Mesocosm study of enhanced bioretention media in treating nutrient rich stormwater for mixed development area

Abstract

A well-designed engineered soil for bioretention is important as it ensures that pollutant removal requirements are met. This laboratory study investigated the nutrient removal efficiency of bioretention media enhanced with 10% (by volume) additives from various waste materials (cockle shell, newspaper, printed paper, coconut husk and tyre crumb) and planted with Red Hot Chinese Hibiscus (Hibiscus rosa-sinensis), a common landscape shrub in tropical countries. The results showed that media enhanced with shredded newspaper demonstrated a significant improvement in total nitrogen (TN) removal (80.4%), compared to standard bioretention media (57.5%) without compromising total suspended solids (TSS) and total phosphorus (TP) removal, when dosed with actual runoff. The thick root system and rapid growth rate of the plant was proven to contribute to TN removal. This study concluded that shredded newspaper can be a potential addition to enhance bioretention media performance in treating stormwater, especially nutrient rich runoff from mixed development areas.

Keywords:

• Bioretention media
• best management practices (BMPs)
• nutrients removal
• stormwater treatment
• tropical climate

Acknowledgement

The authors would like to acknowledge the technical staff from River Engineering and Urban Drainage Research Centre (REDAC) for their effort and collaboration throughout the study's duration.