Assessment of Factors Affecting the Removal Efficiency of Suspended Solids and Particulate Matters for Pretreatment Units in a Stormwater Management Facility

Non-point source (NPS) pollution is one of the primary sources of contamination in aquatic systems, such as rivers and lakes. Various techniques and devices, including low impact development (LID) and best management practice (BMP) devices, can reduce NPS pollution. These devices are installed with pretreatment units to remove NPS pollutants more efficiently and to facilitate maintenance. In this study, suspended solids (SS) and particle size distributions (PSD) were investigated in a pilot-scale facility to determine the effect of various pretreatment unit types and inflows on SS removal. We found that the efficiency of SS concentration and particulate matter removal changed significantly (p < 0.05) based on the aspect ratio of the pretreatment unit. Three flow conditions were also tested (10, 15, and 20 m3/h); SS removal was most efficient at 15 m3/h. These findings can be applied to the design of NPS management facilities, which is expected to help increase the efficiency of new NPS facilities while reducing operating costs.