No abstract

No abstract

View related articlesView Crossmark data Citing articles: 4 View citing articlesEvaluation of antioxidant and antibacterial activities of methanolic extract of medlar (Mespilus germanica L.) leaves

No abstract

Biosorption is a suitable heavy metal remediation technique for the treatment of aqueous effluents of large volume and low pollutant concentration. However, today industrial applications need the selection of efficient low-cost biosorbents. The aim of this work is to investigate brown alga such as Fucus serratus (FS) as a low-cost biosorbent, for the fixation of metallic ions, namely Cu(2+), Zn(2+), Pb(2+), Ni(2+), Cd(2+) and Ce(3+), in a batch reactor. Biosorption kinetics and isotherms have been performed at pH 5.5. For all of the studied metallic ions, the equilibrium time is about 450 min and a tendency based on the initial sorption rate has been established: Ce(3+) > Zn(2+) > Ni(2+) > Cu(2+) > Cd(2+) > Pb(2+). The adsorption equilibrium data are well described by the Langmuir equation. The sequence of the maximum adsorption capacity is Pb(2+) approximately equal Cu(2+) >> Ce(3+) approximately equal Ni(2+) > Cd(2+) > Zn(2+) and values are ranged between 1.78 and 0.71 mmol g(-1). These results indicate that the FS biomass is a suitable biosorbent for the removal of heavy metals from wastewater and can be tested in a dynamic process. The selected pilot process involves a hybrid membrane process: a continuous stirred tank reactor is coupled with a microfiltration immersed membrane, in order to confine the FS particles. A mass balance model is used to describe the adsorption process and the breakthrough curves are correctly modelled. Based on these results, it is demonstrated that FS is an interesting biomaterial for the treatment of water contaminated heavy metals.

To assess the potential of Pb+2 accumulation in different parts of Acacia victoria, one year old A. victoria seedlings were exposed to Pb2+(NO3)2 in 5 different concentrations: 0, 50, 250, 500 and 1000 (mg Pb2+ L(-1)) for 45 days. Subsequently, Pb2+ uptake was quantified in roots, shoots and leaves of the seedlings by Atomic Absorption Spectroscopy (AAS). In addition, some physiological parameters such as biomass production, shoots and roots length, plant appearance, tissue concentrations and chlorophyll content were examined. Tissue concentrations increased as Pb2+ concentration increased for A. victoria. The visible toxicity symptoms (chlorosis and necrosis) appeared only to the highest concentration (1000 mg Pb2+ L(-1)), resulting in photosynthesis decrease, plant height, root length and dry biomass reduction. Almost 70% (up to 3580 mg Kg(-1) of dry tissue) from the Pb2+ was accumulated in the entire plant tissues was retained in the roots in the seedlings exposed to 1000 mg Pb2+ L(-1). The seedlings accumulated between 403 to 913 mg Kg(-1) of Pb2+ in shoots and 286 to 650 mg Kg(-1) of Pb2+ in leaves at different treatments. Bioconcentration and translocation factors were determined 5.14 and 0.255, respectively. The results show that A. victoria is suitable for lead-phytostabilization in Pb(2+) -contaminated soil.

The antioxidant and antibacterial activities of six edible plants were evaluated. The active constituents of the edible plants were extracted using boiling water or 80% methanol. Results demonstrated that extraction of antioxidants by boiling water was more efficient. Lycium depressum and Berula angustifolia had the highest antioxidant activities and, therefore, could be rich sources of natural antioxidants. The antibacterial activities of the extracts were tested against Staphylococcus aureus, Escherichia coli, Entrococcus faecalis and Proteus mirabilis. Further research is needed to isolate, characterize, and identify the bioactive compounds present in these plants.

No abstract