• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.467-474
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• 2012

This study was carried out to evaluate effect of temperature condition on nitrogen mineralization of organic matter, distribution of microbial group by PLFA profiles, and soil microbial community structure in volcanic ash soil. Dried soil 30 g mixed well each 2 g of pellet (OFPE) organic fertilizers, pig manure compost (PMC), and food waste compost (FWC). And then had incubated at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$, respectively. Nitrogen mineralization rate increased with increasing temperature and that was in the order of FWC>OFPE>PMC. Distribution ratio of microbial group by PLFA profiles were different significantly caused by incubation temperature and the type of organic matter. As incubating time passed, density of microbial group decreased gradually. The Gram-bacteria PLFA/Gram+ bacteria PLFA, Fungi PLFA/Bacteria PLFA, and Unsaturated PLFA/saturated PLFA ratios were decreased according to the increasing temperature gradually. But cy19:0/$18:1{\omega}7c$ ratio increased both FWC and PMC treatment. Principal component analysis using PLFA profiles showed that microbial community structure made up clearly at both 75 days ($10^{\circ}C$) and 270 days ($30^{\circ}C$) by temperature factor. As incubating time passed, microbial community structure shifted gradually.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.98-104
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• 1997

Soil pollution intensity at Mt. Namsan in Seoul city which was expected to show significant soil contamination due to long-term air pollution was evaluated by comparing soil chemical properties at Mt. Kyebangsan in Hongcheon area as a control, and the bacteria participating in nitrogen or sulfur mineralization were assayed simultaneously in order to evaluate the validity of N and/or S mineralization bacteria as an index of soil contamination. The soil of Mt. Namsan showed 10 times higher concentration of hydrogen ion compared to that of Mt. Kyebangsan, which indicated that the soil had relatively been acidified seriously. Especially, large amount of canons were thought to be leached out from the soil, while the amount of extractable Al was getting larger and larger, which result in serious problems in soil ecosystem of the mountain. I could infer from soil chemical properties of the four study sites that the major reason of soil acidification was SOx deposition. However, the sulfur-reducing bacteria were not significantly different between the two regions, which indicated that the microbial dynamics of the soil ecosystem was not controlled by simple factor, but by multiple factors. By the way, the dynamics of bacteria participating in denitrification process was different between the two regions, which was more active at Mt. Kyebangsan than at Mt. Namsan. Thus, the microbial assay for nitrogen mineralization is desirable to be examined as a tool for evaluating soil health or microbial activity in soil ecosystem.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.16-21
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• 1998

To study the possibility of agricultural utilization of sewage sludge, the changes of the substances physico-chemical and microbiological properties composting periods such as inorganic matter, the form of organic matter and nitrogen and the kinds and the population number of microorganisms were investigated. The results were summarized as follows ; Temperature and $CO_2$ generation, they were the highest in the second day of composting periods and then were gradually fallen. pH value was not changed in first day during composting periods, but in second day was rapidly increased and then it was constant of the range of 8.4∼8.6. The contents of $P_2O,\;K_2O$, CaO and Fe were a little increased during composting periods, while that of ${SO_4}^{2-}$and Mn were big increased with 253${\sim}$331% and 191${\sim}$208% in late composting periods in comparing with early composting periods, respectively. The contents of ether extracted materials, water soluble polysaccharides, hemicellulose and cellulose were decreased but that of resins and lignin were not changed during composting periods. The contents of total and organic nitrogen during composting periods were decreased with 15${\sim}$20% and 22${\sim}$35%, respectively, while that of inorganic nitrogen was decreased with 75${\sim}$116%. The population numbers of microorganism during composting periods was much too changed according to the kinds of microorganism and composting periods.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.7-14
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• 2011

Bacillus subtilis JK-1 showed degradation activity against crude oil, gasoline, kerosene, and light oil, and this strain was used as a crude biosurfactant producing microorganism in this study. To optimize the culture medium for production of crude biosurfactant, the influences of various carbon, nitrogen and mineral sources were assessed. The highest biosurfactant production by B. subtilis JK-1 was observed after 96 h cultivation, containing 1.0% (w/v) soluble starch as a carbon source and 0.5% (w/v) skim milk as a nitrogen source, and carbon to nitrogen concentraion (C/N) ratio was 2.0. For the biosurfactant production 0.1% (w/v) of $KNO_3$ was the most effective mineral source. Comparison of biosurfactant production indicates that B. subtilis JK-1 produces more biosurfactant in the optimum medium established in this study than LB and TSB. Under the optimum medium, the surface tension of culture broth of B. subtilis JK-1 was decreased from 47.3 dyne/cm to 24.0 dyne/cm after cultivation of 48 h.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.311-318
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• 1994

We examined spatial and temporal patterns of root decomposition for three and half years, from October 1986 to April 1990, in semi-arid Chihuahuan Desert. Decomposition of roots occurred in a two-phased pattern: an early period of rapid mass loss followed by a period of slower loss. The rate of root decomposition had a high negative correlation with the initial lignin concentration in roots (r=-0.84, p<0.05). Annual mass loss rate of Baileya multiradiata, a herbaceous annual, was the highest with the value of 0.60, while that of Panicum obtusum. a perennial grass which was restricted to playa, was the lowest with 0.13. The mass loss rate of roots in the playa was the lowest among the vegetation zones along the transect. After 42 months elapsed, fluffgrass roots in playa lost 40% of the initial mass, while in other sites it lost on average 55% of the initial mass. In all roots except for desert marigold, there was an initial release of nitrogen early in decomposition followed by net nitrogen immobilization. Nitrogen concentration of the desert marigold roots showed linear increase from the beginning. Lignin concentration of perennial grass roots were higher than those of herbaceous annual and woody perennial root.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.380-386
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• 2011

Tip burn has been reported as one of the most serious physiological disorder in Chinese chives (Allium tuberosum Rottl.) cultivated in plastic film house. In this study, a physiography and chemical properties of 132 plastic film house soils were investigated to elucidate factors affecting tip burn symptom. Also influence of soil properties on tip burn was statistically determined by path analysis and association analysis including a chi-square test or logistics analysis. Probability distribution of inorganic aqueous species, such as ammonia (g) was calculated using MINTEQ program. Soil order and chemical properties, especially pH, exchangeable calcium and inorganic nitrogen, showed a significant relationship with tip burn of Chinese chives. Tip burn symptoms occur mainly in an alkaline soil classified as Alfisols. Result of linear regression and path analysis exhibited that formation of ammonia (g) from soil solution depend upon soil pH and were associated with ammonium resulting from soil organic matter or nitrate. These results indicate that tip burn symptom of Chinese chives is directly affected by ammonia gas originated from alkaline soil condition.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.357-365
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• 2018

This study was carried out to evaluate the weight loss rates, carbon and nitrogen dynamics of wood stakes following soil amendment treatments (CLB: compound fertilizer + lime + biochar; LB: lime + biochar) in a post-fire restoration area, Ulsan Metropolitan city, southern Korea. Soil amendments in the fire-disturbed area were applied to two-times (Mar. and Jun. 2015, 2016) during the study period. Wood stakes on Mar. 2015 were buried at a top 15cm of mineral soil in two soil amendment and control treatments of Liriodendron tulipifera, Prunus yedoensis, Quercus acutissima, Pinus thunbergii plantations and an unplanted area in the post-fire restoration area. Wood stakes were collected at Oct. 2015, Mar. 2016 and Oct. 2016 to measure weight loss rates, organic carbon and nitrogen concentrations. Weight loss rates of wood stakes were not significantly affected by soil amendment treatments. However, remaining carbon of wood stakes were lowest in the control treatment (43.7%), followed by the CLB (71.3%) and the LB (71.6%) treatments. Remaining nitrogen of wood stakes was less in the control treatment (29.7%) compared with the LB treatment (52.6%). The results indicate that carbon and nitrogen mineralization of wood stakes in post-fire restoration area were delayed by soil amendment treatments.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.855-859
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• 2011

The main pollutants from zirconium alloy tubing manufacturing process in nuclear industry are nitrate ($NO_3-N$) and fluoride (F-)Nitric acid, and hydrofluoric acid is used for acid pickling. The process for the removal of nitrate and fluoride is composed of 1st chemical coagulation, SOD (Sulfur Oxidation Denitrification) process using sulfur-oxidizing denitrification, and 2nd chemical coagulation. The characteristic of the wastewater treatment is an application of SOD process. The SOD Process is highly received attention because it is significantly different from existing processes for sulfur denitrification. A JSC (JeonTech-Sulfur- Calcium) Pellet is unification of sulfur and alkalinity material. According to result of SOD process in wastewater treatment plant, the removal efficiency of T-N was over 91% and the average concentration of T-N from influent was 147.55 mg T-N/L and that from effluent was 12.72 mg T-N/L. Therefore, SOD process is a useful to remove nitrogen from inorganic industrial wastewater and a new development of microbial activator was shown to be stable for activation of autotrophic bacteria.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.279-280
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• 2002

$TiO_2$의 흡착에 의한 폐수처리는 거의 없으며, 본 실험의 T 산업 폐수에 평균 65mg/L 포함된 다량의 Cl￣ 이온은 광산화 반응의 억제제(inhibitor)로서 작용하는 것으로 사료되었다. 암모니아성 질소가 초기 40 mg/L에서 운전시간 24 시간 후에는 60 mg/L까지 증가함을 알 수 있었으며, 질산성 질소의 농도는 15 mg/L 까지 증가하였다. ${PO_4}^{3-}$ 의 농도 변화는 거의 없었으며 1 mg/L 이하의 낮은 농도로 존재하였으며, 무기탄소 양은 매우 소량으로 거의 변화가 없었다. 운전기간 동안 pH 2.4 ～ 2.6으로 수렴하였고 반응속도의 변화는 거의 없었으며, CODcr에 대한 $BOD_{5}$의 분율은 반응이 진행될수록 증가하는 것으로 보아 난분해성의 폐수가 광촉매 반응 후 생물학적 처리가 가능한 폐수로 변화되었음을 알 수 있었다.

• The Korean Journal of Ecology
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• v.21 no.6
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• pp.751-757
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• 1998

Nitrogen dynamics in mineral soils of an alder (Alnus maximowiczii) stand established on volcano Mt. Showa-Shinzan were measured by laboratory incubation method in order to clarify characteristics of $NH_{4}^{+}$ mineralization and nitrification rate, from August 1994 to July 196. Contents of total N and organic matter were relatively low, but increased in May-July. Extractable $NH_{4}^{+}$ concentrations and $NH_{4}^{+}$ mineralization were high in June and July, and decreased in midsummer and fall. Extractable $NO_{3}^{-}$ concentrations did not vary seasonally. Negative values at $NH_{4}^{+}$ mineralization and nitrification rate were observed in August and September. $NH_{4}^{+}$ mineralization was positively correlated with soil organic matter, and nitrification rates were influenced by extractable $NH_{4}^{+}$ concentration and $NH_{4}^{+}$ mineralization.