• Journal of the Korean Society of Groundwater Environment
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• v.5 no.1
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• pp.30-36
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• 1998

For successful soil flushing process selection of appropriate flushing reagents is essential. Futhermore, obtaining operating parameters for site remediation application through various bench-scale tests is also important. In this research a series of organic acids (acetic, citric, oxalic, and succinic acids) were tested for flushing capability. Copper-contaminated natural soil was used as a test medium, and flushing experiments were performed with batch system. All the organic acids used did not provide effective flushing conditions at concentration of 1 mM. At the acid concentration of 50 and 100 mM copper was removed efficiently although 50 and 100 mM did not show any significant differences in removal efficiencies. Citric acid and oxalic acid removed copper more efficiently than the others, and especially, citric acid showed over 87% of removal efficiency of copper at near neutral pH of 5 to 7. Speciation of extracted copper using GEOCHEM simulation showed majority of extracted copper existed as complexed with organic acids and only small portion of organic acids were complexed with copper indicating promising application of soil flushing with organic acid to heavy metal-contaminated site remediation.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.45-54
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• 2000

Several chemical washing procedures were applied to Zn and Cd contaminated soil. Batch and column tests were performed to determine the metal extraction efficiency as a function of pH and concentration. Washing efficiencies by water and NaOH are very low but those by HCI, EDTA and Oxalic acid are high. The most efficient washing occurs in case of using HCI because heavy metal is ionized easily at the condition of low pH. EDTA and Oxalic acid are also effective to extract Zn and Cd because they have a high complexation affinity for heavy metals forming active surface complexes. More Zn is released than Cd is and release trend is increased as pH is decreased and concentration of washing solution is increased. When heavy metal contaminated soil is remediated, HCI and EDTA are more effective to remove Zn than others are. Meanwhile HCI and Oxalic acid are more effective to remove Cd than others are.

• Korean Journal of Environmental Agriculture
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• v.12 no.1
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• pp.35-40
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• 1993

In order to find the effect of humic substances affecting to the behavior of diazinon in submerged soil, the adsorption rate of diazinon was investigated with different soil humic substances like as humin, humic acid and fulvic acid. The adsorption rate of diazinon(1.8 ppm) was 12.4% in humin, 11.9% in fulvic acid and 10.4% in humic acid at 1% concentration of humic substances, also were not much differences at 0.1 and 0.5%. But it showed much similar level ($10.2{\sim}10.6%$) at 1.0% concentration in 5ppm diazinon treatment. As a result, because adsorption rate of diazinon on humic substances were about $10{\sim}12%$, disappearance of diazinon in submerged soil may be affected by the other factors such as soil microorganism.

• Analytical Science and Technology
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• v.28 no.5
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• pp.317-322
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• 2015

Simultaneous analytical method has developed for the determination of anion biocides in soil by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Chlorite and chlorate in soil were extracted with pure water, and cyanuric acid and sodium dodecylbenzenesulfonate (Na-DBS) were extracted with mobile phase (0.25 mM ammonium formate in 20 mM formic acid : acetonitrile (1:1)). The extract was injected into the LC-MS/MS system after filtration. The method detection limits in this study were 0.04 mg/kg for chlorite, 0.04 mg/kg for chlorate, 0.27 mg/kg for cyanuric acid, and 0.05 mg/kg for Na-DBS, respectively. The method was applied to the analysis of 50 soil samples collected from 40 sites sprayed with biocides and 10 background sites. As a result, anion biocides were not detected in all sites.

• Journal of Environmental Science International
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• v.9 no.5
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• pp.437-441
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• 2000

A study on the removal of Pb ion from Pb-contaminated soil was carried out using ex-site extraction process. Tartaric acid (TA) and iminodiacetic acid sodium salt(IDA) as a washing agent were evaluated as a function of concentration reaction time mixing ratio of washing agent and recycling of washing agent. TA showed a better extraction performance than IDA. The optimum washing condition of TA and IDA were in the ratio of 1:15 and 1:20 between soil and acid solution during 1 hr reaction. The total concentrations of Pb ion by TA and IDA at three repeated extraction were 368.8 ppm and 267.5 ppm respectively. The recovery of Pb ion from washing solution was achieved by adding calcium hydroxide and sodium sulfide form the precipitation of lead hydroxide and lead sulfide and optimum amounts of sodium sulfide and calcium hydroxide were 7 g/$\ell$ for the TA washing solution and 4 g/$\ell$, 5g/$\ell$ for the IDA washing solution respectively. The efficiency of recycle for TA and IDA washing solution were 78.8% , 95.1%, and 89.2%, 96.6% at third extractions under $Na_2S$ and $Ca(OH)_2$, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.3
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• pp.213-217
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• 2015

Soil moisture shortage can reduce yield of waxy corn because maize is one of the sensitive crops to the drought stress. Farmers cannot irrigate due to limited water resource and irrigating facilities although applying water is the most effective practice to solve the drought problem. The study was conducted to investigate the pre-treatment effect of salicylic acid on reducing drought damage of waxy corn (Zea mays L.). Salicylic acid at concentration of 0.2 mM was applied at seven-leaf stage or ten-leaf stage three times. Drought stress was imposed by withholding irrigation from 11 days before anthesis to 10 days after anthesis. Application of salicylic acid significantly increased ear length by 11.0~12.3% and yield by 8.8~11.3% compared with non-treated control, indicating that the drought injuries of waxy corn can be alleviated through pre-treatment of salicylic acid at the vegetative stage.

• The Korean Journal of Ecology
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• v.21 no.2
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• pp.117-124
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• 1998

To clarify the effects of acid precipitates on histological damage, water status, and growth of Pinus densiflora green house experiment applyin simulated acid rain was carried out. Contact angle of water droplet on needles of P. densiflora seedlings treated with simulated acid rain of different pHs simulated acid rain was, the more rapid transpiration was. Leaf water potential after water withdrawal was also reduced rapidly in proportion to acidity of simulated acid rain. Height growth of P. densiflora seedlings treated with simulated acid rain of pH 2 decreased, while growth of seedlings treated with that of pH 3 and 4 increased comparing with that treated with normal rain of pH 5.6. pH of cultivated soil in pH 2 plot was acidified with the amount of simulated acid rain applied but that in pH 3 and 4 plots did not show any directional change. From those results, it could be interpreted that decrease of height growth in pH 2 plot was originated from multiple effects of water deficit from rapid transpiration and soil acidification. On the other hand, increased of height growth in pH 3 and 4 plots would be originated from the supply of N and S included in simulated acid rain.

• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.541-546
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• 2012

The biodegradation of phenol in laboratory-contaminated soil was investigated using the Gram-positive soil bacterium Corynebacterium glutamicum. This study showed that the phenol degradation caused by C. glutamicum was greatly enhanced by the addition of 1% yeast extract. From the toxicity test using Daphnia magna, the soil did not exhibit any hazardous effects after the phenol was removed using C. glutamicum. Additionally, the treatment of the phenol-contaminated soils with C. glutamicum increased various soil amino acid compositions, such as glycine, threonine, isoleucine, alanine, valine, leucine, tyrosine, and phenylalanine. This phenomenon induced an increase in the seed germination rate and the root elongation of Avena sativa (oat). This probably reflects that increased soil amino acid composition due to C. glutamicum treatment strengthens the plant roots. Therefore, the phenol-contaminated soil was effectively converted through increased soil amino acid composition, and additionally, the phenol in the soil environment was biodegraded by C. glutamicum.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.294-303
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• 1986

The effects of insecticides on biochemical precesses in soil were studied by determining the effects of the chemical structure of each insecticides on enzyme activities, pesticide residue and total number of bacteria revealed when soil treated with urea was incubated at $28{\pm}1^{\circ}$ for 56 days. The inhibition effects of insectides on enzyme activites in soil decreased in the order: dithiophosphoric acid > thiophosphhoric acid > phosphoric acid > carbamate insecticides for urease and phosphatase, thiophosphoric acid > dithiophosphoric acid > phosphoric acid > carbamate insecticides for L-glutaminase and protease. The inhibition effects of organophophorus insecticides on enzyme activities in soil were maintained longer than those of carbamate insecticides. Carbamate insecticides increased the activities of protease and L-glutaminase at 56 days. When insecticides were treated in soil together with urea, the degradation of insecticides was accelerated. By treatment of insecticides, the total number of bacteria was decreased at the early stage of treatment but thereafter increased according to phosphoric acid and carbamate insecticides.

• Journal of the Korean Society of Clothing and Textiles
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• v.3 no.1
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• pp.13-18
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• 1979

Many researches have found that the anionic surfactants are effective when the anionic soil is attached to the cotton fabrics. However, this research investigated the relationship of the super soil removal and surfactants when the anionic and cationic soil was attached to the cationic cotton fabrics. The result is that the cationic surfactants are vary effective for soil removal in the cationic cotton fabrics. The processing and nature of cationic cotton fabrics are treated and investigated as follows: Cotton fabrics are heated in the presence of ethylenimine and acetic acid dissolved in benzene to contain a significant amount of fixed nitrogen. Some polymer was formed but removal by washing with benzene and water. The optinium molor ratio of acid-to-ethylenimine seemed to be in the range 1: 10. The treated cotton fabrics dyed with acid Orange II dyes, and nitrogen content in the treated cotton fabrics were determined by the Kjeldahl method.