Physical and chemical characterization of biochars derived from different agricultural residues

[摘要] Biochar is widely recognized as an efficient tool for carbon sequestrationand soil fertility. The understanding of its chemical and physicalproperties, which are strongly related to the type of the initial materialused and pyrolysis conditions, is crucial to identify the most suitableapplication of biochar in soil. A selection of organic wastes with differentcharacteristics (e.g., rice husk (RH), rice straw (RS), wood chips of appletree (Malus pumila) (AB), and oak tree (Quercus serrata)(OB)) were pyrolyzed at different temperatures (400, 500, 600, 700, and800 °C) in order to optimize the physicochemical properties ofbiochar as a soil amendment. Low-temperature pyrolysis produced high biocharyields; in contrast, high-temperature pyrolysis led to biochars with a high Ccontent, large surface area, and high adsorption characteristics. Biocharobtained at 600 °C leads to a high recalcitrant character, whereasthat obtained at 400 °C retains volatile and easily labile compounds. Thebiochar obtained from rice materials (RH and RS) showed a high yield andunique chemical properties because of the incorporation of silica elementsinto its chemical structure. The biochar obtained from wood materials (AB andOB) showed high carbon content and a high absorption character.

[学科分类] 地球化学与岩石