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What Is It?[edit]

Biochar is a carbon-rich material produced by pyrolysis of organic feedstocks such as municipal, agricultural, and forestry wastes. It has a high surface area, which enhances soil aggregation, water holding capacity, and organic carbon content. However, biochar properties and effectiveness for pollutant sorption depends on feedstock and pyrolysis conditions. [1]

How is it being used?[edit]

No evidence was found of biochar being used for LID projects in Ontario yet.

  • If you have used biochar in LID design, please let us know.


One study states that the mixing of biochar with compost did not decrease the phosphorus leaching from the mixture. [1] Based on this study, it would seem that biochar is ineffective for phosphorus removal. However, some other papers indicate that biochar mixed with sand was able to retain some trace organic contaminants (TOrCs), [2] and that after six months of operation, biochar-amended biofilters improved removal of total dissolved phosphorus and other TOrCs by greater than 60%. [3] Amendment of LID systems with biochar has shown promise for improved removal of heavy metals, bacteria, nutrients, and TOrCs. [4]

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  1. 1.0 1.1 Iqbal H, Garcia-Perez M, Flury M. Effect of biochar on leaching of organic carbon, nitrogen, and phosphorus from compost in bioretention systems. Science of the Total Environment. 2015;521-522: 37-45. doi: 10.1016/j.scitotenv.2015.03.060
  2. Ulrich B, Im E, Werner D, Higgins C. Biochar and Activated Carbon for Enhanced Trace Organic Contaminant Retention in Stormwater Infiltration Systems. Environ. Sci. Technol. 2015;49:6222-6230. doi: 10.1021/acs.est.5b00376.
  3. Ulrich B, Loehnert M, Higgins C. Improved contaminant removal in vegetated stormwater biofilters amended with biochar. Environ. Sci.: Water Res. Technol.,2017;3:726-734. doi: 10.1039/C7EW00070G
  4. Ulrich B, Vignola M, Edgehouse K, Werner D, Higgins C. Organic Carbon Amendments for Enhanced Biological Attenuation of Trace Organic Contaminants in Biochar-Amended Stormwater Biofilters. Environ. Sci. Technol. 2017;51:9184-9193. doi: 10.1021/acs.est.7b01164.