• 한국농공학회지
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• 제44권3호
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• pp.146-156
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• 2002

The objective of this study was to develop a modified CREAMS model for paddy field conditions. The model simulates daily balance of water and nutrient from irrigated paddies using meteorological, irrigation, and agricultural management data. The model simulates daily evapotranspiration of paddy using Penman equation and determines daily flooding depth changes. Total nitrogen and phosphorus concentrations within flooding water, surface runoff, and leaching water from a paddy field also can be simulated. Parameters of the model were calibrated using observed data of the Agricultural Experiment Station of the Seoul National University in Suwon Korea. The model was applied for the irrigation period of paddy field in Gicheon area when 1,234 mm annual rainfall was occurred. The simulated losses of the total nitrogen and total phosphorous were 11.27 kg/ha and 0.98 kg/ha, respectively. There was a good agreement between observed and simulated data. It was found that CREAMS-PADDY model was capable of predicting runoff and nutrient losses from irrigated paddy fields.

• Environmental Engineering Research
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• 제21권1호
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• pp.52-57
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• 2016

Sediment is a useful natural source but deteriorated continually by anthropogenic and industrial sources. Therefore, it is imperative to search a suitable method for improving or restoring sediment quality. Sediment has been tested to identify the effects of some external agents on a polluted area for 28 days. Chemical analysis and total viable counts (TVC) test have been conducted for 4 days interval to assess their performance. The analyses of chemical oxygen demand (COD), acid volatile sulfide (AVS), total phosphorous (T-P), total nitrogen (T-N) indicate that the chemical agents was more efficient to improve sediment quality whereas the microbial agent was more efficient for nutrient releasing from sediment. Oxygen releasing property of the chemical agent was thought to be providing with more congenial environment for the higher growth of the bacterial community than the direct application of microbial agents.

• 한국농림기상학회지
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• 제16권3호
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• pp.188-196
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• 2014

경기도 광릉의 국립수목원 내의 토양과 빛 환경이 서로 다른 낙엽활엽수림과 전나무림에서 하층식생으로 생육하는 까치박달의 자원의 획득과 이용 및 분배를 이해하기 위하여, 잎의 질소와 인 농도의 계절 변화와 재전류, 엽록소와 LMA를 조사하였다. 엽면적 지수가 상대적으로 낮은 낙엽활엽수림은 유입되는 광량이 많았고, 전반적인 토양 양분의 수준이 양호하였으나, 유효인산의 농도는 전나무림의 1/3 수준으로 현저히 낮았다. 이로 인해, 낙엽활엽수림에서 생육하는 까치박달의 경우, 잎의 인 농도가 전나무림의 까치박달 보다 연중 낮았고, 재전류율은 상대적으로 높게 나타났다. 토양 내 질소 농도는 상대적으로 낙엽활엽수림에서 높았으나, 계절별 잎의 질소농도와 질소의 재전류율은 임분간의 유의적 차이는 없었다. 빛의 유입이 적은 전나무림에서는 까치박달의 LMA와 엽면적당 질소 분배가 상대적으로 낮았으며, 또한 엽록소 a/ｂ율은 낮고, 총 엽록소 함량은 높여 질소에 대한 엽록소의 비율이 높았다. 이러한 결과는 임분 조건이 서로 다른 낙엽활엽수림과 전나무림에서 생육하는 까치박달이 주어진 토양과 빛 환경에 순응하여 양분의 동태와 분배의 전략적 차이를 달리하여 생육하고 있음을 시사한다.

• Environmental Engineering Research
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• 제10권5호
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• pp.247-256
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• 2005

A combination of the submerged membrane activated-sludge bioreactor(SMABR) equipped with non-woven fabric filter and oyster-zeolite (OZ) packed-bed adsorption column was studied to evaluate the advanced tertiary treatment of nitrogen and phosphorous. The non-woven filter module was submerged in the MBR and aeration was operated intermittently for an optimal wastewater treatment performance. Artificial wastewater with $COD_{Cr}$ of 220 mg/L, total nitrogen (T-N) of 45 mg/L, and total phosphorous (T-P) of 6 mg/L was used in this study. MLSS was maintained about $4,000\;{\sim}\;5,000\;mg/L$ throughout the experiments. The experiments were performed for 100-day with periodic non-woven filter washing. The results showed that $COD_{Cr}$ could be effectively removed in SMABR alone with over 94% removal efficiency. However, T-N and T-P removal efficiency was slightly lower than expected with SMABR alone. The permeate from SMABR was then passed through the OZ column for tertiary nutrients removal. The final effluent analysis confirmed that nutrients could be additionally removed resulting in over 87% and 46% removal efficiencies for T-N and T-P, respectively. The results of this study suggest that the waste oyster-shell can be effectively reclaimed as an adsorbent in advanced tertiary wastewater treatment processes in combination with SMABR equipped with non-woven fabric filter.

• Journal of Nutrition and Health
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• 제44권5호
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• pp.394-405
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• 2011

Osteoporosis is a rising problem, as the older age population is increasing due to prolongation of life. Genetic and environmental factors play key roles in bone metabolism, and diet is also an important factor. We investigated the relationship among factors affecting bone mineral density (BMD), including daily food intake and nutrient intake in men aged >50 years. Seventy-eight men, who visited the health promotion center at one of the university medical centers, were divided into normal and osteopenia groups according to their BMD. The body weight of the normal group was significantly higher than that of the osteopenia group. The osteopenia group showed significantly higher carbohydrate intake and lower calcium and vegetable calcium intake compared to those in the normal group. Lumbar spine BMD was negatively correlated with energy, fat, vitamin B1, and sodium intake in the normal group. Additionally, femoral neck BMD was negatively correlated with total animal protein, energy, protein, fat, phosphorous, iron, animal iron, potassium, vitamin B1, B2, B6, and niacin intake. Lumbar spine BMD was positively correlated with fruit, calcium, vegetable calcium, animal calcium, and vitamin C intake in the osteopenia group. Femoral neck BMD was negatively correlated with meat, dairy product, total animal protein, plant protein, animal protein, vitamin A, and cholesterol intake. A stepwise multiple regression analysis revealed that several dietary factors affected BMD, including energy, fat, vitamin B1, B2, B6, niacin, sodium, protein, iron, animal iron, phosphorous, potassium, and animal protein in the normal group and zinc, calcium, vegetable calcium, animal calcium, vitamin C, fruit, protein, animal protein, meat, dairy product, carbohydrates, cholesterol, vegetables, mushrooms, and seasonings in the osteopenia group. These results indicate that adequate nutrient intake plays an important role maintaining optimum bone health in middle aged men.

• Asian-Australasian Journal of Animal Sciences
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• 제32권4호
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• pp.527-532
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• 2019

Objective: Phosphorous (P) sources with greater bioavailability might increase animal production efficiency and decrease environmental pollution. The objective of current study was to determine animal performance, nutrient digestibility, blood metabolites and fecal P concentration in finishing lambs fed a diet with either di-calcium phosphate (DCP) or di-ammonium phosphate (DAP) as a P source. Methods: Twelve 4-month-old male lambs (initial body weight $24.87{\pm}3.4kg$) were randomly allocated to a diet with either DCP or DAP (~261 g/kg of total diet P) fed ad libitum for 93 days. Diets were iso-nitrogenous and iso-energetic and had same calcium (Ca) and P concentrations. Results: The DAP contained 19.7 g/kg of dry matter (DM) Ca, 185.4 g/kg DM P and 14,623 ppm fluorine, while DCP contained 230.3 g/kg DM Ca, 195.2 g/kg DM P and 1,039 ppm fluorine. The diet with DAP contained 60 ppm fluorine while the diet with DCP contained 13 ppm fluorine. Lambs fed the diet with DAP tended to have a greater daily DM intake compared to those fed diet with DCP (p = 0.09). Lambs fed DAP had greater plasma P concentration and alkaline phosphatase activity ($p{\leq}0.01$) compared with lambs fed DCP. Dry matter and organic matter digestibility of the diets were similar between two treatments at days 60 and 90, while they were greater in lambs fed DCP (p<0.05) at day 30 of the trial. Feeding DAP increased P digestibility (58.7% vs 50.2%; p<0.05) and decreased fecal P concentration in lambs compared with feeding DCP (3.1 vs 3.8 g/kg DM; p<0.05). Conclusion: Providing ~261 g/kg of total diet P as DAP in the diet of finishing lambs improved the bioavailability of P in the body and decreased excretion of P in feces without affecting lamb performance.

• 한국광물학회지
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• 제21권2호
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• pp.117-127
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• 2008

카올리나이트 KGa-2 (표준 점토)의 인산염 흡착-탈착 특성을 규명하기 위하여 벳치(batch) 흡착 실험을 실시하였으며, 흡착 상태를 알아보기 위하여 ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) 분광분석을 실시하였다. 인의 함량은 UV-VIS-IR 분광분석 기를 사용하여 측정하였으며, 이 때 파장은 820 nm를 이용하였다. pH 4에서 pH 9 범위 내에서 카올리나이트 KGa-2의 인산염 흡착량은 pH가 증가하면 대체적으로 증가하는 경향을 나타내지만, 인산염 농도에 따라 매우 다른 형태를 보여준다. 카올리나이트 KGa-2의 인산염 흡착 특성은 랑미어 흡착등온선, 템킨 흡착등온선, 프로인드리히 흡착등온선 순으로 잘 부합하며, 랑미어 최대 흡착능은 $204.1{\sim}256.5\;mg/kg$, 평균간은 232.5 mg/kg으로서, 카올리나이트 KGa-1b에 비하여 높은 인산염 흡착능을 가진다. 카올리나이트에 흡착된 대부분의 인산염이 탈착되기보다, 광물 내에 고착되는 경향을 나타내지만 이에 대해서는 후속적인 실험이 필요한 것으로 판단된다. ATR${\sim}$FTIR 스펙트럼에서 카올리나이트에 의한 흡수피크의 위치가 인 피크와 거의 중첩되고, 카올리나이트에 의한 흡수 피크의 강도가 인 피크에 비하여 월등히 크기 때문에 카올리나이트에 흡착된 인에 의한 피크를 카올리나이트 자체에 의한 피크로부터 분리하는 것이 거의 불가능하였다.

• 한국환경복원기술학회지
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• 제12권6호
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• pp.86-98
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• 2009

This study was carried out to investigate vegetation structure and soil properties of Adenophora racemosa population distributed in Jeombongsan, Seoraksan, Odaesan and Dutasan in Gangwon-do, Korea. From August 2007 until September 2009, $2m{\times}2m$ quadrate was established in native area of Adenophora racemosa in order to record a dominants and coverage, and soil factors at 22 sites. It was found that the altitude in the distributed areas for Angelica gigas population was 800 m or more. Adenophora racemosa population was classified into Rhododendron mucronulatum dominant population, Geranium var. hirsutum dominant population, Caret siderosticta dominant population and Aruncus dioicus var. kamtschaticus dominant population. In the site of study, soil pH, electrical conductivity, soil organic matter, available phosphorous, and exchangeable potassium, exchangeable calcium, exchangeable magnesium, exchangeable sodium concentration and total nitrogen were ranged from 5.0~7.1, 0.06~0.65dS/m, 0.96~8.94%, 12.3~32.8mg/kg, 0.12~0.89cmol+/kg, 0.34~10.08cmol+/kg, 0.1~l.4cmol+/kg, 0.02~0.29cmol+/kg and 0~8.4% respectively. According to the results of DCCA, Adenophora racemosa population were distributed in the high available phosphorous and exchangeable potassium, and Rhododendron mucronulatum dominant population was situated on low available potassium and high slope degree, Geranium var. hirsutum dominant population was high altitude, electrical conductivity and exchange magnesium, and Carex siderosticta dominant population and Aruncus dioicus var. kamtschaticus were distributed on high total nitrogen, organic matter, available phosphorous.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.611-614
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• 2003

A Korean Type Biofilter system combined with a conventional anoxic tank(septic tank) process was investigated in regard to its feasibility for removing organic as well as nutrients from the rural wastewater in Korea. At recirculation, the removal rate in BOD and SS increased slightly as much as 93 and 95% compared with non-recirculation system. On the other hand, removal rates of the total nitrogen(T-N) and total phosphorous(T-P) in recirculation system increased significantly as much as 62 and 57%, respectively compared with non-recirculation system. The recirculation system provides sufficient treatment to improve the removal rate in T-N and T-P.

• 한국농공학회지
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• 제43권6호
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• pp.163-173
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• 2001

This study describes the characteristics of concentrations of pollutants such as total nitrogen(T-N), total phosphorous(T-P), and chemical oxygen demand(COD) at paddy areas during 2-year irrigation periods. The most common order in average concentrations of T-P and COD is podded water > irrigation(or drainage) water > percolated water. Most of pollutants concentrations in drainage water are lower than those in irrigation water after early July due to large uptake of pollutants by rice crop and denitrification. The exponential L (load)-Q(discharge) equations for classified irrigation periods are significant at 0.001 level for irrigation and drainage waters. For drainage water, the concentrations of T-N and COD slightly decrease with discharge, while the T-P concentrations slightly increase with discharge.