| Abstract |
| While more attention has been paid to urban point source pollution control in recent years, less studies have been focused on urban non-point source(NPS) pollution control systems. Contaminants from NPS deposited on urban impermeable surfaces such as roads and highways are easily released to the public waters by rainfall, leading to the deterioration of water quality in urban area. Experiments were performed using the system and real rainwater runoff from road surfaces at various pollutant loading and rainfall intensity to determine the basic design parameters of the facilities for treating road runoff. The central composite design(CCD) of response surface methodology(RSM) was used to evaluate the effects of bed depth, rain intensity, and packing ratio and investigate the optimum conditions for SS removal. These three elements are the basic design parameters for effective SS removal in the non-point source (NPS) pollution management facilities. The results showed that increasing the bed depth and packing ratios resulted in the significant increase of the suspended solids(SS) removal efficiency, however the SS removal efficiency decreased when rain intensity exceeded 10 mm/hr. Furthermore, predicted optimum conditions for maximizing SS removal were : bed depth 60 cm, packing ratio 79.9%, and rain intensity 4.7 mm/hr attaining 92.7% removal efficiency. Verification experiment of the estimated optimum conditions confirmed that the RSM was useful for optimizing the SS yield from effluent of treatment facilities of urban non-point pollutants. |
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| Key Words |
| Non-point source(NPS) pollution, Central Composite Design(CCD), Response Surface Methodology(RSM), Suspended solids(SS) |
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