간행물
한국환경과학회지 KCI 등재 Journal of Environmental Science International
- 발행기관 한국환경과학회
- 자료유형 학술지
- 간기 월간
- ISSN 1225-4517 (Print)2287-3503 (Online)
- 수록기간 1992 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제22권 제8호 (2013년 8월) 13건
ORIGINAL ARTICLE
1.
2013.08
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In this study, a comprehensive field monitoring was conducted to understand habitat conditions of fish species in up and downstream of Hoengseong Dam. Based on the monitoring data, riverine health conditions such as composition ratio of fish species, bio-diversity (dominance index, diversity, evenness and richness), index of biological integrity (IBI) and qualitative habitat evaluation index (QHEI) were assessed, and optimal ecological flowrates (OEF) were estimated using the habitat suitability indexes (HSI) established for three fish species Coreoleuciscus splendidus, Pungtungia herzi and Microphysogobio longidorsalis selected as icon species using the physical habitat simulation system (PHABSIM). The total number of species sampled was 20 species, and two species of Zacco platypus (30.4%) and C. splendidus (20.9%) dominated the fish community. As a result, it was revealed that IBI and QHEI values decreased from upstream to downstream along the river. The estimated IBI value ranged from 24 to 36 with average being 30.9 out of 50, rendering the site ecologically fair to good health conditions. HSI for C. splendidus were determined according to three different month in terms of season: Spring (April), Summer (August) and Autumn (October). HSI for flow velocity were estimated at 0.7 to 0.8 m/s for the Spring, 0.5 to 1.0 m/s for the Summer and 0.8 to 0.9 m/s for the Autumn. HSI for water depth were estimated at 0.3 to 0.5 m for the Spring; 0.3 to 0.5 m for the Summer; and 0.3 to 0.4 m for the Autumn. OEF was estimated at 4.2 and 6.5 m3/s for the Spring and Autumn, and 12.0 m3/s for the Summer. Overall, it was concluded that the Hoengseong Dam has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.
2.
2013.08
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Ozone concentrations in water and air, and resulting disinfective properties, were measured following generation by either an ozone generator or a low-temperature dielectric barrier discharge plasma generator. In freshwater, ozone concentrations of 0.81 and 0.48 mg/L O3 were observed after the ozone and plasma generators had been operated for five minutes, respectively. Higher levels of dissolved O3 were attained more easily with the ozone generator. In seawater, both systems were capable of creating concentrations greater than 3.00 mg/L O3 after 5minutes of operation. Higher ozone levels were attained more easily in seawater than in freshwater. Rates of bacterial sterilization in seawater after three minutes were 96% and 88%, using the plasma and ozone generators, respectively. In freshwater, higher concentrations of ozone were released into the atmosphere by the ozone generator than by the plasma generator. In creating equivalent levels of dissolved ozone in freshwater, the plasma generator released 4.5 times more ozone into the atmosphere than did the ozone generator. This shows that ozone generators are more effective than plasma generators for creating ozonated water. For the same concentration of dissolved ozone in seawater, more ozone was released into the atmosphere using the ozone generator than using the plasma generator. Therefore, with regard to air pollution, plasma generators seem to be less expensive than ozone generators.
3.
2013.08
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Alumina-supported catalysts containing different transition metals such as Cu, Cr, Mn, Zn, Co, W were investigated for their activity in the selective oxidation of toluene. Catalytic oxidation of toluene was investigated at atmospheric pressure in a fixed bed flow reactor system over transition metals with Al2O3 catalyst. The result showed the order of catalytic activities for the complete oxidation of toluene was Mn > Cu> Cr> Co> W> Zn for 5wt.% transition metals/Al2O3. Mn/Al2O3 catalysts containing different amount of Mn were characterized by X-ray diffraction spectroscopy for decision of loading amount of metal to alumina. 5 wt.%Mn/Al2O3 catalyst exhibits the highest catalytic activity, over which the toluene conversion was up to 90% at a temperature of 289℃.
4.
2013.08
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Reliable long-term streamflow forecasting is invaluable for water resource planning and management which allocates water supply according to the demand of water users. Forecasting of seasonal inflow to Andong dam is performed and assessed using statistical methods based on hydrometeorological data. Predictors which is used to forecast seasonal inflow to Andong dam are selected from southern oscillation index, sea surface temperature, and 500 hPa geopotential height data in northern hemisphere. Predictors are selected by the following procedure. Primary predictors sets are obtained, and then final predictors are determined from the sets. The primary predictor sets for each season are identified using cross correlation and mutual information. The final predictors are identified using partial cross correlation and partial mutual information. In each season, there are three selected predictors. The values are determined using bootstrapping technique considering a specific significance level for predictor selection. Seasonal inflow forecasting is performed by multiple linear regression analysis using the selected predictors for each season, and the results of forecast using cross validation are assessed. Multiple linear regression analysis is performed using SAS. The results of multiple linear regression analysis are assessed by mean squared error and mean absolute error. And contingency table is established and assessed by Heidke skill score. The assessment reveals that the forecasts by multiple linear regression analysis are better than the reference forecasts.
5.
2013.08
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Reliable long-term streamflow forecasting is invaluable for water resource planning and management which allocates water supply according to the demand of water users. It is necessary to get probabilistic forecasts to establish risk-based reservoir operation policies. Probabilistic forecasts may be useful for the users who assess and manage risks according to decision-making responding forecasting results. Probabilistic forecasting of seasonal inflow to Andong dam is performed and assessed using selected predictors from sea surface temperature and 500 hPa geopotential height data. Categorical probability forecast by Piechota's method and logistic regression analysis, and probability forecast by conditional probability density function are used to forecast seasonal inflow. Kernel density function is used in categorical probability forecast by Piechota's method and probability forecast by conditional probability density function. The results of categorical probability forecasts are assessed by Brier skill score. The assessment reveals that the categorical probability forecasts are better than the reference forecasts. The results of forecasts using conditional probability density function are assessed by qualitative approach and transformed categorical probability forecasts. The assessment of the forecasts which are transformed to categorical probability forecasts shows that the results of the forecasts by conditional probability density function are much better than those of the forecasts by Piechota's method and logistic regression analysis except for winter season data.
6.
2013.08
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This study aims at classifying and interpreting on the vegetation structure, the correlation between a vegetation and an environment, a species diversity and a life-form of Evergreen Broad-Leaved Forest(EBLF) located in Gageo-do Island. It is also the objective that the estimation of vegetation change founded on the species composition and characteristics. The vegetation of EBLF was classified into three forests or four community units as Machilus thunbergii forest (Polystichum polyblepharon-M. thunbergii community and Phaenosperma globosum-M. thunbergii community), Ilex integra-Castanopsis sieboldii community, Quercus acuta community and Neolitsea sericea stand. The ordination analysis by DCA is analogous with the vegetation structure analysis. As a result of the correlation (Pearson's correlation coefficient) with environmental conditions, the Altitude has the significance with the distribution of communities. The total vegetation change by progress of succession will not be wandered away from the present vegetation structure practically, and the vegetation on the underlayers will be a little changed.
7.
2013.08
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Electrochemical degradation of phenol was evaluated at DSA (dimensionally stable anode), JP202 (Ru, 25%; Ir, 25%; other, 50%) electrode for being a treatment method in non-biodegradable organic compounds such as phenol. Experiments were conducted to examine the effects of applied current (1.0~4.0 A), electrolyte type (NaCl, KCl, Na2SO4, H2SO4) and concentration (0.5~3.0 g/L), initial phenol concentration (12.5~100.0 mg/L) on phenol degradation and UV254 absorbance as indirect indicator of by-product degraded phenol. It was found that phenol concentration decreased from around 50 mg/L to zero after 10 min of electrolysis with 2.5 g/L NaCl as supporting electrolyte at the current of 3.5 A. Although phenol could be completely electrochemical degraded by JP202 anode, the degradation of phenol COD was required oxidation time over 60 min due to the generation of by-products. UV254 absorbance can see the impact of as an indirect indicator of the creation and destruction of by-product. The initial removal rate of phenol is 5.63 times faster than the initial COD removal rate.
8.
2013.08
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Perfluorooctanoic acid (PFOA) and perfluorooctyl sulfonate (PFOS) is a new persistent organic pollutants of substantial environmental concern. This study investigated the potential of magnetic ion exchange resin (MIEXⓇ) as the adsorbent for the removal of PFOA and PFOS from Nakdong River water. In our batch experiments, we studied the effect of some parameters (pH, temperature, sulfate concentration) on the removal of PFOA and PFOS. The results of sorption kinetics on MIEXⓇ show that it takes 90 min to reach equilibrium but the economical contact time and dosage were 30 min and 10 mL/L. An increase in pH (pH 6∼10) leads to a decrease in PFOA (2.0%) and PFOS (3.6%) sorption on MIEXⓇ. The sorption of both PFOA and PFOS decreases with an increase in ionic strength for sulfate ion (SO4 2-), due to the competition phenomenon. An increase in water temperature (8℃∼28℃) in water leads to a increase in PFOA (2.8%) and PFOS (4.3%) sorption on MIEXⓇ. Based on the sorption behaviors and characteristics of the adsorbents and adsorbates, ion exchange and hydrophobic interaction were deduced to be involved in the sorption, and hemi-micelles possibly formed in the intraparticle pores.
9.
2013.08
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Sulfur hexa-fluoride has been used as a etching gas in semiconductor industry. From the globally environmental issues, it is urgent to control the emissions of this significant greenhouse gas. The main objective of this experimental investigation was to find the effective catalyst for SF6 decomposition. The precursor catalyst of hexa-aluminate was prepared to investigate the catalytic activity and stability. The precursor catalyst of hexa-aluminate was modified with Ni to enhance the catalytic activities and stability. The catalytic activity for SF6 decomposition increased by the addition of Ni and maximized at 6wt% addition of Ni. The addition of 6wt% Ni in precursor catalyst of hexa-aluminate improved the resistant to the HF and reduced the crystallization and phase transition of catalyst.
10.
2013.08
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In this study, eight episode days of high-concentration PM10 occurrences in the Gimhae region between 2006 and 2011 were analyzed. Most of them appeared in winter and the highest concentration was observed around 12 LST. Furthermore, the wind direction, wind velocity, and temperature elements were compared with observed values to verify the WRF numerical simulation results used in this study, and they simulated well in accordance with the trend of the observed values. The wind was generally weak in the high-concentration episode days that were chosen through surface weather chart and the numerical simulation results for wind field, and the air pollutants were congested due to the effects of the resulting local winds, thereby causing a high concentration of air pollutants. Furthermore, the HYSPLIT model was performed with the WRF numerical simulation results as input data. As a result, they originated from China and flowed into Gimhae in all eight days, and the lowest concentration appeared on the days when recirculation occurred.
11.
2013.08
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This study was conducted to investigate the correlations between the PM10 concentration trend and meteorological elements in the Gimhae region and analyze the transportation routes of air pollutants through back-trajectory analysis. Among the air quality measuring stations in the Gimhae regions, the PM10 concentration of the Sambangdong station was higher than that of the Dongsangdong station. Also, an examination of the relationships between PM10 concentration and meteorological elements showed that the greater the number of yellow dust occurrence days was and the lower the temperature and precipitation were, the higher the PM10 concentration appeared. Furthermore, a cluster analysis through the HYSPLIT model showed that there were 4 clusters of trajectories that flowed into the Gimhae region and most of them originated in China. The meteorological characteristics of the four clusters were analyzed and they were similar to those of the air masses that influence South Korea. These analyses found that meteorological conditions affect the PM10 concentration.
12.
2013.08
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The shortwave aerosol direct radiative forcing (SWARF) was analyzed using the Clouds and Earth’s Radiant Energy System (CERES) data in the East Asian region from 2001 to 2010. In the Yellow Sea and the Korean Peninsula, located in the leeward side of China, significantly negative high SWARF at the top of atmosphere (TOA) occurs due to the long-range transport of anthropogenic (e.g. sulphate) and natural aerosols (e.g. mineral dust) from the East Asian continent. Conversely, eastern China has much higher levels of SWARF at the surface (SFC) due to anthropogenically emitted aerosol than in the Yellow Sea and the Korean Peninsula. Since the radiative forcing of aerosols in the atmosphere are different in type, aerosol types were classified into sea salt+sulphate, smoke, sulphate and dust by using satellite data. The analysis on the SWARF by the classified aerosol types indicated that sulphate occupies a predominant portion of the atmosphere in the Yellow Sea and the Korean Peninsula in the summer. In particular, the annual averages of the summer TOA SWARF increased in the Yellow Sea and the Korean Peninsula from 2001 to 2010.
13.
2013.08
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To overcome the ecosystem-crisis of resource depletion and climate change, we should maintain and develop a 'Sustainability' of our society.
'After-market' is defined like this : any market where customers who buy one product or service are likely to buy a related follow-on product. This is related to a automotive, electric and electronic, and remanufacturing industry.
'After-market' will be helpful for reuse and recycling of resources aspects, cost and economic efficiency, low-carbon, climate protection, and new industries and job creation effects,
To promote 'After-Market', we need to guarantee the quality of products. In this regard, we refer and introduce a new standard, for example, BS8887, PAS141 and ISO20245 etc.
In order to promote 'After-Market', first of all, product quality assurance and safety must be demonstrated in the process of reuse. Second, many aspects of a device that protects the rights of consumers to be provided. And third, the related laws and standards should be reviewed. Finally, original manufacturer's awareness for environmental protection and resource conservation and government's institutional support are needed.
