title: Adsorption and desorption kinetics of carbofuran in acid soils.
abstract: Carbofuran adsorption and desorption were investigated in batch and stirred flow chamber (SFC) tests. The carbofuran adsorption capacity of the soils was found to be low and strongly dependent on their clay and organic carbon contents. Carbofuran sorption was due mainly (>80%) to fast adsorption processes governed by intraparticle diffusion. The adsorption kinetic constant for the pesticide ranged from 0.047 to 0.195 min(-1) and was highly correlated with constant n in the Freundlich equation (r=0.965, P<0.05). Batch tests showed carbofuran desorption to be highly variable and negatively correlated with eCEC and the clay content. The SFC tests showed that soil organic carbon (C) plays a key role in the irreversibility of carbofuran adsorption. Carbofuran desorption increased rapidly at C contents below 4%. The desorption kinetic constant for the compound (0.086-0.195 min(-1)) was generally higher than its adsorption kinetic constant; therefore, carbofuran is more rapidly desorbed than it is adsorbed in soil.
authors: Soil and Agricultural Science Group, Plant Biology and Soil Science Department, Faculty of Science, University of Vigo, Ourense Campus, E32004 Ourense, Spain.
authors: Alipio
authors: A
authors: Bermúdez-Couso
authors: David
authors: D
authors: Fernández-Calviño
authors: Miriam
authors: M
authors: Pateiro-Moure
authors: Juan Carlos
authors: JC
authors: Nóvoa-Muñoz
authors: Jesús
authors: J
authors: Simal-Gándara
authors: Manuel
authors: M
authors: Arias-Estévez
mesh_terms: D000143:Acids; D000327:Adsorption; D002235:Carbofuran / Q000737:chemistry / Q000302:isolation & purification*; D002800:Cholinesterase Inhibitors; D004058:Diffusion; D007306:Insecticides; D007700:Kinetics; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*
chemical_list: D000143:Acids; D002800:Cholinesterase Inhibitors; D007306:Insecticides; D012987:Soil; D012989:Soil Pollutants; D002235:Carbofuran