• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.416-421
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• 1988

Humic acids were extracted from straw of wheat and rye at three different stages of decomposition. Contents and distribution of amino acids in the hydrolysates of humic acids were examined and the results obtained can be summarized as the following: 1. Contents and distribution of amino acids in the hydrolysates of humic acids differ from plant to plant and from one stage of decomposition to another. 2. Neutral amino acids as a group take the largest portion of the total amino acids in humic acid hydrolysates followed by the acidic and the basic. 3. The total amount of amino acids in decomposed wheat straw at the 90 days of humification was greater than that in the case of rye straw. 4. Contents of amino acids other than arginine, histidine and tyrosine were increased in the case of wheat straw, while only the contents of lysine, phenylalanine, tyrosine and methionine were observed to increase in the case of rye straw. 5. Exceptionally high contents of phenylalanine and tyrosine were measured in the hydrolysate from rye straw taken at the end of experimental period. 6. No amount of arginine was detected in any hydrolysate of humic acids from decomposed plant residues.

• Analytical Science and Technology
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• v.13 no.5
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• pp.659-665
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• 2000

The changes in $UV_{254}$ and concentrations of $H_2O_2$ formed by ozonation of aqueous humic acid in ozone/high pH, peroxone process and in the presence of radical scavenger, $HCO_3{^-}$ were investigated. This study confirmed that the formation of $H_2O_2$ by ozonation may undergo different reaction pathways compared to those of $UV_{254}$ reduction in the degradation of the humic acid. The concentration of $H_2O_2$ produced by ozonation was found to be increased with decreasing pH of the sample solution due to the higher stability of ozone molecules at acidic conditions. On the while, $UV_{254}$ reduction was found to be higher at alkaline conditions or larger amount of $H_2O_2$ additions as a radical promoter in which the producing of ${\cdot}OH$, ${\cdot}HO_2$ radicals can be more favorable. From the results, it has been suggested that the formation of $H_2O_2$ by ozonation depends mainly on the direct reactions of ozone with humic acid molecules, while $UV_{254}$ reduction is affected by both the indirect reactions of the radicals and direct reactions of ozone with humic acid.

• Analytical Science and Technology
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• v.13 no.2
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• pp.241-249
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• 2000

In this paper, ozonation of humic acid in water was characterized using $UV_{254}$ absorbance, TOC, Ultra Filtration and $^{13}C-NMR$. Also, carbonyl compounds in ozonated water were analyzed by GC/MS using PFBOA method. Ozonation by-products of water containing humic acid were determined as formaldehyde, acetaldehyde, acetone, glyoxal and methylglyoxal. Results of $UV_{254}$ absorbance and TOC with ozonation time at humic acid 20, 100ppm represent that decrease rate of 80% within ozonation time is 20 min and TOC removal rate of 40-50% within ozonation time is 30 min. Results for $^{13}C-NMR$ and Ultra Filtration, humic acid of high molecular weight by ozonation are oxidated and decomposed so that it was conversed low molecular weight such as aldehydes, carboxylic acid.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.254-263
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• 1988

Contents and distribution of amino acids in the humic acid and fulvic acid fractions of different types ($R_p$, B, A, P) were investigated. Extracted humic and fulvic acids were purified and analyzed. The results are summarized as the following: (1) Composition of Humus The total humus ($H_T$), amount of humic acid (a), amount of fulvic acid (b), and ${\Delta}logK$ all decrease in the order of $R_p$ > B > A > P type. The same trend was observed in the total nitrogen and carbon. (2) Contents and composition of amino acids in humic acids. 1) The total amounts of amino acids in the humic acid fraction of different types were in the following order for soils under coniferous forest trees: $R_p$ > B > A > P type, but for soils under deciduous forest trees the order was P > A > $R_p$ > B type. There were positive correlationships between total amino acids and total carbon and ${\Delta}logK$ for humic acids from soils under coniferous forest trees, but a negative correlationship was existed. between total amino acids and C/N ratios. No significant correlation was found for samples taken from soils under deciduous forest trees. 2) The ratios of one group of amino acids to the others were compared. The ratios of acidic amino acids were in the order of P > $R_p$ > B > A type. those of neutral amino acids followed the order of $R_p$ > B > A > P type and those of the basic amino acids were in the order of B > A >$R_p$ > P type for soils under coniferous forest trees. Contents of total amino acids were in the order of the neutral > the acidic > the basic amino acids. For the soils under deciduous forest trees the order of the ratio was different. Acidic amino acids followed the order of A > P > B > $R_p$ type, neutral ones followed the order of P > $R_p$ > A > B type, and the basic amino acids did the order of $$P{\geq_-}$$ A > B $$\geq_-$$ $-R_p$ type where the difference was very small. 3) In general aspartic aicd, glycine and glutamic acid were the major components in all samples. Histidine, tyrosine and methionine belonged to the group contained in a small amount. (3) Contents and composition of amino acids in fulvic acids. 1) The total amounts of amino acids of different types of fulvic acids were in the order of $R_p$ > B > P > A type regardless of origin of samples. There were positive correlationships observed between the toal amino acids and total carbon and ${\Delta}logK$ for soils under coniferous forest trees. For soils under deciduous forest trees, positive correlationships were observed among total amino aicds, total nitrogen, total humus ($H_T$), total humic aicd (a), and ${\Delta}logK$, but a negative correlationship existed between total amino acids and C/N ratio. 2) Thr ratio among acidic amino acids, neutral amino acids and basic amino acids of different types were $R_p$ > B > P > A type. In this respect there was no difference between the two soils. 3) In general glycine, aspartic acid, and alanine were the major constituents in all samples of different types, while tyrosine and methionine were contained in a small amount. Virtually no amount of arginine was measured.

• Korean Journal of Environment and Ecology
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• v.14 no.1
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• pp.88-98
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• 2000

본 연구는 국립공원의 산림관리에 필요한 기초자료를 제공하고자 계곡부식생을 조사하였다 계룡산국립공원의 계곡부식생을 ZM학과의 식물사회학적인 방법으로 분류한 결과 까치박달군락으로 구분되었다 까치박달군락은 다시 고로쇠나무아군락, 조릿대아군락, 병꽃나무아군락 등 3개의 아군락으로 서어나무군락은 쥐똥나무아군락 쪽동백아군란 등 2개의 아군락으로 구분되었다 까치박달군락은 서어나무군락보다 해발고가 높고 습한 지역에 분포하였다 또한 동일한 계곡이라 할지라도 입지조건 중 특히 계곡부가 위치해 있는 사면의 방위에 따라 식생구성의 차이를 나타냈다.

• Journal of Industrial Technology
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• v.19
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• pp.343-350
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• 1999

The separation of humic acid by ultrafiltration was most influenced by pressure difference. when pressure difference increased from latm to 3atm, permeate flux increased from 40% to 60% but rejection rate reduced from 97% to 91% because of adsorption of molecules of humic acid at membrane surface. Since physical adsorption was more dominant than chemical adsorption, adsorption of membrane surface was reduced 50% when slow rate increased at same conditions.

• Journal of Industrial Technology
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• v.19
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• pp.409-413
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• 1999

Chemical oxidation of humic acid by ozonation process was investigated in the batch reactor. Aldehydes and ketone were identified as PFBOA derivatives in ozonated humic acid solutions using gas chromatography with PDECD. The formaldehyde was as a main by-product of ozonation. The characteristics of the formaldehyde production were discussed with respect to concentration at different experimental conditions.

• Journal of Industrial Technology
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• v.29 no.A
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• pp.89-94
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• 2009

The efficiency of heterogeneous catalysts has been investigated in ozonation process for organic removal. Heterogeneous catalytic ozonation was conducted for the degradation of humic acid in the presence of Granular Activated Carbon or Zeolite as a solid catalyst. And the results were compared to those of ozonation alone and adsorption alone without ozonation. The degradation characteristics of humic acid in each process were examined with the values of pH, TOC, $UV_{254}$ and $COD_{Cr}$.

• Journal of Industrial Technology
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• v.18
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• pp.417-423
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• 1998

Experiments were performed to evaluate UV/VIS absorbance and TOC of humic acid solutions which were ozonated at different pH values. The optimum conditions for ozonation of humic acid from this study are pH 9 (buffered) and 0.84 ($H_2O_2/HA$, w/w) for $H_2O_2$ dosage.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.2
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• pp.91-97
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• 1979

1. Nitrogenous compounds of-organic materials as nitrogen sources for Korean ginseng were characterized according to their solubility and chemical forms. 2. The extractable fractionation was as follows : Yakto group : non-extractable N > acid hydrolyzable N > acid nonhydrolyzable N > water sol. N, Litter group : acid hydrolyzable N > non-extractable N > water sol. N > acid non-hydrolyzable N, Bone meal : acid hydrolyzable N > water sol. N > acid non-hydrolyzable N. 3. Nitrogenous compounds in the water sol. fraction were : Yakto group and Litter group : humus N > amino acid N > nitrate N (recognized only in Yakto group) > ammonia N > hexosamine N > amide N, Bone meal : amino acid N > humus N > ammonia N > amide N. And nitrogenous compounds in the acid hydrolyzable fraction were : amino acid N > humus N ${\simeq}$ ammonia N > hexosamine N. 4. Availability was discussed about the major nitrogenous compounds (amino acid, humus and inorganic N) and the solubility.