• 한국토양비료학회지
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• 제17권1호
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• pp.35-38
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• 1984

실험실내(實驗室內)에서 유효규산함량(有效珪酸含量)이 다른 2개(個) 식양질(埴壤質) 토양(土壤)에 석회(石灰)와 전분(澱粉)을 첨가(添加)하고 $25^{\circ}C$로 1개월간(個月間) 담수항온(湛水恒溫) 처리(處理)한 뒤 토양(土壤)의 유효규산(有效珪酸)과 수용성(水溶性) 규산(珪酸)의 행동(行動)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 담수토양(湛水土壤) 중(中) 유효규산함량(有效珪酸含量)은 pH상승(上昇)과 Eh저하(低下)에 의하여 증가(增加)되었고 동일(同一) pH조건(條件)에서는 Eh가 낮은 토양(土壤)에서 높았다. 2. 수용액(水溶液) 중(中) 규산(珪酸)이 토양(土壤)에 흡수(吸收)되는 량(量)은 전분처리(澱粉處理)로 현저(顯著)히 증가(增加)되었다. 3. 석회처리(石灰處理)에 의한 토양(土壤)의 규산흡수량(珪酸吸收量) 증감(增減)은 일정(一定)한 경향(傾向)을 보이지 않았으나 첨가용액(添加溶液)의 규산농도(珪酸濃度)가 낮은 경우(境遇)는 석회시용(石灰施用)으로 흡수량(吸收量)이 다소(多少) 증가(增加)되었다. 4. 답토양(畓土壤)의 규산흡수양상(珪酸吸收樣相)은 Langmuidr 등온흡착식(等溫吸着式)과는 전혀 달랐고 Freundlich 등온흡착식(等溫吸着式)과 유사(類似)하였다.

• 한국미생물·생명공학회지
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• 제48권1호
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• pp.12-23
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• 2020

Edible films containing antimicrobial agents can be used as safe alternatives to preserve food products. Essential oils are well-recognized antimicrobials. However, their low water solubility, volatility and high sensitivity to oxygen and light limit their application in food preservation. These limitations could be overcome by embedding these essential oils in complexed product matrices exploiting the encapsulation efficiency of β-cyclodextrin. This study focused on the maximization of β-cyclodextrin production using cyclodextrin glucanotransferase (CGTase) and the evaluation of its encapsulation efficacy to fabricate edible antimicrobial films. Response surface methodology (RSM) was used to optimize CGTase production by Brevibacillus brevis AMI-2 isolated from mangrove sediments. This enzyme was partially purified using a starch adsorption method and entrapped in calcium alginate. Cyclodextrin produced by the immobilized enzyme was then confirmed using high performance thin layer chromatography, and its encapsulation efficiency was investigated. The clove oil/β-cyclodextrin inclusion complexes were prepared using the coprecipitation method, and incorporated into chitosan films, and subjected to antimicrobial testing. Results revealed that β-cyclodextrin was produced as a major product of the enzymatic reaction. In addition, the incorporation of clove oil/β-cyclodextrin inclusion complexes significantly increased the antimicrobial activity of chitosan films against Staphylococcus aureus, Staphylococcus epidermidis, Salmonella Typhimurium, Escherichia coli, and Candida albicans. In conclusion, B. brevis AMI-2 is a promising source for CGTase to synthesize β-cyclodextrin with considerable encapsulation efficiency. Further, the obtained results suggest that chitosan films containing clove oils encapsulated in β-cyclodextrin could serve as edible antimicrobial food-packaging materials to combat microbial contamination.

• 한국환경과학회지
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• 제23권9호
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• pp.1627-1634
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• 2014

Odor control technology include absorption, adsorption, incineration and biological treatments. But, most of processes have some problems such as secondary organic acids discharge at the final odor treatment facility. In order to solve the problems for effective treatment of organic acids in odor, it is necessary to develop a new type advanced odor control technology. Some of the technology are plasma only process and plasma hybrid process as key process of the advanced technology. In this study, odor removal performance was compared DBD(Dielectric Barrier Discharge)plasma process with PCHP(plasma catalysis hybrid process) by gaseous ammonia, formaldehyde and acetic acid. Plasma only process by acetic acid obtained higher treatment efficiency above 90%, and PCHP reached its efficiency up to 96%. Acetic acid is relatively easy pollutant to control its concentration other than sulfur and nitrogen odor compounds, because it has tendency to react with water quickly. To test of the performance of DBD plasma process by applied voltage, the tests were conducted to find the dependence of experimental conditions of the applied voltage at 13 kV and 15 kV separately. With an applied voltage at 15 kV, the treatment efficiency was achieved to more higher than 13 kV from 83% to 99% on ammonia, formaldehyde and acetic acid. It seems to the odor treatment efficiency depends on the applied voltage, temperature, humidity and chemical bonding of odors.

• 공업화학
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• 제2권3호
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• pp.262-269
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• 1991

${\beta}$-carotene의 오존산화반응을 통하여 불포화 색소물질에 대한 오존의 탈색효과와 반응성분의 변화를 정량적으로 비교하였으며, 카로티노이드계 색소가 주요 발색원인물질인 beeswax 에 대한 오존의 산화반응을 물, 0.5%와 1.0% 수산화나트륨수용액, 20% 와 95% 초산수용액에서 실시하여 각 반응계에 따른 탈색효과를 비교검토하였고, 과산화수소의 첨가효과도 검토하였다. ${\beta}$-carotene의 불포화이중결합의 감소와 탈색효과는 정량적으로 비례하였으며 beeswax의 탈색효과도 잘 일치하는 결과를 얻었다. Beeswax의 탈색효과는 1.0 % 수산화나트륨수용액에서 반응한 것이 가장 우수하였으며. 과산화수소의 첨가(왁스의 2%)시 390 nm 에서의 흡광도가 0.045 로 좋은 탈색효과를 얻을 수 있었다. Beeswax의 탈색에 있어 오존산화반응이 물리흡착보다 효과적이라는 결론을 얻을 수 있었다.

• 한국토양비료학회지
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• 제17권4호
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• pp.381-388
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• 1984

객토원(客土源)을 구(求)하기 어려운 평야지(平野地) 사질답(砂質畓)의 토양개량제(土壤改良劑)로서 객토대체자원(客土代替資源)으로 Zeolite 시용(施用)의 가능성(可能性)을 검토(檢討)하기 위하여 포장시험(圃場試驗)과 실내시험(室內試驗) 결과(結果)를 요약(要約)하면 다음과 같다. 1. 점토함량(粘土含量) 16%인 토양(土壤)에 규산(珪酸)을 적량시용(適量施用)하고 질소(窒素)를 흡착(吸着)시킨 Zeolite 시용(施用)은 벼 생육(生育) 및 수량(收量)에 있어 객토(客土) 40M/T/10a 시용(施用)과 동등(同等)한 효과(效果)가 인정(認定)되었다. 2. 최고수량(最高收量)을 낸 질소시용량(窒素施用量)은 무개량구(無改良區), 객토(客土), Zeolite구(區)에서 각각(各各) 15.0, 18.2, 18.1kg/10a 이었다. 3. 객토구(客土區)와 Zeolite구(區)에서 수확기(收穫期) 질소(窒素) 및 $SiO_2$, 흡수량(吸收量)이 무개량구(無改良區)에 비(比)해 현저(顯著)히 많았다. 4. 토양(土壤), 객토원(客土源) 및 Zeolite의 암모늄 흡착양상(吸着樣相)은 Langmuir 등(等) 온흡착식(溫吸着式)을 따랐고 암모늄 최대흡착(最大吸着)은 각각(各各) 16.7, 20.5, 890mg/10a이었다.

• 한국토양비료학회지
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• 제47권6호
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• pp.443-450
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• 2014

To determine Pb species in soils following the immobilization process, sequential extraction has been used despite the possibility of overestimating Pb species from unintended reactions during chemical extraction. Meanwhile, the application of extended X-ray absorption fine structure (EXAFS) has been shown to provide a more precise result than chemical extraction. In this study, the immobilization of Pb in contaminated soils treated with liming materials such as oyster shell (OS) or eggshell (ES) was evaluated with thermodynamic modelling and EXAFS analysis. Thermodynamic modelling by visual MINTEQ predicted the precipitation of $Pb(OH)_2$ in OS and ES treated soils. In particular, the values of saturation index (SI) for $Pb(OH)_2$ in OS (SI=0.286) and ES (SI=0.453) treated soils were greater than in the control soil (SI=0.281). Linear combination fitting (LCF) analysis confirmed the presence of $C_{12}H_{10}O_{14}Pb_3$ (lead citrate, 44.7%) by citric acid from plant root, Pb-gibbsite (Pb adsorbed gibbsite, 26.4%), and Pb-kaolinite (Pb adsorbed kaolinite, 20.3%) in the control soil. On the other hand, $Pb(OH)_2$ (16.8%), Pb-gibbsite (39.3%), and Pb-kaolinite (25.6%) were observed in the OS treated soil and $Pb(OH)_2$ (55.2%) and Pb-gibbsite (33.8%) were also confirmed in the ES treated soil. Our results indicate that the treatment with OS and ES immobilizes Pb by adsorption of Pb onto the soil minerals as a result of the increase in soil negative charge and the formation of stable $Pb(OH)_2$ under high pH condition of soils.

• 해양환경안전학회지
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• 제7권1호
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• pp.7-14
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• 2001

The amount of petroleum consumption has been Increased according to the industrialization and It leads to the increase of the possibility of marine oil pollution. In Korea, some countermeasures including oil skimmer, gelling agent and herding agent of oil have been used for the remediation of the pollution. However, most of them have lets of shortcomings in the application under in-situ condition, because they are sensitive to the situation such as geographical feature, the wind and the tide. In reported literature, the natural powdered oil absorbent which is made of peat moss is an effective mean to clean spilled oil from lake or coast. However, the peat moss is a natural resource which is only Produced from a specific cold weather are like Canada. This indicates that the alternative materials which is readily obtained from everywhere are needed for powdered oil absorbent. Therefore. in the study, same natural materials including pine leaves and straw are tested as the alternative materials for the absorbent. The raw materials were dried and treated by heat at various temperature during several Periods and then. shattered by a grain cracking machine. The oil sorption capacity of the prepared materials was compared according to the methods of heat treatment and their sizes. The proportion of hydrogen cyanide to combustion of the absorbents was measured to confirm their final disposal methods. The biodegradability test of the absorbents was carried our to evaluate possibility of a side pollution in the coast. In was found that the heat treatment of pine leaves enhanced the capacity of oil sorption and decreased the water sorption. The maximum oil sorption was observed for the material treated at 18$0^{\circ}C$for 60 min. The amount of hydrogen cyanide from the combustion were 0.09ml/g, 0.07ml/g for pine leaves and straw respectively meaning that the final disposal by combustion might be feasible. The amount or organic carbon extracted from pine leaves during 7 days was up to 0.015g organic carbon from one gram of pine leaves. but the degradation was as fast as for glucose. It is concluded that the pine leaves can be served as a good raw material for the powdered oil absorbent like peat moss.

• 한국분말재료학회지
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• 제16권1호
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• pp.22-27
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• 2009

To improve the filtration efficiency of porous materials used in filters, an extensive specific surface area is required to serve as a site for adsorption of impurities. In this paper, a method for creating a hybridized porous alloy using a powder metallurgical technique to build macropores in an Al-4 wt.% Cu alloy and subsequent surface modification for a microporous surface with a considerably increased specific surface area is suggested. The macropore structure was controlled by granulation, compacting pressure, and sintering; the micropore structure was obtained by a surface modification using a dilute NaOH solution. The specific surface area of surface-modified specimen increased about 10 times compare to as-sintered specimen that comprised of the macropore structure. Also, the surface-modified specimens showed a remarkable increase in micropores larger than 10 nm. Such a hybridized porous structure has potential for application in water and air purification filters, as well as membrane pre-treatment and catalysis.

• Environmental Engineering Research
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• 제21권3호
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• pp.291-296
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• 2016

Application of photocatalytic nanoparticles has been recently gaining an increased attention as air purifying material for sustainable urban development. The present work reports the photocatalytic removal of gaseous phase nitrogen oxides ($NO_x$) using $TiO_2$-coated zeolite to be applied as a filter media for the urban green infrastructure such as raingardens. The $TiO_2$-coated zeolite was synthesized by simple wet chemistry method and tested in a continuous-flow photo-reactor for its removal efficiency of $NO_x$ under different conditions of the weight percentage of $TiO_2$ coated on the zeolite, and gas retention time. The removal efficiency of $NO_x$ in general increased as the weight percentage of $TiO_2$ coated on the zeolite increased up to 15-20%. Greater than 90% of $NO_x$ was removed at a retention time of one minute using the $TiO_2$-coated zeolite ($TiO_2$ weight percentage = 20%). Overall, $TiO_2$-coated zeolite showed greater efficiency of $NO_x$ removal compared to $TiO_2$ powder probably by providing additional reaction sites from the porous structure of zeolite. It was presumed that the degradation of $NO_x$ is attributed to both the physical adsorption and photocatalytic oxidation that could simultaneously occur at the catalyst surface.

• 멤브레인
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• 제23권3호
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• pp.220-225
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• 2013

친수성 단량체를 polyvinylidene fluoride (PVDF) 분리막 표면에 열중합으로 lamination하여 분리막을 친수화하였다. 친수화 처리 후 접촉각은 $95^{\circ}$에서 $55^{\circ}$까지 감소하였고 수투과량은 10배 이상 증가하였으며 bovine serum albumin (BSA) 흡착량은 1/4 수준으로 감소하였다. 열중합 공정에서 각 공정변수별 영향을 조사하였고 이를 최적화하였다. 단량체 중 dimethyl oxobuthyl acrylamide (DOAA)가 친수성이 높아 다른 단량체에 비하여 친수화 효과가 우수하였다. 단량체의 농도가 증가함에 따라 성능이 향상되었으나 30 wt% 이상의 경우 homopolymerization을 유발하여 성능을 저하시켰다. 개시제로 사용되었던 azobis (isobutyronitrile)(AIBN)의 활성 온도 범위가 benzoyl peroxide (BPO)의 활성온도 범위보다 넓기 때문에 높은 친수화 효율을 나타내었다. 개시제를 먼저 도포시켜주고 단량체를 나중에 첨가하는 2단계 lamination 방식이 일괄 공급하는 1단계 방식보다 친수화도는 크게 향상됐지만 pore blocking현상이 나타나면서 순수투과도는 매우 감소하였다.