• 한국환경농학회지
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• 제22권4호
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• pp.266-272
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• 2003

호주 시드니 인근 도 농 복합 소도시로부터 발생하는 비점오염원을 처리하기 위하여 설치된 Plumpton park와 Woodcroft park 인공습지의 처리효율을 살펴본 결과, 수생식물의 밀도가 증가하고 식생이 안정된 Plumpton Park 인공습지에서 T-P의 26.2%, T-N의 38.3%, 식생분포가 안정적이지 않은 Woodcroft park에서 14.0%와 20.2%가 각각 제거됨으로서 인공습지에서 식물체와 식물체 근권 미생물에 의한 T-P 및 T-N의 제거 효율이 상당히 큼을 알 수 있었다. 또한 T-N와 T-P에 비하여 $NH_4-N$, $NO_3-N$, $PO_4^{-3}$의 제거율이 높았던 것은 무기태 형태의 영양염류가 식물 및 미생물에 더 쉽게 이용되었기 때문으로 생각된다. 이상의 결과로 볼 때 인공습지에서 식물체와 근권 주위 미생물에 의한 염류제거는 인공습지가 설치한지 오래되었을 때도 효과적이었고, 또한 인공습지는 무기태 영양염류의 제거효율이 더욱 높았으므로 무기화학비료 등의 용탈이 일어나기 쉬운 농경지 비점오염원으로 부터 발생하는 수질오염의 개선에 이용할 수 있는 경제적이고도 효율적인 system으로 고려되었다.

• 한국환경농학회지
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• 제21권4호
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• pp.269-273
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• 2002

근자연형 인공습지에 식재한 부들이 거의 죽지 않고 활착하였으며, 7월부터 새줄기가 일부 나오기 시작하였다. 부들의 활착과 성장은 양호한 편이었다. 개수부에는 부들의 새줄기가 나오지 않았다. 조사기간 인공습지의 평균 $NO_3-N$와 평근 TN 제거율은 각각 85.8 $mg/m^2/day$, 174.4 $mg/m^2/day$를 나타냈다. 북미에서 운영중인 인공습지의 평균$NO_3-N$ 제거율 125 mg $N/m^2/day$와 평균 TN 제거율 513 mg $N/m^2/day$ 보다는 다소 낮다. 이들 북미습지는 조성 후 수년이 지나 습지의 기질층이 $NO_3-N$ 및 TN 제거에 양호한 조건을 갖춘 습지들이다. 본 연구 인공습지의 조사기간이 조성 후 초기이고, 조사기간에 겨울철 일부 기간이 포함되어 있는 점을 고려하면 $NO_3-N$과 TN제거율이 양호한 편이라 사료된다. 본 연구습지의 부들이 2$\sim$3년 후 개수부 이외의 습지를 완전히 덮고, 부들의 잔재물이 습지바닥에 쌓여 탈질화에 필요한 탄소공급원의 역할을 하면 $NO_3-N$ 및 TN 제거율이 높아질 것으로 사료된다. 기존의 인공습지는 수질정화 측면을 강조하여 일정한 수심유지와 유입수의 단기이동 방지를 위해 습지바닥을 수평으로 균일하게 조성하여 왔다. 최근 들어 인공습지 설계에서 친환경적인 측면이 강조되는 추세이다. 본 근자연형 인공습지는 제방에 면한 습지바닥의 일부에 완만한 경사를 두고 습지외곽의 모습을 타원형으로 조성하여 자연습지의 모습과 가급적 유사한 모습으로 조성하였다. 초기 조사분석결과 질소정화가 정상적으로 이루어지고 있어, 습지일부에 완만한 경사를 도입하여 자연습지와 유사한 모습으로 수질정화 인공습지의 조성이 가능할 것으로 사료된다.

• 한국작물학회지
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• 제54권1호
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• pp.29-35
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• 2009

The aim of the present study was to update the calibration that is used for the measurement of the total nitrogen content in the rice plant samples by using the visible and near infrared spectrum. Before the equation merge, correlation coefficient of calibration equation for nitrogen content on each rice parts was 0.945 (Leaf), 0.928 (Stem), and 0.864 (Whole plant), respectively. In the calibration models created by each part in the rice plant under the various regression method, the calibration model for the leaf was recorded with relatively high accuracy. Among of those, the calibration equation developed by Partial least squares (PLS) method was more accurate than the Multiple linear regression (MLR) method. The calibration equation was sensitive based on variety and location variations. However, we have merged and enlarged various of the samples that made not only to measure the nitrogen content more accurately, but also later sampling populations became more diversified. After merging, $R^2$ value becomes more accurate and significantly to 0.950 (L.), 0.974 (S.), 0.940 (W.). Also, after removal of outlier, R2 values increased into 0.998, 0.995, and 0.997. In view of the results so far achieved, Standard error of prediction (SEP) and SEP (C) were reduced in the stem and whole plant. Biases were reduced in the leaf, stem as well as whole plant. Slopes were high in the stem. Standard deviation reduced in the stem but $R^2$ was high in the stem and whole plant. Result was indicated that calibration equation make update, and updating robust calibration equation from merge function and multi-variate calibration.

• 한국습지학회지
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• 제6권2호
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• pp.57-63
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• 2004

습지는 환경 생태적으로 다양한 기능을 가지고 있으며, 이 중 특히 수질정화기능에 초점을 두고 전 세계적으로 1000여개 이상의 습지가 수처리 및 수질개선에 이용되고 있다. 자연습지 및 인공습지를 이용한 수처리 과정에서 BOD, SS, N, P, 대장균과 중금속의 제거효율을 확인한 결과, BOD의 제거효율은 약 84%로 가장 높게 나타났으며, 질소의 제거효율은 48%로 가장 낮았다. 또한 인의 제거효율은 평균 67%이며 유입되는 인의 농도가 높을수록 인의 처리 효율이 떨어지는 것을 알 수 있었다. 국내 관련연구의 경우, 대부분 습지의 유입수와 유출수의 농도 변화조사와 식물체내 영양염류 농도 조사가 주를 이루어 실질적으로 인공습지 내에서 영양염류가 제거되는 기작을 밝히는 연구 및 영양염류 제거에 관여하는 미생물에 관한 연구가 미흡한 실정이다. 따라서 수질정화에 최적의 인공습지 건설 및 운영이 가능하기 위해서는 복합적 영양염류 제거기작의 규명 및 지질학적, 수리학적인 연구가 병행되어야 할 것이다.

• Journal of Microbiology
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• 제42권1호
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• pp.1-8
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• 2004

Changes in the bacterial populations of a 5-stage biological nutrient removal (BNR) process, with a step feed system for wastewater treatment, were monitored by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA fragments. DGGE analysis indicated seasonal community changes were observed, however, community profiles of the total bacteria of each reactor showed only minor differences in the samples obtained from the same season. The number of major bands was higher in the summer samples, and decreased during the winter period, indicating that the microbial community structure became simpler at low temperatures. Since the nitrogen and phosphate removal efficiencies were highly maintained throughout the winter operation period, the bacteria which still remaining in the winter sample can be considered important, playing a key role in the present 5-stage BNR sludge. The prominent DGGE bands were excised, and sequenced to gain insight into the identities of the predominant bacterial populations present, and most were found to not be closely related to previously characterized bacteria. These data suggest the importance of culture-independent methods for the quality control of wastewater treatment.

• 한국환경복원기술학회지
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• 제10권3호
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• pp.1-7
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• 2007

For waste water treatment, artificial wetland was constructed in 1998. The size of artificial wetland is 20m${\times}$200m, with sand and gravel as media and Phragmites japonica was implanted. The removal rate of BOD, TN, and TP were 86%, 33% and 25% from June 2004 to November 2005 respectively, while those were 88%, 38% and 55% in 1999. Organic materials and nitrogen compounds are still effectively removed, after 6 years of construction, but the removal efficiency of phosphorus compounds is reduced. So for sustaining of artificial wetland as waste water treatment system, the removal efficiency of phosphorus compounds must be elevated.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권3호
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• pp.194-199
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• 2001

Chlorella kessleri cultivated in artificial wastewater using diurnal illumination of 12h light/12h dark (L/D) cycles. The inoculum density was 10(sup)5 cells/mL and the irradiance in light cycle was 45$\mu$mol㎡s(sup)-1 at the culture surface. As a control culture, another set of flasks was cultivated under continuous illumination. Regardless of the illumination scheme, the total organic carbon (TOC) and chemical oxygen demand (COD) was reduced below 20% of the initial concentration within a day. However, cell concentration under the L/D lighting scheme was lower tan that under the continuous illuminating scheme. Thus the specific removal rate of organic carbon under L/D cycles was higher than that under continuous illumination. This result suggested that C. kessleri grew chemoorganotrophically in the dark periods. After 3 days, nitrate was reduced to 136.5 and 154.1mg NO$_3$-N/L from 168.1mg NO$_3$-N/L under continuous illumination and under diurnal cycles, respectively. These results indicate nitrate removal efficiency under continuous light was better than that under diurnal cycles. High-density algal cultures using optimized photobioreactors with diurnal cycles will save energy and improve organic carbon sources removal.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.363-369
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• 2011

Total ammonia nitrogen (TAN) removal efficiencies of a sand filter (SF), polystyrene microbead filter (PF), and Kaldnes bead filter (KF) media were evaluated under ammonia loading rates of 5, 25, and 50 g $m^{-3}day^{-1}$. The volume of each filter media tested was 7 L, and the water flow rate for all filter media was 24 L/min. The specific surface areas of the SF, PF, and KF were 7,836, 3,287, and 500 $m^2/m^3$, respectively. Sand was fluidized and the other two media were trickle filtered. The volumetric TAN removal rate increased with increasing ammonia loading rate for all filter media. Mean volumetric TAN removal rates under the ammonia loading rates of 5, 25, and 50 g $m^{-3}day^{-1}$ in SF (39.3, 168.6, and 322.7 g $m^{-3}day^{-1}$, respectively) were higher than those in PF (35.0, 157.4, and 310.5 g $m^{-3}day^{-1}$, respectively) and KF (32.1, 142.5, and 288.1 g $m^{-3}day^{-1}$, respectively). These results were related to differences in the specific surface areas of the filter media. PF was the most economic media for efficiently removing TAN.

• 한국축산시설환경학회지
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• 제1권1호
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• pp.47-53
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• 1995

An efficient Treatment of animal wastewater is one of the hot issues for preventing the environmental pollution. It should be established the design parameter in order to purify the animal wastewater. A test is carried on in the pilot plant as a simplified activated sludge process. A vibration sieve separator is deviced to keep the pollution load constant by means of separation of solid matter. The BOD removal efficiency of the vibration sieve showed over 50%. As the test results, the BOD contents of the influent was in average of 3,000 mg/I and that of the effluent 85 mg/I. So, the BOD removal rate showed 97% in average. The SS-contents in the primary chamber was about 3,300 mg/I and that of effluent 92 mg/I. The SS removal efficiency showed 97%. The removal rate of total nitrogen and phosphore were in average of 82% respectively. Carrying out in winter season, it showed relatively good results; The design parameter approved in this test can be applied to the full-time farmers.

• Carbon letters
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• 제7권1호
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• pp.1-8
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• 2006

The activated carbon "C" was obtained by carbonization followed by activation with steam at 40% of burn-off. Oxidized carbons C-N, C-P and C-H were obtained by oxidizing the activated carbon C with concentrated nitric acid, ammonium peroxysulfate and hydrogen peroxide, respectively. The textural properties of the carbons were determined from nitrogen adsorption at 77 K. The acidic surface functional groups were determined by pH titration, base neutralization capacity and electrophoretic mobility measurements. The cation exchange capacities of un-oxidized and oxidized carbons were determined by the removal of Cu(II) and Ni(II) from their aqueous solutions. The surface area and the total pore volume decreased but the pore radius increased by the treatment of activated carbon with oxidizing agents. These changes were more pronounced in case of oxidation with $HNO_3$. The surface pH of un-oxidized carbon was basic whereas those of the oxidized derivative were acidic. The removal of Cu(II) and Ni(II) was pH dependent and the maximum removal of the both ions was obtained at pH of 5-6. Cu(II) was more adsorbed, a phenomenon which was ascribed to its particular electronic configuration.