• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.70-78
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• 1998

This study was conducted to investigate the adsorption-desorption characteristics of herbicide paraquat on clay minerals, humic materials, and soils under the laboratory conditions. Adsorption time of paraquat on clay minerals was faster than organic materials and soils. Adsorption amount on montmorillonite, 2:1 expanding-lattice clay mineral, was largest among the adsorbents tested. The adsorption capacity of paraquat was approximately 21 % of cation exchange capacity in soils, 45.1 % in kaolinite, and 80.6% in montmorillonite. Humic materials, humic acid and fulvic acid isolated from soil II, adsorbed larger amount of paraquat than kaolinite and soils. Distribution of tightly bound type of paraquat was larger in clay mineral and soils but loosely bound type was larger in humic acid and fulvic acid. In oxidized soil, the adsorption amount of paraquat was decreased to 85.1-95.5% of original soils. Distribution of unbound and loosely bound type of paraquat was decreased in oxidized soil but tightly bound type was increased. The competition cations decreased paraquat adsorption on humic materials and soils but not affected on montmorillonite. No difference was observed as the kinds of cations. In cation-saturated adsorbents, the adsorption amount was decreased largely in humic materials and soils but decreased a little in montmorillonite. The tightly bound type of paraquat in all adsorbents was not desorbed by pH variation, sonication, and cation application but loosely bound type was desorbed. However, the desorption amount was different as a kinds of adsorbents and desorption methods.

• Journal of the Korean GEO-environmental Society
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• v.1 no.1
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• pp.35-42
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• 2000

The settlement characteristics of waste landfill site must be considered in the design of sanitary landfill as well as in the course of the rehabilitation of the landfill site. Among prediction methods for settlement of landfill site, especially Gibson and Lo model and Power Creep Law have been successfully applied to the landfill site where the amount of settlement was large and the secondary settlement was obvious. Therefore, the effects of organic content on the model parameter values utilized in both Gibson Lo model and Power Creep Law were studied by using a large consolidation testing apparatus. The organic content is each 20%, 40%, 60% of total volume and consolidation load is $0.1{\sim}1.6kg/cm^2$. The main results can be summarized as follows: (1) The reference compressibility of Power Creep Law is decreased according to the increments of consolidation load: (2) The field measurement is more similar to the Power Creep Law than the Gibson and Lo model.

• Clean Technology
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• v.10 no.1
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• pp.37-45
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• 2004

This study examined the separation characteristics of some of the most commonly used disperse, reactive and acid dyes by nanofiltration membrane. The chemical characteristics of three major dye solutions such as chemical oxygen demand, total nitrogen, total organic carbon, color, suspended solids, total dissolved solids, conductivity were investigated in this work. Experiments showed that the types of dye had a significant effect on both permeate flux and rejection efficiencies mainly due to the differences among their chemical structures and natures. Especially, the nanofiltration of reactive dye solutions showed higher permeate flux, lower total dissolved solid rejection efficiency and higher organics rejection efficiency than those of disperse dye solutions.

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.83-91
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• 2015

This study is measured the change of chlorophyll-${\alpha}$ concentration and phytoplankton density, the grazing rates (GR) and pseudofaeces production (PFP), by grazing of freshwater apple snail, Pomacea canaliculata, to investigated that the snails are able to control of phytoplankton bloom. The experiments are performed to evaluate the GR and PFP at different conditions such as incubation time (0, 2, 4, 6, 8, 10 and 12 hr), shell height (1.0 to 4.0 cm, n=108), snail density (1, 1.5, 2.5, 3.5 and 5 indiv. $L^{-1}$) and food concentration (200, 400, 600, 800 and $1000{\mu}g$ $L^{-1}$). Regarding feeding time, the highest GR (2.5 L. $gAFDW^{-1}h^{-1}$) and PFP (15.3 mg $AFDW^{-1}$) showed at 4 hr after snail stocking, respectively. The snail, smaller than 1.5 cm in body size, showed the highest of GRs (2.54 L. $gAFDW^{-1}h^{-1}$) for the initial period (2 hr of stocking), compared to those greater than 1.5 cm, which showed a stable FR, higher than 0.099 L. $gAFDW^{-1}h^{-1}$. Upon snail density effect, the density of 5 indiv. $L^{-1}$ induced the most effective inhibition on phytoplankton biomass with the highest PFP. On the food concentration, the highest GR (0.54 L. $gAFDW^{-1}h^{-1}$) and PFP (8.5 mg $gAFDW^{-1}$) were induced at the level of $600{\mu}g$ $L^{-1}$, respectively. We checked that it is possible to control of phytoplankton bloom by the grazing of apple snail as well as Reeve. However, it required a through research for the remove of pseudofaeces and 2nd problem by the decomposition of the organic materals.

• Journal of the Korean Electrochemical Society
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• v.16 no.3
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• pp.123-128
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• 2013

Organic carbons such as methanol, ethanol, iso-propanol, methoxy ethanol, glucose are added(1, 2, 3%) in the 2000 ppm $NH_3$ and $H_3PO_4$. As vol.%. cyclic voltammetry measurement of the capacity with the addition of organic carbon, the results of $NH_3$ + 3 vol.% Methanol Addition, $H_3PO_4$ + 2 vol.% iso-propanol addition of the increase in capacity was observed. Applying to the CDI Module cell with an addiction of organic carbon is confirm that remove $NH_4$-N and $PO_4$-P in sewage. Namely, the removal efficiency of $NH_3$ was increase of 16.4% during adsorption, 30.4% during desorption and the removal efficiency of $H_3PO_4$ was increase of 63% during adsorption, 54.7% during desorption. Therefore, the result of this research is confirm that effect of the N, P removal and considered that reduction of the operating costs without removing the organic matter in the influent wastewater.

• Korean Journal of Organic Agriculture
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• v.14 no.2
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• pp.205-217
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• 2006

This research was carried out to investigate the effects of some organic materials such as rice straw, compost, hairy vetch, phosphate rock, magnesium lime powder and ash in the organic paddy fields, and also to develope the new technique for better soil management using described materials. The results are as follows; Height and tiller of rice plants were higher in chemical fertilizer than rice straw or compost, however, those of rice plants in hairy vetch-rice cropping system reached to chemical fertilizer. The Eh value of soil has decreased consecutively since on 30th, May because of the rising of soil temperature by an increase in the activity of microbes. As a result of measuring yield and yield components, there is not significant difference between treatment. The application of organic materials enriched the contents of available phosphorus, exchangible potassium and calcium in soil, and, also improved the physical properties such as pore space rates and bulk density. From the viewpoint of soil management technology in organic paddy fields, the application of rice straw or organic compost might cause the decrease of yield compared with conventional cultivation system, chemical fertilizer, however, the application of hairy vetch residues of soil compensated for growth and yield as well as improved the physicochemical property. Therefore, it is assumed that the cultivation of hairy vetch for winter season can be one of the useful methods for organic farming system.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.4
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• pp.66-73
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• 2009

Temperature phase anaerobic co-digestion process was conducted with the one to one mixture of food wastewater with livestock wastewater, and the presence and the dynamics of various pathogenic microorganisms was analyzed. The mixture contained various enteric and pathogenic bacteria, such as Escherichia coli. Enterobacteriaceae, Coliform bacteria. Staphylococcus aureus, Salmonella, Shigella, Listeria, and Yeast. Anaerobic digestion has become stabilized around 21 days after the reaction started, showing about 80% to 90% of remarkable reduction rates of microorganisms until this period in acidogenic reactor (AR) and methanogenic reactor (MR), respect ively. After stabilization, the average reduction rate of organic matter was recorded as around 60% in MR. Most microorganisms in the effluent were not detected at around the last period of the reaction, except Listeria and S. aureus, which showed the growth even at the last day of the reaction.

• Journal of Animal Science and Technology
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• v.54 no.5
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• pp.349-354
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• 2012

In this experiment, two inclusion levels (15 and 30% of diets, as-fed basis) of brown rice (BR) were tested against a control diet with 0% BR (51% wheat flour of diet). Six female Miniature Poodles (8~9 months age, initial mean body weight of 3.5 kg) were assigned to treatments in replicated $3{\times}3$ Latin square design. Total tract digestibilities of DM, OM, CP, acid hydrolyzed fat and gross energy increased linearly (P<0.05), and observed digestible energy and metabolizable energy values also increased linearly (P<0.001 and P=0.007, respectively) with increasing BR inclusion levels. Wet and dry fecal output decreased linearly (P=0.001) with increasing BR inclusion levels in the diets. Linear (P<0.05) effects was observed in fecal score for dogs fed BR and fecal ammonia concentration increased linearly (P<0.05) in response to increasing BR inclusion level. It seems that the increase in fecal ammonia concentration may be partially related to the decrease in short-chain fatty acid concentration (P<0.01). This study clearly demonstrates that BR improves nutrients digestibility and fecal characteristics of dog.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.70-78
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• 1998

Dissipation, adsorption and desorption of oxadiazon were examined in two soils containing different amounts of soil organic matter. In addition, reactivity of oxadiazon with humic monomers was searched to clarify binding mechanism of oxadiazon to soil organic matter in the presence of a laccase of Myceliophthera thermophila. Half lives of oxadiazon were 38 days in Soil I and 45 days in Soil II. Freundlich constant, k values of fresh soils were higher than those of oxidized soils. Adsorption rates of oxadiazon were increased 17.1% in Soil I and 9.3% in Soil II in the presence of a laccase but no significant increase was observed in oxidized soils. Desorption rates of oxadiazon in fresh soils were lower than those in oxidized soils. Desorption rates of adsorbed oxadiazon in soils addes with the enzyme were not changed in oxidized soils but decreased in fresh soils. The herbicide oxadiazon alone underwent no transformation by a laccase but in the presence of catechol, guaiacol and gallic acid as humic monomer, transformation rates of it were from 20% to 24%.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.131-131
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• 2003

왕겨 활용의 일환으로 파쇄과정을 거쳐 돈분과 혼합하여 퇴비화에 미치는 영향 및 물질의 특성 변화를 조사하였다. 왕겨 입자는 1mm 이하, 1~2mm, 2mm 이상 등 3가지로 분리하여 돈분과 부피비(4 : 3)로 혼합한 후 정체식 퇴비화 시설에 적하하여 $250m^3/hr.$의 송풍기로 10min./day씩 강제송풍을 시켰다. 처리구는 톱밥구(Control), 왕겨구(RH), 1~2mm 왕겨구(MRH), 1mm이하 왕겨구(SRH) 등 4개였으며, 수분함량은 혼합물질의 특성에 따라 차이를 보였다. 온도변화는 퇴비화 시작 3일째부터 온도 상승이 시작되었으며, RH구에서 가장 빨리 $60^{\circ}C$로 상승하였다. 그 후 가장 먼저 온도가 하강하였으며 40일째 온도가 대기온도와 같았다. pH는 모든 처리구에서 10일 이내에서 감소하였지만 그 후 지속적으로 증가하는 경향을 보였다. 유기물은 퇴비화 초기와 후기에 큰 차이를 보이지 않았지만 RH구의 감소율이 다른 처리구에 비해 높았다. 공극률이 높은처리구일수록 암모니아 휘산이 적어 T-N함량이 높았고 C/N율은 20~40사이로 적당하였다. 퇴비화 과정 중 온도 변화는 용적밀도의 차이에 의한 것이며, 화학성분의 함량 차이는 두 물질사이의 혼합량 차이에 의한 것이었다.