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유기산을 사용하는 가수분해반응에 의한 키토산 올리고당 제조
최광진(Guang Jin Choi),김현상(Hyun Sang Kim),심상준(Sang Jun Sim),김영대(Young Dae Kim),우경자(Kyoung Ja Woo),조영상(Young Sang Cho) 한국키틴키토산학회 1999 한국키틴키토산학회지 Vol.4 No.2
N/A Chitosan has been degraded by chemical and enzymatic processes, and the efficiency and oligosaccharide distribution of the products were compared. When chemically hydrolyzed with 12 N HCI at 80 ℃, the reaction product contained the monomer to octamer, in which the yield of high degree of polymerization (dp) chitooligosaccharides was low and glucosamine was identified as major product. When enzymatically hydrolyzed with Bacillus sp. P16 chitosanase, the reaction products contained dimer to nanomer, in which the yield of high dp chitooligosaccharides was relatively high, and Pentamer and hexamer were identified as major products. Thus, enzymatic processes have advantages over chemical hydrolysis in terms of the efficiency and distribution of high dp chitooligosaccharides.bacillus sp. P16 chitosanase was evaluated as a potential source for the production of high dp chitooligosaccharides from chitosan.
알루미나시멘트와 생석회를 이용한 오염수 중의 음이온 침전 제거
김영대,이경희,최의소,조영상,심상준,강창덕,최광진,우경자 한국화학공학회 1999 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.37 No.5
회분식 반응기에서의 알루미나 시멘트와 생석회를 이용한 고농도 오염수에서의 질산염과 다른 오염 음이온의 침전 제거에 관하여 살펴보았다. 알루미나 시멘트와 생석회를 질산염을 비롯한 여러 음이온 오염수에 첨가하면 수화된 알루미네이트 음이온 착화합물을 형성하여 침전시킴을 알 수 있다. 회분식 반응기에서 침전에 의한 음이온제거를 위한 최적조건을 살펴보았고 질산염 침전에 대한 다른 음이온의 효과를 알아보기 위해 질산염과 여러 음이온을 이용한 일련의 실험을 수행하였다. 이를 통해 질산염 제거속도와 제거율은 다른 음이온의 존재에 따라 영향을 받는다는 사실을 확인하였다. 침전반응후 수화된 알루미나 시멘트의 특성은 주사전사현미경(scanning electron microscopy, SEM), 열질량분석법(thermogravimetric analysis, TGA), 및 X-선 회절분석법(X-ray diffractometry, XRD) 분석을 통해 살펴보았다. 후처리 공정으로 Na₂CO₂와 황산을 이용한 중화반응을 통하여 처리수 중 녹아있는 알루미나 및 칼슘 이온을 각각 제거할 수 있음을 확인하였다. The removals of nitrate and other undesirable anions by adding alumina cement and lime from highly polluted water with various anions were studied in a batch reactor. By adding alumina cement and lime to the anion polluted water, various anions including nitrate, sulphate, phosphate, and chloride were precipitated, formed to hydrates of anion aluminate complex. The precipitation conditions of anion removal in batch reactor was optimized. To determine the influence of specific anions in nitrate precipitation, a series of tests were performed with nitrate and various specific anions. As the result, the removal rate and yield of nitrate were found to be affected by the existence of other specific anion. After the precipitation reaction, the characteristics of hydrated alumina cement including specific anions were investigated by scanning electron microscopy, thermogravimetric analysis, and X-ray diffractometry. Post-treatments including sodium carbonate addition and neutralization with sulfuric acid alleviated the levels of aluminium and calcium ion concentrations dissolved in treated water.