title: Influence of soil biochar aging on sorption of the herbicides MCPA, nicosulfuron, terbuthylazine, indaziflam, and fluoroethyldiaminotriazine.
abstract: 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.
authors.affiliation: Department of Soil, Water & Climate, University of Minnesota , 1991 Upper Buford Circle, St. Paul, Minnesota 55108, United States.
authors.forename: Carmen
authors.initials: C
authors.lastname: Trigo
authors.forename: Kurt A
authors.initials: KA
authors.lastname: Spokas
authors.forename: Lucia
authors.initials: L
authors.lastname: Cox
authors.forename: William C
authors.initials: WC
authors.lastname: Koskinen
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry*; D007192:Indenes / Q000737:chemistry*; D007700:Kinetics; D011725:Pyridines / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*; D013453:Sulfonylurea Compounds / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry*
chemical_list: D006540:Herbicides; D007192:Indenes; C571026:N-(2,3-dihydro-2,6-dimethyl-1H-inden-1-yl)-6-(1-fluoroethyl)-1,3,5-triazine-2,4-diamine; D011725:Pyridines; D012987:Soil; D012989:Soil Pollutants; D013453:Sulfonylurea Compounds; D014227:Triazines; C540010:biochar; D002606:Charcoal; C416723:nicosulfuron; C037565:terbutylazine
keywords: MCPA; aging; biochar; indaziflam; nicosulfuron; terbuthylazine