Improving the Treatment Performance of Low Impact Development Practices—Comparison of Sand and Bioretention Soil Mixtures Using Column Experiments

Abtin Shahrokh Hamedani,Marcio Giacomoni,Hanieh Soleimanifar,Heather Shipley,Arianne Bazilio

doi:10.3390/w13091210

Abtin Shahrokh Hamedani, Marcio Giacomoni + Show 3 more

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https://doi.org/10.3390/w13091210

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Abstract

Low impact development (LID) practices, such as bioretention and sand filter basins, are stormwater control measures designed to mitigate the adverse impacts of urbanization on stormwater. LID treatment performance is highly dependent on the media characteristics. The literature suggests that bioretention media often leach nutrients in the stormwater effluent. The objective of this study was to analyze the treatment performance of different sand and bioretention soil mixtures. Specifically, this investigation aimed to answer whether the use of limestone and recycled glass could improve the treatment performance of bioretention systems. Column experiments were designed to assess (1) the removal efficiencies of different sand and bioretention soil mixtures and (2) the impact of plant uptake on removal rates. Enhanced pollutant removal was observed for the custom blends with addition of limestone sand, indicating mean dissolved and total phosphorus removal of 44.5% and 32.6% respectively, while the conventional bioretention soil mixtures leached phosphorus. Moreover, improved treatment of dissolved and total copper was achieved with mean removal rates of 70.7% and 93.4%, respectively. The results suggest that the nutrient effluent concentration decreased with the addition of plants, with mean phosphorus removal of 72.4%, and mean nitrogen removal of 22% for the limestone blend.

Highlights

Low impact development (LID) practices or green infrastructure (GI) are strategies used to mitigate the adverse impacts of urbanization on the hydrologic regime and the environment by restoring the natural hydrologic flow [1]
Bioretention systems have the potential to improve the removal of dissolved pollutants because of the chemical and biological processes that occur within the soil media and plants, including adsorption, biotransformation, bioaccumulation, and bio-uptake [1,10,11,12]
Each column was built with three layers following the typical design of bioretention systems specified by the San Antonio River Authority (SARA) LID Technical Design Guidance [11]

Summary

Introduction

Low impact development (LID) practices or green infrastructure (GI) are strategies used to mitigate the adverse impacts of urbanization on the hydrologic regime and the environment by restoring the natural hydrologic flow [1]. Studies have shown that sand filter basins perform well in reducing the peak flow and runoff volume as well as removing particulate pollutant. They are not effective in the removal of dissolved pollutants [3,8,9]. Bioretention systems have the potential to improve the removal of dissolved pollutants because of the chemical and biological processes that occur within the soil media and plants, including adsorption, biotransformation, bioaccumulation, and bio-uptake [1,10,11,12]. Bioretention systems might retain the antibiotic-resistant bacterial communities in the stormwater, leading to contaminated soil and plants that can later be transmitted to humans [13]

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