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        검색결과 10

        4.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 회분여과방식을 이용하여 부하율에 따라 생성되는 생물대사성분의 특성 및 분포를 관찰하였다. 실험에 사용된 기질은 단일 탄소인 phenol을 사용하였으며, 분자량 분포실험을 위하여 분자량이 각각 30K, 100K Dalton 및 0.45mu membrane filter를 이용하여 구하였다. 페놀농도가 120, 230 및 440 mg/L 일 때 비기질이용율(q)은 각각 0.639, 1.281, 1.744 (mgTOC/mg MLSS/day)로 나타났으며 Run C일 때 가장 높은 이용율을 나타냈다 . 내생단계에서 미생물의 사멸율(Kd)는 각각 0.0536, 0.0661, 0.0749(day1)이며 생성계수 (SMPe) 는 각각 0.006, 0.0058, 0.0057(day1)로 나타났다. 초기 유입된 기질이 기질분해에 의해 생성된 SMPs로 분해되어지며, 시간경과에 따라 SMPnd 로 진행됨을 알수 있었다. 기질분해 완료 후 미생물의 내생단계에 접어들면서 SMPe성분으로 전환되었다. 유입부하율에 따른 분자량 분포 측정결과는 운전시간이 경고함에 따라 점차 저분자 물질이 고분자의 난분해성 물질로 전환되었다.
        4,000원
        5.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        Anaerobic mesophilic batch tests of food waste and food waste leachate collected from food waste treatment facility were carried out to evaluate their ultimate biodegradability and two distinctive decay rate coefficients (k1 and k2) with their corresponding degradable substrate fractions (S1 and S2), respectively. Each 3 liter batch reactor was operated for more than 60 days at substrate to inoculum ratio (S/I) of 0.5 as an initial total volatile solids (TVS) mass basis. Result of Ultimate biodegradability of 74 ~ 83% for food waste and 85 ~ 90% for food waste leachate were obtained respectively. The readily biodegradable fraction of 85 ~ 93% (S1) of food waste Biodegradable Volatile Solids (BVS, So) degraded within the initial 15 days with a range of of 0.151 ~ 0.168 day−1, whereas the rest slowly biodegradable fraction (S2) of BVS degraded for more than 53 days with the long term batch decay rate coefficients of 0.009 ~ 0.010 day−1. For the food waste leachate, the readily biodegradable portion (S1) appeared to be 92 ~ 94% of BVS (So), which degrades with of 0.172 ~ 0.206 day−1 for an initial 15 days. Its corresponding long term batch decay rate coefficients were 0.005 ~ 0.009 day−1. It is recommended that the hydraulic retention times of mesophilic anaerobic digesters be 16 days for the food waste and 15 days for the food waste leachate, respectively. However a safety factor should be considered when designing a full scale plant.
        6.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        Anaerobic mesophilic batch tests of dairy cow manure, dairy cow manure/saw dust mixture and dairy cow manure/ rice hull mixtures collected from bedded pack barn were carried out to evaluate their ultimate biodegradability and two distinctive decay rates (k1 and k2) with their corresponding degradable substrate fractions (S1 and S2). Each 3 liter batch reactor was operated for more than 100 days at substrate to inoculum ratio (S/I) of 1.0 as an initial total volatile solids (TVS) mass basis. Ultimate biodegradabilities of 37 ~ 46% for dairy cow manure, 32 ~ 40% for dairy manure/saw dust mixture and 31 ~ 38% for dairy cow manure/rice hull mixture were obtained respectively. The readily biodegradable fraction of 90% (S1) of dairy manure BVS (So) degraded with in the initial 29 days with arange of k1 of 0.074 day−1, where as the rest slowly biodegradable fraction (S2) of BVS degraded for more than 100 days with the long term batch reaction rate of 0.004 day−1. For the dairy manure/saw dust mixture and dairy manure/rice hull mixture, their readily biodegradable portions (S1) appeared 71% and 76%, which degrades with k1 of 0.053 day−1 and 0.047 day−1 for an initial 30 days and 38 days, respectively. Their corresponding long term batch reaction rates were 0.03 day−1.
        7.
        2013.11 서비스 종료(열람 제한)
        Prediction method for the long-term chemical leaching amount from by-product/recycled materials such as waste concrete and steel slag and so on is necessary to widely promote their effective utilization and evaluate their environmental safety. Although there are the batch leaching tests and the column leaching test as the testing methods for evaluating the long-term leaching behavior, the leaching mechanism and the testing result compatibility in both tests has insufficiently been clarified yet. Thus, the prediction of the leaching behavior from the by-product/recycled materials used in actual civil works and their environmental safety evaluation are by no means certain. This paper shows the difference between the batch leaching tests and the column leaching tests in the chemical leaching behavior of Cu-slag. The batch leaching tests were conducted under liquid/solid ratio = 10, liquid = distilled water, stirring strength = 0, 30, or 120 rpm. After a certain elapsed time, the leaching solution was exchanged with the pure distilled water and then the stirring was restarted. The elapsed time was set at 1, 2, 4, 8, 16, 32 days. The column leaching tests were also conducted under the same conditions as those of the batch leaching tests in order to evaluate the effects of the pore distribution and the pore flow velocity in the Cu-slag column on the leaching behavior. In the column leaching tests, the effluent passing through the column was circulated as the influent (Fig. 1). The leaching duration in the column tests can be equivalent as that in the batch tests, so that the difference in the leaching behavior between the batch leaching tests and the column leaching tests may be dependent on the pore-scale heterogeneous flow and path generated in porous materials. Figure 2 shows the leaching rate evaluated from the batch leaching tests and the column leaching tests. In the same fluid velocity levels, the leaching rate in the column tests was larger than that in the batch tests. The leaching rate has been considered large with the fluid velocity. Although the fluid velocity generated by the stirring was the same as the flushing velocity on the surface of the Cu-slag in the batch tests, the fluid velocity in the column tests was enhanced because the permeant liquid was concentrated into the limited pore space in the Cu-slag column. Thus, the pore-scale heterogeneous flow and path generated in porous materials should be evaluated in order to clarify the compatibility between the batch leaching tests and the column leaching tests.
        8.
        2013.04 서비스 종료(열람 제한)
        Recently, it is requests the reduction of self-load at structure and the cross section reduction due to the trend of making higher, larger of buildings. But The experiment of Lightweight concrete is mostly implemented in Laboratory and is rarely implemented in patch plant for application of construction site. therefore, this study will be useful at base, when the lightweight aggregate concrete is applied to construction site. so We had a comparative experiment of physical performance with in laboratory and Batch plant for lightweight aggregate concrete.
        9.
        2002.12 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using ozonation process. For raw water, Nakdong River was used. By conducting batch test of ozonation, the following results were obtained. When ozone dosage of 5 mg/ℓ was used, ozone transfer and utilization efficiencies of the ozonation were 94 to 92%, respectively. Removal efficiencies of single VOC compound or mixed VOC compounds in the raw water were 80% to 90% by the ozonation with 2 mg/ℓ dosage and 10 minutes contact time. Removal efficiencies of ABS by the ozonation with 1 mg/ℓ, 3 mg/ℓ dosage and 20 minutes contact time were 83% to 96% , respectively. Almost 67% of chlorophyll-a at the concentration of 38.4㎍/ℓ was removed by ozonation at ozone dosage of 1 ㎎/ℓ for 20 min. Considering the efficiency of ozone utilization and water treatment, the most effective ozonation could be obtained with high ozone dosage and short contact time.
        10.
        2001.12 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using ozonation. For raw water, Nakdong River was used. By conducting batch ozonation test, the following results were obtained. When ozone dosage of 5㎎/ℓ was used, preozonation of raw water reduced turbidity, KMnO4 consumption, DOC(dissolved organic carbon), UV254 absorbance, THMFP(trihalomethane formation potential) as much as 3.9 NTU, 5.5㎎/ℓ, 1.15㎎/ℓ, 0.112 and 0.065㎎/ℓ, respectively. In case of postozonation of sand filtered water, water quality was also improved with decrease in turbidity, KMnO4 consumption, DOC, UV254 absorbance and THMFP at the amount of 0.08NTU, 2.6㎎/ℓ, 0.88㎎/ℓ, 0.042 and 0.018㎎/ℓ, respectively. On the other hand, contents of dissolved oxygen increased at the level of 1.3㎎/ℓ after preozonation process' and 1.0㎎/ℓ after postozonation process. The effect of ozone dosage was higher than that of its contact time for the removal of the pollutants.