• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.97-102
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• 2007

The piggery wastewater is the major source of the water pollution problem in the rural area. The treatment alternatives for piggery wastewater are limited by the characteristics of both high organic and nitrogen(N) content. In order to investigate an efficient N removal system, the thermophilic aerobic digestion process was examined. The experiment was investigated organic and nitrogen removal efficiency at various HRTs and air supply volume. The results of semi-continuous experiment indicated that a higher removal of the soluble portion of COD was achieved with the longer HRTs. However, the inert portion of COD in piggery wastewater was not much changed by thermophilic aerobic digestion. In addition, with the higher HRT of 3 days, up to 79% of NH4-N removal efficiency was achieved. Lower the HRTs, a decrease of NH4-N removal was founds. The gas samples from the lab reactor were analyzed along with the N content in influent and effluent. The N2O formation in our system indicates a novel aerobic deammonification process occurred during the thermophilic aerobic digestion. Both N02 and N03 were not presented in the effluent of thermophilic aerobic digester. With the HRT of 3 days, 36.4% of influent N(or 57.5% removal N) was aerobically converted to N2O gas. The ammonium conversion to N2O gas significantly decrease to 4.5% at low HRT of .05 day..

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.729-735
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• 2015

This study was carried out to analyze the community structure and distribution of macrobenthos in Hakampo sandy shore. As for the environmental factors of sampling stations, the average grain size of the sediments from the sampling stations was $2.37{\phi}$ with the range of $1.90{\phi}{\sim}2.52{\phi}$, which represents the typical medium sand sedimentary facies of sandy beach. The average sediment organic content was 1.15% with the range of 0.90%~1.46%. Most stations had low sediment organic content which is typical of sandy beach. The number of species were total 59 from 6 taxa and the individuals was $668inds./m^2$ in the 10 stations of the study area. Based on the Bray-Curtis similarity analysis, the 10 stations of the study area were broadly divided into 3 groups. The highest part of intertidal zone was St. 2~St. 4, the middle part of intertidal zone was St. 5~St. 8, and the lower part of intertidal zone was St. 9~St. 10. A spatial community structure was observed which is divided into the highest, middle, and lower parts.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.777-784
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• 2015

This study verified the correlations between vegetation factors, such as the number of individual species and species diversity, and soil factors in Chamaecyparis obtusa (CO) stands in Jeollanam-do. Also, the site environmental factors that affect the annual growth of CO ring width were analyzed. Positive correlations were found between the species diversity index and Cation Exchange Capacity (CEC), available phosphate, and exchangeable $K^+$ (P<0.01). In addition, strong positive correlations were also found between the number of species that appeared in the study site and CEC, available phosphorus, exchangeable $K^+$ and exchangeable $Mg^{2+}$ (P<0.01). Tree ring growth showed strong correlations with the nutrient holding capacity and fertility of soil, including available phosphate, exchangeable $K^+$, CEC, and electrical conductivity (P<0.01). The explanatory variables of tree ring growth in CO were composed of exchangeable $K^+$, organic matter content, and soil pH. The regression model had a high level of explanatory power, 74.4%. In this model, the annual growth of CO ring width increased when exchangeable $K^+$ and organic matter content were higher but decreased when soil pH was lower. According to the analysis, it is found that the annual growth of CO ring width was significantly affected by soil fertility, including available phosphate, exchangeable $K^+$, CEC, and electrical conductivity. In addition, the soil fertility of CO stands seems to be significantly affected by the supply of fallen leaves from the understory vegetation of CO.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.147-150
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• 2002

To investigate the effects of Harvesting time and additives on the quality of peanut silage, the silage was mixed in combination with peanut leaf and stem, rice and barley straw, inoculant etc. Harvesting time at peanut growth stage was the best at 90 days after flowering with 30 branches,81 g of 100-seed weight, and 77% of shelling rate with low diseases in leaf and stem. By delay of harvest, diseases and lodging were increased. The yield of forage was the highest at 90 days after flowering as 52 t/ha, and seed yield was at 110 days as 3.72 t/ha. The yields between forage yield and seed yield ($r^2$=0.62$^{**}$) were correlated positively. The value of silage as a forage came over 90 days after flowering in combination with peanut leaf+stem+vice straw+inoculant treatment. The treatment was increased dry matter (DM) yield and neutral detergent fiber (NDF), the coarse protein (CP), and total digestible nutrient (TDN) content of silage in comparing with control (peanut leaf+stem). The pH at the organic matter contents of silage in combination of peanut leaf+stem+rice straw+lactic acid treatment was 5.04 to 5.10, the content of butyric and lactic acid were 3.12 to 4.64%, 2.07 to 7.34%, respectively.y.

• Journal of Soil and Groundwater Environment
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• v.17 no.3
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• pp.1-9
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• 2012

According to the agreement on WTO/TBT, we are under the situation to adopt international standard (ISO standard) as a national standard if it exists. However, in case of environmental area, it is a domestic legal obligation to use Korean environmental standard method(KESM) for analyzing various contaminants. Therefore it is necessary to assess the comparability between KEM and ISO standard prior to apply ISO standard to soil conservation law in Korea. The main purpose of this study is to assess the comparability of both methods for analyzing heavy metals in soil. We looked over various aspects like pre-treatment, calibration curve range, detection wavelength, soil organic matter content and so on. Apparently, the procedure of both methods is almost same. However in details, both methods are different in stationary time before aqua-regia extraction using reflux system, calibration curve range for Cu, Pb, Ni and measuring wavelength for Pb. According to the results of comparison test, the results were significantly different when the different calibration range was used. In case that all the extracts independent of methods were reanalyzed with the same calibration range of each method, both methods showed statistically same results. Other conditions like different stationary time, measuring wavelength of AAS and soil organic matter content did not have any influence on the analytical result. Therefore, we suggest to extend the calibration curve range to 0~8 mg/L which is used in KS I ISO standard(Korean standard related with environment which is translation version of ISO standard without any technical change). In case of $Cr^{6+}$, the results showed no significant differences between two methods even though the pretreatment, instrumentation and other analysis conditions were different. In addition to UV/Visble spectrometry of KESM for soil contamination, we suggest to adopt ion chromatography of ISO 15192(US EPA method 7199) for analyzing $Cr^{6+}$ with the consideration of laboratory work efficiency.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.4
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• pp.278-285
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• 1991

This study was conducted to manufacture a good qualified organic fertilizer with cow dung through rapid composting process, and the proposal guideline of the degree of maturity could be estimated with the measurement of final product. It included total nitrogen content of above 2% on an oven-dry material basis, C/N ratio of below 20, CEC of more than about 60 me/100g, ratio of carbon in reducing sugar to the total carbon of below 35%, and temperature in pile of above $60^{\circ}C$. The total nitrogen content, the C/N ratio, and the Paper Chromatographic method couldn't be the guideline to evalute the maturity of cow dung compost. CEC was increased in increased fermentation and it was high in the high fermented temperature plots which were cow dung+ shredded bark in 1988, cow+dung+wood chips in 1989, and cow dung+rice straws in 1990. The ratio of carbon in reducing sugar to total carbon in 1990 was lower in cow dung+saw dust than cow dung+rice straws that was the highest temperature in pile. Generally cow dung was mixed well with saw dust and thus the total carbon of the product was high. The measurement of the temperature in pile seems to be a indirect guideline of maturity.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.105-118
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• 2015

This study was carried out to investigate the effects of profile disturbance with different artificial accumulation history on physico-chemical properties of soil under plastic film house. The investigations included soil profile description using soil column cylinder auger F10cm x h110cm, in situ and laboratory measurements of soil properties at five sites each at the cucumber (Site Ic ~ Vc) and grape (Site Ig ~ Vg) plastic film houses with artificial soil accumulation. The sites except sites Ic, IVc, IVg and Vg, belong to ex-paddy area. The types of accumulates around root zone included sandy loam soil for 3 sites, loam soil for 1 site, saprolite for 2 sites, and multi-layer with different accumulates for 3 sites. Especially, Site IIg has mixed plow zone (Ap horizon) with original soil and saprolite, whereas disturbed soil layers of the other sites are composed of only external accumulates. The soil depth disturbed by artificial accumulation ranged from 20 cm, for Site IIg, to whole measured depth of 110 cm, for Site IVc, Vc, and Site IVg. Elapsed time from artificially accumulation to investigation time ranged from 3 months, Site IIc, to more than 20 years, Site Vg, paddy-soil covering over well-drained upland soil during land leveling in 1980s. Disturbed top layer in all sites except Site Vg had no structure, indicating low structural stability. In situ infiltration rate had no correlation with texture or organic matter content, but highest value with highest variability in Site IIIc, the shortest elapsed time since sandy loam soil accumulation. Relatively low infiltration rate was observed in sites accumulated by saprolite with coarse texture, presumably because its low structural stability in the way of weathering process could result in relatively high compaction in agro-machine work or irrigation. In all cucumber sites, there were water-transport limited zone with very low permeable or impermeability within 50 cm under soil surface, but Site IIg, IIIg, and Vg, with relatively weak disturbance or structured soil, were the reverse. We observed the big change in texture and re-increase of organic matter content, available phosphate, and exchangeable cations between disturbed layer and original soil layer. This study, therefore, suggest that the accumulation of coarse material such as saprolite for cultivating cash crop under plastic film house might not improve soil drainage and structural stability, inversely showing weaker disturbance of original soil profile with higher drainage.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.138-146
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• 2000

This study was performed to determine the best fermentation soil in vanishing composting of individual residence garbage. At the result, temperature, weight, water content, volatile solid were reduced gradually by reaction of microorganism in the reactors after food was inserted for 9 days. The vanishing possibility was observed in all reactors. The best reactor was F and 4 that seeded microorganisms which were provided at S University. In addition it was possible to shorten cycle of putting in food waste. Inactivated reactors will be bad because of increased water content for long reaction time. Sodium chloride was accumulated and not vanished as time passed. But reactor was not insulated, the activities of microorganism in the reactor were affected highly by cold weather(about less than $12^{\circ}C$). When the study was extended to find out the feasibility of application, the retention time could be shortened to 3days form 9 days, when the microorganism reactor that used the fermentation soil seeded microorganisms which were provided at S University was maintained about $20^{\circ}C$.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.86-92
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• 2000

This study was conducted to determine the optimal mixing ratio of the paper mill sludge(PMS) and pig manure(PM). Since the former contains lots of total carbon and low nitrogen, it was used as carbon source. Also, dried paper mill sludge(DPMS) was added to the mixture to control the water content. The treatments was composed of four as follows, PMS-100(PM 0%+PMS 80%+DPMS 20%), PMS-85(15+65+20), PMS-70(30+50+20), and PMS-55(45+35+20). The mixtures were composted under aerobic condition in $1.25m^3$ static piles. The piles were aerated for 15 minutes per day and turned over the mixture once a week at the early stage of composting. To estimate the maturity of composts, the changes of physico-chemical properties such as temperature, pH, C/N ratio and color were monitored every week. The 25-30 and 55-60% as optimal condition of C/N ratio and moisture content were respectively recommended for effective composting by the evaluation of the changes of phsico-chemical properties for materials taken from compost files during the composting period. When the 30 and 45% of PM were mixed with PMS, the maturity time at least demanded to the stable state were shortened and the qualify of the final product was improved in a view of nutritional components.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1799-1805
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• 2015

Rice vinegar (RV) is primarily made from fermented rice or rice wine in Korea, China, and Japan. Ten commercially available naturally-fermented rice vinegars produced in Korea (KRV1~4), China (CRV1~2), and Japan (JRV1~4) were comparatively investigated for their physicochemical properties and antioxidant activities. KRV showed a significantly higher total acidity range (5.07~6.27) than both CRV (4.67~4.84) and JRV (4.64~4.84). These acidity ranges corresponded with respective standards of each country: Korea (Food Code), China (GB), and Japan (JAS). Six different organic acids were detected in RVs; acetic acid and succinic acid were the most prominent. Thirty different amino acids were detected in RVs, and main identified amino acids were alanine (KRV), phenylalanine and aspartic acid (CRV), and leucine and alanine (JRV). ${\gamma}-Aminobutyric$ acid was detected at high concentration in KRV1. KRV1 showed maximum total phenolic content, and DPPH and ABTS radical scavenging activities of samples were also determined with significantly increasing tendency. KRV1 (produced from brown rice with aging period of >1 year) exhibited the highest free amino acid content and antioxidant activity as compared to CRV and JRV.