• Title/Summary/Keyword: Sang Do

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제약폐수 활성슬러지 공정에서 DO농도에 따른 미생물의 활성 변화 측정

  • Mun, Sun-Sik;Lee, Sang-Hun;Sin, Jong-Cheol;Choe, Gwang-Geun;Lee, Sang-Hun;Mun, Heung-Man;Lee, Jin-Won
    • 한국생물공학회:학술대회논문집
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    • 2002.04a
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    • pp.355-358
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    • 2002

  • In this study, we have tried to find the maximum microbial efficiency at the various dissolved oxygen (DO) concentration conditions in the treatment of pharmaceutical wastewater. Experiments of activated sludge process were performed to examine the relation between microbial activity and DO concentration in a continuous bioreactor. The reduction rate of COD (chemical oxygen demand) was low at the DO concentration between 0 ppm and 1.0 ppm, but it went higher and showed maximum between 1.5 ppm and 3.0 ppm. Then the COD reduction rate was quickly decreased above the DO concentration of 3.0 ppm.

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Outlook for consumption of subtropical vegetables and required cultivation area (아열대채소의 소비량과 필요재배면적 전망)

  • Lee, Hong-Jin;Kim, Sung-Yong;Kim, Yun-Sik;Jeon, Sang-Gon
    • Korean Journal of Agricultural Science
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    • v.40 no.4
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    • pp.425-434
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    • 2013

  • Nowadays, the korean peninsula has endured weather changes toward to the subtropical climate. Also demographical structure has changed into multi-cultural society in which many people from subtropical areas have immigrated into Korea. Therefore, consumption and production of subtropical vegetables become important. For the analysis, we choose eight important subtropical crops. EDM (Equilibrium Displacement Model) with many parameters and elasticities is used for the forecast of consumption and required cultivation area. The simulation focuses on the changes of the number of foreign workers and immigrated women in Korea to predict the quantity of consumption and required area in Korea. The results show that we need additional land area about 581~1,065 ha for the cropping subtropical vegetables in Korea. Finally, these required area can be provided by the cities and counties in coast area in Gyeongsangnam-Do, Jeonranam-Do and Jeju-Do. Climate change will be continued in the future. Together with climate change, the change of demographical structure into multi-culture may increase consumption and production of subtropical vegetables. Forecasting of increased consumption and required cultivation area for subtropical vegetables is significant.

  • https://doi.org/10.7744/cnujas.2013.40.4.425 인용 PDF KSCI

Effect of By-Product Gypsum Fertilizer on Methane Gas Emissions and Rice Productivity in Paddy Field

  • Park, Jun-Hong;Sonn, Yeon-Kyu;Kong, Myung-Suk;Zhang, Yong-Seon;Park, Sang-Jo;Won, Jong-Gun;Lee, Suk-Hee;Seo, Dong-Hwan;Park, So-Deuk;Kim, Jang-Eok
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.1
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    • pp.30-35
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    • 2016

  • Rice cultivation in paddy field affects the global balance of methane ($CH_4$) as a key greenhouse gas. To evaluate a potential use of by-product gypsum fertilizer (BGF) in reducing $CH_4$ emission from paddy soil, $CH_4$ fluxes from a paddy soil applied with BGF different levels (0, 2, 4 and $8Mg\;ha^{-1}$) were investigated by closed-chamber method during rice cultivation period. $CH_4$ flux significantly decreased (p<0.05) with increasing level of BGF application. $8Mg\;ha^{-1}$ of BGF addition in soil reduced $CH_4$ flux by 60.6% compared to control. Decreased soil redox potential (Eh) resulted in increasing $CH_4$ emission through a $CO_2$ reduction reaction. The concentrations of dissolved calcium (Ca) and sulfate ion (${SO_4}^{2-}$) in soil pore water were significantly increased as the application rate of BGF increased and showed negatively correlations with $CH_4$ flux. Decreased $CH_4$ flux with BGF application implied that ${SO_4}^{2-}$ ion led to decreases in electron availability for methanogen and precipitation reaction of Ca ion with inorganic carbon including carbonate and bicarbonate as a source of $CH_4$ formation under anoxic condition. BGF application also increased rice grain yield by 16% at $8Mg\;ha^{-1}$ of BGF addition. Therefore, our results suggest that BGF application can be a good soil management practice to reduce $CH_4$ emission from paddy soil and to increase rice yield.

  • https://doi.org/10.7745/KJSSF.2016.49.1.030 인용 PDF KSCI