Transport of Heavy Metals in Materials With Diameter Analogous to Xylem Vessels

In vascular plants, the soil solution is transported from the roots to the leaves through small diameter vessels found in the xylem; this transport not only allows the nutrient uptake but also the accumulation of heavy metals in their shoots. By analogy to this phenomenon, the present study aimed at the evaluation of heavy metals transport (Pb, Cr, As, Cd, Zn, Ni and Al) in pH 4 and pH 8 solutions using a capillary siphon consisting of small pore diameter materials. Determination of the metal concentration in the solutions was performed by means of Inductively Coupled Plasma. The largest transport of metal ions is produced at pH 4, on ascending order, Cr < Pb=Al < As < Ni < Zn < Cd. Results showed that there is capillary transport of aqueous solutions with heavy metals in materials with pore diameter similar to that found in the xylem of plants. Some authors have argued that there is a remarkable similarity between soil and xylem, which makes possible the soil-plant-atmosphere system continuity; in this sense, the performance of the tested materials should be investigated under similar conditions to those present in the interface soil-xylem in a bid to replicate this continuity.