The effects of meteorological and reclaiming conditions on the reduction of suspended particles are investigated using a computational fluid dynamics (CFD) model with the k-ε turbulence closure scheme based on the renormalization group (RNG) theory. Twelve numerical experiments with different meteorological and reclaiming conditions are performed. For identifying the meteorological characteristics of the target area and providing the inflow conditions of the CFD model, the observed data from the automatic weather station (AWS) near the target area is analyzed. Complicated flow patterns such as flow distortion, horse-shoe vortex, recirculation zone, and channeling flow appeared due to the topography and buildings in the domain. Specially, the flow characteristics around the reclamation area are affected by the reclaiming height, reclaiming size and windbreak height. Reclaiming height affected the wind speed above the reclaiming area. Windbreak induces more complicated flow patterns around the reclaiming area as well as within the reclaiming area. In front of the windbreak, flow is distorted as it impinges on the windbreak. As a result, upward flow is generated there. Behind the windbreak, a secondary circulation, so called, a recirculation zone is generated and flow is reattached at the end of the recirculation zone (reattachment point). At the lower part of the recirculation zone, there is a reverse flow toward the windbreak. Flow passing to the reattachment point starts to be recovered. Total amounts of suspended particles are calculated using the frictional and threshold frictional velocities, erosion potential function, and the number of surface disturbance. In the case of a 10 m-reclaiming and northerly wind, the amount of suspended particles is largest. In the presence of 5 m windbreak, the friction velocity above the reclaiming area is largely reduced. As a result, the total amount of the suspended particles largely decreases, compared to the case with the same reclaiming and meteorological conditions except for the windbreak The calculated suspended particle amounts are used as the emission rate of the dispersion model simulations and the dispersion characteristics of the suspended particles are analyzed.

본 연구는 점착성 퇴적물 예측에 가장 중요한 인자인 침강속도를 강 항만 저수지 그리고 호수에 녹아있는 이온 의 첨가 및 밀도의 변화 아래 실시되었다. 정수 중에 부유된 미립자(alumina와 quartz)의 침강 속도는 압력센서(최대 10 mbar)로 측정되었다. 초기 농도 20 g/l에서 alumina와 quartz의 평균 침강속도는 미립자의 응집현상 때문에 최고 값을 보였으며, 이때 각각 최대 평균 침강속도는 0.185 mm/s(alumina)와 0

부유사의 거동을 나타내는 데는 이송-확산 방정식이나 이 방정식을 간략화한 식들이 이용된다 이 방정식은 여러 가지 가정하에서 유도되었으나, 이러한 가정에 대해서는 심도있는 검토가 되지 못한 상태에 있다 그 이유는 난류의 측정 자체가 매우 힘들며, 유사가 혼합된 흐름의 경우 물과 유사의 속도를 구별해서 측정하기 매우 힘들기 때문이다. 본 연구는 입자 영상 유속계(PIV, Particle Image Velocimeoy)의 일종인 입자 추적 유속계(PTV, P

This study aimed to elucidate the relationship between theoretical parameters affecting the coagulation process and the real coagulation phenomenon applied to the dye wastewater. Emphasis was placed on the effective removal of the suspend particulates. Parameters studied in this study are pH, coagulant concentration and surface potential. Optimal dosages of coagulants by the measurement of the zeta potential at lower then 25℃ are 5×10-3 M of FeCl3 and 1.4×10-6 M of Fe2(SO4)3. The results were well agreeded with the separate jar-test results. Emphasis was also placed on the relationship between water quality and the content of SS. It was found that the wastewater quality is greatly dependent on the amount of SS. At the condition with the best removal of SS, COD and DOC were reduced to 65 % and 85 %, respectively The turbidity at the above condition was reduced from 300 NTU to 0∼1 NTU. Efforts were made to clarify the behavior of the suspend solid as affecting the water quality. 12,000∼13,000 particles/l0mL in 1∼50㎛ size range particulates in the raw wastewater were reduced to 300 particle/l0mL in the same range after treatment. This research has proposed the methodology to find out the optimal condition of coagulation for small scale wastewater treatment plant or chemical coagulation process.