Bio-retention systems for storm water treatment and management in urban systems

Among different anthropogenic activities, urbanization has greatly influenced the hydrological cycle. Due to increased impervious surfaces, the amount of infiltration has been reduced, thereby increasing the runoff volume leading to flood conditions even for low rainfall events. Storm water flow along these impermeable surfaces finally ends up in surface water reservoirs. Urban systems are fundamentally responsible for a lot of pollutants by different sources: vehicle, industries, atmospheric deposition, soil erosion, etc., which may release various types of pollutants such as metals, organics, nutrients, oil and grease, detergents, surfactants, etc., into the atmosphere. With the storm water runoff, these pollutants may end up in surface waters. This indicates the importance of storm water treatment. Although there are several storm water treatment methods available, low-cost environmental-friendly methods (e.g., bio-retention systems) will be more sustainable with urban systems. Bio-retention systems can manage storm water and improve water quality through containment and remediation of pollutants within the urban system. However, the limitation of these systems is its finite capacity to hold contaminants. Hence, suitable plants grown along the bio-retention systems will be an effective phytoremediation option to address the challenges encountered in these remedial systems.