• Journal of the Korean Ceramic Society
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• v.49 no.2
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• pp.151-154
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• 2012

Flower-like and plate-like CuO nanopowder has been successfully synthesized using a facile microwave-assisted synthetic route. The morphology and size of the final products strongly depended on microwave power. The phase, structures and morphologies of the as-prepared products were investigated in detail by BET surface area analysis, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). In addition, the chemical oxygen demand of polluted lake water was employed for characterization of these new photocatalysts. The results showed correlations between the morphology of CuO micro-crystals and their catalytic properties.

• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.50-55
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• 2001

Different polluted water samples were collected from a wastewater treatment plant, agricultural drainage canals, the River Nile, and irrigation canals. The samples were examined for the enumeration of Pseudomonas aeruginosa in the Sohag area, Egypt over a period of one year. A total of 240 isolates were collected and tested for their resistance to 12 common antibiotics and 6 heavy metals. The isolates were found to be less resistant to norfloxacin(1.7%), ofloxacin(4.6%), amikacin(9.6%), tobramycin (10.4), carbenicillin (15.4), and gentamycin (41.3%), yet more sensitive to rifampicin (75%), kanamycin (89.6%), ampicillin (90.8%), chloramphenicol (91.7%), streptomycin (92.9%), and tetracyclin(96.3%). In contrast, 7.1%, 12.9%, 25.4%, and 53.7% of the isolates were resistant to lead, cadmium, mercury, and zinc, respectively. None of the isolates had developed a resistance to silver or molybdenum. The high frequency of metal-antibiotic double resistance existed between lead and amikacin (56.5%), cadmium and ofloxacin (72.7%), zinc and norfloxacin (100%), and mercury and carbenicillin (94.6%). The high occurrence of antibiotic-resistant bacteria in natural water could be related to the widespread use of antibiotics, with possible public health hazard.

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.357-365
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• 2011

The QUAL2K has the same basic characteristics as the QUAL2E model, which has been widely used in stream water quality modeling; in QUAL2K, however, various functions are supplemented. The QUAL2Kw model uses a genetic algorithm(GA) for automatic calibration of QUAL2K, and it can search for optimum water quality parameters efficiently using the calculation results of the model. The QUAL2Kw model was applied to the Gangneung Namdaecheon River on the east side of the Korean Peninsula. Because of the effluents from the urban area, the middle and lower parts of the river are more polluted than the upper parts. Moreover, the hydraulic characteristics differ between the lower and upper parts of rivers. Thus, the river reaches were divided into seven parts, auto-calibration for the multiple reaches was performed using the function of the user-defined automatic calibration of the rates worksheets. Because GA parameters affect the optimal solution of the model, the impact of the GA parameters used in QUAL2Kw on the fitness of the model was analyzed. Sensitivity analysis of various factors, such as population size, crossover probability, crossover mode, strategy for mutation and elitism, mutation rate, and reproduction plan, were performed. Using the results of this sensitivity analysis, the optimum GA parameters were selected to achieve the best fitness value.

• Particle and aerosol research
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• v.10 no.2
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• pp.61-75
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• 2014

Five on-road measurements were made using a mobile laboratory (ML) to characterize spatial and temporal air pollutant distributions over roads around a day-care center in urban area on 30 August 2013. Fixed monitoring was also done near the day-care center using the ML during the periods between on-road measurements. On-road air pollution monitoring route was classified into seven sections and three zones to identify severe polluted roads among many roads having different traffic volumes and directions. Typical pollutants emitted from vehicles such as $NO_x$, black carbon, particle-bound polycyclic aromatic hydrocarbons, and submicron particles including nanoparticles were monitored using real-time instruments. Peak concentration episodes were frequently observed during the on-road measurements and most peaks were simultaneously monitored at four pollutants. Colored on-road air pollution map for each pollutant provides an insight on spatial air pollution distribution, showing heavily polluted roads and sections. Average on-road $NO_x$ concentration of each run was similar to that monitored at the nearest roadside air monitoring station.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.400-406
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• 2009

In this study, in order to find the movement of polluted substance that is flown into the river and the characteristics of dispersion, the experiment that used the RI (Radioactive Isotope) tracer in the river was undertaken, and by using the experiment result, the figure modelling was undertaken to analyze the general type of pollutant dispersion. In addition, in order to calculate more accurate dispersion range and moving time, the experiment was done in about 2km from the measuring points of Namdae Stream around the Yongdam Dam of the upper Geum River to the lower stream. In order to find out the flow of river and dispersion of polluted substance, RMA (Resource Modeling Associates)-2 and RMA-4 program are used in study. The site experiment using the RI was implemented for the experiment in the applied area and the same area, and the distance between each zone was set for 1km with the slight difference for site situation and measured the density date of one second distance through the NaI apparatus to measure the density data of one second interval. On the basis of this measured data, it is compared and analyzed with the result of figure copy of the models to make the comparison and analysis of density distribution following the change in expansion coefficient that makes great influence on expansion range and dispersion in natural rivers.

• Fisheries and Aquatic Sciences
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• v.4 no.3
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• pp.150-158
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• 2001

A study on the amount, distribution and item of bottom litter on the sea-bed was conducted by the bottom trawl net at 5 sections in Chinhae Bay over a year. The number and weight of litter found per unit of swept area (1 hectare) in each section were estimated as the range of 8.76-80.63 pieces, 3.51-108.39kg, respectively. The seasonal variation of high (Aug., '97) and low season (Feb., '98) in quantity was small, and it was about 2 times as the range of 24.58- 52.61 pieces/ha between them. But the weight variation between high (Apr., '98) and low season (Aug., '97) was very large, about 30 times as the range of 4.06-119.64kg/ha. The largest and second composition on the weight of bottom litter in Chinhae Bay are $76\%$ in other-litter with compound and bulky materials, and $93\%$ in fishing gear, respectively. The relationship between quantity and weight of bottom litter was not occurred due to the variety of specific gravity. Of the fishing gear, fishing nets was portioned to be 2.571kg/ha in weight and $84.9\%$ in composition. So these results prove that fishing nets were discarded as the most part of fishing gear during fishing activity in the bay. The largest composition of the soiled state classified into 3 styles in overall bottom litter was $69\%$ in very soiled state, and the second one of $28\%$ in the soiled state. On the other hand, new state is very small and portioned in $3.0\%$ of all. Chinhae Bay was estimated to be about 10 times in quantity and about 36 times in weight of Tokyo Bay. Therefore, these suggest that Chinhae Bay is a very serious polluted estuary caused by the bottom litter such as heavy and bulky wastes, fishing gear.

• 한국해양학회지
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• v.21 no.1
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• pp.56-71
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• 1986

In order to clarify the influence of environmental factors on the phytoplankton cmmunity in Kyeonggi Bay, the hydrological and water quality data were obtained from 20cruises from May, 1981, to September, 1982 in this bay. Physical conditions at the mouth of the bay are more stable than those at the head of the bay. Temperatures and salinities of the upper part of the bay show great seasonal fluctuations due to the river discharge. By the extending effects of freshwater, a weak two-layer flow system is formed from the upper part of the bay to Palmi Island. In summer thermal stratification are formed in the middle and outer parts of the bay. In winter, However, the temperature shows no vertical temperature gradient. The inner bay and the vicinity area of Incheon Harbour are relatively polluted and eutrophicated due to both the runoff of freshwater from the Han River and the waste discharge from Incheon industrial complex. However, except the polluted area, the study areas are well oxygenated with more than 90% saturation.

• 한국해양학회지
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• v.13 no.2
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• pp.31-41
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• 1978

The planktonic algal communities of the Han River with a particular emphasis on water pollution was studied over a twelve month of period. Results of observing many algal communities from 7 stations of the Han River have shown that these communities are generally composed of many species, most of which have relatively small populations with a few exceptional dominant species. The distribution of the total standing crop of phytoplankton in the studid area is characteristic, summer in the polluted zone. Diversity indices of all samples were computed and have shown that the H values of 7 stations are relatively low. However, a detailed examination of these H values reveals that the seasonal fluctuations of the species diversity remarkably coincide with those fo phytoplankton standing crop.No reduction in the species diversity at stations 4, 5, 6, and 7 where the water is heavily polluted indicates that a great number of species capable of invading stations, 4, 5, and 6 from the various tributaries, and the station 7 from the contaminated with sea water are probably more important in the functional changes of the communities than the size of sampling area. It is evident that the diversity index in a lotic environment does not indicate water quality as far as phytoplankton communities are concerned.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.3
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• pp.1-10
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• 1986

Nowadays, air pollution by increasing consumption of fossil fuels resulting from rapidly growing population and industrialization has caused the adverse effects on terrestrial ecosystems and become one of the most serious problems causing environmental discriptions. Air pollution such as $SO_2, HF, NO_X,$ fly ash, ozone and PAN might influence plant growth, reproduction, nutrient cycling, photosynthesis and predisposition to entomological and pathological stresses on plants. Furthermore, accumulation of those toxic substances in forests might cause subtle or serious changes in the structure and function of forest ecosystems. Since 1970s, a number of large industrial complexes had been constructed as a part of industrialization plan in Korea. Accordingly, the forest exosystems around them has been under chronic influences of air pollution and effects of air pollution on plants became a matter of concern. In Yocheon Industrial Complex which consisted of lots of petrochemical plants and a phosphatic fertilizer manufacturing plant, forests has been exposed to chronic air pollution, mainly HF and $SO_2$ gas, Various reports were available to investigate the potential effects of air pollution on crops and forest trees in Yocheon. Kim and Kim surveyed vegetation by naked eye method and reported 71 families, 150 genera and 158 species were growing within a 2 km from air pollution sources in 1981. Needle injuries on Pinus spp. in the polluted area water reported by Kim, et al. and Kim, et al. Kim, et al. investigated the primary production of Pinus thunbergii forests in the polluted area and verified that growth inhibition of Pinus thunbergii was attributable to air pollution. Thus, previous reports suggested that forest ecosystems around Yocheon Industrial Complex were influenced adversely by air pollution. The objective of this study was to investigate the subtle ecological changes in forest community exposed to chronic air pollution in Yocheon.

• Journal of Environmental Science International
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• v.19 no.5
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• pp.591-605
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• 2010

This study were to simulate major criteria air pollutants and estimate regional source-receptor relationship using air quality prediction model (TAPM ; The Air Pollution Model) in the Seoul Metropolitan area. Source-receptor relationship was estimated by contribution of each region to other regions and region itself through dividing the Seoul metropolitan area into five regions. According to administrative boundary, region I and region II were Seoul and Incheon in order. Gyeonggi was divided into three regions by directions like southern(region III), northern(IV) and eastern(V) area. Gridded emissions ($1km{\times}1km$) by Clean Air Pollicy Support System (CAPSS) of National Institute of Environmental Research (NIER) was prepared for TAPM simulation. The operational weather prediction system, Regional Data Assimilation and Prediction System (RDAPS) operated by the Korean Meteorology Administration (KMA) was used for the regional weather forecasting with 30km grid resolution. Modeling period was 5 continuous days for each season with non-precipitation. The results showed that region I was the most air-polluted area and it was 3~4 times more polluted region than other regions for $NO_2$, $SO_2$ and PM10. Contributions of $SO_2$ $NO_2$ and PM10 to region I, II and III were more than 50 percent for their own sources. However region IV and V were mostly affected by sources of region I, II and III. When emissions of all regions were assumed to reduce 10 and 20 percent separately, air pollution of each region was reduced linearly and the contributions of reduction scenario were similar to those of base case. As input emissions were reduced according to different ratio - region I 40 percent, region II and III 20 percent, region IV and V 10 percent, air pollutions of region I and III were decreased remarkably. The contributions to region I, II, III were also reduced for their own sources. However, region I, II and III affected more regions IV and V. Shortly, graded reduction of emission could be more effective to control air pollution in emission imbalanced area.