• The Journal of Engineering Geology
• /
• v.28 no.1
• /
• pp.25-34
• /
• 2018

The physical properties and unsaturated characteristics of acid sulfate soils were investigated and analyzed. As the results of measuring physical properties of the acid sulfate soils obtained around the Ilkwang mine area, the dry unit weight is $1.246t/m^3$ and this soil is classified into the silty sand (SM) by USCS. Soil Water Characteristics Curves (SWCC) of the drying and wetting paths were measured by the automated SWCC apparatus. Also, Hydraulic Conductivity Functions (HCF) of the drying and wetting paths were estimated by the van Geunchten (1980) model which is the most well-known parameter estimation method. The hydraulic conductivity of acid sulfate soils in the dry path was continuously decreased with increasing the matric suction. However, the hydraulic conductivity in the wetting path was decreased relatively small with increasing matric suction and decreased suddenly just before water entry value of matric suction. Meanwhile, the hysteresis phenomenon was occurred in SWCCs and HCFs during the drying and wetting paths.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.260-265
• /
• 2004

Acid mine drainage(AMD) is one of the most serious environmental concerns associated with the mining industry around the world. The objective of this study is to assess the potential of sewage sludge as a carbon source for sulfate reducing bacteria and waste lime and steel slag as a neutralize agent for acid mine drainage bioremediation for use in permeable reactive materials. The study was performed using synthetic AMD in six column experiments. The effluent solution was systematically analysed throughout the experiments. The results of the study indicated that sewage sludge, waste lime and steel slag were the most effective for the AMD treatment as a permeable reactive materials.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.2 no.2
• /
• pp.105-108
• /
• 1997

A search was undertaken to screen microorganisms that produce an enzyme capable of deacylating glutary1-7-amincephalosporanic acid to 7-aminocephalosporanic acid in soil samples. The screening was carried out by preparing enrichment cultures containing glutary-7ACA and cephalosporin C as selective carbon sources. A non-${\beta}$-lactam model compound,, glutary-p-nitroanilide, was synthesized as a substrate suitable for the rapid screening of microorganisms isolated from the enrichment cultures. Two isolates exhibiting acylase activity, designated BY7.4 and BY8.1, were identified as strains of Pseudomonas species. Pseudomonas BY8.1 showed higher acylase activity toward G1-7ACA than Pseudomonas BY7.4. Environmental conditions for the optimal acylase activity of Pseudomonas BY8.1 were shown to be pH9 and 30$^{\circ}C$.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.03a
• /
• pp.343-346
• /
• 2002

The chemical compatibility of leachate with the two natural materials was analyzed by performing the hydraulic conductivity test. The selected liner materials were natural marine clay and weathered soil sampled from Kimpo wastefill and Daehwa Dong, Kyonggi Do, respectively. PARAFIX, which is mainly composed of paraffin, cement, stearic acid, PVA etc., was used as solidifying agent. The chemical solutions used in the test were 10% acetic acid, 10% methanol, and real leachate from Kimpo wastefill and the results of tests were compared with that of distilled water. The results of tests show that hydraulic conductivity of solidified clay was increased slightly with permeation of acetic acid, methanol and the increase of hydraulic conductivity was not shown with permeation of leachate, distilled water and in case of weathered soil. Based on the tests, it is ascertained that the tested liner materials can be stable with the solution of low concentration.

• Journal of the Korean Society of Tobacco Science
• /
• v.10 no.2
• /
• pp.99-107
• /
• 1988

Pot experiment was conducted to find out the effect of lime application on yield and chemical composition of burley tobacco in 1986, Lime increased exchangeable calcium and pH of soil, but decreased Al, Fe and Mn concentrations. Yield was increased by lime application, however lime could not be caused to yield increasing in the soil with high calcium contents. Cored leaves of limed Plot contained higher Mg. K, total nitrogen, NO3-nitrogen, water soluble and insoluble ash, alkalinity number of water soluble and insoluble ash, citric and malic acid, but lower Fe, Mn, protein-nitrogen, NH3-nitrogen, nicotine petroleum ether extract, palmitic and linolenic acid concentrations than those of unlined plot. The linoleic acid and volatile neutral constituents of cured leaves were not affected by liming. Lime increased yield, however it did not affect leaf duality in respect to chemical characteristics, suggesting that liming should be necessary for tobacco cultivation.

• Journal of Soil and Groundwater Environment
• /
• v.16 no.4
• /
• pp.31-37
• /
• 2011

The feasibility study of soil flushing was investigated to remediate lubricant oil and zinc contaminated railway soil. In this study, mixed washing agents of surfactant and inorganic acid/base were used for the simultaneous removal. The mixed washing agent of non-ionic surfactant and HCl removed 15% of the lubricant oil and 40% of zinc, respectively. Alkaline-enhanced soil washing process increased the removal of lubricant oil up to 40%. This is because alkaline solution reduced the interfacial tension between water phase and lubricant oil phase due to the soap formation reaction. To simulate in-situ soil flushing for the remediation of railroad-related contamination, two dimensional soil flushing was carried out based on the results of batch soil washing. In the soil flushing, the removal efficiencies of lubricant oil and zinc were 34% and 16%, respectively. Even though the removal efficiency was low, the mixed washing agent can remove metal and lubricant oil simultaneously.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.5
• /
• pp.8-19
• /
• 2008

The physicochemical properties of soils having high uranium content, located around Duckpyungri in Korea, were investigated and the lab scale soil washing experiments to remove uranium from the soil were preformed with several washing solutions and on various washing conditions. SPLP (Synthetic Precipitation Leaching Procedure), TCLP (Toxicity Characteristic Leaching Procedure), and SEP (Sequential Extraction Procedure) for the soil were conducted and the uranium concentration of the extracted solution in SPLP was higher than Drinking Water Limit of USEPA (30 ${\mu}g$/L), suggesting that the continuous dissolution of uranium from soil by the weak acid rain may generate the environmental pollution around the research area. For the soil washing experiments, the uranium removal efficiency of pH 1 solution for S2 soil was about 80 %, but dramatically decreased as pH of solution was > 2, suggesting that strong acidic solutions are available to remove uranium from the soil. For solutions with 0.1M of HCl and 0.05 M of ${H_2}{SO_4}$, their removal efficiencies at 1 : 1 of soil vs. washing solution ratio were higher than 70%, but the removal efficiencies of acetic acid, and EDTA were below 30%. At 1 : 3 of soil vs. solution, the uranium removal efficiencies of 0.1M HCl, 0.05 M ${H_2}{SO_4}$, and 0.5M citric acid solution increased to 88%, 100%, and 61% respectively. On appropriate washing conditions for S2 soil such as 1 : 3 ratio for the soil vs. solution ratio, 30 minute for washing time, and 2 times continuous washing, TOC (Total Organic Contents) and CEC (Cation Exchange Capacity) for S2 soil were measured before/after soil washing and their XRD (X-Ray Diffraction) and XRF (X-Ray Fluorescence) results were also compared to investigate the change of soil properties after soil washing. TOC and CEC decreased by 55% and 66%, compared to those initial values of S2 soil, suggesting that the soil reclaimant may need to improve the washed soils for the cultivated plants. Results of XRF and XRD showed that the structural change of soil after soil washing was insignificant and the washed soil will be partially used for the further purpose.

• Korean Journal of Environmental Agriculture
• /
• v.27 no.2
• /
• pp.133-138
• /
• 2008

Fire can affect microbial community structure of soil through altered environmental conditions, nutrient availability, and biotic source for microbial re-colonization. We examined the influence of fire on chemical properties and soil enzyme activities of soil for 10 months. We also characterized the soil microbial community structure through ester-linked fatty acid analysis(EL-FAME). For this study, we established five burned plots(1*1 m) and 5 unburned plots outside the margin of fire. Soil was sampled three soil cores in a each plots and composited for analysis at 1, 3, 5, 8, and 10 month after fire. The fire caused an increase in soil pH, exchangeable Ca, and Mg, organic matter, available $P_2O_5$ compared to unburned sites. The content of $NH_4-N$ in burned site was significantly higher than that of unburned site and this effect continued for 8 months after fire. There was no difference of $NO_3-N$ content in soil between burned and unburned site. Fire caused no change in acid phosphatase and arylsulfatase activities but $\beta$-glucosidase and alkaline phosphatase activities in burned site were increased compared to unburned site. Microbial biomass as estimated by total concentration of EL-FAMEs in burned sites was significantly higher than that of unburned sites at one month after fire. Burned site decreased the EL-FAMEs indicative of gram-positive bacteria and tended to increase the fatty acid associated with gram-negative bacteria at one and three months after fire. The sum of EL-FAME compound $18:2{\omega}6,9c$ and $18:1{\omega}9c$ as served fungal biomarkers was decreased in burned site compared to unburned site.

• Korean Journal of Soil Science and Fertilizer
• /
• v.8 no.4
• /
• pp.171-176
• /
• 1975

The rate and extent of decomposition of rice straw and compost in an acid sulfate soil amended with urea and lime and incubated under aerobic and anaerobic(flooded) conditions were investigated in the laboratory. Results are summarized as follows: 1. The rate of compost(alone) decomposition in a flooded soil was more than twice as high as all other treatments, which included rice straw+urea, rice straw+lime, rice straw (alone), and compost+lime. Lime appeared to suppress the decomposition of compost in a flooded soil but actually enhanced its decomposition under aerobic conditions. 2. Compost decomposition in both anaerobic and aerobic environments was characterized by single maximum peak rates of $CO_2$ evolution that were reached soon after the start of incubation. 3. Both urea and lime greatly increased the rate and extent of rice straw decomposition in the soil when incubated aerobically, although urea had a greater effect than did liming. Decomposition rates were characterized by the appearance of two maximum peak rates, a greater primary peak and a smaller secondary peak. 4. The percent decomposition of rice straw in soil incubated aerobically was approximately half (10.8%) that of compost(23.1%). However, percent decomposition of these substrates in soil amended with lime was essentially the same; i.e., rice straw+lime (29.4%) and compost+lime(31.6%). 5. There is a need to investigate the possible interaction between the addition of lime (pH) and supplemental nitrogen applied to acid sulfate soils and how this interaction might affect the decomposition of organic wastes and residues.

• Korean Journal of Soil Science and Fertilizer
• /
• v.29 no.1
• /
• pp.44-52
• /
• 1996

Humic substances of 17 organic fertilizers available on the market were the objects of study. The list of ingredients for formulation of them comprised fish meal. bone meal, oil-cakes, brewer's grains, peat, sawdust, wood bark, zeolite, soil conditioner, live-stock droppings, amino acid fermentation byproduct, chaff, limestone and others. Humic and fulvic acids were isolated from those substances and given chemical and spectroscopic analyses. Nutritional values of the organic fertilizers showed big diversity. Humification of organic matter was incomplete for some of the fertilizers as indicated by a high C/N ratio. Extractable humic acid percentage was higher, in general, than that of fulvic acid. Also the relative content of humin increased with advanced humification. Total acidity was closely related to phenolic hydroxyl groups. Relationships between carboxyl and hydroxyl groups. and carboxyl and alcoholic hydroxyl groups were very significant. Ultraviolet and visible light absorption spectra of humic and fulvic acids were substantially similar. The types of humic acids were B. P, and Rp. Two humic acids of the 17 samples belonged to B type. 3 to P type and all the rest to Rp type.