• Title, Summary, Keyword: Marine sediment

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A Study on Electricity Generation of Marine Sediment Cells (해양 퇴적토전지의 발전 특성에 대한 연구)

  • Lee, Eun-Mi;Kwon, Sung-Hyun;Rhee, In-Hyoung;Park, Byung-Gi;Cho, Dae-Chul
    • Journal of Environmental Science International
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    • v.20 no.5
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    • pp.647-653
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    • 2011
  • Sediment cell is renewable energy which produces electric energy using immanent ingredients or reducing power of marine sediment as natural resources. Also the cell has an advantage that environmental pollution can be reduced through conversion of organic and inorganic contaminants into inert matter with generation of the energy. In this paper, we compared characteristics of electricity generation of the two different sediment cells, and investigated the regeneration effect of the sediment cells with manipulation of the sediment such as mixing and re-positioning. The results showed that 14.1 $W/m^2$ of power was obtained with the aluminum electrode, and the mixing of the sediment could increase the power by 4 $W/m^2$ compared to the control. Also, mixing the sediment has kept electricity for 4 weeks at a relatively constant level, which implied 'fuel regeneration effect'. Meanwhile, the sediment cell was proved to be effective in reduction of COD, which was up to 28.6%.

Occurrence of butyltin compounds in marine environment of Gwangyang Bay, Korea

  • Park, Hee-Gu;Kim, Sang-Soo;Moon, Hyo-Bang;Gu, Bon-Kyu
    • Journal of Environmental Science International
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    • v.11 no.8
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    • pp.793-800
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    • 2002
  • Butyltin (BT) compounds were measured in seawater, sediment, sediment core, settling solids, and plankton from Gwangyang Bay in 2001, Tributyltin (TBT) was detected in seawater from 1 out of the 7 seawater sampling sites and in sediment from 18 out of the 35 sediment sampling sites. The highest concentration of TBT was found in the sediment from the site near Yeosu Harbor (53 ng Sn/g dry wt), acting as the point source for TBT The mean concentrations of TBT were in the order of plankton> settling solids> sediment. The degradation indexes ([DBT]+[MBT]/[TBT]) for the plankton were less than 1, indicating the possibility of recent inputs of TBT. The indexes for the sediment and settling solids ranged from 1.14 to 8.73. The composition of the BT compounds found in the settling solids was similar to that found in the sediment. The vertical profile of the total BT compounds in the sediment was characterized by an abrupt decline from the surface. However, no butyltin compounds appeared below a depth of 10 cm, corresponding to the 1980s. Accordingly, the current results demonstrated that the levels of all butyltin species in the environment of Gwangyang Bay were relatively lower than those in other polluted coastal areas. The vertical profile also suggested a fairly recent history for the down-core.

Biogeochemical Organic Carbon Cycles in the Intertidal Sandy Sediment of Nakdong Estuary (낙동강 하구 갯벌 사질 퇴적물에서 생지화학적 유기탄소순환)

  • Lee, Jae-Seong;Park, Mi-Ok;An, Soon-Mo;Kim, Seong-Gil;Kim, Seong-Soo;Jung, Rae-Hong;Park, Jong-Soo;Jin, Hyun-Gook
    • The Sea
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    • v.12 no.4
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    • pp.349-358
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    • 2007
  • In order to understand biogeochemical cycles of organic carbon in the permeable intertidal sandy sediments of the Nakdong estuary, we estimated the organic carbon production and consumption rates both in situ and in the laboratory. The Chl-a content of the sediment and the nutrient concentrations in below surface pore water in the sandy sediment were lower than in the muddy sediment. The sediment oxygen consumption rates were relatively high, especially when compared with rates reported from other coastal muddy sediments with higher organic carbon contents. This implied that both the organic carbon degradation and material transport in the sandy sediment were enhanced by advection-related process. The simple mass balance estimation of organic carbon fluxes showed that the major sources of carbon in the sediment would originate from benthic microalgae and detrital organic carbon derived from salt marsh. The daily natural biocatalzed filtration, extrapolated from filtration rates and the total area of the Nakdong estuary, was one order higher than the maximum capability of sewage plants in Busan metropolitan city. This implies that the sandy sediment contributes greatly to biogeochemical purification in the area, and is important for the re-distribution of materials in the coastal environment.

Effect of oyster shell powder on nitrogen releases from contaminated marine sediment

  • Khirul, Md Akhte;Kim, Beom-Geun;Cho, Daechul;Yoo, Gilsun;Kwon, Sung-Hyun
    • Environmental Engineering Research
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    • v.25 no.2
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    • pp.230-237
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    • 2020
  • Nitrogen flux release from organically enriched sediments into overlying water, which may have significantly influence on water quality and increasing continuous eutrophication. The purpose of this study is to evaluate the remediation efficiency of oyster shell powder and its treated product into organically enriched sediment in terms of nitrogen flux, organic matter, chlorophyll-a, pH and dissolved oxygen (DO). The TOSP was mainly composed of CaO2. The application of TOSP into the sediment has increased the pH, DO and significantly decreased the concentrations of NH4+-N and T-N compared to other basins. On the other hand, nitrate was enriched with the addition of treated oyster powder, an oxygen releasing compound on both phases. Furthermore, chlorophyll-a was found to be increasing with time in the control basin meanwhile it dropped drastically with the addition of TOSP, which implied on the repression of algal growth owing to blockage of nitrogen source migrating from the sediment. This study has shown that the TOSP was effective to improve sediment-water quality, diminish eutrophication and control harmful algae blooms in a marine environment. Therefore, it is a good reference as an effective environmental remediation agent.

Effectiveness of external agents in polluted sedimentary area

  • Alam, Md. Mahabub;Haque, Md. Niamul;Cho, Daechul;Kwon, Sung-Hyun
    • Environmental Engineering Research
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    • v.21 no.1
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    • pp.52-57
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    • 2016
  • Sediment is a useful natural source but deteriorated continually by anthropogenic and industrial sources. Therefore, it is imperative to search a suitable method for improving or restoring sediment quality. Sediment has been tested to identify the effects of some external agents on a polluted area for 28 days. Chemical analysis and total viable counts (TVC) test have been conducted for 4 days interval to assess their performance. The analyses of chemical oxygen demand (COD), acid volatile sulfide (AVS), total phosphorous (T-P), total nitrogen (T-N) indicate that the chemical agents was more efficient to improve sediment quality whereas the microbial agent was more efficient for nutrient releasing from sediment. Oxygen releasing property of the chemical agent was thought to be providing with more congenial environment for the higher growth of the bacterial community than the direct application of microbial agents.

Behaviors of nitrogen, iron and sulfur compounds in contaminated marine sediment

  • Khirul, Md Akhte;Cho, Daechul;Kwon, Sung-Hyun
    • Environmental Engineering Research
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    • v.25 no.3
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    • pp.274-280
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    • 2020
  • The marine sediment sustains from the anoxic condition due to increased nutrients of external sources. The nutrients are liberated from the sediment, which acts as an internal source. In hypoxic environments, anaerobic respiration results in the formation of several reduced matters, such as N2 and NH4+, N2O, Fe2+, H2S, etc. The experimental results have shown that nitrogen and sulfur played an influential, notable role in this biogeochemical cycle with expected chemical reductions and a 'diffusive' release of present nutrient components trapped in pore water inside sediment toward the bulk water. Nitate/ammonium, sulfate/sulfides, and ferrous/ferric irons are found to be the key players in these sediment-waters mutual interactions. Organonitrogen and nitrate in the sediment were likely to be converted to a form of ammonium. Reductive nitrogen is called dissimilatory nitrate reduction to ammonium and denitrification. The steady accumulation in the sediment and surplus increases in the overlying waters of ammonium strongly support this hypothesis as well as a diffusive action of the involved chemical species. Sulfate would serve as an essential electron acceptor so as to form acid volatile sulfides in present of Fe3+, which ended up as the Fe2+ positively with an aid of the residential microbial community.

Pollution of Polycyclic Aromatic Hydrocarbons (PAHs) in Seawater and Marine Sediments from Anmyundo Coastal Area after Oil Spill (유류사고 이후 안면도 연안 해수 및 퇴적물의 다환방향족탄화수소(PAHs) 오염에 관한 연구)

  • Lee, Wan-Seok;Park, Seung-Yoon;Kim, Pyoung-Joong;Jeon, Sang-Baeck;An, Kyoung-Ho;Choi, Yong-Seok
    • Journal of Environmental Science International
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    • v.19 no.12
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    • pp.1421-1430
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    • 2010
  • Polycyclic aromatic hydrocarbons (PAHs) were investigated in seawater and marine sediment from Anmyundo coastal area after oil spill. The concentrations of total PAHs in surface and bottom of seawater at August were 31.1 to 142.6 ng/L and 5.9 to 50.9 ng/L in August and November, respectively. The concentrations of PAHs in sediment were 21.0 to 102.9 ng/g D.W. and 32.3 to 57.4 ng/g D.W. in August and November, respectively. PAHs concentrations in seawater and sediment in August were higher than those in November about 2.5 and 1.4 times, respectively. Diagnostic ratio (PhA/AnT and FluA/Pyr) were investigated to identify source of PAHs in seawater and sediment. The PAHs in seawater originated from pyrolytic source and those in sediment originated from pyrolytic and petrogenic source. The glass, wood and coal origin was higher than petroleum origin on the combustion origin of PAHs in seawater and sediment. The seawater of Anmyundo costal area recovered from oil spill, but the sediments of that were weakly influenced by oil spill until now. Because this area is developed many fishing grounds, demanded Long Term Environmental Monitoring Program (LTEMP). The concentrations of PAHs on depth of sediments were investigated at station 8 and 10. The concentrations of PAHs were decreased with increasing depth.

Sediment Toxicity of Industrialized Coastal Areas of Korea Using Bioluminescent Marine Bacteria

  • Choi, Min-Kyu;Kim, Seong-Gil;Yoon, Sang-Pil;Jung, Rae-Hong;Moon, Hyo-Bang;Yu, Jun;Choi, Hee-Gu
    • Fisheries and aquatic sciences
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    • v.13 no.3
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    • pp.244-253
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    • 2010
  • The quality of marine sediments from the industrialized coastal areas of Korea (Ulsan Bay, Masan Bay, and artificial Lake Shihwa) was investigated using a bacterial bioluminescence toxicity test. Sediment toxicity results were compared with the levels of chemical contamination (trace metals, organic wastewater markers, acid volatile sulfides, total organic carbon). Effective concentration 50% (EC50) of sediments ranged from 0.014 to 1.126 mg/mL, which is comparable to or lower than values in contaminated lakes, rivers, and marine sediments of other countries. Sediment reference index (SRI) ranged from 13 to 1044, based on the EC50 of the negative control sample. Mean average SRI values in Masan Bay and Lake Shihwa were approximately 8 and 9 times as high as that in Ulsan Bay, indicating higher sediment toxicity and greater contamination in the two former regions. Sediment toxicity were strongly associated with the concentrations of some chemicals, suggesting that this test may be useful for determining potential chemical contamination in sediments.

Consolidation Settlement of Capped Sediment (I): Centrifuge Simulation by Modeling of Models Technique (캡이 설치된 퇴적층의 압밀 침하 (I) : 원심모형시험기를 이용한 모델링 방법)

  • Kim, Tae-Hyung;Hong, Won-Pyo;Moo-Young, Horace-K
    • Journal of the Korean Geotechnical Society
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    • v.19 no.3
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    • pp.33-38
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    • 2003
  • Marine sediment capping is a technique where clean sand is placed over contaminated sediment to reduce the migration of contaminants to the environment. The design of in-situ caps placed over marine sediment must take into consideration the self-weight consolidation of the cap and the consolidation of the sediment as a result of adding the cap layer. Centrifuge tests were adopted to simulate the effects of consolidation settlement of capped marine sediment caused by the placement of a clean sand layer. The modeling of models technique was utilized to verify the correct modeling procedures used in this study. Two centrifuge tests were conducted with the same boundary conditions at different gravitational accelerations of 100 g and 50 g. There was good agreement between these tests. It can be concluded that the centrifuge experiment is able to model consolidation settlement of capped marine sediment.

Community Structure, Diversity, and Vertical Distribution of Archaea Revealed by 16S rRNA Gene Analysis in the Deep Sea Sediment of the Ulleung Basin, East Sea (16S rRNA 유전자 분석방법을 이용한 동해 울릉분지 심해 퇴적물 내 고세균 군집 구조 및 다양성의 수직분포 특성연구)

  • Kim, Bo-Bae;Cho, Hye-Youn;Hyun, Jung-Ho
    • Ocean and Polar Research
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    • v.32 no.3
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    • pp.309-319
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    • 2010
  • To assess community structure and diversity of archaea, a clone sequencing analysis based on an archaeal 16S rRNA gene was conducted at three sediment depths of the continental slope and Ulleung Basin in the East Sea. A total of 311 and 342 clones were sequenced at the slope and basin sites, respectively. Marine Group I, which is known as the ammonia oxidizers, appeared to predominate in the surface sediment of both sites (97.3% at slope, 88.5% at basin). In the anoxic subsurface sediment of the slope and basin, the predominant archaeal group differed noticeably. Marine Benthic Group B dominated in the subsurface sediment of the slope. Marine Benthic Group D and Miscellaneous Crenarchaeotal Group were the second largest archaeal group at 8-9 cm and 18-19 cm depth, respectively. Marine Benthic Group C of Crenarchaeota occupied the highest proportion by accounting for more than 60% of total clones in the subsurface sediments of the basin site. While archaeal groups that use metal oxide as an electron acceptor were relatively more abundant at the basin sites with manganese (Mn) oxide-enriched surface sediment, archaeal groups related to the sulfur cycle were more abundant in the sulfidogenic sediments of the slope. Overall results indicate that archaeal communities in the Ulleung Basin show clear spatial variation with depth and sites according to geochemical properties the sediment. Archaeal communities also seem to play a significant role in the biogeochemical carbon (C), nitrogen (N), sulfur (S), and metal cycles at each site.