Original scientific paper
Development of some Models for Assessment the Dynamic Migration Processes of Phosphates in Soil Columns
Oanamari D. Orbulet
; University Politehnica of Bucharest, Faculty of Applied Chemistry and Material Science, Department for Inorganic Chemicals’ Technology and Environmental Protection, Polizu 1-7, 011061 Bucharest, Romania
Tudor Casandroiu
; University Politehnica of Bucharest, Faculty of Biotechnical Systems Engineering, Department for Biotechnical Systems, Splaiul Independentei 313, 060042 Bucharest, Romania
Gheorghe Voicu
; University Politehnica of Bucharest, Faculty of Biotechnical Systems Engineering, Department for Biotechnical Systems, Splaiul Independentei 313, 060042 Bucharest, Romania
Alexandra R. Miron
; University Politehnica of Bucharest, Faculty of Applied Chemistry and Material Science, Department for Inorganic Chemicals’ Technology and Environmental Protection, Polizu 1-7, 011061 Bucharest, Romania
Cristina Modrogan
; University Politehnica of Bucharest, Faculty of Applied Chemistry and Material Science, Department for Inorganic Chemicals’ Technology and Environmental Protection, Polizu 1-7, 011061 Bucharest, Romania
Abstract
Due to complexity of phosphate (P) migration in soil columns, the problem of theoretical approach of modeling the process is specially difficult. So, numerous semiempirical models based on admission of simplifying assumptions were developed, some of them being apart from the real phenomenon.
In this paper are presented the breakthrough curves, the phosphate (P) usage degree in soil, based on a dynamic study, realised in order to determine phosphate sorption rate on the granules of two soil types (cambic chernozem and psamosoil) from Romania. Due to random character of the process, which is influenced by many naturally variable factors, this can be addressed from stochastic point of view.
Experimental data regarding phosphate migration in soil column evolution process are represented like curves with sigmoid profile. Based on this observation, Rosin- Rammler and Schuhman sigmoid profile curves, known models and logistic type equations were used as simulation models representing phosphate transport and sorption kinetics for laboratory experiments in columns.
Testing the models with the experimental data resulted with the conclusion that the most appropriate models describing the process of phosphate migration in soil columns are Rosin-Rammler and logistic type equation, C = 1-exp(-btn) and C = [1+exp(α+βt)]-1, (C – relative concentration; t – time; b, n, α, β - constant coefficients determined from experimental data by non-linear regression) for which the correlation coefficient is R2 ≥ 0.983 for both types of soil.
Keywords
sorption of phosphates; mathematical model; soil; dynamic regime
Hrčak ID:
97501
URI
Publication date:
18.12.2012.
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