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
제18권 제6호 (2009년 6월) 12건
1.
2009.06
서비스 종료(열람 제한)
The effects of the cation-to-anion resin ratio and bed depth on ion exchange performance of mixed-bed were studied at ultralow solution concentration. Breakthrough curves were experimentally obtained for NaCl solution as functions of resin ratio and bed depth. The bed depth affects the pattern of the sodium breakthrough curve but not the chloride breakthrough curve in beds because of the selectivity difference. Resin selectivity determines the shape of breakthrough curves. Some sodium and chloride breakthrough curves crossed at a point as a function of resin ratio. The lower cation-to-anion resin ratio showed the higher effluent concentration or treated volume of the crossover point regardless of the total resin weight.
2.
2009.06
서비스 종료(열람 제한)
Activated sludge sewage treatment processes are difficult to be controlled because of their complex and nonlinear behaviour, however, the control of the dissolved oxygen level in the reactors plays an important role in the operation of the facility. For this reason, this study is designed to present a system which accurately measures DO, MLSS, pH and ORP in the aeration tank to alleviate situations above and provide the automatization of a sewage treatment plant (STP) using new DO control system. The automatic control systems must be guaranteed the accuracy. Therefore, the proposed automatic DO control system in this study could be commercial applications in the aeration tanks by means of operating cost analysis and user-friendly for operation and maintenance. We could get accurate data from the lab tank which has water quality checker because there was no vortex and air bubble during the measurement process. Improvement of confidence in the lab tank enabled effective and automatic operation of sewage treatment plants so that operation costs and manpower could be saved. If this result is put in place in every sewage treatment plant nationwide for practical purposes, it is estimated to cost 18.5 million dollars in installing the lab tank and to save 9.8 million dollars in management cost a year, except for cost saved by automation.
3.
2009.06
서비스 종료(열람 제한)
SWAT-K model is a modified version of the original SWAT, and is known to more accurately estimate the streamflows and pollutant loadings in Korean watersheds. In this study, its hydrological components were compared with those of HSPF in order to analyse the differences in total runoff including evapotranspiration(ET), surface flow, lateral flow and groundwater flow from the Chungju Dam watershed during 2000~2006. Averaged annual runoff with SWAT-K overestimated by 1%, and HSPF underestimated it by 3% than observed runoff. Determination coefficients(R2) for observed and simulated daily streamflows by both the models were relatively good(0.80 by SWAT-K and 0.82 by HSPF). Potential ET and actual ET by HSPF were lower in winter, but similar or higher than those by SWAT-K. And though there were some differences in lateral and groundwater flows by two models because of the differences in hydrological algorithms, the results were to be reasonable. From the results, it was suggested that we should utilize a proper model considering the characteristics of study area and purposes of the model application because the simulated results from same input data could be different with models used. Also we should develop a novel model appropriate to Korean watersheds by enhancing limitations of the existing models in the future.
4.
2009.06
서비스 종료(열람 제한)
Rare earth contents(REE) were analysed for the plants, M. sinensis, A. vulgaris and R. crataegitolius, from two different soils serpentine area consisting of serpentinite(SP) and non-serpentine area, containing amphibole schist(AS) of Gapyeong area, and were compared with soils and host rocks. The AS were high with the differences of several times in the top soils, and with the differences of several to ten times in the host rocks relative to the SP. In the same area, the SP were high in the soil, but the rocks for the AS. In the plants, the A. vulgaris were high, but low in the R. crataegitolius. Root parts were higher than the upper parts. Differences between the upper and root parts were big in the SP rather than the AS, and were big in the R. crataegitolius, but small in the M. sinensis. Among the parts of the plants, high elements were shown in the R. crataegitolius of the SP, and the A. vulgaris and M. sinensis of the AS. In the correlation coefficients, most of the REE showed positive relationships among the element pairs, especially high positive correlation coefficients in the upper parts of the SP. Differences of the soils and plants(average) were smalle in the M. sinensis and big in the R. crataegitolius. In the upper parts. contents of the A. vulgaris were close to the soils while the R. crataegitolius showed large discrepancies with the soils. In the root parts, contents of the A. vulgaris showed discrepancies with the soils regardless of soil types, but close in the R. crataegitolius of the SP and M. sinensis of the AS.
5.
2009.06
서비스 종료(열람 제한)
The vascular plants in the Gyeryongsan National Park were listed 227 taxa; 71 families, 148 genera, 196 species, 1 subspecies, 26 varieties and 4 forms. Among them, trees and herbs were 103 taxa (45.4%), 124 taxa (54.6%), respectively. The rare plants were identified 6 taxa such as Paeonia obovata (Legal protection species), Viola albida, Acanthopanax chiisanensis, Lilium distichum, Lilium callosum and Goodyera schlechtendaliana by the Korea Forest Service. Based on the list of Korean endemic plants, 8 taxa were recorded; Cephalotaxus koreana, Pseudostellaria multiflora, Thalictrum uchiyamai, Indigofera koreana, Acanthopanax chiisanensis, Asperula lasiantha, Weigela subsessilis and Carex okamotoi. Based on the list of approved for delivering overseas of plants, 6 taxa were recorded; Viola albida, Acanthopanax chiisanensis, Asperula lasiantha, Carex okamotoi, Lilium distichum and Lilium callosum. Specific plant species by floral region were total 21 taxa (9.3%); Paeonia obovata in class Ⅴ, 5 taxa (Betula davurica, Acer palmatum, Asperula lasiantha, Lonicera subhispida, Phaenosperma globosa) in class Ⅲ, 4 taxa (Viola orientalis, Acanthopanax chiisanensis, Ostericum melanotilingia, Lilium distichum) in class Ⅱ and 11 taxa (Cephalotaxus koreana, Betula schmidtii, Quercus variabilis, Aphananthe aspera, Ilex macropoda, Meliosma oldhamii, Tilia amurensis, Lilium callosum, Erythronium japonicum, Polygonatum inflatum, Hosta capitata) in class Ⅰ. It is important that relationship between national and local government will be needed for preservation of natural environment of Gyeryongsan National Park. As well, a long time of monitering and systematical management counterplan will be required.
6.
2009.06
서비스 종료(열람 제한)
Lab-scale Electrodialysis(ED) system with different membranes combined with before or after pyroma process were carried out to remove nitrate from two pickling acid wastewater containing high concentrations of NO3-(≈150,000 mg/L) and F-(≈160,000 mg/L) and some heavy metals(Fe, Ti, and Cr). The ED system before Pyroma process(Sample A) was not successful in NO3- removal due to cation membrane fouling by the heavy metals, whereas, in the ED system after Pyroma process(Sample B), about 98% of nitrate was removed because of relatively low NO3- concentration (about 30,000 mg/L) and no heavy metals. Mono-selective membranes(CIMS/ACS) in ED system have no selectivity for nitrate compared to divalent-selective membranes(CMX/AMX). The operation time for nitrate removal time decreased with increasing the applied voltage from 10V to 15V with no difference in the nitrate removal rate between both voltages. Nitrate adsorption of a strong-base anion exchange resin of Cl- type was also conducted. The Freundlich model(R2 > 0.996) was fitted better than Langmuir model(R2 > 0.984) to the adsorption data. The maximum adsorption capacity (Q0) was 492 mg/g for Sample A and 111 mg/g for Sample B due to the difference in initial nitrate concentrations between the two wastewater samples. In the regeneration of ion exchange resins, the nitrate removal rate in the pickling acid wastewater decreased as the adsorption step was repeated because certain amount of adsorbed NO3- remained in the resins in spite of several desorption steps for regeneration. In conclusion, the optimum system configuration to treat pickling acid wastewater from stainless-steel industry is the multi-processes of the Pyroma-Electrodialysis-Ion exchange.
7.
2009.06
서비스 종료(열람 제한)
This study aims to identify the impacts of air quality in the Korean Peninsula according to the China's environmental policies in preparation of the Beijing 2008 Olympic Games. The measurement of emission variations in China, aircraft measurement, and modelling were carried out. The reduction measures in Beijing, China and its emission changes resulted in 30~65% in decrease out of the total emissions within the Beijing region, whereas when it comes to the whole nation of China, the reduction rate was about 4~9%. Comparing the concentration of the air pollutants in Seoul and Ganghwa in August 2008 during around the period of Beijing Olympic Games with one in 2004~2007 showed that the SO2 concentrations in the past was above 5ppb, while the concentration in the 2008 olympic period was 4ppb and below. The NOx at the Seokmori site in Ganghwa tended to be lower in concentration in 2008 than in between 2004~2007. As for O3 and PM2.5, the concentration tended to be rather low since August 11. The air current track that showed during the period of aircraft measurement presented to be flowed into Korea through the Northeast part of China and the coast of Bohai Bay, while the concentrations of SO2, NOx, and O3 over the west sea on August 20 and 24 were 0.54 (0.28ppb), 0.86 (1.84ppb), and 54.0 (41.5ppb) respectively, similar or lower than the ones measured in the past in the similar current patterns. The modelling result showed similar patterns to the data of aircraft measurement, in particular in SO2. Overall, the reduction measures in Beijing, China affected directly and indirectly the air quality in the Korean peninsular, but the impact was not significant as it was momentary and limited to the intended area.
8.
2009.06
서비스 종료(열람 제한)
This study has carried out to evaluate the effect of NaCl as electrolyte of single (electrolysis and UV process) and complex (electrolysis/UV) processes for the purpose of removal and mineralization of Rhodamine B (RhB) dye in water. It also evaluated the synergetic effect on the combination of electrolysis and UV process. The experimental results showed that RhB removal of UV process was decreased with increase of NaCl, while RhB removal of electrolysis and electrolysis/UV process was increased with increase of NaCl. The decolorization rate of the RhB solution in every process was more rapid than the mineralization rate identified by COD removal. The latter took longer time for further oxidation. Absorption spectra of an aqueous solution containing RhB showed a continued diminution of the RhB concentration in the bulk solution: concomitantly, no new absorption peaks appeared. This confirmed the decolorization of RhB, i.e., the breakup of the chromophores. It was observed that RhB removal in electrolysis/UV process is similar to the sum of the UV and electrolysis. However, it was found that the COD of RhB could be degraded more efficiently by the electrolysis/UV process than the sum of the two individual process. A synergetic effect was demonstrated in electrolysis/UV process.
9.
2009.06
서비스 종료(열람 제한)
Sludge minimization from wastewater treatment plant is becoming more important to save disposal costs and to contribute to sustainable development. For the reduction of sludge production, solubilization and dewaterability of sludge are important factors in sludge processing. Ultrasonic treatment has been used to enhance sludge solubility and dewaterability with anaerobic digestion sludge, primary sludge, and activated sludge. At the ultrasonic power of 0.2 kW/L for 1 hour, anaerobic sludge and activated sludge showed higher solubilization efficiency than the primary sludge in terms of COD, proteins, and suspended solids. Ultrasonic treatment decreased sludge dewaterability and sludge settling characteristics up to 720 kJ/L of ultrasonic energy. In conclusion, ultrasonic treatment was effective for sludge solubilization but it deteriorate dewaterability (specific resistance) and settling characteristics (SVI) of sludge at the experimental conditions.
10.
2009.06
서비스 종료(열람 제한)
The water quality of reservoir can be controled by water quality prediction model because it can not only grasping the present water state but also predicting the water quality in future. In this study, WASP model is used to predict the water quality of Chungju reguration reservoir. This model has some special option which predicts the pollutant outflow phenomenon caused by the contamination sources. So this model is widely used because that can present the scientific basis in this field. This model can help the managers make the right choice of water quality policy. Environmental grade of Chungju reguration reservoir is in Ⅲ,Ⅳgrade which is in bad condition comparatively. The water contamination will be in poor as the year passes. When considering T-N, T-P which are the nutrient to control eutrophication, the concentrated administration about contamination sources is in urgent.
11.
2009.06
서비스 종료(열람 제한)
Trickling filter has been extensively studied for the domestic wastewater treatment especially for the small scale plants in rural area. The performance of the trickling filter depends on the microbial community and their activity in the biofilms on the media. Nitrification, denitrification, and phosphorus removal of the trickling filter from the wastewater depend on the activity and the amount of the specific microorganisms responsible for the metabolism. For the estimation of the performance of a trickling filter, batch nitrification experiment and fluorescence in situ hybridization (FISH) were carried out to measure the microbial activity and its distribution on the media of the trickling filter. Batch nitrification activity measurement showed that the top part of the 1st stage trickling filter had the highest nitrification activity and the maximum activity was 0.002 g NH4-N/g MLVSS․h. It is thought that higher substrate (ammonia) concentration yields more nitrifying bacteria in the biofilms. The dominant ammonia oxidizer and nitrite oxidizer in the biofilm were Nitrosomonas species and genus Nitrospira, respectively, by FISH analysis. Less denitrifiers were found than nitrifiers in the biofilm by the probe Rrp1088 which specifically binds to Rhodobacter, Rhodovulum, Roseobacter, and Paracoccus. Phosphorus accumulating bacteria were mostly found at the surface of the biofilm by probe Rc988 and PAO651 which specifically binds to Rhodocyclus group and their biomass was less than that of nitrifiers.
12.
2009.06
서비스 종료(열람 제한)
This research was composed over a period of 10 times and was performed to be conducted in an environmental education class for 4 months from September to December of 2008 by selecting 32 experimental group students and 32 control group students from OO Middle School in the Busan area. An environmental education program utilizing IIM(independent investigation method) was composed by selecting a theme for environmental education among the environmental curriculum in middle schools. The results of analyzing the effects which influence environmental sensitivity and environment-friendly behaviors after applying the environmental education program utilizing IIM are as follows. First, it was revealed that the environmental education program utilizing IIM is more effective among experimental group students than control group students in regards to environment-friendly sensitivity. Second, it was revealed that the environmental education program utilizing IIM is more effective among experimental group students than control group students in regards to environment-friendly behaviors. Third, it was seen that even students responded very favorably toward environmental education program utilizing IIM.
