate the relationship between geochemical characteristics and benthic facies of the sediments from the Oenaro Island where red tide proliferation is first observed every year including this year, surface and short multiple core sediment samples were analyzed in terms of geochemical and benthic facies variation. The contents of organic carbon, carbonate, and sulfide gas were relatively low. The variation in C/N ratios, which indicate nature of organic carbon, suggested that the organic carbon recorded in the study area is composed of mixtures of marine and terrigenous organic matters. The concentration of minor elements found at the surface and multiple core sediment samples were also low as well as the enrichment factors(Ef) for the seven heavy metals indicated that the sediment of this area is not polluted significantly. The macrobenthic faunal community comprised 61 species, and their mean density was 708 ind./m2. Polychaete worms were major taxa of this benthic community. A crustacean amphipod, Melita sp. was the most abundant species accounted for 20.7% of total abundance, and the small polychaetes such as Heteromastus filiformis, Paralacydonia poradoxa, Magelona japonica, and Sigambra tentaculata were the next dominant species. The macrobenthos around the Oenaro Island were more diverse and abundant than that in Gamak Bay. The benthic communities in the study area sustained somewhat different species composition based on the cluster analysis and the MDS ordination. The benthic community health condition at three stations seemed to be unbalanced, and slightly polluted based on the biological index such as BPI and BC. There was no clear relationship between the geochemistry characteristic and the benthic faunal facies attributed by the micro-algal blooms in this coastal area.

침식률 측정장치인 SEDFLYME을 사용하여 직접 측정한 침식률 자료를 이용하는 퇴적물 수송에 관한 2차원 모형이 개발되었다. 개발된 모형은 현장 적용성을 높이기 위하여 경계밀착좌표계를 수평방향에 대해 사용하며, 퇴적물 이동 모의시 침식률 산정에서 불확실성을 줄이기 위해 침식률 측정자료를 직접 사용한다. 개발된 모형은 부유사와 소유사 이동을 모두 고려한다. 모형의 정확성을 검토하기 위하여 1차원 수로에서 장갑화 현상을 모의하고 실험자료와 비교하였다. 비

In an attempt to evaluate the possibility of producing an organic fertilizer using sediments from coastal farming areas, the chemical composition, bacteriological quality and heavy metals in the sediments alkalized by quicklime and magnesium hydroxide were analyzed. The optimum reaction was obtained from the following conditions : a 1:4 mixture of dry sediment to food wastes and the addition of 30% quicklime to the mixture. According to the classification standard for compost constituent by Higgins, all composts had a low or intermediate grade in T-N and K2O content, a low grade in P2O5 and a high grade in CaO and MgO content. Stabilization by quicklime and magnesium hydroxide is likely to inhibit the bacterial decomposition of organic matter and the activity of pathogenic organisms. Raising the pH of stabilized sediments to 12 for 2 hours(PSRP criteria of EPA) allowed 99.99% of the coliform group, fecal group and viable cell count to be reduced. The results suggested that the crude fertilizer produced by alkaline stabilization method was innoxious and thereby the sediments from coastal farming areas could be used as organic fertilizer.

본 연구에서는 원심력을 이용한 하이드로싸이클론을 준설된 호소 퇴적물의 처리 공정에 적용하는 실험을 수행하였다. 준설된 퇴적물의 안정화 및 위생적 처리를 위해서는 경우에 따라 탈수 및 분급공정이 필요하다. 본 연구에서는 이러한 공정에 하이드로싸이클론을 적용하였으며, 실온에서 실제 호소 퇴적물과 폐 석탄회를 이용하여 분리효율을 실험하였다. 본 연구 결과 하부배출구의 크기는 한계분리입경(d(sub)50)에 큰 영향을 미치는 것을 알 수 있었고, 비중이 큰 입

The observations on the seasonal fluctuation and distributional characteristic of organic matters on surface sediments and its origin were carried out at the 25 stations in Keogeum-sudo, southern coast of Korean Peninsula from February to October in 1993. I made an analysis on the environmental factors for surface sediments such as temperature, ignition loss, chemical oxygen demand, pheopigment, total sulphide, water content, mud content in grain size, COD/IL ratio and COD/sulphide ratio. The results are as follows ; 1) The range of temperature on the surface sediments was between 6.2℃ and 24.6℃. The highest mean temperatuer of mud was 24.0℃ in summer, the lowest 6.6℃ in winter. 2) Ignition loss(IL) fluctuated between 1.2% in winter and 16.8% in spring, that is to say, the seasons of increasing in temperature were very high ignition loss. 3) Chemical oxygen demand(COD) showed the highest mean value of 20.52 ㎎/g dry in summer within the range of 15.46∼32.78 ㎎/g dry, while showed the lowest of 5.79 ㎎/g dry in winter within the range of 7.4∼17.39 ㎎/g dry. 4) Pheopigment concentrations showed the highest mean value of 4.85 ㎍/g dry in autumn within the range of 0.84∼9.21 ㎍/g dry, while it did the lowest mean value of 1.97 ㎍/g dry in summer within the range of 0.23∼4.83 ㎍/g dry. 5) Total sulphide (H2S) fluctuated between no detect(ND) in spring, and 2.43 ㎎/g dry in autumn. The highest mean value was 0.68 ㎎/g dry in autumn, the lowest was 0.16 ㎎/g dry in spring. 6) Water content(WC) and mud content in grain size showed the mean value of 43.2% within the range of 26.5∼59.7% and 91.0% within the range of 57.8∼99.2%, respectively. 7) By the analytical results on the source of organic matter, it had been dumped from the seaweed farms in Keogeum-sudo coastal waters.

To investigate size distribution and metallic elements of surface sediments in Hampyong Bay, the southwestern coast of Korea, sedimentological and geochemical studies on surface sediments are carried out. The surface sediments of Hampyong Bay are classified into gravel, muddy sandy gravel, gravelly muddy sand, gravelly sandy mud, mud facies in accordance with areal characteristics. The coarse sediments are distributed on the subtidal zone along the main tidal channel and southeast intertidal flat of Hampyong Bay. On the other hand, the fine sediments are dominated in northeast and west intertidal flat of Hampyong Bay. Most metallic elements except for Ba in the sediments are closely interrelated with fine sediments and mutually with each element. Ba is maybe related with sandy sediments and inversely related with carbonate contents. Normalized by Al content, the sediment do not show any remarkable metal enrichments influenced by resonable artificial or environmental factors.

In order to determine the changes of sediment facies and metal levels in surface sediments after the construction of Shiwha Lake, surface sediments were sampled at 8 sites located on the main channel monthly from June, 1995 to August, 1996 and analysed for 12 metals (Al, Fe, Mn, V, Cr, Co, Ni, Cu, Zn, Cd, As and Pb) by ICP/AES and ICP/MS. Two groups of sampling sites (the inner lake with 3 sites and the outer lake with 5 sites) are subdivided by the surface morphology; the inner lake is a shallow channel area with a gentle slope, while the outer lake is relatively deep and wide channel with a steep slope which has many small distributaries. After the construction of dam, fine terrestrial materials were deposited near the outer lake, which resulted in the change of major sediment facies from sandy silt to mud. With the deposition of fine sediments in the outer lake, anoxic water column induced the formation of sulfide compounds with Cu, Cd, Zn and part of Pb. Metal (Cr, Ni, Cu, Zn and Cd) contents in sediments increased up to twice within 2 years after the construction of dam. This is due to the direct input of industrial and municipal wastes into the lake and the accumulation of metals within the lake. In addition, frequent resuspension of contaminated sediments in a shallow part of the lake may make metal-enriched materials transport near the outer lake with fine terrestrial materials. As the enrichment of Cu, Zn, Cd and part of Pb in the Shiwha Lake may be related to the formation of unstable sulfide compounds by sulfate reduction in anoxic water or sediment column, the effect of mixing with open coastal seawater is discussed.

The purpose of the present study is to estimate the release of dissolved inorganic nitrogen and phosphorous from sediments of Deukryang Bay. One method used in this study is to calculate nutrients released from a concentration gradient between sediment porewaters and the overlying water based on the Fick`s law, and the other method is to measure nutrients released from the sediment-core experiments. The calculated and measured ammonium released from the sediments were 8.93㎍-atN/㎡·hr and 60.4㎍-atN/㎡·hr, respectively in July. 8.57㎍- atN/㎡·hr and 32.9㎍-atN/㎡·hr, respectively in October. The ammonium was released more highly in July than in October, and the measured ammonium flux was higher than the calculated one. The calculated nitrate plus nitrite released from the sediments were 0.31㎍-atN/㎡·hr in July and 0.84㎍-atN/㎡·hr in October. The measured nitrate plus nitrite released from the sediments was 282㎍-atN/㎡·hr in October. The calcuated was lower than the measured because the content of the nutrients in the sediments was always much more than in the overlying waters, and it has shown a differently seasonal pattern compared to the ammonium flux. The calculated phosphorous released from the sediments were 0.97㎍-atN/㎡·hr and measured negative fluxed -6.50 ㎍-atN/㎡·hr in July, and calculated 0.18 ㎍-atN/㎡·hr and measured 24.6 ㎍-atN/㎡·hr, respectively in October.

Thirty-eight sediment samples collected from the Youngsan River channel were analysed for Fe, Mn, Co, Cr, Cu, Ni, Zn and Pb to recognize the extent of contamination. Results showed that a wide range of contents was apparent for every metal over the study area. These differences have been mainly related to the textural variability of sediments. Exceptions to this were found in the contents of Cu, Zn, Pb and possibly Mn. The contents of Cu, Zn, Pb and Mn were particularly higher in the sediments from the confluence of tributaries. Downstream profile of metal/Al ratios indicates that pollutant inputs from the Kwangju tributary are mainly responsible for enrichment of these metals in bed sediments of the Youngsan River.

A total of 24 surface sediment samples collected from coastal region and fronting of sea cliff on Cape Cod in southeastern Massachusetts, were analyzed to investigate the sediment transport mechanism. According to the result of grain-size analysis, the overall trend of grain size decreases from the north(Wood End Beach) to the south(Nauset Light Beach). The coarser materials tend to be deposited at the foreshore than at the backshore. Especially gravel content(%) is very high in northern beaches. The gravel fraction tended to concentrate at the toe of the beach. In addition to gravel, the beach and nearshore bar also tended to be deposite of very coarse sand and the finer fraction accumulate in the offshore bar. Grain-size analyses of sediment indicates that the coarsest sands including gravel accumulate in the beach and nearshore bar, the finer fraction winnowed out by wave action to be deposited in the offshore bar. The beach and nearshore bar sands and gravel are subsequently transported laterally by the wave-driven longshore drift, and finally they come to rest in the distal end of Provincetown Hook. The finer offshore sands are trnasported laterally to the south by net southward-directed longshore current.

The temporal variations of the suspended material concentration (SMC) during spring-neap tidal cycle was investigated at more than 30 stations in Deukryang Bay, Korea, in 1 and 23 July, 1992. The averaged total SMC in spring tide was two times more than those in neap tide. It can be explained that the strong tidal current in spring tide disturbed bottom waters and induced higher SMC in the bay. The areal distributions of SMC for the surface and the bottom layers in the bay shows much different patterns during spring and neap tidal cycle. We concluded that the vertical stratification intensity of water mass is important factor of the horizonatal distribution of SMC in the bay.

In the Chinhae Bay, Korea, sedimentation rates and sedimentary record of anthropogenic metal loads were determined by ^210Pb dating and heavy metal analysis of four sediment cores. The sedimentation rates varied from 0.16g/㎠/yr(3.1㎜/yr) at Sta. C4, located within narrow waterway to 0.24g/㎠/yr(4.8㎜/yr) at Sta. C1, located in Haengam Bay. Maximum contents of Mn, Zn, Cu and Cr were observed at Sta. C2 located near the mouth of Masan Bay, while minimum contents were observed at Sta. C4. Mn/Fe ratios at Sta. C2 and Sta. C4 showed gradually increasing and decreasing downward, respectively, in the upper layer of sediment cores. This suggests that Mn may be diagenetically redistributed in highly reduced environment. At Sta. C2, the concentrations of Zn and Cu began to increase from 1920s by anthropogenic input and have been remarkablely increasing since mid 1960s. At Sta. C3, located near Sungpo, anthropogenic input of these two elements has also slightly increased after 1970s. However, pollution of these two elements was not significant in Haengam Bay(Sta. C1) and Chiljun waterway(Sta. C4). The pollution of Co, Ni and Cr was not remarkable in all core samples except surface sediment of Sta. C2. The total input of anthropogenic Zn and Cu since 1920s was estimated to be 28∼792 ㎍/㎠ and 0∼168㎍/㎠, respectively. Sta. C2 showed remarkablely higher values relative to other stations: anthropogenic loads of Zn and Cu constituted 27% and 29% of the total sedimentary inventories at the present day, respectively. Fe, Ni, Cr and Co contents showed good correlation(r>0.8) with each other. Anthropogenic Zn and Cu also showed a very good positive correlation(>0.9). However, correlation between these two group of element was quite scattered, indicating different sources and geochemical behaviors.