• Membrane Journal
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• v.24 no.1
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• pp.39-49
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• 2014

The effects of pH and oxygen back-flushing were investigated in hybrid process of ceramic microfiltration and PES (polyethersulfone) beads loaded with titanium dioxide ($TiO_2$) photocatalyst for advanced drinking water treatment in viewpoints of membrane fouling resistance ($R_f$), permeate flux (J), and total permeate volume ($V_T$). As increasing pH, $R_f$ decreased and J increased. Finally the maximum $V_T$ could be acquired at pH 9. Treatment efficiencies of turbidity was almost same independent of pH. Treatment efficiency of dissolved organic matters (DOM) decreased as increasing pH. As results of comparing the oxygen and nitrogen back-flushing, $R_{f,180}$ at oxygen back-flushing was the lower than that at nitrogen back-flushing, and the dimensionless final permeate flux ($J_{180}/J_0$) by initial permeate flux ($J_0$) at oxygen back-flushing was maintained the higher than that at nitrogen back-flushing except 10 and 12 min of back-flushing period (FT). Treatment efficiency of turbidity at oxygen back-flushing was a little higher than that at nitrogen back-flushing. Treatment efficiency of the DOM at nitrogen back-flushing was the higher than that at oxygen back-flushing. Also, treatment efficiency of turbidity at saturated oxygen was similar with those of oxygen and nitrogen back-flushing, but the treatment efficiency of DOM was increased significantly because OH radical could be generated by reaction between saturated oxygen and photocatalyst.

• Korean Journal of Weed Science
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• v.18 no.1
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• pp.20-27
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• 1998

This experiments were conducted to investigate the effects of fertilizer for herbicides phytotoxicity of rice(Oryza sativa L. japonica cv Dongjin). The shoot and root growth of rice were inhibited more by pyrazosulfuron-ethyl or pyrazosulfuronethyl+molinate than bensulfuron methyl or bensulfuron methyl+dimepiperate application in nitrogen or nitrogen mixed solution. In phosphate or phosphate mixed solution, rice growth were inhibited more by bensulfuron methyl or bensulfuron methyl+dimepiperate than pyrazosulfuron-ethyl or pyrazosulfuron-ethyl+molinate application. In solution mixed with nitrogen and phosphate or fertilizer three elements, rice shoots were more. inhibited by pyrazosulfuron-ethyl or pyrazosulfuron-ethyl+molinate treatments, roots were inhibited more relatively by bensulfuron methyl or bensulfuron methyl+dimepiperate treatments. In all fertilizer solutions, rice plant heights were reduced by dimepiperate and molinate applications, but root growth was reduced only by nitrogen and phosphate mixed solution. Rice growth in sulfonylurea or their mixed herbicide application were more inhibited in high :nitrogen concentration arid by phosphate exclusion than by nitrogen exclusion culture.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.468-469
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• 2007

대기 오염원인 sulfite가 식물체에 미치는 영향을 살펴보고 또한 이러한 환경 오염원에 스트레스를 받은 식물에게 질소원을 공급함으로써 이를 극복할 수 있는지를 광합성의 형광분석을 통하여 알아 본 결과 식물은 sulfite에 의해 광합성 활성이 저해를 받으나 질소원을 같이 공급하여 주면 활성이 감소하지 않았다.

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.219-224
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• 2001

This experiment was conducted to evaluate net mineralization and nitrification in rain shelter soil incorporated with wine sludge. Net mineralization and nitrification rates varied among treatments during pepper growing periods. In general, net mineralization increased up to 90 days after transplanting before its decrease during the rest growing periods. Maximum net mineralization and nitrification in upper 0-15 cm layer soil were observed in T4 at 90 days after transplanting. The greatest amount of mineralization in upper layer soil was 272.5 mg.kg$^{-1}$ at 30 days in the control and 843.3 mg.kg$^{-1}$ at 90 days after transplanting in T4. Overall, both net mineralization and net nitrification were greater in the upper layer soil than in the lower 15-30 cm layer soil.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.301-306
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• 2009

This study was conducted to determine the physiological differences betweenhealthy and wilted plants with respect to nitrate assimilation and ascorbic acid content. Wilting was artificially induced in spinach plants by treating the seeds with nutrient solution containing high nitrogen and low potassium. The plants were cultured in different plots 4 types of media: 1N-1P-1K (control), 6N-1P-0K (0K), 6N-1P-0.5K (0.5K), and 6N-1P-2K (2K). The rate of wilting among the plants was as follows: control, 0%; 2K, 10%; 0.5K, 40%; and 0K, 70%. This shows that under high nitrogen conditions, the lower the amount of potassium provided, higher was the rate of wilting. There were no differences in plant growth among the plants treated with different levels of potassium under high nitrogen conditions.The nitrate content in both the leaves and the roots was higher in plants grown under high nitrogen media than those in the control. Furthermore, the nitrate level decreased with increasing potassium concentration. The ascorbic acid content of spinach under high nitrogen conditions was lower than those of the control.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.5
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• pp.383-390
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• 1993

This experiment was carried out in the green house at Tokyo University of Agriculture in 1992 to investigate the relationship between lodging resistances and specific morphological characters and to examine the effects of nitrogen top-dressing and growth retardant on changes of the endogenous ethylene content in rice plant. Inabenfide did not affect significantly yield, yield component, chlorophyll content, and $CO_2 assimilation but, decreasing plant height when growth regulators were applied at booting stage, decreasing internode elongation, and increasing culm thickness and diameter of the third and fourth internode. While, nitrogen top-dressing usually showed to effect increasing vegetative growth such as plant height, tiller number, and morphological characteristics but, were not significantly affected the chlorophyll content and $CO_2 assimilation. Ethylene evolution was dramatically changed with nitrogen top-dressing and growth retardant. Application of Inabenfide at 15 days before heading inhibited ethylene evolution in the all nitrogen levels. Higher nitrogen top-dressing showed higher ethylene evolution than that of low nitrogen level. High positive correlation was detected between nitrogen application and ethylene evolution.

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.9-15
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• 2005

Soil aquifer treatment is a water reuse technology that secondary or tertiary treated wastewater is infiltrated into the aquifer in which physical and biochemical reactions occur. Major consideration in SAT is the removal and transport of DOC and nitrogen species. In this study, reaction mechanism in SAT was examined considering nitrification, denitrification and organic oxidation. In addition, SAT modeling system was developed as the reaction mechanism was applied to groundwater flow and transport model. In verification of the reaction module by 1-dimensional unsaturated soil column test, the experimental data of all of the species, ammonium, nitrate, DOC and DO, were well matched with the simulation results. In sensitivity analysis, ammonium partition coefficient, dissolved oxygen inhibition constant and biomass decay rate affect ammonium, DOC and DO concentration of effluent, respectively.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.137-142
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• 2014

This study was conducted to investigate the effect of silicate mixed with nitrogen fertilizer on improving the growth and reducing nitrogen input of zoysiagrass. Plant height, fresh and dry weight of shoots, roots, and stolons, the number of shoots and total of stolons length were increased with highest in silicate mixed with nitrogen 24 kg/10a than nitrogen 24 kg/10a, and it showed no significance in silicate mixed with nitrogen 18 kg/10a. Nitrogen use efficiency in mixed silicate fertilizer was increased by 25-30% than single nitrogen fertilization. Moreover, the contents of available $SiO_2$, and organic matters of silicate fertilization on soil was higher than not silicate fertilization on soil. The silicate enhanced the growth and density of zoysiagrass, while it was a crucial factor to affect the chemical property of the soil.

• Journal of Navigation and Port Research
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• v.28 no.3
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• pp.253-258
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• 2004

There have been several problems in treating shipbard sewage due to special environmental conditions of ship, such as limited space, rolling and pitching, change of temperature and so on It was suggested that Sequence Batch Reactor (SBR) might be suitable process for overcome these problems in terms of small size, high capacity of treating wastewater and full automation. In this study a SBR process was employed for biological treatment of organic wastes in the shipboard sewage. This process was able to remove nitrogen and phosphorus as well as organic matter efficiently. Afore than 95％ of chemical oxygen demand(COD) were removed. In addition, about 97％ of total nitrogen (T-N) was reduced. The total phosphorus(T-P) reduction averaged 93％. A disturbance operation caused by the treatment of Methylene Blue Active Substances(MBAS) was not observed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.253-259
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• 2001

The purpose of this study was loused on understanding of uptake of nutrients by plants, the behaviors of nutrients in soil and the possibility of leaching loss when N fertilizer (urea) and mature compost were applied. Lysimeters (volume 0.15㎥, diameter 62cm, height 62.8cm) were installed for collecting leachate in the Jeju volcanic ash soils. Lysimeter study consisted of thirteen treatments: fellow, fellow with weeding, cropping without fertilizer and compost, three N fertilizer soil surface applications (16, 32, and 64 kg/10a), three N fertilizer and compost soil surface applications (16+800i 32+1600, and 64+3200 kg/10a), two water dissolved N fertilizer applications(16 and 32 kg/10a), and low and high plant densities. The growth of corn (preceding crop) and potatoes (succeeding crop) and leaching loss were determined during the experimental period. The amount of leachate from lysimeter was remarkably greater at bare conditions than at cropping conditions for corn and potatoes. The N content of plants (corn and potatoes) tended to increase as fertilizer rate increased. Fertilization of urea dissolved in water to soil was more efficient than surface fertilization for the growth, yield, and the N uptake N of corn and potatoes. There were no differences in dry matter yield of plants between medium and high N rates, but N, Ca, K and Mg concentrations of plants were higher at higher N rates. There were significant correlations between N uptake and each of Ca, K and Mg uptakes in corn and potatoes. Total N uptake by plants increased with increased N fertilizer and compost applications. Plane absorbed 54.9% of applied N at low N rate and 31.0 to 34.0% at high N rates. The proportion of N leaching losses was lower at low N rate and high plant density.