title: Phenylurea herbicide sorption to biochars and agricultural soil.
abstract: Biochar is increasingly been used as a soil amendment to improve water-holding capacity, reduce nutrient leaching, increase soil pH, and also as a means to reduce contamination through sorption of heavy metals or organic pollutants. The sorption behavior of three phenylurea herbicides (monuron, diuron and linuron) on five biochars (Enhanced Biochar, Hog Waste, Turkey Litter, Walnut Shell and Wood Feedstock) and an agricultural soil (Yolo silt loam) was investigated using a batch equilibration method. Sorption isotherms of herbicides to biochars were well described by the Freundlich model (R(2) = 0.93-0.97). The adsorption KF values ranged from 6.94 to 1306.95 mg kg(-1) and indicated the sorption of herbicides in the biochars and Yolo soil was in the sequence of linuron > diuron > monuron and walnut shell biochar > wood feedstock biochar > turkey litter biochar > enhanced biochar > hog waste biochar > Yolo soil. These data show that sorption of herbicides to biochar can have both positive (reduced off-site transport) and negative (reduced herbicide efficacy) implications and specific biochar properties, such as H/C ratio and surface area, should be considered together with soil type, agriculture chemical and climate condition in biochar application to agricultural soil to optimize the system for both agricultural and environmental benefits.
authors.affiliation: a Department of Land, Air and Water Resources, University of California Davis , Davis , California , USA.
authors.forename: Daoyuan
authors.initials: D
authors.lastname: Wang
authors.forename: Fungai N D
authors.initials: FN
authors.lastname: Mukome
authors.forename: Denghua
authors.initials: D
authors.lastname: Yan
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Kate M
authors.initials: KM
authors.lastname: Scow
authors.forename: Sanjai J
authors.initials: SJ
authors.lastname: Parikh
mesh_terms: D000327:Adsorption; D000383:Agriculture; D002606:Charcoal / Q000737:chemistry*; D004237:Diuron / Q000737:chemistry; D006540:Herbicides / Q000737:chemistry*; D008044:Linuron / Q000737:chemistry; D008372:Manure; D008782:Methylurea Compounds / Q000737:chemistry; D010671:Phenylurea Compounds / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D014934:Wood
chemical_list: D006540:Herbicides; D008372:Manure; D008782:Methylurea Compounds; D010671:Phenylurea Compounds; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D008044:Linuron; D002606:Charcoal; D004237:Diuron; C100088:monuron
keywords: Biochar; diuron; linuron; monuron; phenylurea herbicides; sorption isotherm