Engineered (bioretention) media organic material properties and specifications.
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Property Biochar Coir Compost Peat Wood chips
Phosphorus leaching No [1] No to slight
Phosphorus retention No to slight [2] No
Handling concerns Potential explosive concerns in closed space situations; volatile compounds (depending on pyrolysis temperature) [3] Dust
Soil hydraulic properties Significant improvement [4] Significant improvement
Soil physical properties [5] Significant improvement Moderate improvement
Plant/microbial effects Beneficial but varies with feedstock [6] Beneficial
Availability Multiple distributors [7] Widely available
Specifications/standards available Limited due to variability with feedstocks [8] Yes
Cost
Research needs Feedstocks suitable for stormwater applications Phosphorus fate in stormwater applications
Applications [9] [10]
Chemical properties [11] [12]
Sustainability Sustainable, but has current market constraints [13] Sustainable
Potential contaminants Minor risk - metals and polycyclic aromatic hydrocarbons (PAHs) Low risk - possible chloride depending on preparation method
Test methods Not standardized but International Biochar Initiative widely used [14] Not standardized but multiple methods available [15]
Effects of aging/Life expectancy Varies with production method [16] Decomposes slowly unless nutrients are added [17]
Notes Characteristics vary with feedstock and pyrolysis temperature Coir must be composted or incorporated with compost, lime, fertilizer, and/or microbes