• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.3
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• pp.426-433
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• 1995

The interaction and detergency between liquid oily soil and surfactant solution were studied by the mechanism of formation of liquid crestal(LC). Samples used were triolein as a triglyceride, oleic acid as a free fatty acid and sodium dodgily sulfate (SDS) as a surfactant. The results were as follows: In the phase diagram of SDS/oil/Water system, the area of liquid crystalline phase region were in the order of SDS/trillion/water< SDS/oleic acid/water< SDS/mixture of trillion and oleic acid/water. In the system of oleic acid alone or mixture of trillion and oleic acid contacted with SDS solution, the LC phase was formed right after or after some time with SDS concentration. But in a case of trillion alone, the LC phase was not formed although the concentration of the SDS solution was relatively high. The detergency of model oily soils were seldom changed with temperature, and the detergency of oleic acid was very high compared to that of the trillion. The detergency of mixed soil was improved with the increase of the ratio of oleic acid in the mixture.

• Journal of Soil and Groundwater Environment
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• v.27 no.3
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• pp.41-49
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• 2022

This study utilized citric acid as a floating agent in biological denitrification process and assessed its role under different carbon supplying conditions. Several microcosm tests including citric acid active (CAA), precipitating tablet release active (PTRA) and floating tablet release active (FTRA) were conducted to evaluate nitrate denitrification efficacy. In CAA reactors, nitrate removal was accompanied by the formation of denitrification by-products such as nitrite and nitrous oxide, with the extent of nitrate removal being proportional to citric acid concentration. These results suggest that citric acid induced heterotrophic biological denitrification. PTRA reactor that incorporated CAA and the same electron donor showed a similar denitrification efficiency to CAA reactor. FTRA reactor, which contained the same amount of fumarate as PTRA, enhanced denitrification by 7% as compared to the PTRA reactor. The overall results of this work indicate that surplus citric acid can be efficiently utilized in heterotrophic denitrification.

• Ecology and Resilient Infrastructure
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• v.4 no.4
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• pp.193-199
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• 2017

In this study, changes of soil properties including soil texture, specific surface area, organic matter content, pH, cation exchange capacity and exchangeable cations content were investigated in response to strong acid or base accident. The properties changed significantly when the soil reacted with 10 M HCl or 1 M NaOH (i.e., when one gram of soil received 50 and 5 mmol of HCl or NaOH), respectively. When the soil reacted with 10 M HCl or 1 M NaOH solution, soil texture changed from sandy loam to loamy sand and specific surface areas decreased from $5.84m^2/g$ to 4.85 and $1.92m^2/g$, respectively. The soil organic matter content was reduced from 3.23% to 0.96 and 0.44%, and the soil pH changed from 5.05 to 2.35 and 10.65, respectively. The cation exchange capacity decreased from 10.27 cmol/kg to 4.52 and 5.60 cmol/kg, respectively. Especially, high concentrations of $Al^{3+}$ or $Na^+$ were observed in acidic or basic spills, respectively, which is likely to cause toxicity to terrestrial organisms. The results suggest that restoration of soil properties, as well as soil remediation, needs to be carried out to maintain the soil function in chemical spill sites.

• Economic and Environmental Geology
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• v.30 no.2
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• pp.105-116
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• 1997

This study is for extent of polluted area by acid mine drainage from the Daeseong coal mine, Keumsan. Black shales of the Changri Formation containing the Daeseong coal mine are geochemically similar to those from the North America as well as Europe. Comparing with geochemical compositions and relative ratios, coal bearing and non-coal bearing soils are similar to the stream sediments influenced and not influnced by the acid mine drainage, respectively. These characteristics suggest that acidification of the soils and of the stream sediments are related to the the coal bearing black shale. Soil waters beneath the coal bearing soil have low pH and high cation contents than those beneath non-coal bearing soil, suggestive of extractions of cations with increasing oxidizations within the soils. Surface waters show that those influenced by the acid mine drainage are low pH, and have high $SO_4{^{2-}}$, $Mg^{2+}$, $Fe^{2+}$, Mn and slightly lower DO, suggesting that heavy pollutions have been progressed in these area. Geochemical comparisons between the polluted surface water and adjacent black shales suggest that pollutions of the surface water are related to the black shales.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.587-593
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• 2010

Three hundred and seventy-four rhizobacteria were isolated from the rhizosphere soil (RS) or rhizoplane (RP) of Echinochloa crus-galli, Carex leiorhyncha, Commelina communis, Persicaria lapathifolia, Carex kobomugi, and Equisetum arvense, grown in contaminated soil with petroleum and heavy metals. The isolates were screened for plant growth-promoting trait (PGPT), including indole acetic acid (IAA) productivity, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, and siderophore(s) synthesis ability. IAA production was detected in 86 isolates (23.0%), ACC deaminase activity in 168 isolates (44.9%), and siderophore(s) synthesis in 213 isolates (57.0%). Among the rhizobacteria showing PGPT, 162 isolates had multiple traits showing more than two types of PGPT. The PGPT-possesing rhizobacteria were more abundant in the RP (82%) samples than the RS (75%). There was a negative correlation (-0.656, p<0.05) between the IAA producers and the ACC deaminase producers. Clustering analysis by principal component analysis showed that RP was the most important factor influencing the ecological distribution and physiological characterization of PGPT-possesing rhizobacteria.

• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.122-132
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• 2011

Mercury accumulates in biota mainly as methylmercury. In nature, methylmercury shows high affinity to organic matter and $CH_3Hg^+$-organic matter complexation affects the mobility and bioavailabiity of methylmercury. In this study, we examined the methylmercury binding sites in an aquatic humic acid as affected by the pH condition using Hg $L_{III}$-edge extended X-ray absorption fine structure (EXAFS). We evaluated methylmercury binding humic ligands using methylmercury-thiol, methylmerury-carboxyl, and methylmercury-amine complexation models. When $CH_3Hg^+$-to-humic reduced sulfur ratio is 0.3, we found that most of $CH_3Hg^+$ binds to thiol ligands at pH 5 and 7. At pH 7, however, some carboxyl or amine ligand contribution is observed, unlike at pH 5 where $CH_3Hg^+$ almost exclusively binds to thiol ligands. The carboxyl or amine ligand contribution may indicate that some types of thiol ligands in the natural organic matter have relatively low complexation constants or acid dissociation constants compared to those of some carboxyl or amine ligands. Analysis results indicate that ~0.2 fraction of methylmercury binds to amine or carboxyl ligands and ~0.8 to thiol ligands at pH 7.

• Korean Journal of Environmental Agriculture
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• v.33 no.2
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• pp.78-85
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• 2014

BACKGROUND: Recent studies using various industrial wastes for heavy metal stabilization in soil were conducted in order to find out new alternative amendments. The acid mine drainage sludge(AMDS) contains lots of metal oxides(hydroxides) that may be useful for heavy metal stabilization not only waste water treatment but also soil remediation. The aim of this study was to investigate the applicability of acid mine drainage sludge for heavy metals stabilization in soils METHODS AND RESULTS: Alkali soil contaminated with heavy metals was collected from the agricultural soils affected by the abandoned mine sites nearby. Three different amounts(1%, 3%, 5%) of AMDS were applied into control soil and contaminated soil. For determining the changes in the extractable heavy metals, $CaCl_2$ and Mehlich-3 were applied as chemical assessments for metal stabilization. For biological assessments, lettuce(Lactuca sativa L.) and chinese cabbage(Brassica rapa var. glabra) were cultivated and accumulation of heavy metals on each plant were determined. It was revealed that AMDS reduced heavy metal mobility and bioavailability in soil, which resulted in the decreases in the accumulation of As, Cd, Cu, Pb, and Zn in each plant. CONCLUSION: Though the high level of heavy metal concentrations in AMDS, any considerable increase in the heavy metal availability was not observed with control and contaminated soil. In conclusion, these results indicated that AMDS could be applied to heavy metal contaminated soil as an alternative amendments for reducing heavy metal mobility and bioavailability.

• Korean Journal of Microbiology
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• v.44 no.3
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• pp.237-243
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• 2008

Chemical and microbial characteristics of bacterial populations were investigated in a quercus and pine humus forest soil. Soil pH was $5.3\pm0.4$ and $4.1\pm0.9$ from each sample of a quercus and pine humus forest soil; C/N ratio of humus forest soil was $17.84\pm4.6%$ and $21.76\pm8%$, respectively. Total organic acid was investigated as 69.57 mM/g dry soil and 53.72 mM/g dry soil in each humus forest soil. Glutamine, pyruvate, succinate, lactic acid and acetic acid of pine humus forest soil were $1.5\sim4.5$ times higher than those of quercus humus forest soil. As we evaluated phylogenetic characteristics of bacterial populations by 16S rRNA-ARDRA analysis with DNA extracted from each humus forest soil. Based on the 16S rRNA sequences, 44 clone from ARDRA groups of quercus humus forest soil were classified into 7 phyla: ${\alpha},{\beta},{\gamma},{\delta}$-Proteobacteria, Acidobacteria, Actinobacteria, and Firmicutes. Thirty-two clone from ARDRA groups of pine humus forest soil were classified into 8 phyla: ${\alpha},{\beta},{\gamma}$-Proteobacteria, Acidobacteria, Bacteroides, Verrucomicrobia, Planctomycetes, and Gemmatomonadetes. According to PCA (Principal Component Analysis) based on 16S rRNA base sequence, there were three main groups of bacteria. All clone of Cluster I were originated from quercus humus forest soil, while 67% clone of Cluster II and 63% clone of Clusters III were separated from pine humus forest soil.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.87-91
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• 1997

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.107.1-107
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• 1996

No Abstract, See Full Text