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Heavy Metal Displacement in a Sandy Soil at the Field Scale: II. Modeling
Author(s) -
Streck Thilo,
Richter Jörg
Publication year - 1997
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1997.00472425002600010009x
Subject(s) - sorption , soil science , monte carlo method , dispersion (optics) , leaching (pedology) , cadmium , chemistry , soil water , environmental science , mathematics , physics , adsorption , statistics , organic chemistry , optics
Although several studies have tested leaching models on field‐scale data, a comparable case study on heavy metal transport has not yet been undertaken. Data concerning heavy metal displacement after 29 yr of controlled wastewater irrigation were used to compare several simple modeling approaches to predict total and solution phase concentration profiles in the soil. Approaches employed comprise parallel soil column (PSC) models and the application of the convection dispersion equation at the field scale (CD). The PSC simulations were either realized by one‐dimensional (ID) simulations at points in the field where soil properties had been determined experimentally (grid model; GM) or by the Monte‐Carlo (MC) method. Sorption was described with an extended Freundlich equation as a function of the spatially variable soil properties organic C content and pH. The CD simulations were based on conventional sorption isotherms of mixed samples determined in laboratory batch experiments. Cadmium profiles predicted by the PSC models agree very well with measured profiles, while leaching of Zn was somewhat underestimated. Grid model and MC simulations yielded largely similar results if correlation of random variables was considered in the MC simulations. In the PSC simulations no parameters were fitted to the measured concentration profiles. Agreement between CD simulations and measured data could only be achieved by adjusting the dispersion length to a value in the upper range of values found in the literature.