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        검색결과 4

        1.
        2018.05 구독 인증기관·개인회원 무료
        막여과 정수장에 고농도 망간이 유입될 경우 심각한 막오염을 유발할 수 있어 망간에 대한 제어가 필요하다. 최근 수처리제로 등록된 NaMnO4의 경우 짧은 반응시간에 망간 제거가 가능하여 정수장 적용이 유리할 것으로 기대되고 있다. 본 연구에서는 NaMnO4 주입에 따른 망간 제거 성능과 막의 여과유속에 미치는 영향을 평가하였다. 유입망간농도 대비 NaMnO4 주입 조건을 평가한 결과반응시간 5분 이내 1배, 1.5배 조건에서 약 90% 이상의 망간 제거 효율을 나타내었으며 0.5배, 2배 조건에서는 제거효율이 감소되었다. 또한, NaMnO4 주입조건과 미주입 조건에 대한 여과유속을 평가한 결과 미주입 조건과 비교하여 주입조건에서의 막오염이 저감되어 미주입 조건과 비교하여 유과유속이 높게 유지되었다.
        2.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Membrane backwashing waste shows seasonally different characteristics and it has bad settleability differently from general backwashing waste in water treatment plant. When chemicals was injected to membrane backwashing waste, the settleability was better than chemicals was not injected. However, when settled lower sludge was not discharged, flowing sludge continuously was concentrated over a certain surface and floatation penomena occurred according to flowing velocity. When the lower sludge was discharged continuously in the thickener to prevent floatation penomena of turbidity materials, the depth of sludge surface was the least and the settleability increased.
        4,200원
        3.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Algal problem in drinking water treatment is being gradually increased by causing deterioration of water supplies therefore, especially taste and odor compounds such as geosmin and 2-MIB occur mainly aesthetic problem by its unpleasant effects resulting in the subsequent onset of complaints from drinking water consumer. Recently, geosmin and 2-MIB are detected frequently at abnormally high concentration level. However, conventional water treatment without advanced water treatment processes such as adsorption and oxidation process, cannot remove these two compounds efficiently. Moreover, it is known that the advanced treatment processes i.e. adsorption and oxidation have also several limits to the removal of geosmin and 2-MIB. Therefore, the purpose of this study was not only to evaluate full scale nanofiltration membrane system with 300 m3/ day of permeate capacity and 90% of recovery on the removal of geosmin and 2-MIB in spiked natural raw water sources at high feed concentration with a range of approximately 500 to 2,500 ng/L, but also to observe rejection property of the compounds within multi stage NF membrane system. Rejection rate of geosmin and 2-MIB by NF membrane process was 96% that is 4% of passage regardless of the feed water concentration which indicates NF membrane system with an operational values suggested in this research can be employed in drinking water treatment plant to control geosmin and 2-MIB of high concentration. But, according to results of regression analysis in this study it is recommended that feed water concentration of geosmin and 2-MIB would not exceed 220 and 300 ng/L respectively which is not to be perceived in drinking tap water. Also it suggests that the removal rate might be depended on an operating conditions such as feed water characteristics and membrane flux. When each stage of NF membrane system was evaluated relatively higher removal rate was observed at the conditions that is lower flux, higher DOC and TDS, i.e., 2nd stage NF membrane systems, possibly due to an interaction mechanisms between compounds and cake layer on the membrane surfaces.
        4,500원
        4.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to evaluate the effect of dietary Yanggu original white kaolin supplementation on the growth performances, nutrients utilizability and meat composition of broiler. A total of 260 broiler chicks was alloted to 5 treatments with 4 replications and 13 chicks per replication. In addition to control group that fed diet without any kaolin supplementation, the treatments are designated by dietary supplementation as follows; white kaolin 400 mesh 1%(T1), white kaolin 10,000 mesh 1%(T2), white kaolin 400 mesh 0.8% + probiotics 0.2%(T3) and kaolin rizen(T4). The specific volume of 10,000 mesh white kaolin was higher than that of 400 mesh white kaolin (p<0.05) with no difference in pH between two different size white kaolins. Pellet durability of kaolins supplemented diet was improved, regardless of fat addition, compared to that of no kaolin supplemented diet. Both weight gain and feed intake of broilers in all the kaolin supplemented treatments were higher than that of control during d 0~21 period (p<0.05) but with no differences during d 22~40, On the other hand, kaolin supplementation into the control diet did not affect F/G of young broiler during d 1~21. Overall F/G of broiler was decreased by kaolin supplementation. Although there was no difference on ether extract, crude ash, total CHO and dry matter utilizabilities among all treatments, both crude protein and energy utilizabilities were improved by kaolin supplementation. Crude protein content of both broiler thigh and breast was the lowest in the kaolin and probiotics combined supplemented group(T3). In conclusion, the supplementation of physico-chemically treated white kaolin does affect growth performances, nutrients utilizability and meat composition of broilers. Therefore, the kaolin can be considered as a beneficial feed additive to improve broiler productivity.
        4,000원