Modelling phosphorus transport in soils and groundwater with two-consecutive reactions

Notodarmojo, S. and Ho, G.E. (1991) Modelling phosphorus transport in soils and groundwater with two-consecutive reactions. Water Research, 25 (10). pp. 1205-1216.

Abstract

A model is presented for one-dimensional transport of phosphorus (P) in soils and groundwater. Convective transport, hydrodynamic dispersion and time-dependent phosphorus sorption are accounted for in the model formulation. Time-dependent sorption of soil-P is considered to follow the two consecutive reaction model of Barrow and Shaw (J. Soil Sci. 30, 67-76, 1979) which has been extensively tested against experimental data and can be described by S = k.C(n)t m. The assumed sorption model allows parameters to be obtained by independent batch and column experiments. A numerical technique is used to solve the solute transport equation incorporating a correction to numerical dispersion to improve the numerical solution. An analytical solution for a simplified case is also presented to test the numerical technique. Parameter sensitivity analysis shows that influent concentration and the parameter k strongly affect the initial breakthrough time of solute, with m and n affecting the shape of the breakthrough curve. Preliminary investigations show that the applicability of the model to describe column experimental breakthrough curves is promising.
A model is presented for one-dimensional transport of phosphorus (P) in soils and groundwater. Convective transport, hydrodynamic dispersion and time-dependent phosphorus sorption are accounted for in the model formulation. Time-dependent sorption of soil-P is considered to follow the two consecutive reaction model of Barrow and Shaw (J. Soil Sci. 30, 67-76, 1979) which has been extensively tested against experimental data and can be described by S = k · C nt m. The assumed sorption model allows parameters to be obtained by independent batch and column experiments. A numerical technique is used to solve the solute transport equation incorporating a correction to numerical dispersion to improve the numerical solution. An analytical solution for a simplified case is also presented to test the numerical technique. Parameter sensitivity analysis shows that influent concentration and the parameter k strongly affect the initial breakthrough time of solute, with m and n affecting the shape of the breakthrough curve. Preliminary investigations show that the applicability of the model to describe column experimental breakthrough curves is promising.