Phosphorus fate and transport in soil columns loaded intermittently with influent of high phosphorus concentrations.
In this study, several columns of different lengths were filled with composite soils sampled from the field at corresponding depths and then loaded intermittently with influent of a high phosphorus concentration to evaluate phosphorus fate and transport in soil. The results indicate that the height of the mass transfer zone, solvent pore velocity, and soil's life expectancy for phosphorus removal increased with depth, while the retained phosphorus per kilogram of soil and the linear adsorption equilibrium coefficient, R, decreased with depth. An equation was developed to link liquid-phase phosphorus with solvent traveling time and soil depth. The results of X-ray diffraction and washout tests indicate that calcium-phosphorus precipitation and/or crystal growth occurred in the columns. The new protocol is useful for evaluation of phosphorus fate and transport in other subsurface systems, because it allows flexible adjustments in hydraulic loadings, feed solution, and sampling schemes.
Zhang
Tian C
TC
Civil Engineering Department, University of Nebraska-Lincoln, Omaha, NE 68182-0178, USA. tzhang1@unl.edu
Dahab
Mohamed F
MF
Nunes
Germana S
GS
Hu
Cong
C
Surampalli
Rao
R
D000327:Adsorption; D004784:Environmental Monitoring / Q000379:methods*; D008956:Models, Chemical; D010758:Phosphorus / Q000737:chemistry*; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry*; D012997:Solvents; D014961:X-Ray Diffraction
D012987:Soil; D012989:Soil Pollutants; D012997:Solvents; D010758:Phosphorus