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        검색결과 5

        2.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        유색 용존 유기물의 빛 흡수와 해빙의 가속화는 수생생태계와 열수지 역동성 간의 양적 피드백에 영향을 줄 수 있으므로 극지 해양에서 유색 용존 유기물의 장기 모니터링이 필요하게 되었다. 그러나 극지 환경에서의 관측은 용이하지 않은 접근성과 거친 기상으로 장기 모니터링이 쉽지 않다. 따라서 유색 용존 유기물의 장기 모니터링 장소로서 남극 세종 기지의 가능성을 확인하기 위해, 마리안 소만과 맥스웰 만에서 유색 용존 유기물의 분포와 외부로부터의 영향을 파악하기 위한 관측을 수행하였다. 맥스웰 만 내의 세종 부두와 세종 곶의 72시간 유색 용존 유기물의 변동성을 관측하고, 외부 영향이 없었던 세종 부두에서 2010년 2월에서 11월까지 10 개월간 유색 용존 유기물의 연간 변화와 계절변동을 관측하였다. 세종 부두의 유색 용존 유기물 농도는 가을과 겨울 동안 가장 높고 봄과 여름에 감소하는 뚜렷한 계절 변동성을 보였고, 남극 인근 해역에서 측정된 유색 용존 유기물 농도 자료와 비교하였다. 따라서 우리는 남극해의 열수지에 대한 중요한 요인이자 광화학적 및 생물학적 환경변화에 관한 지시자인 유색 용존 유기물을 장기 모니터링을 위해 적합한 장소로 맥스웰 만의 세종 부두를 제안한다.
        4,000원
        3.
        1995.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Various humic substances are widely distributed in natural water body, such as rivers and lakes and cause the yellowish or brownish color to water. The evidence that humic substances are precursors of THMs formation in chlorinated drinking water has been reported m the Jiteratures. For the reason of public health as well as aesthetics, needs for humic substances removal have been increased in the conventional water treatment processes. In this research, the characteristics of aluminium coagulation of humic acids and humic acids were investigated. The optimum pH and coagulants dosage to remove these materials simultaneously by coagulation were alto studied. The results are as followed; 1. UV-254 absorptiometry for measuring the concentration of aquatic humic acids showed good applicability and stable results. 2. The optimal pH range for humic acids removal by aluminium coagulation was 5 to 5.5, however, an increase in aluminium coagulant dosage could enhance the removal rate of humic acids in the wide pH range. 3. Coprecipitation of humic acids in the typical pH range of 6.5 to 8 in water treatment processes may require the sweep coagulation mechanism with the excess aluminium coagulant dosage. 4. Using PAC(poly aluminium chloride) or PASS(poly aluminium silica sulfate) as coagulants was able to expand the operating range for removing humic acids. 5. From the coagulation of humic substances(UV-254) and turbidity at pH range of 5.5 - 6.0 and alum dose of 86 ppm, the removal efficiency of turbidity from the reservoir water was above 90% and that of UV-254 was above 70%. 6. By using the reservoir water, the optimum condition of rapid mixing for simultaneous removal of turbidity and UV-254 absorbance was pH of 5.8 and LAS dose of 86 ppm, in this study.
        4,000원
        4.
        2014.09 KCI 등재 서비스 종료(열람 제한)
        A comprehensive fractionation technique was applied to a set of water samples obtained along drinking water treatment process with ozonation and biological activated carbon (BAC) process to obtain detailed profiles of dissolved organic matter (DOM) and to evaluate the haloacetic acid (HAA) formation potentials of these DOM fractions. The results indicated that coagulation-sedimentation-sand filtration treatment showed limited ability to remove hydrophilic fraction (28%), while removal of hydrophobic and transphilic fraction were 57% and 40%, respectively. And ozonation and BAC treatment showed limited ability to remove hydrophobic fractions (6%), while removal of hydrophilic and transphilic fractions were 25% and 18%. The haloacetic acid formation potential (HAAFP)/dissolved organic carbon (DOC) of hydrophilic fraction was the highest along the treatment train and HAAFP/DOC of hydrophilic fraction was higher than hydrophobic and transphilic fraction as 23% 30%, because of better removal for hydrophobic fraction both in concentration and reactivity.
        5.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        In this study we followed biofilm formation and development in a granular activated carbon (GAC) filter on pilot-scale during the 12 months of operation. GAC particles and water samples were sampled from four different depths (-5, -25, -50 and –90 cm from surface of GAC bed) and attached biomass were measured with adenosine tri-phosphate (ATP) analysis and heterotrophic plate count (HPC) method. The attached biomass accumulated rapidly on the GAC particles of top layer throughout all levels in the filter during the 160 days (BV 23,000) of operation and maintained a steady-state afterward. During steady-state, biomass (ATP and HPC) concentrations of top layer in the BAC filer were 2.1 μg·ATP/g·GAC and 3.3×108 cells/g·GAC, and 85%, 83% and 99% of the influent total biodegradable dissolved organic carbon (BDOCtotal), BDOCslow and BDOCrapid were removed, respectively. During steady-state process, biomass (ATP and HPC) concentrations of middle layer (-50 cm) and bottom layer (-90 cm) in the BAC filter were increased consistently. Biofilm development (growth rate) proceed highest rate in the top layer of filter (μATP = 0.73 day-1; μHPC = 1,74 day-1) and 78%∼87% slower in the bottom layer (μATP = 0.14 day-1; μHPC = 0.34 day-1). This study shows that the combination of different analytical methods allows detailed quantification of the microbiological activity in drinking water biofilter.