• Korean Journal of Ecology and Environment
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• v.48 no.3
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• pp.168-175
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• 2015

This study was conducted in autumn to determine phosphorus (P) fraction in sediments of Daechung Lake, to elucidate controlling factors for sedimentary P, and to compare with the other areas. For this study, sediment samples were collected at 6 sites only once on November 2014 using ponar grab and analyzed for solid-phase P (Loosely adsorbed, Fe-bound, Al-bound, detrital apatite, and refractory organic P) by sequential extraction. Total phosphorus (TP) was relatively high in front of Daechung Dam and Hoinam where fish farm was run until 1997. The dominant sedimentary P form was Al-bound P, followed by Fe-bound P, which could be released from sediment to water column during suboxic state. Based on principal component analysis, Al-bound P, Fe-bound, and TP were controlled by grain size of sediments. Loosely adsorbed, detrital apatite, and refractory organic P were relatively highly accumulated at the mouth of major tributaries where suspended sediments were delivered. Sedimentary P concentrations in Daechung Lake sediments were not higher than in other lake sediments. Therefore, based on these results, major controlling factors were grain size and input of suspended sediments from tributaries.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.3
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• pp.16-27
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• 2001

We have studied the phosphorus geochemistry in sediments from anoxic environments of Lake Shihwa. The dominant sedimentary phosphorus forms were detrital apatite P and Al-bound p, whereas the amount of Fe-bound P was low because of anoxic condition. Based on the correlation between TP(Total Phosphorus) and OC(Organic Carbon), the behavior of sedimentary phosphorus was influenced by organic matters. It shows that dissolved and solid phosphorus concentrations, the flux of phosphate and the correlation coefficients between sedimentary phosphorus and organic matter In St. Cl were higher than those in St. C2. The results indicate that the concentrations and distributions of phosphorus In sediments were controlled by organic matters.

• The Korean Journal of Food And Nutrition
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• v.8 no.3
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• pp.230-238
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• 1995

Iron and zinc were bound by neutral detergent fiber (NDF) obtained from 15 kinds of vegetables being consumed commonly in Korea. Binding capacity of Fe and Zn of NDF ranged from 37.8% to 85.5% and from 81% to 25.5%, respectively showing higher binding capacity of Fe to NDF than of Zn. Both Fe and Zn binding capacity of NDF increased as pH increased and reached to a maximum at pH 7 In all vegetables. The amount of mineral (Fe and Zn) bound to NDF increased as mineral concentration Increased.

• Ocean and Polar Research
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• v.32 no.3
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• pp.177-186
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• 2010

A sequential extraction technique was used to study sediment phosphorus speciation and its relative importance in the intertidal flat of Keunso Bay during summer and winter for a better understanding of the phosphorus cycle and bioavailability in intertidal sediments. Loosely sorbed P contents were the lowest among the five P-pools and showed little seasonal or spatial variation. Although Fe-bound P contents were almost constant in winter, they decreased rapidly with sediment depth in summer. The dissolution of Fe oxides, used as an oxidant for the anaerobic respiration, ascribed the rapid decrease of Fe-bound P in summer. Al-bound P contents displayed little seasonal variation, but showed a large spatial variation, with higher values in the upper intertidal flat. Comprising about 50% of total P, Ca-bound P contents were the highest among the five P-pools. Ca-bound P contents were higher in winter than summer, but did not exhibit a clear spatial variation. Organic P contents were higher in summer than winter, which was associated with higher primary production and clam biomass in summer. Organic P contents were higher in the lower intertidal flat than the upper intertidal flat. In Keunso Bay, bioavailable P contents of the intertidal flat comprising about one third of total P ranged from 2.41 to 5.09 ${\mu}molg^{-1}$ in summer and 3.82 to 5.29 ${\mu}molg^{-1}$ in winter. The bioavailability of P contents was higher in the lower intertidal flat than the upper intertidal flat, which was attributed to the large clam production in the lower intertidal flat.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.17 no.2
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• pp.95-106
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• 2006

Iron was bound by neutral detergent fiber(NDF) obtained from 15 kinds of vegetables being consumed commonly in Korea. Binding capacity of Fe of NDF ranged from 37.83% to 85.51%. Fe binding capacity of NDF increased as pH increased and reached to a maximum at pH 7 in all vegetables. The amount of Fe bound to NDF increased as Fe concentration increased.

• Korean journal of food and cookery science
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• v.13 no.4
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• pp.472-477
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• 1997

Iron was bound to neutral detergent fiber (NDF) obtained from 15 kinds of vegetables commonly consumed in Korea. Iron binding capacity of NDF ranged from 37.83% to 85.51%, and it increased as the pH increased and reached to the maximum at pH 7 in all vegetables. The amount of Fe bound to NDF increased as the Fe concentration increased.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.376-379
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• 2004

pH has been regarded as a master variable governing the heavy metal sorption on fly ash. However, the chemical constituents in the fly ash could also suggest a potential sorption site for heavy metals. So, in this study sequential extraction method is employed to evaluate the sorption behavior of fly ash for cadmium. Two different fly ashes (S-fly ash, T-fly ash) were obtained from different power plants in Korea. First, cadmium is adsorbed under four different initial pHs. And, Cd sorbed in fly ash was sequentially desorbed following the sequential extraction method suggested by Tessier. In test results, the effect of pH increase was differently exerted in two fly ash. In S-fly ash, exchangeable fraction was dominated in low initial pH, however, as increasing initial pH, the fraction bound to carbonate increased. In the T-fly ash, regardless of initial pH the fraction bound to carbonate was major part of sorption estimated. The fraction bound to Fe/Mn oxide was about 10% in T-fly ash, and 5% in S-fly ash at high pH.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.893-899
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• 2000

To measure antioxidative activities, the various extracts from Ulmus devidiana were examined in oil emulsion. Water, ethanol, methanol and butanol were used as extract solutions. The activity oxygen species ($H_2O_2,-OH,\;KO_2$) bound the extracts for antioxidative activities were excellent. The extracts bound $Fe^{2+}$ ion and $Cu^{2+}$ ion showed effective antioxidative activities and strong chelating effects. The concentration of $Fe^{2+}$ ion and total ion in ethanol and methanol extracts from Ulmus devidiana root parts (Chinese) were higher than those of the other products. The highest superoxide dismutase-like activities showed butanol extracts from Ulmus devidiana root parts (Chinese) and water extracts from Ulmus devidiana bark parts (Korean). Electron donating abilities and nitric scavenging abilities of ethanol, methanol and butanol extracts were higher than those of water extracts. The nitrite scavenging abilities also reached the maximum at pH 1.2 and the minium at pH 6.0.

• Proceedings of the Korean Biophysical Society Conference
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• 2002.06b
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• pp.18-18
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• 2002

Nitrogenase, comprised of the MoFe and Fe proteins, catalyzes the reduction of dinitrogen to ammonia at ambient temperature and pressure. The MoFe protein contains two metal centers, the P-cluster (Fe8S7-8) and the FeMo-cofactor (Fe7S9：homocitrate), the substrate binding site. Despite the availability of the crystal structure of the MoFe protein, suprisingly little is known about the molecular details of catalysis at the active site, and no small-molecule substrate or inhibitor had ever been shown to directly interact with a protein-bound cluster of the functioning enzyme, until our electron-nuclear double resonance(ENDOR) study of CO-inhibited nitrogenase.(omitted)

• Journal of the Korean Chemical Society
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• v.40 no.1
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• pp.50-58
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• 1996

In the presence of metal ions(Co(Ⅱ), Ni(Ⅱ), Sr(Ⅱ), Cu(Ⅱ), Fe(Ⅲ), U(Ⅵ)), the sedimentation of humic acid was increased at constant pH with increasing metal concentration and the strength was increased in the following order: Sr < Ni < Co < Cu < Fe < U. At constant metal concentration, Cu(Ⅱ), Ni(Ⅱ), and Co(Ⅱ) ions caused an increase in sedimentation of humic acid as the solution pH increased, whereas Fe(Ⅲ) and U(Ⅵ) ions caused a decrease. Sr(Ⅱ) ions did not affect the sedimentation even with the variation of pH. The analysis of FT-IR spectra for the sediments prepared from the reaction between humic acid and metal ions showed that metal ions were bound to humic acid to form complexes, suggesting that the metal complexation plays an important role in the sedimentation of humic acid.