• Environmental Engineering Research
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• 제22권1호
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• pp.12-18
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• 2017

Struvite precipitation has been proven to be an effective method in removing and recovering ammonia nitrogen (N) and phosphate phosphorus (P) from wastewater. In this study, effects of pH, molar ratios and pre-treatment of effluent of anaerobically digested swine wastewater were investigated to improve struvite crystallization. The magnesium : ammonium : phosphate ratio of 1.2 : 1.0 : 1.0 was found to be optimal, yet the molar ratio in the wastewater was 1 : 74.9 : 1.8. From the analysis, the optimum pH was between 8.0 and 9.0 for maximal phosphate P release and from 8.0 to 10.0 for maximal ammonia N and phosphate P removal from real wastewater. Analysis from Visual MINTEQ predicted the pH range of 7-11 for ammonia N and phosphate P removal and recovery as struvite. For pre-treatment, microwave pre-treatment was ineffective for phosphate P release but ultrasound pre-treatment showed up to 77.4% phosphate P release at 1,000 kJ/L of energy dose. Precipitates analysis showed that phosphorus and magnesium in the collected precipitate had almost same values as theoretical values, but the ammonia content was less than the theoretical value.

• 한국응용과학기술학회지
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• 제30권2호
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• pp.264-271
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• 2013

본 연구에서는 monoammonium phosphate가 WPU의 물성에 끼치는 영향을 필름 상태와 피혁(Full-Grain) 표면에 코팅을 하여 기계적 물성을 분석 하였다. DSC 결과 monoammonium phosphate가 많이 함유된 WPU-AM3 샘플이 $382^{\circ}C$로 높은 물성이 측정되었으며, 내용제성은 모든 샘플이 우수함을 알 수 있었다. 인장강도의 경우 monoammonium phosphate가 가장 많이 함유된 WPU-AM3($2.130kg_f/mm^2$)가 가장 낮은 물성을 보였으며, 연실율과 내마모성 역시 monoammonium phosphate가 많이 함유된 WPU-AM3가 615 % 및 52.07 mg.loss로 낮은 물성을 나타내었다.

• 한국토양비료학회지
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• 제41권5호
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• pp.348-353
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• 2008

토양에서 인산가용화 미생물의 역할을 탐색하기 위해, 밭과 시설재배 토양에 서식하는 인산가용화 미생물의 특성을 조사하였다. 노지 밭 토양에 비해 시설재배지 토양에서 EC가 높았으며, 토양 pH, 유기물, 유효인산, 치환성 양이온 및 총 인도 시설재배지에서 비교적 높은 경향이었다. 인산가용화 세균의 수는 시설재배지 토양이 밭 토양보다 높았으나, 인산가용화 세균의 종류는 밭 토양에 많았다. 인산가용화 세균의 밀도와 인산가용화능 간에 정의 상관이 있었다. 밭 토양에서는 Bacillus, Cedecea, Brevibacillus, Paenibacillus Pseudomonas, Serratia속 등이 시설재배지 토양에서는 Bacillus, Cellulomonas 속 등의 인산가용화 세균이 분리되었다.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.726-731
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• 1999

It was discovered that ammonium phosphate in the medium played an important role in both growing mycelium and producing exopolysaccharides (EPS) from G. lucidum. In lower concentration levels of ammonium phosphate (0-3 g/l), an improved mycelial growth was observed by maintaining more filamentous morphology than in high concentrations (5-11 g/l). In addition, it was confirmed by comparing the factual dimension and frequency of the area regarding the mycelial pellets. This must be attributed to limitations of nutrient transfer by maintaining filamentous mycelium during the cultivation in a low ammonium phosphate containing medium. On the other hand, the best EPS production was observed in medium with the absence or low concentration of ammonium phosphate. The shear stress of the culture broth was greatly affected by the shear rate, as compared with that of the culture broth with high ammonium phosphate concentration. The rheological characteristics of the fermentation broth and filtrate worked well according to the Herschel-Bulkley model. It was also found that the morphological changes of the mycelium resulting from the ammonium phosphate concentration directly affected the rheological characteristics of the system and resulted in reversely affecting the EPS production levels. Based on these results, it can be concluded that delicate regulation of the ammonium phosphate concentration in the culture media should be provided in order to obtain optimal mycelial growth and/or EPS production.

• Journal of Nutrition and Health
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• 제30권7호
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• pp.813-824
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• 1997

This study was designed to investigate the effect of dietary calcium and phosphate levels on calcium and bone metabolism in rats. The rats were divided into six groups and each of the groups was fed diets with different Ca/P ratios. The experimental periods were 5 weeks . There was no significant different difference in dietary intake, body weight gain, and organ weight among the groups with different calcium and phosphate intake levels. Fecal calcium excretion was not significantly different among the groups, but urinary calcium excretion was increased by the increase in Ca/P ratio. Fecal phosphate excretion was not different but urinary phosphate excretion was increased by the increase in dietary phosphate intake. There was no significant difference in serum alkaline phophatase activity and urinary hydroxyproline levels were not significantly different among the groups. The low calcium-high phosphate(0.25Ca-1.2% P) group showed the lowest total calcium content in femur and scapula. This may be due to it having the lowest Ca/P ratio among groups. The low calcium-high phosphate(0.2%Ca-1.2%P) group showed that mandible is almost lost and osteolyzed Harversian canal was expanded in femur. Results suggest that phosphate intake affects calcium and bone metabolism more with inadequate calcium nutrition that with adequate calcium intake. Thus , for normal bone growth and metabolism , adequate calcium intake and/or high Ca/P ratio are important.

• 공업화학
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• 제30권5호
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• pp.562-568
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• 2019

Cylindrical shape extrudates of calcium silicate hydrate (CSH) were prepared using different percentages of polyvinyl alcohol (PVA) / sodium alginate (SA) mixtures as binders and an aqueous solution containing 6% $H_3BO_3$ and 3% $CaCl_2$ was used as a cross linking agent. As the quantity of alginate increases, the phosphate removal efficiency and capacity were decreased. Among four different extrudate samples, the sample prepared by 8% PVA + 2% SA showed the highest phosphate removal efficiency (59.59%) and capacity (29.97 mg/g) at an initial phosphate concentration of 100 ppm and 2.0 g/L adsorbent dosage. Effects of the adsorbent dosage, contact time and initial phosphate concentration on the sample were further studied. The removal efficiency and capacity obtained by a 4.0 g/L adsorbent dose at an initial phosphate concentration of 100 ppm in 3 h were 79.38% and 19.96 mg/g, respectively. The experimental data of kinetic and isotherm measurements followed the pseudo-second-order kinetic equation and Langmuir isotherm model, respectively. These results suggested that the phosphate removal was processed via a chemisorption and a monolayer coverage of phosphate anions was on the CSH surface. The maximum adsorption capacity ($q_{max}$) was calculated as 23.87 mg/g from Langmuir isotherm model.

• 자연과학논문집
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• 제12권1호
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• pp.69-79
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• 2002

PDA-calcium phosphate 평판배지를 이용하여 인산가용화활성을 가진 850종의 세균을 분리한 후 인광석에 대한 인산가용활성이 가장 강한 HS-2 균주를 선발하였다. 선정 균주의 형태학적, 배양학적 및 생리생화학적 특성 등을 조사한 결과 Azotobacter sp. HS-2로 동정되었고, 이 균주을 인광석을 0.1%함유한 Potato dextrose Broth배지 (pH 6.0)에 접종하여 $30^{\circ}C$에서 5일 배양했을 때 인광석이 가장 많이 분해되었고 0.5M의 수산을 첨가했을 때 분해율이 약 50% 증가되었다.

• 한국초지조사료학회지
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• 제20권1호
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• pp.67-76
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• 2000

본 시험은 1997년 연암축산원예대학 부속실험목 장에서 석회, zeolite 및 rock phosphate의 조합비율과 피복 종자의 크기를 달리 하였을 때 목초의 발아 및 초기생육에 미치는 영향을 비교하기 위하여 수행되었다. 피복한 tall fescue 및 orchardgrass의 발아세 및 발아율은 피복하지 않은 종자에 비하여 낮았다. Tall fescue 피복종자의 발아율은 석 회 70 %와 rock phosphate 15% 처리구에서 가장 높았다. 그리고 피복종자의 크기는 소형 (직경 2 mm 이하)이 중형 (직경 2~3 mm)과 대형 (직경 3 mm 이상)에 비하여 발아율이 높게 나타났다. 한편 orchardgrass 피복종자의 발아율에 서는 석회 55%와 rock phosphate 30% 처리구가 다른 피복 처리구에 비하여 높았다. 한편 피복종자의 크기는 소형이 대형과 중형보다는 발아울이 높았다 (p<0.05). 피복한 alfalfa 및 bridsfoot trefoil 종자의 말아세 및 발아율은 피복하지 않은 종자에 비하여 낮았다 Alfalfa의 피복종자 중에서는 석회 70%와 rock phosphate 15% 및 석회 45%와 rock phosphate 55% 처리구가 다른 피복 종자보다 발아율이 높았다. 피복종자의 크기간에는 중형이 소형과 대형보 다 발아율이 높았다 (p<0.05). 한편 birdsfoot trefoil의 피복종자 중에서는 석회 45%와 rock phosphate 40% 처리구가 다른 피복종자에 비하여 발아세와 발아율이 높았다. 피복한 tall fescue 및 orchard grass의 정착률과 초기생 육은 유의적인 차이는 없었으나 피복처리구 중에서는 두 초종 모두 석회 45%와 rock phosphate 40% 처리구가 가장 높았다 (p<0.05). Alfalfa의 경우도 정착률과 초기생 육은 처리간에 유의적인 차이가 없었으나 피복처리구 중에서는 석회 75%와 rock phosphate 10% 처리구의 정착률과 초기생육이 각각 46.4% 및 $72.6\;g/\textrm{m}^2$으로 가장 높았다(p<0.05). Birdsfoot trefoil은 피복 처리구 중에서는 석회 55%와 rock phosphate 30% 처리구의 정착률과 초기생육이 각각 46.4% 및 $44.6\;g/\textrm{m}^2$으로 가장 높았다 (p<0.05) 이상의 연구결과를 종합해 볼 때 피복종자의 발아율은 초종 마다 약간의 차이가 있으나 rock phosphate를 증가 시키고 석회를 감소시킬 때 증가하며, 종자의 크기는 alfalfa를 제외하고는 소형종자 (직경 2 mm 이하)가 발아율이 높은 것으로 생각된다. 한편 정착률과 초기생육은 화본과 목초에서는 rock p phosphate를 중가 시키고 석회를 감소시킬 때 증가 할수 있다.

• 대한화장품학회지
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• 제37권1호
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• pp.55-60
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• 2011

본 연구에서는 DOPC 리포좀의 안정성에 대한 염의 영향을 알아보기 위하여 증류수, phosphate buffer, 그리고 phosphate bufferd saline으로 리포좀을 제조하였다. 그리고 염의 추가에 따른 리포좀의 입자크기 및 제타전위 등 기본적인 물성 변화를 확인하였다. 그에 앞서 희석에 대한 영향을 알아보고자 리포좀을 각각 제조시 용매로 40배와 80배로 희석하였고 그 결과 같은 용매로 희석시킬 경우 40배 희석까지는 안정한 것을 확인하였다. 증류수로 제조한 리포좀을 증류수, phosphate buffer, 그리고 phosphate buffered saline으로 희석하였고, phosphate buffer로 제조한 리포좀은 phosphate buffer, 그리고 phosphate buffered saline으로 희석하여 염 농도 증가에 따른 리포좀의 입자크기 및 제타전위 변화를 확인하였다. 그 결과 리포좀 분산액 내에 존재하는 염의 양이 증가할수록 리포좀의 입자크기가 약간씩 작아지는 경향을 나타내었고, 제타전위 또한 염의 양이 증가할수록 0에 가까워지는 경향을 나타내었다. 결론적으로, 리포좀의 입자크기와 제타전위는 리포좀의 안정성을 판단할 수 있는 좋은 요소이며 또한 리포좀 제조시의 용매와 다른 조건의 염농도는 리포좀 입자의 안정성에 큰 영향을 줄 수 있다고 사료된다.

• 한국토양비료학회지
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• 제45권5호
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• pp.817-821
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• 2012

Soil samples collected from abounded mines of Boryeong area in South Korea were used in isolating bacterial strains and their capacity to solubilize inorganic phosphates and heavy metal tolerance were assessed in vitro. Three different inorganic phosphate sources (Ca phosphate, Fe phosphate, and Al phosphate) and four different heavy metals (Co, Cd, Pb and Zn) each with three concentrations ($100{\mu}g\;mL^{-1}$, $200{\mu}g\;mL^{-1}$, and $400{\mu}g\;mL^{-1}$) were used. The bacterial isolates PSB-1, PSB-2, PSB-3, and PSB-4 solubilized significantly higher amount of Ca phosphate during the first five days of incubation though subsequent drop in soluble phosphorus level in the medium was observed at the later stage (after 5 days) of the incubation. Solubilization of Ca phosphate and Fe phosphate was concomitant with the acidification of the culture medium compared to the control where it remained constant. Isolated strains could solubilize Fe phosphate to certain extent ($25-45{\mu}g\;mL^{-1}$) though solubilization of Al phosphate was found negligible. All the isolates were tolerant to heavy metals (Cd, Pb, and Zn) up to the concentration of $400{\mu}g\;mL^{-1}$ except PSB-1 and PSB-8, which were shown to be vulnerable to Co even at $100{\mu}g\;mL^{-1}$. Heavy metal tolerant strains should be further evaluated for plant growth promoting activities also under field conditions in order to assess their agricultural and environmental significance.