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Influence of Soil Biochar Aging on Sorption of the Herbicides MCPA, Nicosulfuron, Terbuthylazine, Indaziflam, and Fluoroethyldiaminotriazine
- Carmen Trigo, Kurt A. Spokas, Lucia Cox, William C. Koskinen
- Journal of agricultural and food chemistry 2014 v.62 no.45 pp. 10855-10860
- terbuthylazine, absorbents, soil remediation, soil pollution, surface area, sorption, porosity, herbicide residues, soil, biochar, carbon, MCPA (herbicide), macadamia nuts, metabolites, nicosulfuron
- Sorption of four herbicides and a metabolite of indaziflam on a fresh macadamia nut biochar and biochars aged one or two years in soil was characterized. On fresh biochar, the sorption was terbuthylazine (Kd = 595) > indaziflam (Kd = 162) > MCPA (Kd = 7.5) > fluoroethyldiaminotriazine (Kd = 0.26) and nicosulfuron (Kd = 0). Biochar surface area increased with aging attributed to the loss of a surface film. This was also manifested in a decline in water extractable organic carbon with aging. Correspondingly, an increase in the aromaticity was observed. The higher surface area and porosity in aged biochar increased sorption of indaziflam (KdBC-2yr = 237) and fluoroethyldiaminotriazine (KdBC-1yr = 1.2 and KdBC-2yr = 3.0), but interestingly decreased sorption of terbuthylazine (KdBC-1yr = 312 and KdBC-2yr = 221) and MCPA (KdBC-1yr = 2 and KdBC-2yr = 2). These results will facilitate development of biochars for specific remediation purposes.