• 보존과학연구
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• s.29
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• pp.137-148
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• 2008

Analyses of ancient DNA (aDNA) from archaeological and historical skeletal material are characterized by low quality. Many soil contaminants such as humic acid, fulvic acid, and bone collagen are often co-extracted with aDNA and inhibit amplification by polymerase chain reaction (PCR). In this study, we compared with two methods of DNA extraction by phenolchloroform extraction and silica-bead extraction. In addition, we applied new protocol, ultra sonication based silica-bead extraction method to extract aDNA from some ancient human skeletal remains. This method was more effective by both mitochondrial DNA (mtDNA) and amelogenin gene amplification.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.96-106
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• 1998

Rice plants were grown for 42 days in the specially made micro-ecosystem(pot) containing two different soils treated with fresh and 60-day-aged residues of [$^{14}C$]quinclorac, respectively, to elucidate the behaviour of the herbicide quinclorac residues in the soils. Amounts of $^{14}CO_{2}$ evolved from two soils treated with different residues with and without vegetation were all less than 2.2% of the total $^{14}C$, indicating that there was little microbial degradation of quinclorac in soil. $^{14}C$-Radioactivity absorbed and translocated into rice plants from soil A and B containing fresh quinclorac residues was 8.4 and 24.2%, respectively, of the originally applied $^{14}C$, while 5.5 and 17.7%, in aged residue soils. These results indicate that larger amounts of $^{14}C$ were absorbed by rice plants from soil B with less organic matter and clay than soil A, and the uptake of [$^{14}C$]quinclorac and its degradation products decreased with aging in soil. After 42 days of rice growing, 84.5 and 61.8% of the $^{14}C$ applied freshly to soil A and B, respectively, remained in soil, whereas, in the case of aged soils, 86.3 and 67.7% of the $^{14}C$ applied did. Meanwhile, without vegetation, more than 98.3% of the $^{14}C$ applied, in both fresh and aged residues, remained in soil, suggesting that quinclorac was relatively persistent chemically and microbiologically. Most of the non-extractable soil-bound residues of [$^{14}C$]quinclorac were incorporated into the organic matter and largely distributed in the fulvic acid portion.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.11
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• pp.769-775
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• 2013

UV-induced transformations in the characteristics of dissolved organic matter (DOM) and the subsequent effects on the disinfection by-product formation potential (DBPFP) were investigated using the mixtures of the two humic substances with different sources, and two different size fractions of Suwannee River fulvic acid (SRFA). 7 day-photodegradation resulted in the decrease of specific ultraviolet absorbance (SUVA) of the mixtures as well as the specific DBPFP. After the irradiation, however, higher specific DBPFP values were consistently observed at the same range of the SUVA values. This suggests that non UV-absorbing components, generated by the UV-irradiation, may contribute to the formation of DBPs. Two different molecular size fractions of SRFA showed dissimilar responses to photodegradation. The behavior was also influenced by the types of the DBPs generated. Higher levels of trihalomethenes (THMs) were formed per organic carbon for the high molecular fraction compared to the low molecular fraction, whereas no differences were found in the formation of haloacetic acids (HAAs) between the two different size fractions. The formation of the two types of DBPs also differed by the irradiation times. Specific formation potential of THMs consistently increased upon the irradiation, whereas HAAs showed the initial increase followed by the decrease in their specific formation potential.

• Korean Journal of Environmental Agriculture
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• v.11 no.3
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• pp.243-252
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• 1992

This research was conducted to investigate the influence of kind and concentration of organic ligands such as humic (HA) or fulvic acid (FA) on the removal of Cu or Pb from the aqueous solution employing the principles in metal-ligand complexation. Increasing HA concentration enhanced the efficiency of Cu or Pb removal, but there existed upper critical concentrations capable of forming maximum HA-metal complex. which ranged 53-289 and 42-315mg/L for Cu and Pb, respectively. At these concentrations. efficiency of removal was 70 to 95 % for Pb, but 13 to 65 % for Cu. Amounts of Cu and Pb which complexed with 100mg HA were estimated to be 7.5 and 34.1mg, respectively. FA-metal complex forming reactions were fitted significantly to the empirical models of Freundlich for Cu and Langmuir for Pb. Fulvic acid precipitated nearly 100% of Pb in solution, but formed precipitates with Cu in only 13 to 29%. Comparing organic ligands. HA had a higher removal efficiency for Cu but FA had such for Pb. Metalligand complex formation was differed from kinds and concentrations of corresponding ligands and metals. Results demonstrated that this principle has a strong potential to be employed for treating heavy metals in aqueous solution.

• Applied Biological Chemistry
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• v.9
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• pp.153-159
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• 1968

In this paper the auther investigated the chemical properties, process of humification and type of humic acid in soils which were reclaimed by farming for cultivation in Kangwondo. The results obtained in this studies were summarized as follows: 1. General chemical components of these soil were similar to the ordinary soil but C.E.C. and humus contents were found much more 2. Humic acid and fulvic acid which were extracted with NaOH from soil were greater than those of Na-pyrophosphate(Na-p.) and NaF. Hmus contents and PQ% were increased much more in the upper layer than in the lower layer. 3. Degree of humification of humic acid extracted with NaOH. was very similar to those extracted with Na-pyrophosphate. Humification degree of humic acid extracted with NaF was lower than humic acid which were extracted with NaOH and Na-pyrophosphate. But humification degree of humic acid extracted with NaOH was similar to that with Na-pyrophosphate. Humic acid in B soil and the upper layer was higher than A, C soil and the lower layer of soil, in humification degree. 4. Humic acids extracted with NaOH and Na-pyrophosphate from soil were fractionated by Mg into two parts ${\alpha}$ type and ${\beta}$ type humic acid. Humic acids of ${\alpha}$ and ${\beta}$ type extracted with NaOH were higher than these of Na-pyrophosphate in humification degree. In this soil the humification degree of humic acid was not changed during the period of cultivation. 5. ${\alpha}$, ${\beta}$ type humic acid extracted with NaOH were very similar to the humic acid extracted with Na-pyrophosphate in shapes of absorption curves.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.936-942
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• 2012

This review was to elucidate the fate of Bentazon(3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide) and its metabolites in soil. Bentazon is rapidly degraded to form polar metabolites which are mostly adsorbed to soil components, such as humin or fulvic acid, as non extractable forms and mineralized into $CO_2$ by light or micro-organisms in both aerobic or nonaerobic condition. The degradation of Bentazon is dependent on the rate of organic matters in soil and the use of land for the tillage. The degradation rate is decreased as the amount of organic matters in soil increases and if the land is under use for tillage. Sorption and mobility of Bentazon depends on soil pH and the content of organic matters in soil. Usually, the sorption of the metabolites of Bentazon is decreased with increase in the mobility and pH. Almost all of Bentazon is degraded within rhizosphere or forms conjugate bonds with soil organic matters before it reaches to the ground water.

• Membrane and Water Treatment
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• v.10 no.2
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• pp.179-189
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• 2019

This study aimed to investigate the effect of temperature and solid retention time (SRT) on membrane fouling in a membrane bioreactors (MBRs). For this purpose, a lab-scale submerged MBR system was used. This system operated at two SRTs of 15 and 5 days, three various temperatures (20, 25 and $30^{\circ}C$) and hydraulic retention time (HRT) of 8 h. The results indicated that decreased the cake layer resistance and increased particles size of foulant due to increasing temperature and SRT. Fourier transform infrared (FTIR) analysis show that the cake layer formed on the membrane surface, contained high levels of proteins and especially polysaccharides in extracellular polymeric substances (EPS) but absorbance intensity of EPS functional groups decreased with temperature and SRT. EEM analysis showed that the peak on the range of Ex/Em=220-240/350-400 in SRT of 15 and temperature of $30^{\circ}C$ indicates the presence of fulvic acid in the cake. In addition, as the temperature rise from 20 to $30^{\circ}C$, concentration of soluble microbial products (SMP) increased and COD removal reached 89%. Furthermore, the rate of membrane fouling was found to increase with decreasing temperature and SRT.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.239-244
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• 1986

This study was conducted to investigate the characteristics of humic substances and the fractional distribution of organic nitrogen in Korean paddy soils. The results are obtained as follows: 1. The content of humus in soils used was 665-2680 mg/100g and the average contents of humic acid in normal paddy soils and in sandy paddy soils were 1436 mg/100g, 970 mg/100g respectively. 2. The humic acid diagrams classed by Kumada method belong to B type, P type and Rp type. 3. The content of Mineral - N to Total - N was 1.04-2.86% and the average contents of that in sandy paddy soils and in normal paddy soils were 1.72% and 1.75% respectively. 4. The fractionations of acid hydrolysable organic - N in sandy paddy soils were Amino acid - N (31.52%), Humin - N (20.63%), Amino sugar - N (18.70%), and Unknown - N (25.73%).

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.3
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• pp.337-346
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• 2011

24-hr integrated measurements of water-soluble organic carbon (WSOC) in PM2.5 were made between May 5 and September 25, 2010, on a six-day interval basis, at the Metropolitan Area Air Pollution Monitoring Supersite. A macro-porous XAD7HP resin was used to separate hydrophilic and hydrophobic WSOC. Compounds that penetrate the XAD7HP column are referred to hydrophilic WSOC, while those retained by the column are defined as hydrophobic WSOC. Laboratory calibrations using organic standards suggest that hydrophilic WSOC includes lowmolecular aliphatic dicarboxylic acids and carbonyls with less than 4 or 5 carbons, amines, and saccharides. While the hydrophobic WSOC is composed of compounds of aliphatic dicarboxylic acids with carbon numbers larger than 4~5, phenols, aromatic acids, cyclic acid, and humic-like Suwannee River fulvic acid. Over the entire study period, total WSOC accounted for on average 48% of OC, ranging from 32 to 65%, and hydrophilic WSOC accounted for on average 30.5% (9.3~66.7%) of the total WSOC. Based on the previous results, our measurement result suggests that significant amounts of hydrophobic WSOC during the study period were probably from primary combustion sources. However, on June 9 when 1-hr highest ozone concentration of 130 ppb was observed, WSOC to OC was 0.61, driven by increases in the hydrophilic WSOC. This result also suggests that processes, such as secondary organic aerosol formation, produce significant levels of hydrophilic WSOC compounds that add substantially to the fine particle fraction of the organic aerosol.

• Journal of the Korean Ceramic Society
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• v.56 no.2
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• pp.146-152
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• 2019

In order to study the transport behavior of tripolyphosphate (TPP) in aqueous solutions, the adsorption process of TPP on synthetic goethite, which exists stably in supergene environment, has been systematically studied. The adsorption properties under different conditions (pH, electrolyte presence, and temperature) were investigated. The adsorption of TPP in the presence of humic acid (HA)/fulvic acid (FA) has also been discussed in this paper. The results indicated that the adsorption capacity quickly increased within the first hour and equilibrium was reached within 24 h. The adsorption capacity decreased from 1.98 to 0.27 mg·g^-1 upon increasing the pH from 8.5 to 11.0, whereas the adsorption of TPP on goethite hardly changed with increasing electrolyte concentration. The results of analysis of the kinetic and isothermal models showed that the adsorption was more in accord with the pseudo second-order equation and Freundlich model. The adsorption capacity decreased obviously regardless of the order of addition of TPP, HA, and goethite. Subsequent addition of FA led to a large increase in the adsorption capacity, which might be attributed to the adsorption ability of FA. According to the predictions of the kinetic and isothermal models and the spectroscopic evidence (X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM)), the adsorption mechanism may be mainly based on surface complexation and physical adsorption.