• Environmental Engineering Research
• /
• v.19 no.3
• /
• pp.185-195
• /
• 2014

Despite the enormous technical and economic efforts to improve environmental conditions, currently about 40% of the global population (or 2 billion people) are still lack access to safe water supply and adequate sanitation facilities. Pollution problems and transmission of water- related diseases will continue to proliferate. The rapid population growth and industrialization will lead to a reduction of arable land, thus exacerbating the food shortage problems and threatening environmental sustainability. Natural systems in this context are a transdisciplinary approach which employs the activities of microbes, soil and/or plants in waste stabilisation and resource recovery without the aid of mechanical or energy-intensive equipments. Examples of these natural systems are: waste stabilisation ponds, aquatic weed ponds, constructed wetlands and land treatment processes. Although they require relatively large land areas, the natural systems could achieve a high degree of waste stabilisation and at the same time, yield potentials for waste recycling through the production of algal protein, fish, crops, and plant biomass. Because of the complex interactions occurring in the natural systems, the existing design procedures are based mainly on empirical or field experience approaches. An integrated kinetic model encompassing the activities of both suspended and biofilm bacteria and some important engineering parameters has been developed which could predict the organic matter degradation in the natural systems satisfactorily.

• Journal of Applied Biological Chemistry
• /
• v.62 no.1
• /
• pp.67-71
• /
• 2019

All countries, including Korea, are currently experiencing the effect of rapid climate change. As a result, the cultivation area of many crops including wheat is changing, or productivity is falling sharply. If enough nitrogen is present in the soil, the increase in atmospheric carbon dioxide due to the greenhouse effect can lead to increased photosynthesis of plants, resulting in increased productivity. By contrast, a low proportion of nitrogen in soil does not increase production, often leading to the use of nitrogen fertilizers to increase crop productivity: this causes serious environmental pollution due to the leakage of nitrogen fertilizers used by crops. Increasing the understanding of the molecular level of the plant nitrogen use efficiency mechanism may contribute to increased productivity of crops and reduced of environmental pollution by nitrogen. In Korea, cultivars have developed 35 kinds of wheat, such as 'keumgang' and 'Chokyeong', which can be used for specific purposes such as baking or noodles. In this study we investigate 'keumgang' and 'Chokyeong' in order to elucidate the mechanism of nitrogen use ability of wheat and contribute to the reduction of environmental pollution by providing guidelines for the proper use of nitrogenous fertilizer.

• Journal of the Korean Society of Food Culture
• /
• v.24 no.2
• /
• pp.164-171
• /
• 2009

The objectives of this study were to determine the recognition of food waste, school lunch leftovers and satisfaction toward school lunch in middle school students in Seoul. Four hundred students were surveyed beginning April, 2007. The results are summarized as follows. The primary means in which students learned about environmental pollution were 'video media' (54.7% males, 39.2% females) and 'by teachers' (23.2% males, 33.0% females). The primary effects on food habits after participating in the school lunch program were 'having a balanced diet' (23.3%) in the females, and 'decreased intake of junk food' (24.9%) in the males. The serving sizes for cooked rice, soup, and meat were higher in the females (3.46, 3.46, and 2,91, respectively) than the males (3.18, 3.29, and 2.73, respectively). The primary school lunch leftovers for one week were cooked rice (4.55), meat (4.35), kimchi (3.84), fish (3.60), vegetables (3.38), and soup (3.08). Importance-performance analysis of the school lunch meal indicated that good taste had high importance, but low performance. Nutritional balance, food safety, cleanliness of tableware and supplies, clean uniforms of employees, and cleanliness of the dining area had both high importance and performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.442-445
• /
• 2007

A noise reduction policy can be more effectively made when automatic environmental noise measurement system is set up. However, the local characteristic of noise pollution requires a lot of measurement points. This study considers that automatic environmental noise measurement system connects with automatic air pollution measurement system and noise map. The measurement points of traffic volume by the National Police Agency and the Ministry of Construction and Transportation are investigated to use at drawing the road traffic noise map. Finally, the effective application method of the environmental noise measurement vehicle is discussed.

• Journal of Korean Society on Water Environment
• /
• v.29 no.4
• /
• pp.466-475
• /
• 2013

Non-point source pollution management is one of the most important issues in Korean water quality/watershed management. In recent years, Low Impact Development (LID) has emerged as an effective approach to control stormwater in an urban area. This study illustrates how to design and evaluate the effect of non-point pollutant management using EPA-SWMM LID module and suggests design parameters for modeling LID facilities. In addition, optimal installation locations of LID can be determined by a simple distributed hydrologic model by using SWMM for a long-term.

• Journal of Environmental Science International
• /
• v.26 no.8
• /
• pp.881-891
• /
• 2017

In this study, the discharge loads of non-point pollution sources were analyzed using a Hydrologic Simulation Program-Fortran (HSPF) model for 46 sub-watersheds in order to guide the management plan for water and streams passing through the city. The results using HSPF showed good applicability in comparison to point measurements, which were based on BOD, TP, and TN. The mean value of the BOD loads was $4.08kg/km^2$ per day, and the highest level of BOD was $17.75kg/km^2$ per day at Namri. Three potential areas of high priority for the installment of constructed wetlands were selected in order to reduce non-point pollution sources based on BOD loads and on environmental and economic conditions. The results for these scenarios indicated a maximum rate of reduction in BOD of 39.12% within the proposed constructed wetlands.

• Journal of Power System Engineering
• /
• v.19 no.3
• /
• pp.29-35
• /
• 2015

Environmental pollution is produced by consumption of fossil fuel, therefore alternative fuels is interested for development of new energy resources and reduction of exhaust emissions for air pollution prevention. Biofuels are produced from new vegetable oil and animal fat, may be used as fuel without change of engine structure in diesel engine. In this paper, the test results on specific fuel consumption, combustion characteristics of neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were presented using four stroke, direct injection diesel engine, especially this biodiesel was produced from biodiesel fuel at our laboratory by ourselves. This study showed that specific fuel consumption is increased slightly, on the other hand cylinder pressure, rate of pressure rise, rate of heat release and soot were decreased slightly in the case of biodiesel blends than neat diesel oil.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.05a
• /
• pp.265-266
• /
• 2018

In recent years, active loess cement has been used instead of cement in order to reduce the amount of cement and industrial byproducts that are the main cause of environmental pollution. We also used polysilicon sludge as a by-product to reduce the amount of cement used and to improve the environmental pollution due to the reduction of carbon dioxide. Polysilicon is a raw material used in the production of panels for solar power generation. When producing 1 ton of polysilicon, 2 tons of sludge is generated. It is an experiment to reduce sludge treatment and cement usage. This study analyzed basic characteristics of polysilicon sludge and active loess cement according to replacment ratio.

• Journal of Korean Society for Atmospheric Environment
• /
• v.12 no.4
• /
• pp.361-367
• /
• 1996

In order to accurately predict air pollution concentration according to reduction of air pollutant emission, a numerical model is needed. And the total emission amount of air pollutants should be estimated to explain the air pollution phenomena. The characteristics of the emission amount from area, line, and point sources in Pusan were studied by using emission data during one year (1992). The result showed that the annual total emission amount of pollutant is about 299,744 tons in Pusan. The emission consists of 31.8% of $SO_2$, 48.4% of CO, 4.6% of HC, 11.0% of NOx and 4.1% of TSP, as well as 52.1% of line, 24.1% of area and 23.7% of point sources. The result also showed that emission amount becomes larger in winter than that of the others.

• International Journal of Automotive Technology
• /
• v.7 no.3
• /
• pp.269-276
• /
• 2006

Running tests on roads were conducted to clarify the influences of road infrastructure, traffic condition and vehicle's emission level to the amount of emission at local roadsides, and to reveal the operation patterns which can reduce the emission peaks. NOx emission peaks of two light duty freight diesel vehicles which have different emission levels were evaluated by using an on-board measurement system. Tests were carried out with various payload conditions and road conditions. As a result many NOx emission peaks were observed when the vehicles were starting or accelerating at intersections. The test vehicle which has higher emission level caused higher frequency and level of NOx emission peaks. Shifting up at lower engine speed in combination with lower acceleration brought out not only reduction of NOx emission peaks level but also of $CO_2$ mass emission.