Struzak, Poor, et al (2024) Evaluation of BiocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More as an Amendment for the Removal of Metals, Nutrient, and Microplastics in Bioretention Systems. Journal of Environmental Engineering. https://doi.org/10.1061/JOEEDU.EEENG-7487

Bioretention systems, employing plants and soil, play a crucial role in purifying stormwater. In this study, researchers investigated the effectiveness of biochar, a substance known for its adsorption properties, as an amendment to bioretention soil media for pollutant removal. Various column configurations, including 0%, 25%, and 50% biochar, were tested to assess their efficiency in removing copper, zinc, phosphorus, nitrogen, and microplastics from stormwater collected from parking lot runoff.

Results revealed that the addition of biochar significantly improved the removal efficiency of zinc (79% with 50% biochar compared to 54% without) and copper (73% with 50% biochar compared to 25% without). The stormwater from biochar-amended columns exhibited substantially lower turbidity (21 NTU) compared to control columns (58 NTU). However, the impact on nitrogen and phosphorus removal was consistent across control and biochar-amended columns.

Notably, all columns effectively removed microplastics, achieving an average removal rate of 86%. The study suggests that while biochar holds promise in reducing metal concentrations in stormwater within bioretention systems, its influence on nutrients and microplastics is limited.