Earticle

This study was carried out to assess nitrate and phospate removal using mixed culture of methanotrophs. The methanotrophs ware isolated from the soil of landfill cover layer and cultured in nitrate minimal salt medium with oxigen and methane supply as a carbon and energy sources. During the growth of methanotrophs in high concentration of nitrate and phospate, 44.1% of nitrate and 50% of phospate were removed in 62 hrs. The utilization rate of methane and oxygen was slightly increased corresponding to rising initial MLVSS concentration. Nitrate removal rate of methanotrophs was decreased to 40% in 64 hrs at the addition of ammonia.

The purpose of this study is to investigate the characteristic of dioxin emission in waste incinerators and to make guideline of Best Available Control Technology(BACT) for its suitable treatment. Industrial waste incinerators are more affected in dioxin emission with 72% contribution ratio compared to the 16~17% of municipal waste incinerators in Korea. By this reason, the enforcement of regulation on dioxin emission was needed to decrease the emission rate in waste incinerators, and was effectively reduced in 2004 since 2003 in which regulation of dioxin emission had been performed. Also, future quantities of dioxin emission are assumed to decrease to 90% over in 2015 compared in 2001 by continuously enhancement of regulation. In field study for pollution control equipment, there are some arguments in its performance of application for various waste incinerators. But it has to prepared the design manual and guidance of best available control technology.

This studies are to investigate of the oxygen transfer efficiency for oxygen dissolver and to evaluate of aerobic liquid-composting system. We design a new kind of high efficiency oxygen dissolver(HEOD) system. Test result of this system, Saturated DO concentration was showed that the fit condition was at 1.0 L/min2 pressurized oxygen pressure and at 0.6 kg/cm2 in pressurized water, respectively. Mass transfer of oxygen in HEOD system, the highest dissolved oxygen concentration is as high as 56.0 mg/L in comparison of only air supply condition and pure oxygen dissolving on the system, DO dissolving level was higher about 34 mg/L in condition of oxygen supply than the air supply. The capture of bubble images was automated by commercial image analyser. The average bubble size in diameter showed that the air injection was 275 ㎛ and oxygen was 28 ㎛, respectively. And the surface area of bubble estimated that the air injection was about 21.8 m2 and oxygen was about 214.3 m2, respectively. In this result, the system efficiency in condition of pure oxygen supply was higher than the air supply, so it inquired further into liquid-composting using by oxygen dissolver.

To test the removal efficiency of the volatile organic compounds(VOCs), the photocatalyst in a removal apparatus of the VOCs is activated with the wireless pole ultraviolet ray lamp being an enough frequency. As the VOCs of xylene, toluene and methyl ethyl ketone (MEK) are inputted respectively into an influx hole of the batch experimental system, a regular consistency is made up 40, 80 or 500 ppm after mixing completely with the pan and motor which attaches on the ceiling in it. And after operating a removal apparatus of VOCs in it, the VOCs consistency is decreased. As the performance test, following results are obtained from this experiment. It takes 75 minutes to control until 5 ppm from the initial 80 ppm xylene consistency and the control efficiency specially appears with 60% to 45 minutes with operating the VOCs removal apparatus. It takes 50 minutes to control until 8 ppm from the initial 40 ppm toluene consistency and takes 70 minutes to almost perfectly treat with operating it. In MEK with the initial 500 ppm consistency, it takes 120 minutes to almost perfectly treat and the removal efficiency shows 80% after 90 minutes with operating it.

The purpose of this study was to investigate the gastrointestinal tract symptoms by upper gastrointestinal series to serve a basis data for preparation of health policy and for developing program of health promotion. The data was collected by a physical examination in 2005. The subjects in this study were 564 citizens in B City, Korea. Based on the results, the physical examination respondents by the upper gastrointestinal series were 44.3% in man, 55.7% in woman ; the highest by 37.6% in fifties. The condition which it felt from the gastrointestinal tract was 72.7% in nothing symptom ; the highest by 71.3% in forties. the normality in nothing symptom was 63.1% ; the normality in complain condition was 46.2%. Symptoms in gastrointestinal tract were that the pyrosis tingle was high in man ; the dyspepsia in woman ; the gastroptosis cascade stomach in all. Symptoms in gastrointestinal tract by ages classification were that the dyspepsia was high in all ; the gastroptosis ․ cascade stomach was high in 40, 50, 60 ages ; the duodenal diverticula was high above 70 ages. The above results showed that symptoms in gastrointestinal tract was the highest in dyspepsia ; was high in gastroptosis cascade stomach by diseases. So health education as well as public information about gastrointestinal tract suitable to the citizens for good health should be needed more and more in future. For this reason, it is suggested that we develop programs to promote life quality for health management, and need to have health education for prevent diseases.

The purpose of this study is to estimate the animal wastes treatment in sunchon-si for animal manure recycling. Animal wastes which were taken out from the house were classified into 3 types ; solid, slurry and wastewater. Solid wastes were applied to composting. slurry was applied to simplified aeration method to produce liquid fertilizer. and wastewater was treated by activated sludge process to discharge clean water. Composting manure is the main treatment method for solid wastes of livestock. The most desirable techniques of animal waste management should involve proper treatment prior to the application to land. How to recycle animal manure without any environmental pollution will be closely connected with how to establish sustainable agriculture with organic fertilizer in Sunchon-si.

This presents a comparison of biogas production by the dry anaerobic digestion with organic fraction of municipal solid wastes(OFMSW). Batch experiments were carried out to assess biological methane production from food waste, tissue paper and copy paper. Sequence batch reactor was tested for biogas production from organic waste(food waste/tissue paper ratio of 8 : 2). The biogas in batch test was produced on average 82.1 mL/g in food waste, while not produced in tissue paper and copy paper on the same condition. The biogas production yields in the sequence batch reactor were 0.45 ㎥/kg VS at the organic roading rate(ORL) of 1.58 kg VS/㎥ ․ d and 0.67㎥/kg VS at the ORL of 3.16kg VS/㎥ ․ d.

The purpose of this study is to take-out of prediction factor as weather conditions on the long-term retardation status of Asian dust in Korea. Recently, the frequencies and retardation days of Asian dust originated from deserts in China and Mongolia have increased a lot in Korea, especially the days of retardation in Seoul have reached to 27 days in 2001 and 9 days per one time in 1998. Of course, the main causes of Asian dust depend on the climate of source area, but it was estimated that the weather factors of Korea are related with the long-term retardation in some degree. After analyzing the relation with weather conditions, following brief summaries was observed as conclusions. Weather and humidities are responded to the long-term retardation of Asian dust in Korea. Continuous haze and smog, also arid climate are contributed to make longer the retardation of Asian dust. But rainy and snowy climate are indicated the end of retardation status. Additionally this study concerning on the long-term retardation goes on to find another factors as atmospheric pressure and temperature etc.