• Journal of Environmental Impact Assessment
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• v.13 no.4
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• pp.213-222
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• 2004

Exergy is defined as the amount of work (entropy-free energy) a system can perform when it is brought into thermodynamic equilibrium with its environment. Exergy measures the distance from the inorganic soup in energy terms. Therefore, exergy can be considered as fuel for any system that converts energy and matter in a metabolic process. The aim of this study is to introduce structural dynamic modelling which is based on maximum exergy principle. Especially, almost ecological models couldn't explain algal succession until now. New model (structural dynamic model) is anticipated to predict or explain the succession theory. If the new concept using maximum exergy principle is used, algal succession can be explained in many actual cases. Therefore, It is estimated that structural dynamic model using maximum exergy principle might be a excellent tool to understand succession of nature from now on.

• Korean Membrane Journal
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• v.11 no.1
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• pp.21-28
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• 2009

We investigated the effect of organic materials on membrane fouling in advanced drinking water treatment by a hybrid module packed with granular activated carbon (GAC) outside multi-channel ceramic microfiltration membrane. Synthetic water was prepared with humic acid and kaolin to simulate natural water resouces consisting of natural organic matter and inorganic particles. Kaolin concentration was fixed at 30 mg/L and humic acid was changed as 2~10 mg/L to inspect the effect of organic matters. Periodic back-flushing using permeate water was performed for 10 sec per filtration of 10 min. As a result, both resistance of membrane fouling (Rf) and permeate flux (J) were influenced highly by concentration of humic acid. It proved that NOM like humic acid could be an important factor on membrane fouling in drinking water treatment. Turbidity and UV254 absorbance were removed up to above 97.4% and 59.2% respectively.

• Journal of the Mineralogical Society of Korea
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• v.15 no.3
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• pp.195-204
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• 2002

Mineralogy and the exposed surface area are two of the most important factors controlling dissolution and weathering rates of soils. The mixture of inorganic and organic materials of various size distributions and structures that constitute soils makes the calculation of weathering rates difficult. The surface area of soil minerals plays an important role in most of programs for calculating the weathering rates and critical loads. The Brunauer-Emmett-Teller (BET) measurement is recommended for the measurement of specific surface area. However, BET values measured without organic matter removal are in fact those far all the N2-adsorbed surface areas, including the surfaces covered and aggregated with organisms. Surfaces occupied by organisms are assumed to be more reactive to weathering by organic activities. Therefore, the BET surface area difference before and after organic removal depicts the area occupied by organisms. The present study shows that the BET values after organic matter removal using $H_2$O$_2$ are larger than those without removal by 1.68~4.87 $m^2$/g. This implies that BET measurement without organic removal excludes the reactive area occupied by organisms and that the area occupied by organisms in soils is much larger than expected. It is suggested that specific surface area measurement for calculating weathering rates of mineral soils should be made before and after organic matter removal. The results of a column experiment are presented to demonstrate the potential retarding influence that this organic matter may have on mineral dissolution and weathering.

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.136-145
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• 1988

To investigate the seasonal changes of various organic and inorganic compounds in compost, carbon compounds in compost were analyzed at various composting periods. Contents of organic matter, cellulose, total carbon, organic carbon and biodegradable carbon in compost were decreased with the progress of composting. In contrast, contents of lignin and nonbiodegradable carbon were increased a little with the progress of composting, but effective contents of lignin were decreased with the lapse of composting time, while effective contents of nonbiodegradable carbon were not changed. Total carbon contents in organic matter in compost were decreased within 9 weeks after composting, and then increased thereafter. Difference between average values of total and biodegradable carbon contents was 6.2%. Actual decay rates of all the carbon compounds were higher than decay rates of the compounds at all the experimental periods. Both of actual decay rate and decay rate of all the carbon compounds were increased rapidly within 2 weeks after composting, and thereafter the rates were increased slightly with the lapse of composting time. Especially the decay rates of cellulose were increased from 9 to 21 weeks after composting. Actual degradation capacity showed the same tendency to degradation capacity of all the carbon compounds in compost. Decay rate and degradation capacity of lignin in compost had minus values, while actual decay rate and actual degradation capacity had plus values. Highly positive correlations were observed among organic matter, cellulose, total carbon and biodegradable carbon one another. Nonbiodegradable carbon showed highly negative correlation with organic matter, cellulose, total carbon, organic carbon and biodegradable carbon, respectively. The same tendencies were observed between lignin and organic matter, cellulose, total carbon, organic carbon and biodegradable carbon. Highly positive correlation was observed between lignin and nonbiodegradable carbon in compost.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.113-118
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• 2016

This experiment was conducted to identify the variations in inorganic nutrients and plant growth in millet (Panicum miliaceum L.) due to soil salinity. The soil series was Munpo and soil texture was silt loam. The experimental soil was amended so that the soil had salinities of $0.8dS\;m^{-1}$, $1.6dS\;m^{-1}$, $3.2dS\;m^{-1}$ and $4.8dS\;m^{-1}$. Millet was transplanted 15 days after sowing. As soil salinity increased, the degree of reduced growth was in the order of seed production > root dry matter > plant dry matter > culm length > tiller number > stem thickness > Panicle length. Seed production was decreased to 18.9% in soil salinity of $1.6dS\;m^{-1}$, 36.9% in of $3.2dS\;m^{-1}$, and 50.7% in EC of $4.8dS\;m^{-1}$. Root dry matter decreased to 35.8% in EC of $3.2dS\;m^{-1}$, and to 40.5% in EC of $4.8dS\;m^{-1}$. As soil salinity increased, Total nitrogen content increased in all aboveground parts, roots and seeds. However, There was no difference in CaO, $P_2O_5$, $K_2O$ and, MgO in soils of different salinity. On the other hand, $Na_2O$ content was higher in the order roots> shoots> seed, and in the case of roots, $Na_2O$ content increased to 1.02% in soil salinity of $4.8dS\;m^{-1}$. However, up to soil salinity of $1.6dS\;m^{-1}$, the $Na_2O$ content of the seed was similar to that in plant grown in the Control conditions($0.8dS\;m^{-1}$). In conclusion, taking into consideration economic factors, millet could be cultivated in soil with salinities of up to approximately $1.6dS\;m^{-1}$, and seed produced from reclaimedland would be suitable for human consumption.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.5
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• pp.485-500
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• 2016

We examined acidity state of inorganic aerosol and oxidation state of organic aerosol by High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) at Baengnyeong Super site from Jan 2012 to Dec 2013. Additionally, we carried out the analysis for the aerosol component group of organic matter ($C_xH_y$, $C_xH_yO_1$, $C_xH_yO_z$, $C_xH_yO_zN_p$) and elemental composition to calculate H/C, O/C, N/C, OM/OC and identify the oxidation state. The aerosol chemical composition in this study is dominated by sulfate ($SO_4{^{2-}}$), nitrate ($NO_3{^-}$) plays a smaller role in aerosol acidity. Ammonium ($NH_4{^+}$) was found in a formation of $(NH_4)_3H(SO_4)_2$. However, the binding formations of $NH_4NO_3$ and $NH_4Cl$ increase in the winter. $C_xH_yO_1$ indicating the oxidized state of $PM_{1.0}$ has the highest ratio of 41% while $C_xH_y$ indicating the non-oxidized state has a lower ratio of 36%, meaning that the oxidation level of $PM_{1.0}$ in Baengnyeong Island is high. The ratio between H/C and O/C was 1.33 and 0.78 respectively, showing the characteristic of LV-OOA (Low volatility-Oxygenated Organic Aerosol). Acidic and oxidized aerosols sampled during this field study were largely anthropogenic in origin from Chinese continent and photochemically aged.

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.2
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• pp.17-28
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• 1997

To study the possibility of agricultural utilization of industrial wastewater sludge, the changes of the substances, such as temperature, pH, inorganic and organic matter, the form of nitrogen, fatty acid and the population number of microorganisms during composting periods were investigated. Temperature and $CO_2$ generation were the highest in the second day of composting peroids, and then were gradually fallen. And they were similar to room temperature after the sixth day of composting periods. C/N ratio was a little increased as time went by. pH value was not changed in early composting periods and then pH had been gradually decreased since it was rapidly increased. It was in the range of 8.7~8.8 in late composting periods. The contents of $P_2O_5$, $K_2O$, CaO, MgO and Fe were a little increased and that of ${SO_4}^{2-}$ was increased with 62~67% in late in comparing with early composting periods. 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 were decreased but that of inorganic nitrogen was increased during composting periods. The population number of microorganism during composting periods was too much changed according to the kinds of bulking agents and microorganisms, and the composting periods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.348-354
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• 2001

This study was conducted to estimation of change characteristics for water quality by the dyke gate operation in the Keum River estuary. The estimation data made use of surveyed data in Keum River estuary by NERDI (National Fisheries Research and Development Institute) during $1990\~1999$. Shown to compare water quality changes at st. A and st. D in Figure 1, the concentrations of TSS, COD and nutrients at st. A were as high as about $2\~4$ times than those at st. D due to affection of fresh water discharge in the Keum River. The percentages of water quality change at surface water by dyke gate operation in the Keum River estuary were shown that TSS (Total Suspended Solid) was decrease to $56\%,\;47\%$ at st. A and D, and COD (Chemical Oxygen Demand) was increase to $68\%,\;71\%$ at st. A and D, respectively. The changes percentage of DIN (Dissolved Inorganic Nitrogen) by dyke gate operation in the Keum River estuary were increase high to $95\%$ at surface water and $7\sim30\%$ at bottom water, but those of DIP (Dissolved Inorganic Phosphorus) were increase to $2.8\sim8.6\%$ at surface water and $28\%$ at bottom water. The range of fluctuation for water quality at each station by dyke gate operation has shown that salinity and TSS are little better than before dyke gate operation, but COD show highly fluctuation. Also we studied estimation of characteristics of water quality change by the season, COD was increased except the summer, TSS was decreased to all season. DIN was increased to about $61\sim172.1\%$ for all season, but DIP was increased to the spring and decreased to the autumn, DIN enrichment in the estuary by dyke gate operation are interpreted to improvement of organic matter decomposition and nitrification by increasing the residence time and to increase nutrient flux in sediments due to decreasing dissolved oxygen and increasing a deposit matter.

• The Korean Journal of Ecology
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• v.22 no.3
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• pp.131-137
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• 1999

This study was carried out to investigate the activity of nitrogen fixation and accumulation of heavy metal and inorganic matter in Vicia amoena community at lower region in Kumho riverside, including Youngchon, Chimsangyo, Paldalgyo, Talseochon and Kumhogyo. The contents of inorganic matter and heavy metal of Kumho riverside soil increased in the down stream in each organ of the plant growing in the riverside. Generally, V. amoena community showed rapid growth of shoot and high value of Top/Root ratio. V. amoena community showed higher water content of shoot at late growth stage and higher chlorophyll content. The root nodule of V. amoena community appeared in April and increased by 0.30, 0.27, 0.24, 0.06 and 0.14 g/plant, and nitrogen fixation activity of nodule attained 20.1, 16.8, 15.4, 8.5 and 5.3 μmol·C₂H₄·g fw nodule/sup -1/·h/sup -1/ for non-contaminated area Youngchon, Chimsangyo, Paldalgyo, Talseochon and Kumhogyo, respectively, in June:. Nodule formation and nitrogen fixation activity were reduced in the down stream by the soil contamination and heavy metal accumulation and showed minimum values. at Talseochon and Paldalgyo. V. amoena showed growth adaptation against heavy metal toxicity by restricting heavy metal such as Pb, Cu, Zn, Fe from transport, and by accumulating high Ca ion in shoot, nitrogen and phosphorus in root at late growth stage than those at early one, respectively, but total heavy metal per plant showed higher values in shoot than those in root by high T/R ratio of plant growth.

• Journal of Bio-Environment Control
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• v.13 no.3
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• pp.172-177
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• 2004

This experiment was conducted to investigate the effect of daytime temperature on fruit crack-ing in the paprika cv. Fiesta and cv. Jubilee under soil culture experiment of vinyl house for two years from 2003 to 2004. The rate of cracked fruit was higher in cv. Fiesta than cv. Jubilee and was the highest at the high daytime temperature of $34\pm$$1^{\circ}C$. and then rapidly increased after April becomes better weather conditions. The flesh hardness and the rate of flesh dry weight were lower in cv. Fiesta than cv. Jubilee and were the lowest at the high daytime temperature of $34\pm$1$^{\circ}C$. but the thickness of flesh was thicker in cv. Fiesta than cv. Jubilee and was the thinnest at the high daytime temperature of $34\pm$$1^{\circ}C$. Inorganic matter contents of flesh was observed no difference to the cultivars and also the temperature treatments. Root condition in harvesting time was better in cv. Fiesta than cv. Jubilee and was not difference in temperature treatments. Therefore, the rate of cracked fruit showed up a positive correlation to the flesh hardness, flesh dry weight, flesh firmness and root condition, and has not correlation to the flesh thickness and inorganic matter con-tents. In conclusion, differences in cultivar sensitivity and the highest rate of cracked fruit in daytime temperature of $34\pm$$1^{\circ}C$ may be partly due to difference in flesh characteristic and root condition but additional factors may be involved.