Why use biochar for water purification?
Biochar has high porosity and a large surface area and therefore a high cation exchange capacity, as in a good ability to bind positive ions. The ability to bind ions allows biochar to capture heavy metals from the water that passes through the plantings where it is used. The quality of the drainage water therefore increases, which in turn reduces the risk of contaminating lakes, seas and other watercourses. The ability to bind heavy metals makes biochar a very interesting material in green-blue-grey systems in street spaces aimed at handling storm water.