Earticle

본 연구에서는, 초기강우 유입수 및 하수처리장 월류수 중의 SS와 Turbidity제거를 위한 부상방법에 대하여, 일정한 압력조건에 맞추어 공급되는 공기량을 고정시킨 상태에서 최고의 SS와 Turbidity의 제거효율을 나타내는 버블을 생성하는 노즐의 선정방법의 일반화가 연구되었다. 강우강도가 10 mm/hr 미만에서 실트성 또는 토사질의 채거름한 SS입자들을 0~63 μm 이하의 분포가 주로 나타나며 강우량이 증가하면서 0~150 μm 이하의 분포, 0~300 μm 이하의 분포로 확대되므로 이를 반영하여 3가지 입경분포의 시료를 KSF2306(입도) 방식으로 제조하여 최적의 SS제거율을 갖는 노즐을 선정하기 위해 서로 다른토질특성과 분포 특성 속에서 실험하였다. 본 연구의 결과, 토사질과 실트질의 유사 모두의 경우 부상방법의 요구제거율이 나타나는 노즐선정 방법의 일반화가 가능하였다. 그 내용을 보면, 63 μm 이하의 토질분포는 노즐N1에 요구제거율에 이르는 부상시간이 짧았고 150 μm 이하의 토질분포는 중간구경의 노즐에, 300 μm 이하의 토질분포는 노즐N3에 적합하였다. 이러한연구결과에 근거하여, 강우량에 따라 유입되는 SS의 입자 분포로부터 최적화 조건이 결정되어짐을 확인하였다. 따라서, 일정한 압력 하에 공급되는 공기량에 의해 생성되는 버블분포 특성을 통하여 부상법을 설계하기 위한 노즐선정과정의 일반화가가능하고, 버블생성장치의 다양성, 서로 다른 압력, 유사의 특성, 버블의 분포도 등이 운영과 기술진단 및 검증을 위한 판단기준의 일반화방안을 확인하였다.

In this study, for the remove SS and Turbidity in the initial rainfall for runoff and combined sewer overflows at the same condition of air pressure and fixed air quantity, the determination method of the nozzle type that show the distribution of bubble size for the best SS and Turbidity removal ratio, is studied. At the condition of the rainfall intensity is 10 mm/hr below, The SS particles with the sandy soil or silty clay soil is in grain size distribution of 63 μm below are normally observed. rainfall of meteorological phenomena increase, then, grain size distribution of 150 μm below are observed. rainfall intensity is more stronger then 300 μm below are observed. With reflection this, 3type of the distribution soil materials are made by KSF2306 standard method. For the determination of the best SS removal nozzle type, the different soil condition and distributions are done experimantal works. The result of this study, the both of all soil condition, like as the sandy soil or silty clay soil are able to generalize the method of the determination best nozzle type for demanded removal rate in flotation unit. Let see the detail of this, at the soil distribution of 63 μm below, the Nozzel N1 is the short for the demanded removal rate. at 150 μm below soil distribution, the middle Nozzle is, at 300 μm below soil distributiion, the Nozzle N3 is suitable for the condition. Based on the result from this study, it is the verifying this that the inlet SS distribution with rainfall fixed the best condition of flotation method. Therefore, through the bubble distribution, at the same condition of air pressure and fixed air quantity, the generalization of the determination method of nozzle type is possible

청양지역 폐광산의 오염원인인 중금속의 제거를 침출과 이온교환법을 활용한 융합공정을 통해 실험하였으며 중금속에 오염된 토양시료는 통계처리를 하여 분석하였다. 오염토양은 일차로 부선처리법으로 분리하였으며, 사용시약이 증가할수록 선별지수는 증가하였다. 중금속을 제거하기 위한 침출과 이온분리법에 의해 선별도는 더 향상이 되었다. 침출속도는 황산용액이 증가할수록 증가되었으며, 침출용액은 이온교환법에 의해 상당부분 제거가 되었다. 침출과 이온교환법이 결합된 연속융합공정을 개발하여 중금속 제거 실험을 하였으며, 향후 개선을 통해 중금속의 제거효과가 향상될 것이며, 이를 통해 폐광산의 오염토양에 적용 가능함을 알 수 있었다.

The convergence process utilized both leaching and ion exchange techniques has been investigated for the heavy metals removal in the abandoned mine of Chungyang Province, Korea. The contaminated soil samples by heavy metals from Samkwang mine were analysed by statistical analyses. The highly contaminated soils was initially separated by the flotation process. The selectivity indices were increased with increasing flotation reagents. The selectivity of separation was then improved by the use of both leaching and ion exchange processes in order to extract the heavy metals. The results of this study showed that the higher the sulfuric acid concentration, the leaching rate of heavy metals was increased. The lecheate then was removed by the ion exchange method. The anticipating results might imply that convergence process utilized both leaching and ion exchange techniques would somehow apply for the removal of heavy metals in the abandoned mine.

In this study, for the treatment efficiency of the IGF process for the treatment of produced water (PW) discharged from the oil sands plant, the bench-scale oil sands plant PWT package was designed, manufactured and evaluated to verify the efficiency of the process. The microbubble generation efficiency and microbubble size change according to the circulation pump pressure were observed, and the correlation between influent concentration and temperature, residence time and oil-water separation performance was analyzed.

Purificatin of general lake-water shows a limitation in actual purification by not equipping the function that removes only contaminated materials contained to lake-water and sediment to the outside of lake. Therefore, in order to implement selective removal of contaminated materials, flotation process which removes various contaminated materials by absorbing and collecting condensation Floc and low density algae to the rising micro bubble was applied to improve the water quality of reservoir by using the device which is invented to make condensation, confusion, and rising processes to be integrated at inside of lake-water body. The key of rising process is to increase collision efficiency and collision chance with Floc by increasing the number of micro bubble per unit volume and dispersing the size of bubble to the water finely. Therefore, micro bubble condensation & rising device which can occur micro bubble was used for rising process and implemented the chance of improving water quality through analysis while implementing rising process and serial 5 times of elution process. In addition to this, it is researched that when in rising process, the removing ratio of accumulated contaminated materials eluted from sediment.

Harvesting of marine algae, Dunaliella tertiolecta, was studied to optimize Dissolved air flotation(DAF) method for dewatering microalge from microalgae mass culture. It is well known that the mass density of microalgae are usually very low and it is not economic to concentrate for the purpose of biodiesel production. To find out optimal condition for microalgae harvesting by DAF, various chemical flocculants, such as organic flocculants (e.g.,poly aluminium chloride, aluminium sulfate, aluminium potassium sulfate, ferrous sulfate, sodium carbonate, and sodium aluminate), inorganic flocculant (e.g., polyacrylamide), biopolymer flocculants (e.g., chitosan and starch) were tested. Among the tested DAF, poly aluminium chloride and aluminium sulfate, showed best performance.

The algae bloom in river has been issued in Korea. In order to alleviate treatment load of water treatment plant and to meet water treatment capacity of the plant, a high-speed algae pretreatment methods connected with water intake pipe are required. In this study, a pilot-scale of pretreatment system was tested. It was consisted of coagulation and electro flotation processes. The algae pretreatment efficiency by the comparisons of chlorophyll-a, nutrients (total nitrogen, total phosphorous), and chemical oxygen demand (COD) concentration was evaluated. As a result, the system showed about 45% of removal efficiency by the only flotation separation without coagulation judged by chlorophyll-a concentration. On the other hand, the removal efficiency was improved with increase of coagulant dosage and electric power. It was improved to about 80% of chlorophyll-a concentration. The system could treat algae containing solution within a few minutes on the basis of residence time of flotation tank. Consequently, this study suggests that the system could be used as an algae pretreatment step in water treatment process.