• 수산해양기술연구
• /
• 제51권2호
• /
• pp.155-162
• /
• 2015

Abalone (Haliotis discus hannai) is a shellfish that feeds on kelp and, as a product, it can often achieve a high market value. However, the dissolved oxygen (DO) levels in coastal waters in Korea have been negatively impacted by pollution from many anthropogenic sources. Herein, a computational fluid dynamics (CFD) software package was used to analyze the distribution of the DO concentration within an abalone containment structure. A finite volume approach was used to solve the Reynolds-averaged Navier-Stokes equations combined with a $k-{\varepsilon}$ turbulence model to describe the flow. The distribution of DO was determined within the control volume domain, and the transport equations of the pollutants were interpreted using a CFD model. The CFD analysis revealed that more than 60% and 30% of the relative oxygen concentration in one and two containers, respectively, was maintained when the flow acts along the six sheets of polyethylene plates. Therefore, it is clear that the abalone plate shelters should be placed parallel to the flow.

• Journal of Korean Society for Atmospheric Environment
• /
• 제19권E2호
• /
• pp.63-73
• /
• 2003

The atmospheric pollution distribution in the industrial area of Yosu in Korea is calculated using numerical model and the model is validated by comparing the calculations with observed data. The emission of NO$_{x}$ and SO$_{x}$ was estimated for 6 sources, and the emission amount of HC was estimated for 9 anthropogenic sources. The calculated wind speed, wind direction and temperature agreed well with the observed data at two observatories, and the calculated concentration of NO, NO$_2$, $O_3$ and SO$_2$ were also reasonable for 5 monitoring stations. The validity of the model is evaluated using 3 indexes of the EPA, and the model is found to be valid and accurate.ate.

• Environmental Engineering Research
• /
• 제21권1호
• /
• pp.52-57
• /
• 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.

• Advances in environmental research
• /
• 제6권1호
• /
• pp.53-65
• /
• 2017

Assessment of seasonal changes in surface water quality is an important aspect for evaluating temporal variations of river pollution due to natural or anthropogenic inputs of point and non-point sources. In this study, surface water quality data for 15 physico-chemical parameters collected from 7 monitoring stations in a river during the years from 2014 to 2016 were analyzed. The principal component analysis technique was employed to evaluate the seasonal correlations of water quality parameters, while the principal factor analysis technique was used to extract the parameters that are most important in assessing seasonal variations of river water quality. Analysis shows that a parameter that is most important in contributing to water quality variation for one season may not be important for another season except alkalinity, which is always the most important parameters in contributing to water quality variations for all three seasons.

• 한국해양환경ㆍ에너지학회지
• /
• 제18권4호
• /
• pp.245-253
• /
• 2015

완전산분해법과 단일시약(1 M HCl) 추출법을 이용하여 울산-온산연안 표층퇴적물 내 미량금속의 오염도 및 생태위해성을 평가하였다. 표층퇴적물 내 미량금속 중 Cu, Cd, Pb, Zn, Hg의 농도는 울산연안에 비해 온산연안에서 2배 이상 높게 나타났다. 단일시약 추출 분석 결과, Cd과 Pb은 총함량 중 가용성부분의 평균 함량이 각각 72%, 78%로 인위적 기원에 의해서 주로 공급되는 것으로 나타난 반면, Cr, Li, Ni, As는 잔류성부분에서 평균 80% 이상 존재하여 주로 자연적 기원의 영향을 받는 것으로 나타났다. 국내 해저퇴적물 해양환경기준과 비교한 결과, Cu, Pb, Zn, Hg의 총농도는 온산연안 일부 정점에서 관리기준을 초과하였으며, Cr, Ni은 모든 정점에서 주의기준 이하였다. 미량금속의 오염도 및 생태위해성을 다양한 지수(EF, $I_{geo}$, m-PEL-Q, ERI)로 평가한 결과, 울산-온산연안에서 미량금속 중 Cu, Cd, Pb, Zn, Hg의 오염도가 높았으며, 생태계에 잠재적 위해성은 Cd과 Hg이 가장 큰 것으로 나타났다.

• Journal of Ecology and Environment
• /
• 제35권4호
• /
• pp.279-289
• /
• 2012

This study conducted a comparative analysis of benthic macroinvertebrate communities in the Fosu and Benya lagoons in Ghana, based on the anthropogenic effect on the two lagoons. Salinity, oxygen, temperature, conductivity, turbidity and pH were measured, invertebrate richness and species densities were determined. The AZTI Marine Biotic Index (AMBI) and multivariate statistics were used to determine the different responses of fauna to pollution. The fauna were categorized into five ecological groups based on the degree of tolerance of the different species to pollution: disturbance-sensitive species; disturbance-indifferent species, disturbance-tolerant species, second-order opportunistic species; and first-order opportunistic species. The Fosu Lagoon supported more pollution tolerant species, whereas the Benya Lagoon had more species that were sensitive to organic enrichment under relatively unpolluted conditions. Chironomus sp., which is adapted to virtually anoxic conditions, was the most abundant in the Fosu Lagoon whereas Nemertea sp. was the most abundant in the Benya Lagoon. The numerical and relative abundance (%) of all 7 taxa in the Fosu Lagoon was 1,359 and 92.35%, respectively. The numerical and relative abundance (%) of all 34 taxa in the Benya Lagoon was 2,459 and 87.52%, respectively. Expectedly, the level of dissolved oxygen in the less saline Fosu Lagoon was higher than that in the more saline Benya Lagoon. The reduced photoperiod and photosynthetic activities of aquatic plants might account for this trend. There is a need to implement comprehensive monitoring and management initiatives for sustaining the ecological health of coastal lagoons in Ghana in order to support the many people that depend upon these ecosystems for their livelihood.

• 한국수산과학회지
• /
• 제50권6호
• /
• pp.777-787
• /
• 2017

Organic enrichment and pollution was investigated in surface sediments from Jinhae Bay and Geoje-Hansan Bay of Korea, which contain the largest oyster farms in Korean coastal areas. Geochemical indicators (chemical oxygen demand, total organic carbon, ignition loss, and acid volatile sulfide) in sediments, ammonium and nitrate in pore water, and bioluminescence inhibition test for sediment extracts were analyzed. Temporal changes of organic enrichment were also investigated using sediment core samples from Geoje-Hansan Bay. The level of organic pollution in sediments from Jinhae Bay was significantly greater than that of sediments from Geoje-Hansan Bay. Compared with other sites, Jinhae Bay was one of the most polluted coastal areas of Korea. The levels of geochemical indicators in May were comparable to, or higher than, in August. Ammonium concentrations in pore water were two orders of magnitudes greater than the nitrate concentrations, suggesting that the bays are reducing environments. The concentrations of total organic carbon in core sediment samples from shellfish-farming areas increased significantly from 2000 to the present year, and it seems to be associated with increases in anthropogenic activities.

• 한국대기환경학회지
• /
• 제19권3호
• /
• pp.263-273
• /
• 2003

P $M_{2.5}$ fine particles have been collected at the Cosan measurement station in Jeju Island, and the major water-soluble components have been analyzed in order to Investigate the aerosol compositions and pollution characteristics. The mean concentrations of the components were in the order of S $O_4$$^{2-}$> N $H_4$$^{+}$> N $O_3$$^{[-10]}$ > N $a^{+}$> $K^{+}$>C $l^{[-10]}$ >C $a^2$$^{+}$>M $g^2$$^{+}$. The major components were S $O_4$$^{2-}$, N $H_4$$^{+}$ and N $O_3$$^{[-10]}$ , whose compositions were 58％, 18％ and 10％ of the total ions, respectively. Most of the components showed higher concentrations in spring season, and especially $Ca^2$$^{+}$, N $O_3$$^{[-10]}$ and S $O_4$$^{2-}$ concentrations were increased 2.8, 1.9 and 1.2 times higher than the annual mean concentrations. The most parts of S $O_4$$^{2-}$ and N $H_4$$^{+}$ were distributed in fine particles below 2.1 ${\mu}{\textrm}{m}$ size, but the $Ca^2$$^{+}$, N $a^{+}$ and C $l^{[-10]}$ showed relatively higher concentrations in coarse particles. Based on the factor analysis, the P $M_{2.5}$ fine particles were considered to be largely influenced by anthropogenic sources, and followed by sea salt and soil sources. In the variations of concentrations as a function of wind direction, most components have shown higher concentrations notably as the northwesterly prevails.thwesterly prevails.

• 한국수산과학회지
• /
• 제44권6호
• /
• pp.759-771
• /
• 2011

We evaluated the pollution levels of organic matter and metallic element (Fe, Cu, Pb, Zn, Cd, Ni, Cr, Mn, As, and Hg) in the intertidal surface sediments of Aphae Island using several sediment quality guidelines (SQGs) and assessment techniques for sediment pollution. Based on the textural composition of sediment, the surface sediments were classified into two main sedimentary facies: slightly gravelly mud and silt. The concentrations of chemical oxygen demand (COD) and acid volatile sulfide (AVS) in the sediments ranged from 4.6-9.9 (mean $7.4{\pm}1.1$) $mgO_2/g{\cdot}dry$ and from ND-0.53 (mean $0.04{\pm}0.10$) mgS/$g{\cdot}dry$, respectively. These values were considerably lower than those reported from a farming area in a semi-enclosed bay of Korea and for SQGs in Japan. The metallic element concentrations in the sediments varied widely with the mean grain size and organic matter content, implying that the concentrations of metallic elements are influenced mainly by secondary factors, such as bioturbation, the resuspension of sediment, and anthropogenic input. The overall results for the comparison with SQGs, enrichment factor (EF), and geoaccumulation index ($I_{geo}$) indicate that the surface sediments are slightly polluted by Cr and Ni, and moderately polluted by As. Our results suggest that the intertidal surface sediments of Aphae Island are not polluted by organic matter or metallic elements and the benthic conditions are suitable for healthy organisms.

• 한국환경보건학회지
• /
• 제41권4호
• /
• pp.259-267
• /
• 2015

Objectives: This study evaluated the regional and seasonal concentrations of ambient hazardous heavy metals in an industrial complex area in Daegu City. Methods: A total of 64 SPM (Suspended Particulate Matter) samples were collected in non-industrial and industrial areas during 2014 and were analyzed for hazardous heavy metals elements (As, Cd, Mn, Ni, Pb) with ICP after acid extraction. Results: SPM and hazardous heavy metals concentrations showed regional (industrial complex area>non-industrial complex area) and seasonal (spring, winter>fall, summer) variations. All of the hazardous heavy metals were influenced by anthropogenic sources. The pollution index of hazardous heavy metals was very low, showing roughly one-quarter of the level of the air quality guidelines of WHO. The correlation analysis among SPM and hazardous heavy metals indicated that components of non-industrial complex areas were more related to each other than those of industrial complex areas, and the correlation in the winter was higher than in other seasons. Conclusion: It is necessary to control air pollution sources and establish related policy because hazardous heavy metals from industrial areas can influence residential areas.