Green engineered mulch for phosphorus and metal removal from stormwater runoff in bioretention systems
Document Type
Article
Publication Date
8-1-2023
Abstract
Phosphorus and metals in stormwater runoff are major causes of water quality degradation. Bioretention systems are increasingly implemented to improve stormwater quality and to better manage stormwater quantity. Many studies have focused on modifying the composition of the soil bed to improve pollutant removal. However, the pollutant removal performance of bioretention systems can diminish over time, such as when clogging of the media occurs. Sediment accumulation on the soil surface may inhibit infiltration into the soil bed, thus limiting pollutant removal. Soil replacement may be eventually required as pollutants accumulate in the soil. In this study, a green retrofit material, called green engineered mulch (GEM), was generated by coating regular wood mulch with aluminum-based water treatment residuals (WTR) via a simple and low-energy process (patent pending). The GEM was developed to serve as a green retrofit for bioretention systems to enhance the removal of phosphorus and metals from stormwater runoff. The GEM was placed in a rain garden in Secaucus, NJ, USA for 15 months, during which 12 storm events (ranging from 6.0 mm to 89.6 mm) were monitored. Runoff and infiltrate samples were analyzed for dissolved and total concentrations of phosphorus and metals, along with other key water quality parameters. The GEM significantly reduced (p < 0.05) the total concentrations of phosphorus and metals in stormwater infiltrate compared to the inlet, unlike the regular mulch. Minimal or no contact with the GEM resulted in no significant pollutant removal from surface runoff. No significant pollutant export from the GEM was observed. The spent GEM can be disposed of as non-hazardous waste in municipal landfills. This study demonstrates that the GEM is a safe and effective retrofit. Moreover, the GEM is a simple and economical retrofit solution that can be used in place of regular mulch in bioretention systems.
Identifier
85153797346 (Scopus)
Publication Title
Chemosphere
External Full Text Location
https://doi.org/10.1016/j.chemosphere.2023.138779
e-ISSN
18791298
ISSN
00456535
PubMed ID
37116722
Volume
331
Grant
18OAR4170087
Fund Ref
U.S. Department of Commerce
Recommended Citation
Na Nagara, Viravid; Sarkar, Dibyendu; Boufadel, Michel; and Datta, Rupali, "Green engineered mulch for phosphorus and metal removal from stormwater runoff in bioretention systems" (2023). Faculty Publications. 1556.
https://digitalcommons.njit.edu/fac_pubs/1556