• 한국물환경학회지
• /
• 제33권4호
• /
• pp.434-440
• /
• 2017

In order to understand the characteristics of phosphorus in the paddy field, this study analyzed $PO_4-P$ and T-P concentrations of irrigation water, flooding water, and runoff from 2008 to 2010. The variation of phosphorous form within hydrologic cycle around the rice paddy field was investigated using the ratio of $PO_4-P$ to TP. In addition, the correlation between pH, EC, and DO in flooding water was analyzed and the factors affecting phosphorus form in paddy field were investigated. The concentration of T-P in flooding water was high during the survey period, and the concentration of T-P in runoff was assumed to be decreased by dilution due to irrigation and rainfall. On the other hand, the ratio of $PO_4-P$ to T-P was lower in flooding water than those of irrigation water and runoff, which was interpreted to be due to the fact that the phosphorus fertilizer was applied in the paddy field but the adsorption was rapidly occurred to the paddy field by the soil. The similar proportions of $PO_4-P$ to T-P in flooding water and runoff suggest that the form of phosphorus outflowed from the paddy is influenced by the form of phosphorus in the flooding water of paddy field. In addition, DO concentration in flooding water showed negative correlation with the concentrations of $PO_4-P$ and T-P. The effort to survey frequent irrigation water quality data is required for the analysis of phosphorus behavior in the paddy water system since concentration of phosphorous and DO in irrigation water would influence rhe form of phosphorous in flooding water and subsequent runoff.

• 한국농공학회지
• /
• 제41권4호
• /
• pp.47-56
• /
• 1999

The concentration and load of T-N and T-P in paddy field areas in Chongwon, Chungbuk , Korea , were investigated during the irrigation period. The concentration of T-N and T-P in ponded water in paddies is higher than that in the irrigation, drainage and percolation waters. For T-N, the average concentration indrainage water was higher than that in irrigation water until end of Jung, But lower thereafter. The average T-N concentration in irrigation water was 2.3 ∼3.2mg/l and therefore the agricultural water quality standard at on-farm level for T-N should be established realistically . The expontial L(load)-Q(discharge) equations have higher coefficients of determination than the linear L-Q equations . Especially, the exponential L-Q equation of T_N showed a coefficient of determinatino of over 0.9 for irrigation water.

• Mass Spectrometry Letters
• /
• 제12권1호
• /
• pp.26-30
• /
• 2021

The impurity concentration is a crucial parameter for semiconductor thin films. Evaluating the impurity distribution in silicon thin film is another challenge. In this study, we have investigated the doping concentration of boron in silicon thin film using time of flight secondary ion mass spectrometry in dynamic mode of operation. Boron doped silicon film was grown on i) p-type silicon wafer and ii) borosilicate glass using hot wire chemical vapor deposition technique for possible applications in optoelectronic devices. Using well-tuned SIMS measurement recipe, we have detected the boron counts 101~104 along with the silicon matrix element. The secondary ion beam sputtering area, sputtering duration and mass analyser analysing duration were used as key variables for the tuning of the recipe. The quantitative analysis of counts to concentration conversion was done following standard relative sensitivity factor. The concentration of boron in silicon was determined 1017~1021 atoms/㎤. The technique will be useful for evaluating distributions of various dopants (arsenic, phosphorous, bismuth etc.) in silicon thin film efficiently.

• 한국환경과학회지
• /
• 제12권3호
• /
• pp.345-358
• /
• 2003

Jindong bay at the northwestern part of Jinhae bay suffers from the occurrence of red tides in summer every year. In order to study the management methods of coastal environments, an ecological numerical model has been developed. The model experiments was forecasted that the load of nutrients from the land and field concentration will be cut down per 10% each. When we cut down 57.2% nitrogen load in the inner bay and 38.4% phosphorous load in the outer bay of bottom layer of the nutrients load from land and field concentration, the seawater quality standard levels up first grade. When we cut down 86.5% nutrients in the inner bay and 93.0% nutrients in the outer bay, the concentration of chlorophyll a decreases below 3.2 $\mu\textrm{g}$/(equation omitted)(an individual concentration of phytoplankton : 10,000cel1/ml), i.e. the red tides do not occur.

• 한국환경복원기술학회지
• /
• 제9권6호
• /
• pp.78-85
• /
• 2006

This study was to analyze vegetation and soil characteristic, and ordination of Bupleurum latissimum community located in Seo-Myun, Isl. Ulleungdo. The Bupleurum latissimum community was classified into Physocarpus insularis subcommunity and Artemisia stolonifera subcommunity, and there was Artemisia stolonifera subcommunity in destroyed site of Bupleurum latissimum community. In the study sites, soil organic matter, nitrogen, available phosphorous, changeable potassium, changeable calcium, changeable magnesium concentration, cation exchangeable capacity, and soil pH were ranged from 19.0~25.6%, 0.67~0.96%, 47.8~103.0ppm, 2.4~2.8(me/100g), 13.8~15.0(me/100g), 8.4~9.0 (me/100g), 34.0~38.4(me/100g), and 5.9~6.0, respectively. The Bupleurum latissimum community had higher nitrogen, exchangeable magnesium, and available phosphorous concentration than in Bupleurum euphorbioides and Bupleurum longiradiatum community. The Berberis amurensis var. latifolia and Valeriana officinalis var. latifolia that was companion species of Bupleurum latissimum community was found in area of having high soil organic matter and nitrogen concentration. The Ligustrum foliosumwas found in shrubbery, and so the reason could give little competition with Bupleurum latissimum community. The Bupleurum latissimum is the endangered species managed by Ministry of Environments in Korea. Its community has been destroyed, and so we need any action to protect the community.

• 한국물환경학회지
• /
• 제22권5호
• /
• pp.943-951
• /
• 2006

Spatial distribution of water pollution in the Gap Stream was investigated from October to November, 2005. Sampling was conducted three times including effluents discharged from a wastewater treatment plant (WWTP) and a dam reservoir during the low-flow period. As a typical urban stream, total nitrogen and inorganic nitrogen concentrations increased toward downstream. Ammonia concentration was the highest in the treated water of the wastewater treatment plant and the lowest nitrate concentration was found in the effluent of the dam reservoir. A part of soluble reactive phosphorous (SRP) in total phosphorous was 22~54% in the upstream reach of WWTP in the Gap Stream whereas 68~73% in the downstream reach. Mean chlorophyll-a concentration ranged from 1.6 to $11.0{\mu}g/L$ and it tends to increase toward downstream except for WWTP effluent. As expected, untreated wastewater and WWTP effluent were suggested as the major sources of water pollution in the Gap Stream. In this study, the water pollution of the Gap Stream is a significant undergoing typical eutrophication, caused by excessive phosphorus and nitrogen nutrients from WWTP located in the watershed. As a result, the critical factor for the water pollution was evaluated to dissolved inorganic nitrogen and phosphorus nutrients. Particularly, SRP is a most important for the eutrophication. It suggest that may occur in the most urban streams of Korean peninsula. Therefore, because the necessity of water pollution management in the urban stream, inorganic N and P nutrients should be included as an essential component of water quality criteria in the advanced water quality project of Korean Government by enforcing of water quality assessment and total maximum daily loads (TMDLs).

• 환경영향평가
• /
• 제5권2호
• /
• pp.21-31
• /
• 1996

To assess the impact resulted from the slag dumping, we studied that the changes in the concentration of heavy metal were researched through the statistic analysis at 4 stations in Yongil bay, Korea from 1988 to 1995. And in order to clarify resulting from the changes in heavy metal concentration due to be leaked out from dumped slag, it was fulfilled experiments of the slag extraction. In the extracting experiment, Pb and As were only leaked out from slag aged during 10 days but all of heavy metals were not from it aged during 90 or 180 days. It was found that the concentrations of heavy metals in sea water of vincinity of slag dumping area were still remained in similar, comparing with it of control site(site 4) when they were by analysed statistic method, anova test and Mann-Whitney test. The slag recycling ratio of our country is lower than foreign country. While we need to apply a new process for phosphate treatment, foreign country already apply a slag to phosphorous removal. We suggest that slag dumping cannot putatively affected the changes in the concentration of heavy metal. And we thought that impact of heavy metal induced by slag dumping was not severe. So, it is necessary to utilize this process in phosphorous removal, like a foreign country.

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

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

• 한국임상수의학회지
• /
• 제18권1호
• /
• pp.18-21
• /
• 2001

In this study, we assessed the efficacy of a novel B. amyloliquefacience DS11 phytase (DS11 phytase) and that of a commercial Aspergillus ficcum phytase (AF phytase) through their bioavailabilities of phytin-posphorus and -calcium in the diet using cannulated pigs. For the purpose of evaluating the efficacy of the phytases in pigs, we determined phosphorous concentrations from serum and feces, in addition to ingesta obtained from the cannula at the terminal ileum. As results, phosphorus concentration was lower in feces from DS11 group and BASF group by 17% and 10%, and higher in serum from the respective groups by 34% and 20%, as compared to the control group. Both phytases are evaluated to enhance phosphorus availability to the great extent. Calcium concentration of feces were lower in DS11 group and BASF group by 31% and 10%, than that in the control. Calcium concentration of serum was higher in DS11 phytase group by 4% but lower in AF phyase group by 3%, then that in the control group.