• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.325-331
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• 2006

Various environmental conditions affecting total phosphorus removal from farm wastewater in a biofilm filter process were investigated using loess balls and Chromobacterium LEE-38 at a pilot plant. When Chromobacterium LEE-38 was used, the removal efficiency of total phosphorous was approximately 10- or 5-fold higher than that of Acinetobacter CHA-2-14 or Acinetobacter CHA-4-5, respectively. When a loess ball of $11{\sim}14mm$ manufactured at a $960^{\circ}C$ calcining temperature was used, the removal efficiency of total phosphorous was 90.0%. When 70% of the volume fraction was used, the maximum efficiency of total phosphorus removal was 93.1%. Notably, when the initial pH was in the range of 6.0 to 8.0, the maximum removal efficiency of total phosphorus was obtained after 30 days. When the operating temperature was in the range of 30 to $55^{\circ}C$, the maximum removal efficiencies of total phosphorus, 95.6 to 94.6%, were obtained. On the other hand, at operating temperatures below $20^{\circ}C$ or above $40^{\circ}C$, the removal efficiency of total phosphorous decreased. Among the various processes, biofilm filter process A gave the highest removal efficiency of 96.4%. Pilot tests of total phosphorus removal using farm wastewater from the biofilm filter process A were carried out for 60 days under optimal conditions. When Acinetobacter sp. Lee-11 was used, the average removal efficiency in the p-adsorption area was only 32.5%, and the removal efficiencies of chemical oxygen demand (COD) and biological oxygen demand (BOD) were 56.7 and 62.5%, respectively. On the other hand, when Chromobacterium LEE-38 was used, the average removal efficiency was 95.1%, and the removal efficiencies of COD and BOD were 91.3 and 93.2%, respectively.

• 한국환경보건학회지
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• 제18권2호
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• pp.57-61
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• 1992

This study was made for enhanced removal of N and P by intermittented aeration Activated Sludge Process. Experiment were conducted to find the effects of aeration interval and nutrient removal efficiency. When applied aeration interval were 30~60 min, 2~4 h, 4~8 h, organic matter was not affected while phosphorous removal was aeration interval 30~60 min. Also, when applied mixing intensity were 15, 30, 45 and 60 rpm, organic matter was not affected while removal was maximum at 15 rpm. Total nitrogen and phosphorous removal were in the range of 76 and 85%. Density and MLSS of Sludge were in the range of 2.3~2.6 and 7198~7810 mg/l. Release of phosphorous from activated sludge under unaerobic condition was increased as pass time.

• 한국수자원학회논문집
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• 제48권1호
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• pp.9-21
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• 2015

본 연구는 소옥천 호소화 수역의 퇴적물 깊이별 오염도를 조사하고, 표층 퇴적토양을 대상으로 인 용출특성을 실험한 것이다. 퇴적물의 총인 농도는 전 구간에서 대청호 준설 환경기준 1.5mg/g을 초과하였고, T-N은 팔당호 준설기준 1.1 mg/g은 초과하였으나 대청호 준설기준 3.0mg/g보다는 낮게 나타났다. 준설구역은 소옥천 추소수역(WS-6~WS-12)이 적절하다고 판단하였다. 퇴적물 깊이별 오염도 조사 결과 강열감량은 깊이에 따라 낮아지는 경향을 보였고, 총질소는 깊이에 따른 농도 분포 패턴은 나타나지 않았다. 총인 역시 지점과 깊이별로 농도 변이가 적고 특별한 경향성을 보이지 않았다. 소옥천 호저 퇴적물에서 총인의 용출률은 혐기성 조건에서 $7.2{\sim}15.4mg/m^2/d$, 호기성 조건에서는 $0.5{\sim}2.0mg/m^2/d$, 통기성 조건에서는 $2.0{\sim}4.1mg/m^2/d$의 범위로 산정되었다. 혐기성 조건에서 퇴적 표토층의 총인 농도와 용출률의 관계는 결정계수($R^2$)가 0.7871로 나타나 정상관성을 보이고 있다. 또 반응조의 용존산소 농도와 총인 용출률의 관계는 결정계수($R^2$)가 0.8824인 높은 역상관성을 보였다. 퇴적물의 오염도와 반응조건에 따라 용출률이 크게 다르다는 것을 알 수 있었으며, 추소수역에 대한 수중 용존산소 농도 및 퇴적 표토층의 총인 함량과 총인 용출률과의 관계를 해석하였다.

• 한국물환경학회지
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• 제26권2호
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• pp.332-342
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• 2010

A model has been developed to investigate in-river sediment and phosphorus dynamics. This advective-dispersive model is coupled with hydrodynamics and sediment transport submodels to simulate suspended sediment, total dissolved phosphorus, total phosphorus, and particulate phosphorus concentrations under unsteady flow conditions. It emphasizes sediment and phosphorus dynamics in unsteady flow conditions, in which the study differs from many previous solute transport studies, conducted in relatively steady flow conditions. The diffusion wave approaximation was employed for unsteady flow simulations. The first-order adsorption and linear adsorption isotherm model was used on the basis of the three-layered riverbed submodel with riverbed sediment exchange and erosion/deposition processes. Various numerical methods were tested to select a method that had minimal numerical dispersion under unsteady flow conditions. The responses of the model to the change of model parameter values were tested as well.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1379-1394
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• 1993

The purpose of this study is to examine the purification efficiency of the septic tank method which has been applied by the most of Korean livestock farms, in terms of anaerobic and aerobic treatment. Except several days in summer, BOD of effluent shows 1,500 -3,000 ppm by anaerobic process. In most cases , it exceeds according to the seasons show an increase by decrease of temperature. The removal effect on T-N is hardly found. The suspended solids contents of effluent are reduced to the level of 50-90%. Although BOD contents of effluent are kept high in the beginning, the removal rate of BOD shows 80 percent in the latter half by the aerobic treatment . The removal efficiency of total nitrogen does not appear through the experimental period, but the contents of T-N are not increased in the aerobic process unlike in the anaerobic process. The total phosphorous contents in effluent keep a constant level of 14 mg/L in average. The removal rate of phosphorous shows 91 percent i the last stage.

• 한국연초학회지
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• 제2권1호
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• pp.37-52
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• 1980

신개간지 토양에 대한 인산시용 수준별 석회, 퇴비증시, 퇴비와 붕소의 혼합시용에 따른 비옥도 증진의 효과가 연초의 수량 및 품질에 미치는 영향을 2년간에 걸쳐 시험한 결과를요약하면 다음과 같다. 1. 개량제 처리의 효과는 1차년도에서 보다 2차년도에 담배 생육과 엽면적지수와 단위엽 면적중을 월등하게 증가시켰다. 3. 개량제의 시용으로 초년도의 pH, 치환성염기등이 숙전과 같은 수준으로 개선되었으며, 처리별 비옥도 증진효과는 퇴비증시구가 컸다. 3. 2차년도 시험결과에서 수량은 대조구에 비하여 15∼25% 증수되었고, 품질은 처리간에 큰 차 없으나, 개량제 시용으로 대조구에 비하여 3 - 7% 향상되었다. 수익 (10a당 수납대금)은 인산흡수계수에 대한 3 %조절량+퇴비증시구가 가장 높아 대조구보다 34%의 증가를 가져왔다.

• Corrosion Science and Technology
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• 제7권1호
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• pp.16-21
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• 2008

A non-phosphorous program employing an alkyl epoxy carboxylate (AEC) has been successfully applied to petrochemical and other large industrial open recirculating cooling water systems. AEC is a patented non-phosphorous calcium carbonate scale inhibitor that has demonstrated better scale inhibition abilities than traditional organic phosphonates. In addition to its antiscalant properties, AEC inhibits carbon steel corrosion when used at high dosages. AEC can be combined with zinc to form a non-phosphorous program with very low levels of phosphate to provide an environmentally acceptable program. In actual applications, the total phosphate developed in the cooling system from cycling the makeup is below 1 ppm as $PO_4$. This level has complied with the highest standards of wastewater discharge limitations. The performance of two AEC/Zinc applications is reviewed. In both cases excellent corrosion and scale control were achieved with AEC/Zinc programs. One case history details the performance with a low hardness water (100 ppm calcium, as $CaCO_3$) operating at 8-10 cycles of concentration. The corrosive nature of the water and the long retention time of the system stressed both the corrosion and scale control capabilities of the program. The second case history demonstrates the performance of the program with a moderate hardness water (400-600 ppm calcium, as $CaCO_3$), but under harsh conditions of high temperature and low flow. The AEC/zinc combination has been found to be highly effective in controlling the corrosion of ferrous metals. AEC can provide good corrosion inhibition at high concentrations, while zinc is known to be an excellent cathodic inhibitor. The combination of the two inhibitors not only provides a synergistic blend that is effective over a wide range of operating conditions, but also is environmentally friendly.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2471-2476
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• 2014

The aim of the present study is to explore the possibility of utilizing loess for the adsorption of total phosphorous (T-P) and total nitrogen (T-N) in water. Batch adsorption studies were performed to evaluate the influences of various factors like initial concentration, contact time and temperature on the adsorption of T-P and T-N. The adsorption data showed that loess is not effective for the adsorption of T-N. However, loess exhibited much higher adsorption capacity for T-P. At concentration of $1.0mgL^{-1}$, approximately 97% of T-P adsorption was achieved by loess. The equilibrium data were fitted well to the Langmuir isotherm model. The pseudo-second-order kinetic model appeared to be the better-fitting model because it has higher $R^2$ compared with the pseudo-first-order and intra-particle kinetic model. The theoretical adsorption equilibrium $q_{e,cal}$ from pseudo-second-order kinetic model was relatively similar to the experimental adsorption equilibrium $q_{e,exp}$. The thermodynamic parameters such as free energy ${\Delta}G$, the enthalpy ${\Delta}H$ and the entropy ${\Delta}S$ were also calculated.

• 한국농공학회논문집
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• 제51권2호
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• pp.51-57
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• 2009

The purpose of this study was to investigate characteristics of behavior of nutrients such as TN (Total nitrogen), TDN (Total dissolved nitrogen), TP (Total phosphorus) TDP (Total dissolved phosphorous) in runoff water from a nonpoint source dominated watershed ($6.67\;km^2$). Regular and intensive flow measurement and water sampling were taken during two years (February 2002 to January 2004) in the Ingyeong River, a tributary of the Han River. The mean concentrations of nutrients during rainy days were significantly (p < 0.05) higher than those during dry days. The mean TDN/TN ratio in rainy days (95%) is almost identical to that in dry days (96%), but mean TDP/TP ratio in rainy days (24%) significantly decreased compared with that in dry days (66%), suggesting that dominant form of TP is shifted from dissolved form to particulate form. Accordingly, the measures (.eg. filter strips, cover crops) to reduce soil erosion for fallow upland in the rainy season should be taken to control particulate phosphorous.

• 한국환경생태학회지
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• 제22권6호
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• pp.609-615
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• 2008

본 연구는 경기도 백운산, 전남 지리산, 백운산, 조계산, 경남 금산 지역 등에 분포하고 있는 히어리개체군을 대상으로 2005년 8월부터 2006년 9월까지 20개의 방형구를 설치하여 자생지의 생태적 특성을 분석하였다. 식물사회학적 방법으로 분류한 결과 히어리개체군은 피나무우점개체군, 소나무우점개체군, 비목나무우점개체군으로 구분되었다. Ordination 분석 결과 피나무우점개체군은 해발고가 높으며, 전질소, 유효인산, CEC의 함량이 높은 입지에 분포하는 것으로 나타났다. 소나무우점개체군은 해발고가 낮고 전질소, CEC, 유효인산의 함량이 적은 입지에 분포하는 것으로 나타났다. 비목나무우점개체군은 해발고가 높고, 전질소, 유효인산, CEC의 함량이 중간인 입지에 분포하는 것으로 나타났다.