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! Benefit !! Effectiveness !! Notes | ! Benefit !! Effectiveness !! Notes | ||
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− | | Water quality || <font size=6><center>&# | + | | Water quality || <font size=6><center>◑</center></font size> || Benefits are maximized for bioinfiltration. Biofiltration may export phosphorus if not designed properly. |
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| Water quantity/supply || <font size=4><center>◔</center></font size> || Bioinfiltration helps mimic natural hydrology. Some rate control benefit. | | Water quantity/supply || <font size=4><center>◔</center></font size> || Bioinfiltration helps mimic natural hydrology. Some rate control benefit. |
Benefit | Effectiveness | Notes |
---|---|---|
Water quality | Benefits are maximized for bioinfiltration. Biofiltration may export phosphorus if not designed properly. | |
Water quantity/supply | Bioinfiltration helps mimic natural hydrology. Some rate control benefit. | |
Energy savings | ||
Climate resiliency | Provides some rate control. Impacts on carbon sequestration are uncertain. | |
Air quality | ||
Habitat improvement | Use of perennial vegetation and certain media mixes promote invertebrate communities. | |
Community livability | Aesthetically pleasing and can be incorporated into a wide range of land use settings. | |
Health benefits | ||
Economic savings | Generally provide cost savings vs. conventional practices over the life of the practice. | |
Macroscale benefits | Individual bioretention practices are typically microscale, but multiple bioretention practices, when incorporated into a landscape design, provide macroscale benefits such as wildlife corridors. | |
Level of benefit: ◯ - none; ◔; - small; ◑ - moderate; ◕ - large; ● - very high |
Biochar is a charcoal-like substance that’s made by burning organic material from biomass in a controlled process called pyrolysis. Biomass waste materials appropriate for biochar production include crop residues (both field residues and processing residues such as nut shells, fruit pits, bagasse, etc), as well as yard, food and forestry wastes, and animal manures. Clean feedstocks with 10 to 20 percent moisture and high lignin content must be used. Examples are field residues and woody biomass. Using contaminated feedstocks, including feedstocks from railway embankments or contaminated land, can introduce toxins into the soil, drastically increase soil pH and/or inhibit plants from absorbing minerals. The most common contaminants are heavy metals—including cadmium, copper, chromium, lead, zinc, mercury, nickel and arsenic, and Polycyclic Aromatic Hydrocarbons (PAHs).
Biochar is black, highly porous, lightweight, fine-grained and has a large surface area. Approximately 70 percent of its composition is carbon. The remaining percentage consists of nitrogen, hydrogen and oxygen among other elements. Biochar’s chemical composition varies depending on the feedstocks used to make it and methods used to heat it.
Biochar benefits for soil may include the following.
Biochar is also found to be beneficial for composting, since it reduces greenhouse gas emissions and prevents the loss of nutrients in the compost material. It also promotes microbial activity, which in turn accelerates the composting process. Plus, it helps reduce the compost’s ammonia losses, bulk density and odor.
The properties of biochar depend on the feedstock and the conditions under which the biochar is produced.
NOTE - this is from one study, just inserted here as an example
NOTE - this is from one study, just inserted here as an example
The properties of biochar vary depending on the feedstock and conditions under which the biochar is produced. Example to the right. The information in this table and other similar tables would be extracted and synthesized into a broader discussion and summary of recommended properties for pollutant retention