진동세척 장치를 구비한 비점오염원 저감시설의 여과성능 실험연구

Abstract

Recently, point source and non-point pollutant sources keep increasing in Korea, because of erratic rainfall and pollution of water resources caused by the urbanization of the nation and various land use. The installation of reduction facilities for point sources has been achieved significantly, but the effects of reducing the pollution from the non-point sources have not yet been visible to the improvement of water quality. Accordingly, the improvement of facilities and processing the capacity of existing non-point sources facilities is greatly needed by new calculation methods. Therefore, the Ministry of Environment revised the non-point sources Manual to propose a new design basis. The purpose of this study was to develop a filtering device and conduct experiments based on the proposed design basis. For this study, a pilot-scale filter system was designed and built for the experiments, non-point pollutant materials similar to natural initial rainwater were prepared to make artificial initial rainwater. The filter media(fiber ball) filtration efficiency test was conducted using the prepared artificial initial rainfall. In the pilot-scale filtration system designed and fabricated for this study, the loss head of the no-load operation was analyzed. The loss head by filtration no-load operation was 10m/hr to 6.3cm, 20m/hr to 6.5cm, 30m/hr to 7cm, 8cm at 40m/hr, 9cm at 50m/hr, and 14.3cm at 60m/hr. As a result, it was confirmed that the loss head was increased exponentially at a filtration line speed of 60m/hr or more in the filtration apparatus used in this study, and it was not appropriate to proceed with the solids load experiment at this time. Filtration efficiency of artificial specimens made of 250 mg / L powdered activated carbon and loess in a 24.3L / min pilot-scale filtration apparatus using a 3.05 cm diameter fiber ball filter was analyzed. In the case of powdered activated carbon samples, the efficiency of SS filtration was 88.4% compared to the raw water (60 minutes). In the case of the loess soil, the SS filtration efficiency was 75.9% compared to the raw water (60 min), and the SS filtration efficiency of the treated water (60 min) compared to the influent was 70.2%. As a result of the filtration test of the fiber ball filter media, the SS filtration efficiency compared to the raw water and the SS filtration efficiency of the treated water compared to the influent water are not satisfied with 80% of the environment standard. However, all of the artificial first flush samples prepared with powdered activated carbon were satisfied with the criterion of removing the environment. As a result, it is considered that the fiber ball filter material used in this experiment has a high efficiency of removal of nonpoint source pollutants having a carbon content of 64 μm or less. In the pilot-scale filtration system, the concentration of treated water was measured at 10-minute intervals. As a result, the powdery activated carbon sample was 10 minutes to 11.0mg/L, 20 minutes to 15.8mg/L, 30 minutes to 18.0mg/L, 40 minutes to 18.4mg/L, 50 minutes to 21.6mg/L, and 60 minutes to 29.0mg/L. In the case of the loess soil samples, 10 minutes to 39.8mg/L, 20 minutes to 43.0.8mg/L, 30 minutes to 46.4mg/L, 40 minutes to 54.8mg/L, 50 minutes to 55.8mg/L, and 60 minutes to 60.2mg/L. As a result, it was confirmed that the filtration efficiency of the experimental apparatus gradually decreased with the operation time. As a result of washing experiment through the vibration of the filter media, starting from 4929.8g in total, washing sample volume was 1829.2g in the first stage, 692.7g in the second stage, 344.0g in the third stage, 221.5g in the fourth stage, 146.5g, 93.9g of the sixth solution and 70.4g of the seventh solution. Through this, it was found that the wash effect of more than half was obtained by only the vibration of the media layer without washing air injection.