Modelling the Plant Uptake of Metals from Release Rates Obtained by the EUF Method

Abstract

In this study, soil dissolution kinetics were evaluated to predict the metal uptake of lettuce plants under varying conditions of fertilisation and metal pollution. Velocities and time dependencies of soil dissolution obtained by electro-ultrafiltration (EUF), which prevents back reaction, were modelled in three ways, obtained from suspensions in 0.002 M DTPA at determined soil pH levels, for cases in which sampling versus time led to decreasing concentrations. The models yielded a maximum achievable concentration, a timespan needed for it to be reached, a slope, and an intercept of the respective fitted curves. Three geogenically metalliferous soil samples and one ambient soil sample, both as originals, fertilised with PK or soaked with a Cd-Ni-Pb solution, were used as solid samples. The resulting kinetic parameters were correlated with the amounts absorbed by lettuce plants grown with these substrates in pot experiments, which yielded fairly good correlations with Zn, but also with Li and Sr, as well as Ni and Pb, mainly because of differences due to the addition of a metallic salt solution. Plant growth was hardly influenced by the additions.

Investigating the Sorption/Desorption of the Cationic Herbicide Paraquat in Clay Minerals Using Batch and Electro–Ultrafiltration Techniques

“…A useful technique to obtain both quantitative and kinetics information on nutrient availability is electro-ultrafiltration (EUF), introduced by Németh [23] as a multiple-element soil test to determine nutrient availability to plants. Over the years, the application of this technique has been extended, for example, to the modelling of plant uptake of metals [24], the reduction of membrane fouling in industrial processes [25][26][27], and the removal of heavy metals from water [28]. EUF involves a combination of electrodialysis and ultrafiltration to remove electrolytes from aqueous suspensions under controlled electrical field strength and temperature [29,30].…”