• Korean Journal of Weed Science
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• v.7 no.3
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• pp.316-320
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• 1987

In order to determine effects of molinate mixture granular formulations on release rate and weed control efficacy of herbicides and growth of rice plants, zeolite impregnation, slurry, and sand-coating granules were tested in laboratory and greenhouse. Release rate of molinate and simetryn was faster in sand-coating granule than in zeolite impregnation and slurry type granules. Mixture granular formulations of molinate/simetryn or molinate/simetryn/MCPB showed good weed control efficacy and this trend was more remarkably shown in sand-coating granule. Sand-coating granule more inhibited growth of rice plants compared to zeolite impregnation and slurry type granules.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.683-694
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• 2018

The ginseng extract was dried and added forming agents using lactose, glucose and arabic gum to enhance convenience and consumer acceptability. As the addition of lactose increased, the absorption of ginseng granule decreased and the solubility tended to increase as the amount of glucose added decreased. The amount of solubilized saponin from the ginseng granules was affected more by the addition amount of ginseng concentrate than by the kind and amount of the forming agents added. Absorption and solubility tended to increase with increasing amount of arabic gum, and there was no significant difference in color change(p<0.05). The optimal mixing ratio of ginseng granules according to addition of forming agents was 10% of ginseng concentrate, 80% of lactose, 5% of glucose and 5% of arabic gum.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.5
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• pp.351-358
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• 2012

Formation of disinfection by-products (DBPs) including trihalomethans (THM), haloacetic acid (HAA) and haloacetonitriles (HAN) from chlorination of extracellular organic matter (EOM) and cells + intracellular organic matter (IOM) of Microcystis sp., a blue-green algae, during decomposed period was investigated. Microcystis sp. cells + IOM and EOM of Microcystis sp. exhibited a high potential for DBP formation. HAAFP (formation potential) was higher than THMFP during decomposed period. In the variations of HAAFP species during decomposed period, the ratio of di-HAAFP species was gradually decreased and the ratio of tri-HAAFP species was gradually increased in the case of EOM during decomposed period, while the opposite result was in the case of cells + IOM during decomposed period. In the variations of HANFP species during decomposed period, the ratio of di-HANFP species was much higher than the ratio of tri-HAAFP species.

• Journal of the Korean GEO-environmental Society
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• v.11 no.5
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• pp.15-23
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• 2010

Dry sieving, wet sieving and photoscattering analyzer were tested as particle size analyzing methods for sediments from rivers and lakes of Han river, Nakdong river, Youngsan river, and Kumgang river area. Dry sieving showed a big error due to coagulating effect over drying process and this phenomena was severe for lake sediment. Wet sieving and PSA showed an accurate results though wet sieving needs more labor and complicate processes. Freeze-dry or freeze-dry after oxidation of organics with hydrogen peroxide showed improved results but gave lower portion of fine particles in comparing with wet sieving. Heavy metal contents and extractable metal contents were investigated for the sediments and high heavy metal content and extractable amount were obtained from fine particles as expected. Using of proper particle size analyzing method is important and the sediment management should be focused on the fine particles.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1661-1666
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• 2010

본 연구의 목적은 충북대학교 부속농장에서 2009년 영농기간을 중심으로 담수된 논에서의 산화환원전위(Eh)의 변화와 시비에 따라 영양물질인 인(P)의 농도변화 특성을 파악함으로써, 논으로 부터의 인의 유출제어에 관한 기초 자료를 제공하는데 있다. 이 연구는 2009년 5월부터 11월까지 논에서 담수의 총인(T-P)과 인산염 인($PO_4$-P)의 농도변화와 토양의 산화환원전위(Eh)와의 관계 특성을 파악하였다. 관개기의 논에서 인은 분얼비 시기에 인성분이 시비되지 않았는데도 불구하고 T-P농도가 0.68 mg/L로 높게 나타났다. 이는 담수의 영향으로 논이 환원상태로 되어, 논바닥에 침전된 철이온에 흡착되어 있던 인이 철이온의 환원으로 함께 용출하기 때문이라고 생각된다. 높은 Eh는 산화경향을, 낮은 Eh는 환원경향을 나타낸다. 본 연구기간 동안의 Eh 값은 연속적으로 담수되었던 7월 중순까지는 74~112 mV 가량 나타냈고, 그 이후에는 담수상태가 아닌 경우가 많아 179~636 mV로 높게 나타났다. 논 담수의 T-P와 $PO_4$-P 농도는 분얼비 직후 1주일후까지 같이 상승하다가 T-P농도는 약 2주일까지 더 상승한 반면 $PO_4$-P 농도는 하강하였는데 이는 논 토양이 환원상태로 되면서 바닥에 있던 입자성 인이 논 표면으로 떠올랐기 때문으로 사료된다. 그 후에는 담수가 끝나는 시점까지인 농도는 낮아졌다. 관개초기에 인의 농도는 비교적 높게 나타났지만, 7월 이후로는 작물의 생장에 필요한 영양물질 섭취 등으로 인 농도가 낮게 나타났는데 이는 7월 이후의 논은 인의 유출을 억제하고 있는 것으로 추정된다. 또한 논 담수위의 증감에 따른 $PO_4$-P 농도와 Eh 값을 회귀분석 한 결과 각각 정의 상관관계와 부의 상관관계가 있는 것으로 나타났다. 이와 같이 논 담수 및 시비에 따른 인의 유출부하 특성과 산화환원전위(Eh)의 변화 특성이 규명된다면, 향후 환경부하가 작은 물관리가 가능해 질 것으로 판단된다.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.258-264
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• 2014

This study is to investigate water quality changes of nitrogen (N) and phosphorous (P) at Gangjung-Goryeong Weir and Dalseong weir, in 2012-2013. Concentration of COD, TOC, T-N, T-P showed 3.5~6.8 mg/L, 3.4~6.5 mg/L, 1.8~4.0 mg/L, 0.08~0.12 mg/L respectively, in the Nakdong river main stream. Water quality of Dalseong weir showed lower level of contamination than that of Gangjung-Goryeong weir. Because of input loading of nutrients and organic matters from tributaries. At the analysis of sediments at each weirs, sedimentation fluxes of the hypolimnion represented 1.6~2.4 times higher than epilimnion fluxes. Sinking rate (%/d) of SS, N and P of the hypolimion showed in the range of 1.68 %/d~2.42 %/d. It is implied that the suspended matters seem to be floating in the water body. In the result of nutrients release experiment, release flux of nutrients in July showed 3~4 times higher than April. The reason was considered that nutrients is easily released in the anaerobic condition and at high water temperature.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.703-710
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• 2014

The following is the study result of herbal tea roasted at different temperatures between $80{\sim}140^{\circ}C$. Depending on treatment temperature the water content decreased, some carbonization occurred and crude ash content relatively increased. Also crude protein and crude fat decreased little. Solid elution rate of herbal tea showed 0.15~0.32%(w/w) and the rate of solid elution decreased with higher roasting temperature. There was no big change in $80{\sim}110^{\circ}C$ treatment section but the solid elution decreased rapidly in $110{\sim}140^{\circ}C$ section. The reason for decreasing solid elution rate at higher treatment temperature is because the compact inner tissue makes elution difficult. Benzopyrene content (0.29~0.51ppb) showed a tendency to increase with higher treating temperature. From this result, the $B({\alpha})P$ content differed depending on the treatment temperature and raw materials. In case of roasting, the actual inside temperature is around $200^{\circ}C$ but since the surface temperature of the roaster reaches around $2000^{\circ}C$ some portion of $B({\alpha})P$ content was presumed to be produced from the area that came in contact with this surface. When the processing which is a main component of food carbohydrate, protein, fat reason despite serve heat treatment as a whole is to be detected even though the $B({\alpha})P$ in this way is considered to be.

• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.37-43
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• 2008

Inorganic injection material, which is one of the ground improvement materials, consists of cement accelerator and inorganic micro particle. The inorganic injection material is known to overcome the major limitations of water glass type improvement materials, which are leaching and accompanying strength loss. The inorganic injection material is superior in durability and strength, and environmentally friendly since leaching is prevented. In this study, the effectiveness and environment-friendliness of the MIS(Micro Injection-process System) using the inorganic injection material is compared to SGR, which uses the water glass. The performed tests were unconfined compression test, chemical resistance test, and fish poison test. The unconfined compression tests showed that the MIS results in 1.7 times higher 28 day strength compared to the SGR. In addition, the strength continually increased with time for the MIS, while it decreased for the SGR. The chemical resistance tests indicated that the rate of change in length using the MIS is 10~25 times smaller than when using the SGR. The fish poison test proved that MIS was more environmentally friendly. The analysis of chemical ingredients of leached showed that the amount of $Cr^{6+}$, Pb and Si leached from the MIS is less compared to the SGR. Accordingly, the MIS grout is more high-strength than existing SGR grout. It is excellent in shortening of construction period, structural stability of foundation and environmentally friendly. So, it is considered that it has not little the problem about groundwater pollution.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.1
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• pp.21-28
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• 2006

We investigated the mobilization of Cd, Pb, and Cr in two different soils in response to sorption capacities and competition for available sorption site while they moved under saturated water conditions. Two soil samples that were clay and sandy clay loam were collected within 20 cm from the upland surface. To do this, we used three different systems of heavy metal combinations such as single, binary, and ternary as solution phase. And then we observed the breakthrough curve (BTC) and elution as a function of pore volume by applying heavy metal solution and displacing K solution until these curves reached to maximum and minimum. The results showed that BTC and elution curves were not symmetric and it required more pore volumes with increasing species of heavy metals in solution phase, as well as longer tailings. Compared the areas over and under BTC and elution curve, relatively small amount of heavy metal was displaced by K even though there were differences in electronegativity among heavy metals. Conclusively, we assumed that heavy metals transport in soil could be influenced by soil physical nonequilibrium and chemical equilibrium in solution as far as there were more than two species of heavy metals existed.

• Economic and Environmental Geology
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• v.42 no.6
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• pp.609-618
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• 2009

High permeable faults are important geological structures for fluid flow, energy, and solute transport. Therefore, high permeable faults play an important role in the formation of hydrothermal fluid (or hot spring), high heat flow, and hydrothermal ore deposits. We conducted 2-D coupled thermal and hydraulic modeling to examine thermohydraulic behavior in fault zones with various permeabilities and geometric conditions. The results indicate discharge temperature in fault zones increases with increasing fault permeability. In addition, discharge temperature in fault zones is linearly correlated with Peclet number ($R^2=0.98$). If Peclet number is greater than 1, discharge temperature in fault zones can be higher than $32^{\circ}C$. In this case, convection is dominant against conduction for the heat transfer in fault zones.