2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference


Title
Soil Remediation by Biochar Derived from Agricultural Waste

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Author(s)
Dr. Peng Zhang, IEESC (Presenter)
Dr. Gordon Huang, IEESC
Abstract

Biochar is a carbon-rich and porous material produced by heating biomass in an oxygen limited environment. Application of biochar in soil amendment has many benefits, including modification of soil fertilizer, sequestration of carbon, and controlling of (inorganic and organic) contaminants. Especially, the fate and transport of contaminants in soil are impacted by biochar’s special composition and structure, including aromaticity, polarity, cation exchangeable capacity, and surface function groups. However, the composition and structure of different biochars derived from different raw biomass or temperatures vary greatly. Two kinds of biomass (maize straw and pig manure) were heated to produce biochar under two temperatures to investigate the adsorption and catalytic hydrolysis of a pesticide on the biochar. Biochar derived from pig manure had higher ash content than that derived from maize straw. Atom ratio of H/C which was recognized as aromaticity index was higher in biochar derived from maize straw under a higher temperature. While, the BET surface area of biochar was increasing with the temperature. According to FTIR spectra of the biochars, aliphatic carbon decreased with temperature elevated, as well as aromatic carbon and minerals increased. A pesticide was adsorbed efficiently by the biochar. Hydrophobic effect alone could not explain the sorption, and several other processes including pore-filling and ?-? electron donor-acceptor interactions were involved in the adsorption. Hydrolysis of the pesticise could be catalyzed under alkaline condition and was enhanced in the presence of biochar.  The higher temperature derived biochar added; the faster hydrolysis of carbaryl occurred. In hence, the elevated solution pH was the main reason for the enhancement of hydrolysis.