Non-Metabolic Uptake of Al3+by Dead Leaves ofRubus ulmifolius: Comparison With Metabolic Bioaccumulation Data: Water

This paper reports a physicochemical study (thermodynamic and kinetic data) describing the ability of Rubus ulmifolius biomass (dead leaves) for metal uptake. The toxicity of aluminium is a major problem for crops in acidic soils and therefore, aluminium has been selected. The results obtained indicate that dead R. ulmifolius leaves uptake up to 10 000 mg/kg on its surface in less than 60 min. This suggests that R. ulmifolius can be an excellent component with adsorbent properties for aquatic environments and in particular for amendments to be used in acidic soils in order to control aluminium levels, thus its toxicity. The results obtained have been critically analysed and compared with literature on aluminium bioaccumulation. The application of a pseudo-second order kinetic equation, not previously used in toxicity studies, is discussed. Moreover, a good linear correlation between stability constants for Al3+ complexes with several defined ligands and the Langmuir affinity constants obtained from the corresponding adsorption isotherm has been found. Therefore, in addition to its ethno-botanical relevance, applications of R. ulmifolius as a detoxifier for aluminium in a simulated acidic gastrointestinal fluid, as phytostabilization agent in amendments or in natural attenuation cycles or as biomass for wastewater treatment containing aluminium, are suggested.