Assessment of the fertilizer potential of biochars produced from slow pyrolysis of biosolid and animal manures

Excessive amounts of animal manures and production of a large volume of biosolids pose serious environmental issues in terms of their safe disposal and management. Thermochemical treatment of bio-waste materials via pyrolysis can convert them into value-added products such as biochar-based fertilizers. In this study, fourteen biochars were produced from one biosolid and thirteen animal manures by slow pyrolysis at 300 °C. All feedstock and biochar samples were characterized by determining the yield, and physicochemical and surface properties, including the C-containing functional groups. Principal component and cluster analyses were used to classify the feedstock/biochar materials based on their mineral constituents. The biochar yield of various feedstocks ranged from 39 to 81%, with the highest yield for grain-fed cow manure. The…