Desorption of diuron and isoproturon from undispersed clay loam soil

Studies were conducted to investigate the desorption of diuron and isoproturon adsorbed on undispersed clay loam soil, and the influence of residence time in soil on desorption. The soil was treated at 0·6 or 3 mg kg-1, at 70% moisture content and in the presence of sodium azide to prevent degradation. Measurement of herbicide concentrations in soil solution sampled by means of glass microfibre filters showed that adsorption mainly occurred for one day but long-term sorption proceeded for >two weeks. After a one-day or three-week residence time, soil solution was partly replaced (28%). Measurement of concentrations in solution showed rapid desorption, with equilibria being achieved within 1 h (diuron) or a few hours (isoproturon). After 16 successive desorptions done at 30-min or 12-h intervals, equilibration times tended to be longer. For the short residence time, desorption and long-term sorption could occur simultaneously and equilibration might be faster. Residence time had no significant effect on desorption kinetics nor on the small hysteresis observed for diuron. The aging effect, involving long-term sorption only, decreased the proportion of diuron removed from the soil by successive desorptions but, for isoproturon, desorption frequency and desorption kinetics were more important. © 1997 SCI

[1]  P. Gaillardon.  Influence of Soil Moisture on Long-Term Sorption of Diuron and Isoproturon by Soil , 1996 .

[2]  Joseph J. Pignatello,et al.  Mechanisms of Slow Sorption of Organic Chemicals to Natural Particles , 1996 .

[3]  S. K. Xue,et al.  Modeling Adsorption-Desorption Kinetics of Alachlor in a Typic Fragiudalf , 1995 .

[4]  G. Sims,et al.  Clomazone sorption in soil : incubation time, temperature, and soil moisture effects , 1995 .

[5]  M. Locke,et al.  PREDICTING ALACHLOR MOBILITY USING BATCH SORPTION KINETIC DATA , 1994 .

[6]  M. Sabar,et al.  Changes in the concentrations of isoproturon and its degradation products in soil and soil solution during incubation at two temperatures , 1994 .

[7]  M. Locke.  Sorption-desorption kinetics of alachlor in surface soil from two soybean tillage systems , 1992 .

[8]  E. Barriuso,et al.  Modification of atrzine desorption during field incubation experiments , 1992 .

[9]  E. Barriuso,et al.  Dissolved Organic Matter and Adsorption‐Desorption of Dimefuron, Atrazine, and Carbetamide by Soils , 1992 .

[10]  S. Boyd,et al.  Desorption and Bioavailability of Aged Simazine Residues in Soil from a Continuous Corn Field , 1992 .

[11]  G. Soulas,et al.  Study of diuron in soil solution by means of a novel simple technique using glass microfibre filters , 1991 .

[12]  T. Parkin,et al.  Effect of moisture on sorption and biodegradation of carbofuran in soil , 1991 .

[13]  R. E. Jessup,et al.  Nonequilibrium sorption of organic chemicals: elucidation of rate-limiting processes , 1991 .

[14]  J. Pignatello,et al.  Sorptive Reversibility of Atrazine and Metolachlor Residues in Field Soil Samples , 1991 .

[15]  J. Miller,et al.  Fate of fluroxypyr in soil. II, Desorption as a function of incubation time , 1990 .

[16]  M. Th. van Genuchten,et al.  Two‐Site/Two‐Region Models for Pesticide Transport and Degradation: Theoretical Development and Analytical Solutions , 1989 .

[17]  J. Smelt,et al.  Field test of a mathematical model for non-equilibrium transport of pesticides in soil , 1989 .

[18]  J. Boesten,et al.  MODELING ADSORPTION/DESORPTION KINETICS OF PESTICIDES IN A SOIL SUSPENSION , 1988 .

[19]  Allan Walker,et al.  Evaluation of a simulation model for prediction of herbicide movement and persistence in soil , 1987 .

[20]  B. T. Bowman,et al.  Partitioning Behavior of Insecticides in Soil-Water Systems: II. Desorption Hysteresis Effects 1 , 1985 .

[21]  W. C. Koskinen,et al.  Characterization of Hysteresis in the Desorption of 2,4,5-T from Soils 1 , 1979 .

[22]  M. Leistra,et al.  COMPUTED EFFECTS OF ADSORPTION KINETICS ON PESTICIDE MOVEMENT IN SOILS , 1977 .

[23]  R. Hance.  THE SPEED OF ATTAINMENT OF SORPTION EQUILIBRIA IN SOME SYSTEMS INVOLVING HERBICIDES , 1967 .