• The Journal of Engineering Geology
• /
• v.15 no.4 s.42
• /
• pp.381-390
• /
• 2005

S City depends on the T River as source water for water supply. Arsenic and boron from the hot-spring waste-water discharged from the hot-spring spa resort and emerging from the fractures of bedrock of the river have been prevalent contaminant of the T River water. This research was conducted to propose the simple and quick surrogate parameter for water quality management easily. And through making hexa-diagram of principal ions in the water samples, existing state of the water and influence of the human activity or geological origin can be figured out. As a results of characteristics of the T River water quality using principal component analysis, the contributory percentages of the 1st, 2nd and 3rd principal components were $40.80\%,\;21.40\%\;and\;11.31\%$, respectively. Therefore it was clarified that the quality of the T River water could be explained by these three principal components. Concentration of the chloride ion, which is one of the characteristics of the hot-spring water, was well correlated to both arsenic and boron concentrations. Hence concentrations of the arsenic and boron in the raw water of the water reatment plant can be predicted by the measurement of concentration of the chloride ion.

• Korean Journal of Ecology and Environment
• /
• v.45 no.2
• /
• pp.210-217
• /
• 2012

This study investigated the water quality of effluents from the wastewater treatment plants, located at the Gumi Complex 4, Gumi, and Wonpyong, in Gumi. DOC accounted for higher than 70% of TOC, and oxidation efficiencies, calculated from carbon, were 13~43% for BOD and 37~73% for CODMn, respectively. Based on the biological decomposition experiments, R-DOC account for higher than 70% of DOC, mostly being occupied by refractory organic matters. This indicated that the biodegradable organics occupied more proportions of organic loadings than the refractory organics. The effect of the organics from a discharge of a sewage treatment plant on rivers, Gumi industrial Complex 4, Gumi, and Wonpyong on lower streams of the Nakdong River were found to be 15%, 6% and 16% respectively. The ratio of 15% suggests that comparatively, no large portions of TOC loadings are occupied, but the problem is that the biodegradable organic matters occupy a lot more proportions than that of the refractory organic matters. Thus, it is highly estimated that the refractory organics can gradually increase the pollution level of organics and precursors of disinfection by-products to the down-stream water treatment plants.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.29 no.4
• /
• pp.299-306
• /
• 2009

Oxidative stress is the main limiting factor in crop productivity. To solve global environmental problems using the plant biotechnology, we have developed on the oxidative stress-tolerant transgenic tall fescue plants via Agrobacterium-mediated genetic transformation method. In order to develop transgenic tall fescue (Festuca arundinacea Schreb.) plants with enhanced tolerance to multiple environmental stresses, nucleotide diphosphate kinase gene under the control of CaMV35S promoter were introduced into genome of tall fescue plants. Proteomic analysis revealed that transgenic tall fescue not only accumulated NDP kinase 2 protein in their cells, but also induced several other antioxindative enzyme-related proteins. When leaf discs of transgenic plants were subjected to cold stress, they showed approximately 30% less damage than wild-type plants. In addition, transgenic tall fescue plants showed normal growth when transgenic plants were subjected to $4^{\circ}C$ for 3 days treatments. These results suggest that transgene is important in ROS scavenging by induction of antioxidative proteins, and could improve abiotic stress tolerance in transgenic tall fescue plants.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.27 no.2
• /
• pp.109-116
• /
• 2007

Environmental stress is the major limiting factor in plant productivity. As an effort to solve the global food and environmental problems using the plant biotechnology, we have developed transgenic tall fescue (Festuca arundinacea Schreb.) plants via Agrobacterium-mediated gene transfer method. To develop transgenic tall fescue plants with enhanced tolerance to the environmental stresses, both CuZn superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) genes were incorporated in a pIG121 binary vector and the both of the genes were controlled separately by an oxidative stress-inducible sweet potato peroxidase 2 (SWPA2) premoter expressed in chloroplasts. Leaf discs of transgenic plants showed 10-30% less damage compared to the wild-type when they exposed to a wide range of environmental stresses including methyl viologen (MV), $H_2O_2$ and heavy metals. In addition, when $200{\mu}M$ MV was sprayed onto the whole plants, transgenic plants showed a significant reduction of visible damage compared to wild-type plants that were almost damaged. These results suggest that over expression of CuZnSOD and APX genes in transgenic plants might be a useful strategy to protect the crops against a wide range of environmental stresses.

• Korean Journal of Environmental Agriculture
• /
• v.26 no.3
• /
• pp.197-203
• /
• 2007

Zerovalent iron (ZVI) has been widely used in the removal of environmental contaminants from water. The objective of this research was to assess the efficiency of ZVI for immobilization of As (V) in the contaminated water under various chemical conditions. Batch-type experiments showed that the immobilization process followed a first-order kinetic model. Rate constant (k) of the reaction increased consistently and proportionally as increasing ZVI concentrations from 1% (0.158 $hr^{-1}$) to 3% (0.342 $hr^{-1}$), and temperatures from $15^{\circ}C$ (0.117 $hr^{-1}$) to $35^{\circ}C$ (0.246 $hr^{-1}$), respectively. Whereas the rate constant decreased as increasing As (V) concentrations from 1 mg $\Gamma^{-1}$ (0.284 $hr^{-1}$) to 3 mg $\Gamma^{-1}$ (0.153 $hr^{-1}$), and the initial pH from 3 (0.393 $hr^{-1}$) to 9 (0.067 $hr^{-1}$), respectively. Results demonstrated that As (V) in an aqueous solution was rapidly immobilized by ZVI treatments. Zerovalent iron was fast method for remediation of As (V) contaminated water.

• Korean Journal of Crystallography
• /
• v.4 no.2
• /
• pp.63-73
• /
• 1993

Ag+ 이온이 부분적으로 치환된 3가지 제올라이트 A(Ag4Na8-A, Ag6Na6-A 및 Ag8Na4-A)를 완전히 탈수한 후 280℃에서 24시간동안 약 0.1 Torr의 Cs중기로 처리하 였다. 이들의 결정구조는 22(1)℃ 노에서 입방공간군 Pm3m (단위세포상수 a가 각각 12.321(3) A, 12.295(1) A 및 12.380(7) A임)을 사용하여 단결정 X-선회절법으로 해석 하였다. 이들 세가지 구조에서 Cs+이온은 각각 서로 다른 4개의 결정학적 위치에서 발견되었다. 단위세포당 3개의 Cs+이온은 8-링 중심에 위치하고, 약 6.9-7.3개의 Cs+이온 은 큰 동공의 6-링과 마주보는 위치에 있는 3회 회전축상에서 발견되었다. 그리고 약 2.17-2.74개의 Cs+이온은 소다 라이트 동공내에서 발견되며 약 0.5-1.0개의 Cs+'이온은 4링과 마주보는 곳에 위치한다. 또한 이들 구조에서 단위세포당 각각 1.88(5),2.30(3) 및 5.28(10)개의 Ag종이 존재하며 이들은 큰동공의 중심에서 헥사실버 클러스트를 형성한다. 8-링위치가 Cs+이온으로 모두 차있어서 Ag0가 골조밖으로 이동하는 것을 막을 수 있다. 각각의 헥사실버 클러스터는 서로 다른 좌표에 위치하는 14개의 Cs+이온에 의해 안정화된다. 이들 구조에서 발견되는 약 12.35-13.49개의 Cs+이온들은 Cso의 흡착이 일어나 제올라이트 기본 골 격에 있는 음이온 전하와 균형을 맞출 수 있는 12개의 Cs+ 이온 이상의 이온 또는 원자로 존재하고 있다. Cs+의 배열 은 다음과 같은 두 가지 배열로 쉽게 설명할 수 있다. 일부는 2개의 Cs+이온이 소다이트 동공내에 있는 6-링과 마주보는 곳에 위치하고 큰동공내에는 6개의 Cs+이온이 6링 근처에 위치하며 1개는 4-링 근처에 위치한다. 그 나머지는 소다라이트 동공내에 위치하는 3개의 Cs+이온과 한변의 길이를 3.52 A로 갖는 삼각형을 형성한 후 6-링을 통 하여 큰 동공 내에 위치한 3개의 Cs원자와 결합하게 되므로 3m (C3v)의 대칭구조를 갖는 (CS6)4+클러스터를 형성한다. 그 밖의 5개 Cs+이온은 비어있는 큰동공의 6-링에 위치한다.

• Korean Journal of Food Science and Technology
• /
• v.28 no.6
• /
• pp.1095-1103
• /
• 1996

In order to minimize the deterioration of dried apple quality, changes of free sugar content, organic acid and ascorbic and during osmotic dehydration with sucrose at various temperature, concentration and immersion time were investigated in this study, total sugar increased as the temperature, concentration and immersion time were increased. Sucrose showed the largest change in content while fructose and glucose showed no and small changes, respectively. Large amounts of malic and fumaric acids, and small amounts of oxalic, citric, maleic and succinic acids were detected. Organic acids were high at low temperature treatment, and became higher with increasing concentration. Loss of ascorbic acid was small at the low temperature and high concentration. Effect of immersion time was negligible. Changes of free sugar, and organic and ascorbic acid followed the first-order and second-order reaction rate equations, respectively. Arrhenius equation was applied to determine the effect of temperature on reaction rate constants with high $r^2$. To predict the changes of quality, a model was established by using the optimum functions of temperature, concentration and immersion time. The model had high $r^2$ value for the quality changes during drying.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.10 no.2
• /
• pp.132-139
• /
• 2002

This study was carried out to investigate the effects of aging and soil texture on composting of diesel-contaminated soil. The soils used for this study were silt loam and sand. Target contaminant, diesel oil, was spiked at 10,000mgTPH/kg of dry soil. Aging times of diesel-contaminated soils were 15days and 60days, respectively. Fresh diesel-contaminated soil was also investigated. Moisture content was controlled to 70% of soil field capacity. Mix ratio of soil to sludge was 1:0.3 as wet weight basis. Temperature was maintained at $20^{\circ}C$ Volatilization loss of TPH was below 2% of initial concentration. n-Alkanes lost by volatilization were mainly by the compounds of C10 to C17. Diesel in contaminated soil was mainly removed by biodegradation mechanism. First order degradation rate constant of TPH in sandy soil was ranged from 0.081 to 0.094/day, which is higher than that in silt loam(0.056-0.061/day). From fresh to 60day-aged soils, there was little difference of TPH biodegradation rate between the soils. Carbon recovery ranged from 0.61 to 0.89. TPH degradation rate was highly correlated with $CO_2$ production rate.

• Korean Journal of Soil Science and Fertilizer
• /
• v.38 no.5
• /
• pp.238-246
• /
• 2005

We conducted this investigation to observe competitive adsorption phenomena among the heavy metals onto the available sorption sites of soil particle surfaces in sandy clay loam and clay soil collected from Nonsan city, Chungnam and Yoosung, Daejeon in Korea, respectively. Polluted and contaminated soils can often contain more than one heavy metal species, resulting in competition for available sorption sites among heavy metals in soils due to complex competitive ion exchange and specific sorption mechanism. And the adsorption characteristics of the heavy metals were reported that the selectivity for the sorption sites was closely related with electropotential and electro negativity carried by the heavy metals. The heavy metals were treated as single, binary and ternary systems as bulk solution phase. Adsorption in multi-element system was different from single-element system as Cr, Pb and Cd. The adsorption isotherms showed the adsorption was increased with increasing equilibrium concentrations. For binary and ternary systems, the amount of adsorption at the same equilibrium concentration was influenced by the concentration of individual ionic species and valence carried by the respective heavy metal. Also we found that the adsorption isotherms of Cd and Pb selected in this experiment were closely related with electronegativity and ionic potential regardless number of heavy metals in solution, while the adsorption of Cr carried higher valance and lower electro negativity than Cd and Pb was higher than those of Cd and Pb, indicating that adsorption of Cr was influenced by ionic potential than by electronegativity. Therefore adsorption in multi-element system could be influenced by electronegativity and ionic potential and valance for the same valance metals and different valance, respectively. But it still needs further investigation with respect to ionic strength and activity in multi-element system to verify sorption characteristics and reaction processes of Cr, especially for ternary system in soils.

• Journal of the Korean Society of Food Culture
• /
• v.3 no.4
• /
• pp.391-396
• /
• 1988

The method for the measurement of texture hardening phenomena, which is the limiting factor of shelf-life of Yaksik in the market, was established. The changes in the hardening rate by the processing conditions and the storage temperature and time were examined. The standard sample made by traditional method could be kept at room temperature$(20{\circ}C)$ for 3 days and the multipuncture force measured at the end of marketable quality was 700g. The hardening rate increased rapidly by storing at $5^{\circ}C$ and the ratio of hardening rate constants between room temperature and $5^{\circ}C$ storage reached to $1.3{\sim}3.3$ depending on the processing condition. The largest ratio was observed by the sample made from pressure cooker. The addition of corn syrup retarded the hardening rate. The pressure cooking resulted in making too soft product, which diminished the panel preference, but it extend the shelf-life when products were stored at $5^{\circ}C$ microwave cooking resulted in making too hard texture which was not acceptable. The overall quality preference of Yaksik was decided by the textural preference and the latter showed significant inverse correlation with the maximum force of multipuncture test. Therefore, it was concluded that multipuncture test was useful for the measurement of the quality of Yaksik.