Modeling uptake kinetics of cadmium by field-grown lettuce.

Department of Environmental Sciences, University of California, 900 University Avenue, Riverside, CA 92521, USA.
Environmental Pollution (Impact Factor: 3.73). 04/2008; 152(1):147-52. DOI: 10.1016/j.envpol.2007.05.004
Source: PubMed

ABSTRACT Cadmium uptake by field grown Romaine lettuce treated with P-fertilizers of different Cd levels was investigated over an entire growing season. Results indicated that the rate of Cd uptake at a given time of the season can be satisfactorily described by the Michaelis-Menten kinetics, that is, plant uptake increases as the Cd concentration in soil solution increases, and it gradually approaches a saturation level. However, the rate constant of the Michaelis-Menten kinetics changes over the growing season. Under a given soil Cd level, the cadmium content in plant tissue decreases exponentially with time. To account for the dynamic nature of Cd uptake, a kinetic model integrating the time factor was developed to simulate Cd plant uptake over the growing season: C Plant=C Solution.PUF max.exp[-b.t], where C Plant and C Solution refer to the Cd content in plant tissue and soil solution, respectively, PUF max and b are kinetic constants.

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