Environmental Chlorine Pollution Mitigation Using Material-Pollutant Interactions and Field-Scale Applications.

Area of Science:

• Environmental Engineering
• Water Resource Management
• Sustainable Urban Drainage Systems

Background:

• Nature-based solutions and green infrastructure (GI) are vital for sustainable stormwater management.
• GI elements like rain gardens offer integrated approaches for climate change mitigation and pollution reduction.
• Residual chlorine in stormwater, from outdoor disinfection, poses an environmental concern.

Purpose of the Study:

• To investigate the efficacy of rain gardens in retaining residual chlorine from stormwater.
• To evaluate the infiltration capacities of experimental rain garden models using waste materials.
• To assess the suitability of sand-gravel substrates for rain garden filtration.

Main Methods:

• Laboratory column tests and field tests were conducted on simulated rain garden layers.
• Infiltration coefficients were measured to assess water flow through the substrates.
• Chlorine retention efficiency was determined, alongside granulometric analysis of the materials.

Main Results:

• Infiltration coefficients ranged from 1.28 × 10^-5 m/s to 3.4 × 10^-5 m/s, consistent with sand-gravel substrates.
• A significant chlorine retention efficiency of 82.5-87% was achieved.
• Granulometric analysis confirmed the suitability of the chosen fraction sizes for effective rain garden filtration.

Conclusions:

• Rain gardens demonstrate substantial potential for reducing residual chlorine in stormwater.
• The use of waste materials in substrates offers a sustainable approach to rain garden construction.
• Findings support the practical implementation and further research into rain gardens for stormwater pollution control.