• 한국환경보건학회지
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• 제38권6호
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• pp.568-574
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• 2012

Objectives: The purpose of this experiment is to understand the phosphorus removal ratio effects of iron plates per unit of surface area through the iron electrolysis system, which consists of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis, which uses an iron precipitation reactor in anoxic and oxic basins, consisted of iron plates with total areas of 400 $cm^2$, 300 $cm^2$ and 200 $cm^2$ respectively. The FNR process was operated with a hydraulic retention time and a sludge retention time of 12 hours and three days, respectively. Wastewater used in the experiments was prepared by dissolving $KH_2PO_4$ in influent water. Results: The iron plates 400 $cm^2$ (16.6 $mA/cm^2$), 300 $cm^2$ (13.3 $mA/cm^2$) and 200 $cm^2$ (7.3 $mA/cm^2$) in surface area in the phosphorus reactor had respective phosphorus of 2.4 mg/l, 2.7 mg/l and 3.2 mg/l in the effluent and phosphorus removal respective efficiencies of 90.3%, 89.1% and 87.1%. The effluent in the reactor, where the iron plate was not used, had relatively very low phosphorus removal efficiency showing phosphorus concentration of 15.3 mg/l and a phosphorus removal efficiency about 38.3%. Phosphorus removal per ferrous was 0.472 mgP/mgFe in the iron electrolysis system where the surface area of iron was low. Phosphorus pollution load per active surface area and the phosphorus removal efficiency had an interrelation of RE = -0.27LS + 89.0 (r = 0.85). Conclusion: With larger iron plate surface area, the elution of iron concentration and phosphorus removal efficiency was higher. The removal efficiency of phosphorus has decreased by increasing the initial phosphate concentration in the iron electrodes. This shows a tendency of decreasing phosphorus removal efficiency because of decreasing of iron deposition as the phosphorus pollution load per active surface area increases.

• 한국잠사곤충학회지
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• 제9권
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• pp.39-42
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• 1969

1. 무기인은 전반적으로 5령 4일째 공히 감소하고 5령 4일째 증가 하였다가 다시 감소하고 연엽구에 가장 많았고 편엽 중엽 혼엽구어서는 별로 큰 차가 없음을 알수 있었다. 2. 유기인은 5령 1일째부터 5일째까지 계속 증가를 나타냈으나 경엽구 5령 3일째에 증가하고 그 후는 감소하여 5일째에 약간 증가함을 나타내고 중엽구와 혼엽구는 계속 증가함을 알수 있었다. 3. 총 인을 공히 5령 3일째까지 큰 변동이 없었으나 연엽구완 혼엽구에서는 5령 4일째 가장 많았고 5일째까지 변동이 없었으나 경엽구는 5령 3일 이후 5일에 이르기까지 감소하고 중엽구늘 5령 4일째 증가하고 그 후는 감소함 알수 있었다. 4 병잠에서는 무기인 유기인 총인 다같이 5령초기부터 감소함을 알 수 있었다.

• 한국물환경학회지
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• 제34권1호
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• pp.26-32
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• 2018

In order to analyze the effects of sediment on the occurrence of algal bloom on the Giheung Reservoir, the contamination levels of sediments were evaluated. The concentrations of various organic compounds (ignition loss), as well as the total nitrogen, total phosphorus, and heavy metals (Zn, Cr, Co, Ni, Pb, As, Hg, Cd) were analyzed in the sediments taken at eighteen sites of the reservoir. The concentrations of ignition loss and total nitrogen tended to increase from upstream to downstream, and ranged from 4.38 to 12.93% and 2,153 to 4,723 mg/kg, respectively. Heavy metals were in the order of Zn>Cr>Co>Ni>Pb>As>Hg, and the contamination level of the heavy metals was not high as a whole. The concentrations of the total phosphorus were in the range of 765 ~ 3,238 mg/kg, which exceeded the contamination level of the "Sediment Quality Assessment Guideline of River and Lake Sediment (Rule No. 2015-687 of the National Institute of Environmental Research, Korea)" at two upstream sites, four downstream sites, and all downstream sites. These results indicated that the pollution level of the total phosphorus, which is the main factor related to algal bloom, was found to be serious. Therefore, it is necessary to establish a countermeasure for sediment management in order to control the algal bloom which occurs periodically in the reservoir.

• 생태와환경
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• 제40권4호
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• pp.511-519
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• 2007

It is known that phytoplankton biomass or turbidity are lower in waters with submerged macrophytes than those without submerged plants at a given nutrient level. We hypothesize that presence of submerged macrophytes would lower phytoplankton biomass below levels expected by total phosphorus levels through various mechanisms and that phytoplankton biomass would decrease more as the biomass increase of the submerged macrophytes. To find submerged macrophytes effectively lowering phytoplankton growth, we conducted spatial field surveys at 21 water bodies and a temporal monitoring at Seung-un 1 Reservoir, Anmyyeondo Island. We measured chlorophyll ${\alpha}$ concentrations and total phosphorus (TP) concentrations from waters in patches of submerged macrophytes with measurements of submerged plant biomass. Majority of our sites with submerged macrophytes showed much less chlorophyll a concentrations than the predicted ones from literature. Among submerged macrophytes studied, Myriophyllum spicatum and Hydrilla verticillata showed patterns of lowering chlorophyll ${\alpha}/TP$ ratios with increase of their biomass in both spatial and temporal surveys.

• Animal cells and systems
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• 제7권4호
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• pp.289-294
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• 2003

To quantify nutrient loading from emergent macrophytes through leaching in the littoral zones of Paldang Reservoir, we conducted incubation experiments using leaf litter of the emergent macrophyte, Zizaniz latifolia. To separate the leaching process from microbial decay, we used $HgCl_2$ to suppress microbial activity during the experiment. We measured electric conductivity, absorbance at 280nm, total nitrogen and dissolved inorganic nitrogen, total phosphorus and soluble reactive phosphorus, Na, K, Mg and Ca amounts in leaf litter and in water. In addition, we examined the effects of water temperature and ion concentrations of ambient water on the leaching process. A total of 6% of the initial ash-free dry mass of leaf litter was lost due to leaching during incubation (four days). Electric conductivity and A280 continued to increase and saturate during the incubation. To compare reaching rates of different nutrients, we fitted leaching dynamics with a hyperbolic saturation function [Y=AㆍX/(B+X)]. From these fittings, we found that ratios of leaching amounts to nutrient concentration in the litter were in the order of K > Na > Mg > P > Ca > N. Leaching from leaf litter of Z. latifolia was dependent on water temperature while it was not related with ion concentrations in the ambient water. Our results suggest that the leaching process of nutrients, especially phosphorus, from aquatic macrophytes provides considerable contribution to the eutrophication of the Paldang Reservoir ecosystem.

• 한국농공학회지
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• 제44권3호
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• pp.136-145
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• 2002

Monitoring data from agricultural reservoirs throughout the country were analyzed to evaluate the limiting factor fur algal growth and relationships between Chl-a, total phosphorus (TP), and total nitrogen (TN). Total 394 reservoirs ranging from below 500 ㎥ to over 50 million ㎥ in storage volume were monitored from 1990 to 2000 with respect to TP, W, Chl-a, and their annual mean values were used fur the analysis. Based on N/P ratio, the dominant limiting factor for algal growth was turned out to be phosphorus in agricultural reservoirs (about 83%). Therefore, the proper managements of phosphorus in the agricultural watershed appear to be crucial to prevent excessive on algal growth. The effects of phosphorus and nitrogen ware most eminent during the summer period. And the effect of nutrients on the algal biomass (Chl-a) development appeared to be greater in smaller the reservoirs than in larger ones. Generally, Chl-a and TP demonstrated a close relationship while that of Chl-a and TN showed less correlationship. Chl-a and chemical oxygen demand (COD) also showed a good relationship. Beth ratios of Chl-a / TP and Chl-a / COD relationships were within the range of literature values. Quantitative analysis of TP and COD is relatively convenient compared to that of Chl-a, and the relationship between TP and COD and Chl-a from this study could be used beneficially for water quality management of agricultural reservoirs and related water quality modeling.

• 한국환경농학회지
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• 제20권5호
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• pp.335-339
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• 2001

Two successive in vitro experiments were carried out to examine the effect of MPS bacterial inoculation on growth, and nitrogen and phosphorus accumulation of maize plants under greenhouse condition in the same soil. There were four treatments, uninoculated control and three phosphate solubilizing bacterial inoculations, viz., Pseudomonas striata, Burkholderia cepacia and Serratia marcescens. The inoculated plants showed the higher plant height, total dry mass, nitrogen and phosphorus accumulation when compared to uninoculated control plants in both experiments. In the combined data analysis from two experiments, the plants inoculated with P. striata and B. cepacia showed significantly higher plant height, total dry mass and P accumulation when compared to S. marcescens inoculated plant and uninoculated control plants. The P. striata and B. cepacia inoculation enhanced total dry matter accumulation by 14% and phosphorus accumulation by 25% over the uninoculated control plants. The nitrogen and phosphorus concentration of maize plants were also increased due to MPS bacterial inoculation, however, the effect was not significant.

• 한국해양환경ㆍ에너지학회지
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• 제4권3호
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• pp.16-27
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• 2001

시화호 퇴적물에서 인의 지화학적 특성을 연구하였다 퇴적인의 가장 큰 형태는 detrital apatite P와 Al-bound P이며 무산소환경이기 때문에 Fe-bound f는 그 비중이 낮았다. 퇴적총인과 유기물의 상관성으로 볼 때, 퇴적물로 제거되는 인의 거동은 유기물에 의해 조절되는 것으로 나타났다. 또한, 유기물 유입의 영향을 직접적으로 받는 정점 Cl에서 정점 C2에 비해 퇴적인의 함량, 유기물과의 상관성, 황산염환원에 의한 공극수내 인산염의 함량 및 플럭스가 높게 나타났다. 결국 시화호 퇴적물에서 인의 함량, 형태 및 공간에 따른 차이는 유기물에 의해 조절되는 것으로 밝혀졌다.

• 한국식품위생안전성학회지
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• 제12권2호
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• pp.107-110
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• 1997

To examine the effects of residual phosphorus content on color reversion and storage stability of corn germ oil, the changes of Lovibond total color and stability of oxidation were determined according to the different storage periods at room and incubating temperature, respectively. The residual phosphorus content and storage temperature had the synergistic effect on color reversion during short time storage. The extent of color change was the greatest when oils were stored for 1.0∼1.5 years at room temperature and thereafter gradually tended to reverse color reversion. It is supposed that the double bonds of carotenoids in oils were oxidized and then turned to the volatiles such as epoxide, ionone, and etc. In contrast, the residual phosphorus content increased oxidation stability of oils. The residual phosphorus content was closely correlated with the color reversion and storage stability, respectively.

• 한국물환경학회지
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• 제29권2호
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• pp.170-175
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• 2013

Achieving very low phosphorus levels in treated wastewater will require the installation of additional treatment. Phosphorus removal experiments by chemical coagulation were carried out for the effluent of wastewater treatment plant in this study. TP (total phosphorus) or phosphate were highly related to the addition of PAC (poly aluminium chloride) which is one of the inorganic coagulants. But, organic polymer did not significantly affect the phosphorus removal efficiency. Polymer affected the flocculation of particle especially particle matter less than 10 micrometer so, the number of micro particles was decreased by polymer dose. Chlorination would not affect on chemical coagulation process and TP and turbidity could be effectively removed by the co-addition of PAC and polymer.