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 [2] Yes [3]
Phosphorus retention No to slight [4] No [5] No
Handling concerns Potential explosive concerns in closed space situations; volatile compounds (depending on pyrolysis temperature) [6] Dust [7] None
Soil hydraulic properties Significant improvement [8] Significant improvement [9] Significant improvement [10]
Soil physical properties Significant improvement [11] Moderate improvement [12] Significant improvement [13]
Plant/microbial effects Beneficial but varies with feedstock [14] Beneficial [15] Beneficial if not fresh [16]; [17]
Availability Multiple distributors [18] Widely available [19]
Specifications/standards available Limited due to variability with feedstocks [20] Yes [21]
Cost
Research needs Feedstocks suitable for stormwater applications Phosphorus fate in stormwater applications
Applications [22] [23]
Chemical properties [24] [25]
Sustainability Sustainable, but has current market constraints [26] Sustainable [27]
Potential contaminants Minor risk - metals and polycyclic aromatic hydrocarbons (PAHs) [28] Low risk - possible chloride depending on preparation method [29]
Test methods Not standardized but International Biochar Initiative widely used [30] Not standardized but multiple methods available [31]
Effects of aging/Life expectancy Varies with production method [32] Decomposes slowly unless nutrients are added [33]
Notes Characteristics vary with feedstock and pyrolysis temperature Coir must be composted or incorporated with compost, lime, fertilizer, and/or microbes