• 한국환경과학회지
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• 제3권3호
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• pp.185-195
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• 1994

Masan bay is one of the polluted enclosed bays, which has red tides problem and the formation of oxygen deficient water in the bottom layer. Most important factors that cause eutrophication and red tide is nutrient materials containing nitrogen and phosphorus which stem from terrestrial sources and nutrients released from sediment. Therefore, to improve of water quality, reduction of these nutrient loads should be indispensible. At this study, the three-dimensional numerical hydrodynamic and eutrophication model, which were developed by Institute for Resources and Environment of Japan, were applied to analyze the processes affecting the phytoplankton production and also to evaluate the effect of water quality improvement plans on phytoplankton production. In field sorvey, the range of concentrations of chlorophyll-a at surface area was found to be 29.17 - 212.5mg/m3, which were exceeding eutrophication criteria. The constant currents defined by integrating the simulated tidal currents over 1 tidal cycle showed the counterclockwise eddies in the southern part of Budo. The general directions of constant currents were found to be southward at surface and northward at bottom over all the bay. The eutrophication model was calibrated with the data surveyed in the field area in June, 1993. The calculated results are in fairly good agreement with values within relative error of 30%. The pollutant load from the sources such as the input from terrestrial release from the sediment was reduced by the rate of 50, 70, 90, 98% to effect of phytoplankton production. Phytoplankton production was reduced to of the 90% reduction of the input loads from terrestrial sources and 8% in 90% reduction of the load from sediment.

• 한국환경과학회지
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• 제16권4호
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• pp.505-521
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• 2007

This study estimated response of water duality and pollutant behavior according to the discharge and reuse of treated wastewater by three-dimensional eco-hydrodynamic model, and suggest plan that water quality management and environmental restoration in the coastal area including urban stream of Yeosu, Korea. Dispersions of low-saline water and COD by treated wastewater loads (design facility capacity, about $110,000m^3/d$) were very limited in near of effluent site. Nutrients, however, increase compared to the other water quality factors, especially total nitrogen was very sensitive to input loads. When reuse some of treated wastewater to Yeondeung stream, nitrogen was big influence on estuarine water quality. Although current characteristics of treated wastewater such as discharge and water quality were negligible to the change of marine environment, effluent concentration of COD, TN and TP, especially 40% of TN, are reduced within the allowable pollutant loads for satisfy environmental capacity and recommended water duality criteria. Also, controls of input point/non-point sources to Yeondeung stream and base concentration of pollutants in coastal sea itself are very necessary.

• 한국수산과학회지
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• 제35권4호
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• pp.356-365
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• 2002

One of the most important factors that cause eutrophication is nutrient materials containing nitrogen and phosphorus which stem from excreation of terrestial sources and release from sediment. Therefore, to improve water quality, the reduction of these nutrients loads should be indispensible. At this study, the three-dimensional numerical hydrodynamic and ecosystem model, which was developed by Institute for Resources and Environment of Japan, were applied to analyze the processes affecting the eutrophication. The residual currents, which were obtained by integrating the simulated tidal currents over 1 tidal cycle, showed the presence of a typical counterclockwise eddies between Gyewha and Garyuk island. Density driven currents were generated westward at surface and eastward at the bottom in Saemankeum area where the fresh waters are flowing into, The ecosystem model was calibrated with the data surveyed in the field of the study area in annual average. The simulated results were fairly good coincided with the observed values within relative error of $30\%$. The simulations of DIN and DIP concentrations were performed using ecosystem model under the conditions of $40\~100\%$ pollution load reductions from pollution sources. In study area, concentration of DIN and DIP were reduced to $59\%$ and $28\%$ in case of the $80\%$ reduction of the input loads from fresh water respectively. But pollution loads from sediment had hardly affected DIN and DIP concentration, The $95\%$ input load abatement is necessary to meet the DIN and DIP concentration of second grade of ocean water quality criteria.

• 환경영향평가
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• 제4권2호
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• pp.39-57
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• 1995

이 논문은 미국 Pennsylvania의 델라웨어강 유역에서의 토지이용으로 인한 영향을 평가하기 위하여 수질모형 SWAT (Soil and Water Assessment Tool)를 GIS등과 결합하여 (Arc/info 와 GRASS)사용하였다. 이 논문에서는 GIS를 수치수질모형과 결합하여 사용하였으며 그 대상지역은 $250km^2$의 Brodhead Creek 유역이다. 수질모형에 사용된 자료는 1:250,000의 DEM (Digital Elevation Model)에서 추출된 자료와 토양자료 및 관측된 유량 및 질산염 농도와 관련된 자료이다. 그리고 DEM자료, Curve Number 및 기타 입력변수의 민감도를 분석하였다.

• 농촌지도와개발
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• 제16권4호
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• pp.687-711
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• 2009

Recently, environmental-friendly agriculture (EFA) has been pointed out as an alternative for the change of our agricultural conditions. But the excessive amount of nutrients have been used to farmland since 1960s, when the intensive farming method called "High-Input, High-Yield" was expanded in earnest. This study was conducted to examine and compare farmers' purchasing and using fertilizer. For these purpose, data were gathered from a total of 326 farmers of the nation wide (greenhouse horticulture 60, upland cultivating 177, fruit-growing 89). The findings were as follows: First, 70.6% of greenhouse horticulture farmers, 89% of upland-cultivating farmers, 76.3% of fruit-growing farmers purchased fertilizer in Nong-hyup (farmers' cooperative organization). Second, only 54.2% of the greenhouse horticulture farmers, 60.2% of the upland cultivating farmers and 70.4% of the fruit-growing farmers recognized the optimum level of fertilizer. So, governmental organizations and agricultural technology center should carry out various programs for informing the farmers of the right way to use fertilizer and to practice EFA.

• 환경영향평가
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• 제21권3호
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• pp.445-460
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• 2012

In order to evaluate and predict the environmental impact of the low-trophic-level ecosystem to environmental changes in the Yellow Sea and the East China Sea, an ecological modelling study was undertaken. Simulation results of average distribution patterns and concentrations of water quality factors during the summer by the model were acceptable. Phytoplankton and remineralization rate of organic matter were very important parameters by a sensitivity analysis. Water quality factors showed high values in the estuary of the Yangtze River and in the West and South Sea of Korea and low values in the central area of the Yellow Sea. There is a plume of high values, especially nutrients, off the mouth of the Yangtze that expands or contracts with changes in the discharge strength. Characteristics of responses of water quality factors vary for different scenarios of environmental change, such as land-based pollution sources and atmospheric forcing. It is suggested that changes of light intensity, discharges of input sources, and wind play an important role in the marine ecosystem.

• 신재생에너지
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• 제16권1호
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• pp.68-76
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• 2020

Operational testing of the THIOPAQ^® facility that removes H₂S from landfill gas was performed for 746 days. The average H₂S removal efficiency was 99.4%, and the input quantities of air, NaOH, and nutrients per sulfur load were 13.1 ㎥/ton, 1.5 ㎥/ton, and 28.7 L/ton, respectively. The purity of the bio-sulfur produced from the facility was 94.8%, with 3.3% impurities, except for moisture. X-ray photoelectron spectroscopy showed that the compositional contents of amino acids and free amino acids of the bio-sulfur surface were 5,308 and 728 mg/kg, respectively. The mean particle size was 3.41 ㎛, which was much smaller than that of chemical sulfur. Based on these results, a high H₂S removal rate of more than 97% is feasible, and high value-added bio-sulfur, which is used as a fungicide because of its hydrophilic characteristics and small size, can be obtained at this facility.

• 상하수도학회지
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• 제26권6호
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• pp.815-823
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• 2012

Non-point source pollutants in down stream of Nakdong river were simulated by SWAT. GIS was utilized to make input data of SWAT such as landuse pattern and soil. Meteorological data of 2007 and 2009 were applied for the calibration and validation of runoff in SWAT. It was difficult to calibrate and validate the runoff and nutrient results since a study area was influenced by the tidal effects. Jindong site was selected to escape from the bias of runoff simulation in the coastal area. $R^2$ values of calibration and validation were 0.8 and 0.79. However, $R^2$ values of water qualities were very low level in comparison to runoff. These resulted from the concentration scale of water qualities such as BOD, T-N and T-P. Additionally, tidal influence could effected on the measurements of nutrients. The simulated annual averages and patterns of BOD, T-N and T-P in SWAT were similar to the measurement data. 80 ~ 96 % of nonpoint source pollutants at Nakbon M site were released from April to August of 2009. The ratio of T-N and T-P from nonpoint source were above 50 % during the rainy season.

• 한국유기농업학회지
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• 제10권1호
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• pp.35-47
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• 2002

양돈생산에 있어 영양소의 이용율을 증대시키는 것은 절대적으로 필요하다. 가공기술(예를 들면 분쇄, 펠렛팅, 스팀 프레이킹, 로스팅, 익스투르전 및 익스펜딩)의 발전과 더불어, 사료원료의 영양소 이용성이 크게 향상되어 왔다. 분쇄는 입자도의 감소와 함께 가장 널리 사용되는 가공방법이다. 익스펜더는 익스트루더와 유사한 구조이며 짧은 시간으로 고온고압의 과정을 거쳐 생산되어지는 과정이다. 이러한 가공은 펠렛 질을 향상시키기 위해 사용한다. 또한 사료원료의 익스펜딩은 성장 및 영양소 소화율의 향상을 보여준다. 사료 비용은 양돈 생산에 가장 큰 경제적 비중을 차지하기 때문에 영양소 이용률의 극대는 계속적으로 크게 관심이 되어질 것이다. 결국, 이러한 관심은 가축성장과 영양소 소화율에 있어 일률적인 향상을 주게 될 사료가공기술이 계속적으로 되어질 것이다.

• 기술혁신학회지
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• 제2권2호
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• pp.290-308
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• 1999

In this study a system for the treatment or recyling of organic wastes from both urban and rural area was recommended. It was developed based on the resource recovery system regarding human being by four tectnologies; forage, methane production, high-grade composting and complete decomposition. High quality compost can be produced by combining several kind of wastes produced from urban and agricultural areas. High quality compost must possess not only general characteristics of ordinary compost, but also a superior ability to improve the soil properties and must contain more nutrients for plant. Cedar chips were recommended as the main bulking agent to adjust moisture contents and air permeability. Charcoal and zeolite can be used not only as the second bulking agent but also as fertilizer for improve the soil amendment. Complete decomposition of organic wastes is defined by organic matter being completely converted to $CO_2$ and water. All the input water was evaporated by the heat produced through the oxidation of organic matter, In the present study, the complete treatments were successfully achieved for Shochu wastewater, swine wastes, thickened excess sewage sludge, wastes produced by Chinese restaurant and anaerobic digested sludge. First of all, recycling center of organic wastes should be established for the protect the environments and effective recovery of organic resources. This may means the way to derive the recovery of human value.