Development of a stormwater treatment system using bottom ash as filter media

This study investigated the applicability of bottom ash as filter media for a stormwater treatment facility. Filtration test experiments were conducted in a 30 × 15 × 15 cm transparent acrylic test reactor using a synthetic run-off, prepared from run-off collected from a wetted impervious road. The reactor designed as a stormwater treatment system and incorporated bottom ash as filter media was tested for three flow regimes (i.e. 200, 400, and 800 mL/min) to investigate the treatment performance of the system at various intensities during rainfall events. Based on the findings, the bottom ash media was able to reduce 70% of total suspended solids and more than 50% of iron, zinc, and lead from the synthetic run-off. A design guideline was developed which recommended a facility surface area to catchment area ratio of 0.007–0.015 for the effective treatment of 5, 7.5, and 10 mm design rainfall.