RESUMO
This paper analyses the capacity of the rape (Brassica napus) to extract Cd and Zn from the soil and the effect of these metals on the morphometric parameters of the plant (length, weight, surface area, fractal dimension of leaves). Rape plants were mostly affected by the combined toxicity of the Cd and Zn mixture that caused a significant reduction in the rate of seed germination, the plant biomass quantity and the fractal dimension. In the case of Cd soil pollution, the bioaccumulation factor (BAF), bioaccumulation coefficient (BAC) as well as the heavy metal root-to-stalk translocation factor (TF) were determined. The results showed that B. napus had a great potential as a cadmium hyperaccumulator but not as an accumulator of Zn or Cd + Zn mixture. The efficiency of phytoextraction rape was 0.8-1.22 % for a soil heavily polluted with cadmium.
Assuntos
Brassica napus/metabolismo , Cádmio/metabolismo , Poluentes do Solo/metabolismo , Zinco/metabolismo , Biodegradação Ambiental , Biomassa , Brassica napus/efeitos dos fármacos , Brassica napus/crescimento & desenvolvimento , Cádmio/toxicidade , Germinação/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Caules de Planta/efeitos dos fármacos , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/metabolismo , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Poluentes do Solo/toxicidade , Zinco/toxicidadeRESUMO
Layered zirconium phosphate (ZP) that bears fluorinated alkyl chains bonded covalently to the layers (ZPR) was used as a nanofiller in membranes based on a short-side-chain perfluorosulfonic acid (PFSA) to mechanically reinforce the PFSA hydrophobic component. Compared to the pristine PFSA, membranes with a ZPR loading up to 30 wt% show enhanced mechanical properties, and the largest improvement of elastic modulus (E) and yield stress (σY ) are observed for the 10 wt% ZPR membrane: ΔE/E up to 90% and ΔσY /σY up 70% at 70°C and 80% relative humidity (RH). In the RH range 50-95%, the in-plane conductivity of the composite membranes reaches 0.43â S cm(-1) for 10 wt% ZPR at 110°C and is on average 30% higher than the conductivity of the pristine PFSA. The 10â wt % ZPR membrane is as hydrated as the neat PFSA membrane at 50% RH but becomes progressively less hydrated with increasing RH both at 80 and 110°C. The fuel cell performance of this membrane, at 80°C and 30% RH, is better than that of the unmodified PFSA.