Narrow Results

Radionuclides pose a serious threat to both human and environmental health if they are present in the environment. Radioactive waste is produced and released into the environment, both naturally and artificially. Exposure to this waste could lead to severe and potentially fatal illnesses in people. Radionuclide-contaminated habitats host several microbial species that develop a high degree of tolerance to these elements through mechanisms such as biosorption, biotransformation, biomineralization, and intracellular accumulation. These mechanisms involving interactions between microbes and radionuclides have the potential to be used in biotechnology for designing solutions to address various contamination problems through bioremediation. Bioremediation has been proven to be more ecofriendly than physical remediation for the environment. Microorganisms possess inherent genetic, metabolic, and physiological characteristics that render them highly suitable for the purpose of pollutant remediation in soil and groundwater. Microorganism-aided bioremediation can impact the solubility, bioavailability, and mobility of radionuclides. This study presents a comprehensive analysis of several reports in an attempt to understand how microorganisms interact with radioactive substances and how they withstand the effects of ionizing radiation. The review incorporates a multidisciplinary approach and provides an assessment of the current status of research in this field.

Inquiries comparatively was carried out on the ability of biosorption of copper and zinc for the biomass of Phanerochaete chrysosporium UCP 963 and Cunninghamella elegans UCP 596. The strain of C. elegans showed ability to removal of heavy metals in the concentration of 4 mM with incomes of 55% of removal of copper, and 51% of zinc, respectively, and in the concentration of 6 mM zinc was removed 53% and copper 57%, all the treatment using 120 mg of the biomass. The inactivated biomass of P. chrysosporium was more efficient in the copper removal in the concentration of 6 mM with results of 45% of removal and in both zinc concentrations (4 and 6 mM) it presented a sorption of 59-63 %, respectively, during 480 minutes. The results demonstrate that inactivated biomass and/or live biomass of P. chrysosporium and C. elegans presents ability of removal of copper and zinc.

In this work, a novel adsorbent to adsorbed Cd(Ⅱ) from aqueous solution was prepared by immobilized persimmon tannin (PT) on chitosan(CS). The maximum adsorption capacity reached 126 mg/g at 303 K and pH 6.0 when the initial concentration of Cd(II) was 100 mg/L. The Freundlich model and the pseudo-second-order model can well fit to explain its adsorption isothermal and kinetic data, respectively. All these results indicated that the PTCS biosorbent could be used as a low-cost alternative for the adsorption of Cd(II) in waste-water treatment.

Azo dyes are extensively used for coloring textiles, paper, food, leather, drink, pharmaceutical products, cosmetics and inks. The textile industry consumes the largest amount of azo dyes, and it is estimated that approximately 10 – 15% of dyes used for coloring textiles might be lost in waste streams. Almost all azo dyes are synthetic and resist biodegradation, however, they can be readly reduced by a number of chemical and biological reducing systems. Biological treatment is advantageous over physical and chemical method as result of its low cost and little disturbance to the environment. This research focuses on the utilization of Aspergillus oryzae, to remove some kinds of azo dyes from aqueous solutions. The fungi, physically induced in its paramorphogenic form (called, “pellets”),were used in the dyes biosorption studies with both non autoclave and autoclaved hyphas, at differents pH values. Thus the goals are the removal of dyes by biosorption and the decrease of its toxicity.