• 한국수산과학회지
• /
• 제43권5호
• /
• pp.540-546
• /
• 2010

We investigated variations in alkaline phosphatase (APase) activity and alkaline phosphatase hydrolyzable phosphorus (APHP) in northern Gamak Bay from September to December 2009. Dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) decreased gradually, and the DIN/DIP ratio was higher than the Redfield ratio (16) based on molecular concentrations during most of the observation period. The total APase (T-APase) activity increased with decreasing DIP concentration; i.e., the Relationship between T-APase and DIP showed a high negative correlation (r=-0.80, P<0.001), with APase activity being a good indicator of DIP limiting the Redfield ratio. The T-APase was positively correlated with the concentration of chlorophyll a (r=0.73, P<0.001). This suggests that a major portion of APase activity in northen Gamak Bay seawater is attributed to phytoplankton. The proportion of APHP among dissolved organic phosphorus (DOP) was low in September and high in November. Thus, APase-producing phytoplankton may be able to grow by utilizing APHP as a phosphorus source in autumn when DIP is limiting. Thus, APase activity and the use of DOP by phytoplankton may play an important role in the growth of phytoplankton under DIP limiting conditions such as those of northern Gamak Bay.

• 한국농공학회논문집
• /
• 제58권2호
• /
• pp.1-9
• /
• 2016

This study aims to assess the effectiveness of activated carbon (AC) and crushed concrete (CC) as capping material to block the release of nitrogen, phosphorus, and organic substance from reservoir sediments. The efficiency of AC and CC as capping material was evaluated in a reactor in which a 1 or 3 cm thick layer of capping materials was placed on the sediments collected from Mansu reservoir in Anseong-city. Dissolved oxygen (DO) concentration, total nitrogen (T-N), total phosphorus (T-P), and chemical oxygen demand (COD) concentration in reservoir water above the uncapped sediments and capping material were monitored for 45 days. The release rate of T-N was in the following increasing order: AC 3 cm ($1.18mg/m^2{\cdot}d$) < CC 1 cm ($2.66mg/m^2{\cdot}d$) < AC 1 cm ($2.94mg/m^2{\cdot}d$) < CC 3 cm ($3.42mg/m^2{\cdot}d$) < uncapped ($4.59mg/m^2{\cdot}d$). The release rate of T-P was in the following increasing order: AC 3 cm ($0mg/m^2{\cdot}d$) $${\approx_-}$$ CC 3 cm ($0mg/m^2{\cdot}d$) < CC 1 cm ($0.03mg/m^2{\cdot}d$) < AC 1 cm capped ($0.07mg/m^2{\cdot}d$) < uncapped ($0.24mg/m^2{\cdot}d$). The release of nitrogen and phosphorus were effectively blocked by AC capping of 3 cm thickness, and CC capping of 3 cm thickness effectively controlled the release of phosphorus. The order of increasing COD release rate was as follows: AC 3 cm ($0mg/m^2{\cdot}d$) $${\approx_-}$$ CC 3 cm ($0mg/m^2{\cdot}d$) < CC 1 cm ($5.03mg/m^2{\cdot}d$) < AC 1 cm ($7.28mg/m^2{\cdot}d$) < uncapped ($10.05mg/m^2{\cdot}d$), indicating that AC and CC capping effectively interrupted the release of organic contaminants from the sediments. It was concluded that AC and CC could effectively block the release of T-N, T-P and COD release from contaminated reservoir sediments.

• 한국콘텐츠학회논문지
• /
• 제6권10호
• /
• pp.1-8
• /
• 2006

퍼지 적분을 이용하여 금강지천의 수질 오염을 평가하는 새로운 시스템을 연구하였다. 이 논문은 BOD(biochemical oxygen demand, 생물학적인 산소 요구량), COD(chemical oxygen demand, 화학적인 산소요구량), SS(suspended solids, 부유물질), T-N(total nitrogen, 총질소), T-P(total phosphorus, 총인)의 다섯 가지의 수질 오염 평가 항목에 대한 자료를 기반으로 하였다. 퍼지 적분의 측량은 수질 오염이 어떤 요소의 의존 정도에 따라 결정지어진다. 척도들 간의 측정치를 평가하여 금강의 지천을 [0,1]사이에 분포하도록 정규화 시켰다. 퍼지 적분을 이용하여 금강의 지천에 수질 오염 척도를 정량적으로 나타내었다. 결론적으로 금강의 지천에 수질의 오염 정도를 새로운 시스템으로 평가하는 방법을 제시하고자 한다.

• 한국환경농학회지
• /
• 제27권1호
• /
• pp.50-59
• /
• 2008

A greenhouse experiment was conducted to investigate the role of the arbuscular mycorrhizal(AM) fungus, Glomus mosseae(BEG 107) in enhancing growth and arsenic(As) and phosphorus(P) uptake of white clover(Trifolium repens) and evening primrose(Oenothera odorata) in soil collected from a gold mine having concentrations of 381.6 mg total As $kg^{-1}$ and 20.5 mg available As $kg^{-1}$. Trifolium repens and O. odorata are widely distributed on abandoned metalliferous mines in Korea. The percent root colonization by the AM fungus was 55.9% and 62.3% in T. repens and O. odorata, respectively, whereas no root colonization was detected in control plants grown in a sterile medium. The shoot dry weight of T. repens and O. odorata was increased by 323 and 117% in the AM plants compared to non-mycorrhizal(NAM) plants, respectively. The root dry weight increased up to 24% in T. repens and 70% in O. odorata following AM colonization compared to control plants. Mycorrhizal colonization increased the accumulation of As in the root tissues of T. repens and O. odorata by 99.7 and 91.7% compared to the NAM plants, respectively. The total uptake of P following AM colonization increased by 50% in T. repens and 70% in O. odorata, whereas the P concentration was higher in NAM plants than in the AM plants. Colonization with AM fungi increased the As resistance of the host plants to As toxicity by augmenting the yield of dry matter and increasing the total P uptake. Hence, the application of an AM fungus can effectively improve the phytoremediation capability of T. repens and O. odorata in As-contaminated soil.

• Journal of Plant Biology
• /
• 제13권3호
• /
• pp.25-31
• /
• 1970

The ratio of occurrence of azalea (Rhododendron mucromultum T.) was determined on the north and south facing slopes on a mountain in Koyang county, Kyungi Province. Data was actually recorded at the eight aspects facing N, NE, E, SE, S, SW, W and NW on the mountain. In each of the eight aspects, six 10m transect tapes were placed in parallel directly down the slope, each 1m apart, and fifty 1$m^2$ quadrats were constructed between them. Frequency of the azalea in each of these quadrats was determined by counting the central stumps of the bushes Soil samples were also taken from pits dug in each plot to use for determination of the following: Soil pH, soil moisture loss on ignition, total nitrogen, and available phosphorus. The occurrence rate of azalea on the northern slop e was found to be for higher on the northern slope than on the southern slope. The abundance of azalea on the northern slope was found to be partially correlated with soil moisture(r=0.93; 0.01>p) and the amount of humus in the soil (r=0.04;0.01>p). The content of total nitrogen, soil PH, and available phosphorus in the soil, however, were found to have no evident relationship with the abundance of azalea. The conditions for growth in the species of azalea Rhododendron mucronulatum T'. were generally found to be more favorable on the northern slope.

• 한국농공학회지
• /
• 제45권7호
• /
• pp.49-56
• /
• 2003

Nonpoint source pollutant loading from watershed may cause a problem to the water quality of the reservoir and stream. The characteristics of stream flow and water quality were monitored to investigate the runoff loading of the Namdae-cheon watershed from May in 1999 to October in 2003. Stage-discharge rating curve at the stream gauging site was established, and annual stream runoff of the study watershed was estimated as 499.4∼1,330.8mm during four years. The concentrations of total-nitrogen and total-phosphorus of stream water quality ranged from 0.76 to 6.95mg/L and from 0.0010 to 0.2276 mg/L, respectively, where T-N was generally higher than the water quality standard 1.0 mg/L for agricultural water use. The loads by unit generation of pollutant mass with respect to population, livestock, land use in this watershed were calculated. The runoff pollutant loadings by concentrations of total-N and total-P were estimated during study period, where the annual runoff loading of total-P was much less than the load by pollutant mass unit generation. The relations between stream discharge and water quality were analysed, and there was a high correlation for total-N but low for total-P. These results will be used to develop the monitoring techniques and water quality management system of agricultural watershed.

• 환경영향평가
• /
• 제26권6호
• /
• pp.524-537
• /
• 2017

사후환경영향조사 결과의 신뢰도 제고에 대한 문제가 대두되어 왔으나 조사결과에 대한 객관적인 검증을 수행한 연구가 미흡한 실정이다. 본 연구에서는 개발 사업에 의한 수질영향을 조사하였고 그 결과를 바탕으로 사후환경영향조사 시 수질분야에 결과와 비교 분석을 수행하였다. 토석채취사업장 내 오수처리시설 최종방류수에 Biochemical oxygen demand(BOD), Suspended solid(SS), Total nitrogen(T-N), Total phosphorus(T-P) 농도가 높게 나타났다. 사후환경영향조사 결과와 비교한 결과, 오수처리시설 최종방류수의 BOD, SS, T-N, T-P 농도가 사후환경영향조사 시 분기별 농도의 사분범위(Interquartile range, IQR)와 최소값과 최대값의 농도범위보다 높게 나타났다(p<0.05). 체육시설(훈련원) 조성사업의 경우에는 오수처리시설 최종방류수에 BOD, SS, T-N, T-P가 높은 농도로 검출되었고 BOD와 SS 농도는 협의기준을 초과하였다. BOD와 SS 농도는 사후환경영향조사 시 오수처리시설 최종방류수의 농도와 유의한 차이를 나타냈다(p<0.05). 이러한 연구결과, 개발 사업 시 오수처리시설 최종방류수에 대한 체계적인 수질 모니터링과 적절한 수질관리가 수행되어야 할 것이다. 또한 사후환경영향조사결과의 신뢰도 제고를 위한 방안이 모색되어야 할 것이다.

• 한국환경과학회지
• /
• 제28권5호
• /
• pp.511-520
• /
• 2019

This study was investigated to improve the phosphorus release and water quality by transformation of sedimentary P fraction for application of $CaO_2$. For the experiment, 0.5% (w/w) of $CaO_2$ was homogenized in the sediment and incubated with the control for 20 days. The analytical results showed that pH increased with $CaO_2$ and redox potential (ORP) was improved in the sediment of the reactor. The growth rate of chlorophyll-a was lower in the $CaO_2$ reactor and Dissolved Oxygen (DO) of overlying water maintained higher than that of the control. Total phosphorus (T-P) concentration in the overlying water increased from the initial concentration to 0.304mg/L in the control at 20 days. The reactor of $CaO_2$ was lowered by 29.3%. Ex-P, Fe-P and Ca-P in sediment P fraction were increased with the $CaO_2$. The formation of bound Fe-P and Ca-P in the sediments seemed to control the release of P by removing the Soluble Reactive Phosphorus (SRP) presented in the pore water. From the result, this indicated that the reduction of P release from the sediments seems to be effective in suppressing the eutrophication of P and improving the oxygen condition in the water quality with the application of $CaO_2$.

• 한국농공학회논문집
• /
• 제53권1호
• /
• pp.63-69
• /
• 2011

The green algae Scenedesmus acuminatus was cultured in different media: animal wastewater and an artificial culture medium in order to evaluate potential use for tertiary treatment. The experiments were conducted with air flowrate 1~2 L/min at $28{\sim}30^{\circ}C$. The nitrogen and phosphorus showed very similar removal efficiencies (68~77 % and 69~80 % for nitrogen and phosphorus respectively). The optimal fed period was estimated as three days in the semi-continuous experiment. The effects of $CO_2$ (4.5 %) injection on nutrient uptake from animal wastewater (biological treatment effluent) were compared to an air injection under the same conditions of light and photoperiod. The uptake rates of nutrient with air injection were observed 0.009 gN/gChl-a/day, 0.028 gN/gChl-a/day and T-P 0.003 gP/gChl-a/day for nitrate, total nitrogen and phosphorus respectively. The rates were enhanced by addition of $CO_2$ to 0.026 gN/gChl-a/day, 0.076 gN/gChl-a/day and T-P 0.018 gP/gChl-a/day. This study establishes that $CO_2$ addition during nutrient deprivation of microalgal cells may accelerate tertiary wastewater treatment.

• 한국작물학회지
• /
• 제50권2호
• /
• pp.112-119
• /
• 2005

The effects of Rhizobium inoculant, nitrogen, phosphorus, and molybdenum on nodulation, dry matter production, yield attributes, pod and seed yields, protein and phosphorus contents in seed of pea (pisum sativum) var. IPSA Motorshuti-3 were assessed by a field experiment. Among the treatments Rhizobium inoculant in combination with 25kg P and 1.5kg Mo/ha performed best in recording number of nodules/plant, total dry matter yield, number of pods/plant, number of seeds/pod, 1000-seed weight, green pod yield, green and mature seed yields of pea. The highest green pod yield of 15.37 t/ha ($97.05\%$ increase over control) and green seed yield of 9.6t/ha ($69.31\%$ increase over control) were obtained by inoculating pea with Rhizobium inoculant in association with 25kg P and 1.5 Mo/ha. The effects of 60 or 120kg N/ha were comparable to Rhizobium inoculant in most cases. There were positive correlations among yield attributes, yield, protein and phosphorus contents in seeds of pea. From the viewpoint of yield attributes, yield, and seed quality, application of Rhizobium inoculant along with 25kg P and 1.5kg Mo/ha was considered to be the balanced combination of nutrients for achieving the maximum output from cultivation of pea in Shallow-Red Brown Terrace Soil of Bangladesh.