Biochar: a Potential Application to Storm Water Treatment

This study evaluates the use and efficacy of biochar for treatment of source and nonpoint source pollutants in storm water. Biochar is the solid byproduct of incomplete combustion of biomass under low-oxygen and elevated temperature conditions (Keiluweit, 2010, Beesley and Dickinson, 2011, Bracmort, 2010). The source stock for tested biochar was chicken litter (500 °C), Douglas fir (550 °C) and gasification derived biochar (700 °C). This study involved screening three distinct biochars to investigate particle size characteristics, performing constant head column studies to measure saturated hydraulic conductivity, and investigating the sorption rates of three biochars using methylene blue solute batch studies for three different weights (2, 5, and 10 [and 20 g for chicken litter]). Results of the hydraulic conductivity test revealed hydraulic conductivity values of 0.32 cm/s for Douglas fir (r2 0.93), 0.10 cm/s for gasification (r2 0.76) and 9.0 for chicken litter derived biochar (r2 0.34). The methylene blue sorption studies results indicated that gasification derived biochar had the greatest adsorption rate of methylene blue dye.