Effect of Activation and Age on Adsorption of Pesticides by Biochar

Abstract de la comunicación oral presentada en Annual Conference of the American-Society-for-Horticultural-Science (ASHS) Orlando, FL 31 jul-4 ago (2023)

Biochar, the calcium-rich residue resulting from pyrolysis of organic matter, is a potential soil amendment to prevent pollution. When added to soil, biochar binds to organic agrochemicals until they biodegrade by sun exposure, preventing agrochemicals from leaching into and contaminating groundwater. Activation, particle size, age and aging method influence biochar’s shape and thus its ability to bind to agrochemicals. This study examined the effects of different biochar treatments on clay-based biochar’s adsorption of metalaxyl, fluometuron, and terbuthylazine. Types of biochar studied were biochar activated with chitosan, oxalic acid, potassium hydroxide and sodium hydroxide; of particle size 63 µm – 1 mm and 1 mm – 2mm; and unaged and aged one year underground in mesh bags of varying pore sizes. Biochar samples mixed with 1 ppm agrochemical solution were agitated, centrifuged, and analyzed using High Performance Liquid Chromatography. Percent adsorption of agrochemical by biochar was calculated based on initial and final agrochemical concentration. Biochar activated with sodium hydroxide, unaged biochar and biochar of particle size 63 µm – 1 mm most consistently adsorbed a greater concentration of agrochemicals. Biochar activated with oxalic acid showed the highest average adsorption but significant deviation among samples

Peer reviewed