Evaluating equilibrium and non-equilibrium transport of bromide and isoproturon in disturbed and undisturbed soil columns.

摘要: In this study, displacement experiments of isoproturon were conducted in disturbed and undisturbed columns a silty clay loam soil under similar rainfall intensities. Solute transport occurred saturated conditions the unsaturated sieved because greater bulk density compacted compared to soil. The objective work was determine characteristics relative bromide tracer. Triplicate column performed with (structure partially destroyed simulate conventional tillage) preserved) soils. Bromide experimental breakthrough curves analyzed using convective-dispersive dual-permeability (DP) models (HYDRUS-1D). Isoproturon (BTCs) DP model that considered either chemical equilibrium or non-equilibrium transport. described elution well, whereas it overestimated tailing BTCs columns. A higher degree physical found soil, where 56% total water contained slow-flow matrix, 26% best both combined non-equilibrium. Higher degradation rates obtained than batch studies, for This likely caused by hysteresis sorption isoproturon. However, cannot be ruled out due, at least part, adopted first-order model. Results showed intensity, also suggested faster due preferential flow lower fraction sites.