• Journal of Korea Soil Environment Society
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• v.2 no.3
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• pp.69-80
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• 1997

This investigation was conducted to provide information for characteristics of environmental pollution by the heavy metals from the abandoned gold mine in order to characterize the distribution patterns and environmental damages of the contaminants to the surrounding environment. Through analysis of CN, Cd, Cu, Pb, Zn, As, Cr, and Hg in a mine tailings, paddy soils, and stream sediments, the physico-chemical properties of the mine tailings and paddy soils were measured. The pH's were 5.4, 8.4 for the paddy soil and mine tailing, respectively. The maximum contents of CN, Pb, Cd, and As the in mine tailing were 99.98, 1,752.72, 31.88, and 298.50 mg/kg, respectively. The amounts of these ions were higher than the standard level of industrial area in Korea. The average content of CN and heavy metals in the paddy soils were higher than the background level of heavy metals in the unpolluted paddy soils around the mine. Especially, the contents of heavy metals in the paddy soils along the adjacent stream were higher compared to the paddy soil that was not influenced by the mine tailings. The contents of CN and heavy metals in the stream sediment close to the mine area were similar to those of the mine tailings, but decreased along the distance of the stream farther away from the tailings that was the source of these pollutants.

• Food Science of Animal Resources
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• v.27 no.3
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• pp.345-350
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• 2007

This study was carried out to establish the optimal preparation conditions of yoghurt made from goat milk with reduced goaty flavor by adding citrus concentrate and flavor. A central composite design was applied to investigate the effects of citrus concentrate ratio (0.5, 1.0, 1.5, 2.0, 2.5%), citrus flavor ratio (0.01, 0.02, 0.03, 0.04, 0.05%) and fructose ratio (3, 4, 5, 6, 7%). The physico-chemical and sensory characteristics of the sixteen yoghurt samples were compared. The addition of citrus concentrate had a significant (p<0.01) effect on the pH, $a^*,\;and\;b^*$ values. Regarding organoleptic properties, the addition of citrus concentrate had a significant (p<0.01) effect on color, and fructose had an effect on overall palatability. The maximum value of organoleptic goaty flavor was 2.35, more than double the minimum value. The optimum conditions predicted for minimizing goaty flavor of the yoghurt were 1.44% citrus concentrate, 0.0357% citrus flavor, and 6.91% fructose.

• Journal of Hydrogen and New Energy
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• v.24 no.5
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• pp.359-366
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• 2013

This work is investigated for the catalytic decomposition of hydrogen iodide (HI). Platinum was used as active material by loading on $ZrO_2-SiO_2$ mixed oxide in HI decomposition reaction. To obtain high and stable conversion of hydrogen iodide in severe condition, it was required to improve catalytic activity. For this reason, a method increasing dispersion of platinum was proposed in this study. In order to get high dispersion of platinum, zirconia was incorporated in silica by sol-gel synthesis. Incorporating zirconia influence increasing platinum dispersion and BET surface area as well as decreasing deactivation of catalysts. It should be able to stably product hydrogen for a long time because of inhibitive deactivation. HI decomposition reaction was carried out under the condition of $450^{\circ}C$ and 1 atm in a fixed bed reactor. Catalysts analysis methods such as $N_2$ adsorption/desorption analysis, X-ray diffraction, X-ray fluorescence, ICP-AES and CO gas chemisorption were used to measurement of their physico-chemical properties.

• KSBB Journal
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• v.18 no.5
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• pp.412-417
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• 2003

We first investigated basic characteristics of reticulated polyurethane (PU) foams as microbial carriers. In general, the specific surface area of PU foams increases with respect to decreasing pore sizes. However, the number of microbes adhered on the unit surface of reticulated PU foams decreases with respect to decreasing pore sizes. Thus, as a result of totally considering all effects such as apparent density, hydrolysis rate, and adhesion, we can know that PU foams with 45 PPI is the most appropriate microbial carrier. In this study, we can also investigate the effect of various physico-chemical surface treatments on the adhesion of microbes on the surface of PU foams. We used a chitosan treatment, a PEI (Polyethylene Imine) treatment, a xanthane treatment and a plasma treatment. As a result of comparing all surface treatments, the plasma surface treatment was the best.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.882-895
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• 1997

Changes in the benthic communities have been studied to investigate the environmental effects before and after the construction of Shihwa Dike in the West coast of Korea. It is suggested that sequential changes in macrofaunal assemblages progressed in two sucressional directions. In the Shihwa lake under the influence of organic enrichment. First, the appearance of 'azoic tone' or 'grossly polluted zone' developed in the area of less than 6 m in depth resulted from the severe dissolved oxygen depletion due to the eutrophication from the increased organic loading. Second, the 'polluted zone' characterized by the proliferation of the opportunistic species in organically enriched area, was found in the vicinity of the industrial discharges and nearby fluvial inputs. This benthic community succession in the Shihwa lake seemed to be caused by the various ecological events such as an eutrophication in this organically enriched environment after construction of the dike and other physico-chemical parameters like salinity and dissolved oxygen in the bottom water, which may be influenced by the irregular surface water discharge and dilution by outer seawater inflow through the water gate of the dike. On the other hand, the benthic communities in the outside of the dike showed that the species richness was more than doubled and the abundance increased almost seven times more than that before the dike construction. This may be a typical characteristics of the initial phase in benthic eutrophication, suggesting that an increased organic input area may have been reponsible for this faunal change in the study area.

• Korean Journal of Environmental Agriculture
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• v.35 no.4
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• pp.247-255
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• 2016

BACKGROUND: Acrylamide (CAS No. 79-06-1) is known to be a carcinogenic compound, and is classified as a Group 2A compound by the International Agency for Research on Cancer (IARC, 1994). Acrylamide can be generated during the browning process via the non-enzymatic Maillard reaction of carbohydrates such as reducing sugars and of amino acids such as asparagine, both of which occur at a temperature above $120^{\circ}C$. Potato tubers contain reducing sugars, and thus, this will affect the safety of processed potato products such as potato chips and French fries. In order to reduce the level of acrylamide in potato processed products, it is therefore necessary to understand factors that affect the reducing sugar content of potatoes, such as environmental factors and potato storage conditions, as well as understanding factors affecting acrylamide formation during potato processing itself. METHODS AND RESULTS: Potatoes were cultivated in eight regions of Korea; For each of these different environments, soil physico-chemical characteristics such as pH, electrical conductivity, total nitrogen, available phosphate, and exchangeable cation content were measured and correlations with potato reducing sugar content and potato chip acrylamide levels were examined. The reducing sugar content in potato during storage for three months was determined and acrylamide level in potato chip was analyzed after processing. The storage temperature levels were $4^{\circ}C$, $8^{\circ}C$, or $10^{\circ}C$, respectively. The acrylamide content of chips prepared from potatoes stored at $10^{\circ}C$ or $20^{\circ}C$ for one month was analyzed and the different frying times were 2, 3, 5, and 7 min. CONCLUSION: This study showed that monitoring and controlling the phosphate content within a potato field should be sufficient to avoid producing brown or black potato chips. For potatoes stored at low temperatures, a reconditioning period ($20^{\circ}C$ for 20 days) is required in order to reduce the levels of reducing sugars in the potato and subsequently reduce the acrylamide and improve chip coloration and appearance.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.2
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• pp.55-62
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• 1996

The purpose of this study is the evaluation of adsorption capacity of casts for heavy metals comparing with the activated carbon. The casts was obtained from vermicomposting of the mixed organic sludges which were generated from the treatment facilities for leather wastewater and cattle wastewater. The physico-chemical characteristics of cast was investigated. Also, the batch adsorption experiments of cast and activated carbon for heavy metals were carried out, and the results were analyzed by Freundlich isotherm. The buffering capacity to the acidic wastewater was founded in the cast, and the cation exchange capacity of cast impling adsorption capacity for soluble substances was evaluated as about 55me/100g. Those were implied that the cast have a large potential as a good adsorbent for soluble pollutants in wastewater. From the results of batch experiments, the removal efficiencies of tested various heavy metals including Pb, Cu, Cd, and Cr were very high value as 89-98% for the activated car-bon, and 80~95% for the casts except for Zn. The adsorption equilibriums for the two materials were achieved within 90 minutes. The order of preferable metals in the adsorption was found to be Pb>Cu>Cd>Cr>Zn on the cast and to be Pb>Cd>Cu>Cr>Zn on the activated carbon, respectively. From the above results, it might be con-cluded that cast is effectively available as a good adsorbent to treating the heavy metal bearing wastewater.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.251-259
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• 2000

Monthly variations of physico-chemical and biological parameter were determined in near the Kum River mouth at lower discharge period from January 1998 to September 1999. The characteristics of water quality was showed hypertrophic with average values of total nitrogen (TN), total phosphorus (TP), chlorophyll-a and transparency are 3.9 mg N/l, $160\;{\mu}g/l$, $73\;{\mu}g/l$ and 0.8 m, respectively. Among a nitrogen component, inorganic and organic nitrogen comprised 34% and 66% of TN, $NH_4$ and $NO_3$ comprised 30% and 70% of inorganic nitrogen respectively. SRP concentration comprised below 9% of TP. TN/TP and DIN/SRP ratio in winter were higher than in summer. SRSi fluctuation was very wide as ranged from 0 to 3.0 mg Si/l and the highest after flood event in summer. Long-term depleted pattern of Si was observed, that is considered to be important nutrient for algal growth. Chlorophyll-a concentration was very high as $113\;{\mu}g/l$, $162\;{\mu}g/l$ in winter and summer respectively, which persisent bloomed diatom Stephanodiscus and blue-green algae Microcystis. In consequence, water quality management of these periods are considered very important.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.271-278
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• 2017

Low impact development (LID) technology has been recently applied for the treatment of nonpoint source pollutants. Rain garden is one of the widely used LIDs since it utilizes various mechanisms such as biological and physico-chemical treatment to reduce pollutants. However, problem such as clogging has been one of the issues encountered by the rain garden that do not undergo constant maintenance. Therefore, this research was conducted to develop and determine the component arrangement of a rain garden system for a more efficient volume and pollutant reduction. Two hybrid rain garden systems having different characteristics were developed and evaluated to determine the optimum design and arrangement of the system. The results showed that the components arranged in a series manner showed a volume reduction of 93% and a pollutant reduction efficiency of approximately 99%, 93% and 95% was observed for particulates, nutrients and heavy metals, respectively. While when the system is connected in a combined series-parallel, the volume and average pollutant reduction efficiency for the TSS, nutrients and heavy metals are 65%, 94%, 80% and 85%, respectively. Moreover, the component arrangement in the order of sedimentation tank, infiltration tank and plant bed exhibited a high pollutant reduction efficiency compared when the infiltration tank and plant bed were interchanged. The findings of this research will help in the further development and optimization of rain garden systems.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.57-63
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• 2011

Changes in food preferences and dietary habits of Korean prone to decrease consumption of the traditional energy source, rice. The exceeding condition of rice production in Korea is now not only impacting on the profit structure of farmers but also threatening food security. Although there have been several efforts to increase rice consumption rate, by developing various processed foods using rice flour, grain hardness of rice has been the most significant limiting factor. In this study, we addressed the suitability of the Namil(SA)-flo1, a mutant rice line has floury endosperm, in terms of producing rice flour by using dry-milling method, which is lower cost and more eco-friendly than other available methods such as wet-milling. Rice flour of the Namil(SA)-flo1 exhibited superior physico-chemical characteristics to any other check varieties including the wild type, Namil, in terms of distribution of granule sizes and content of damaged starch.