Stabilization of bacterial cells culture on immobilized Alginate beads and optimization of Congo red decolorization

544-552The paper deals with the primary objective to optimize different parameters such as concentration, temperature, pH, time and size of cells for the decolorization of azo dye (Congo red) by using bacterial isolates by the method of immobilized bacterial cells. Staphylococcus aureus immobilized beads show a maximum dye decolorization of 94% under optimum condition and found to be more efficient in dye decolorization. The optimum value for degradation is found to be 35°C, for 400 mg/L of concentration of dye at the medium pH of 7. The order of the reaction was found to be first order with the rate constant of 0.073 h-1. The dye adsorbed on the bead surface follows Freundlich adsorption isotherm with the constant values are K = 1.368 and 1/n = 0.773. Studies have been carried out by FTIR, GC-MS analysis for confirming the biodegradation of Congo Red by the immobilized bacterial cells. The results reported warrant further investigation to establish the usefulness of these isolates for bioremediation and biodegradation application such as wastewater treatment

Stabilization of bacterial cells culture on immobilized Alginate beads and optimization of Congo red decolorization

The paper deals with the primary objective to optimize different parameters such as concentration, temperature, pH, time and size of cells for the decolorization of azo dye (Congo red) by using bacterial isolates by the method of immobilized bacterial cells. Staphylococcus aureus immobilized beads show a maximum dye decolorization of 94% under optimum condition and found to be more efficient in dye decolorization. The optimum value for degradation is found to be 35°C, for 400 mg/L of concentration of dye at the medium pH of 7. The order of the reaction was found to be first order with the rate constant of 0.073 h-1. The dye adsorbed on the bead surface follows Freundlich adsorption isotherm with the constant values are K = 1.368 and 1/n = 0.773. Studies have been carried out by FTIR, GC-MS analysis for confirming the biodegradation of Congo Red by the immobilized bacterial cells. The results reported warrant further investigation to establish the usefulness of these isolates for bioremediation and biodegradation application such as wastewater treatment

One-Step Fabrication of Amino-Functionalized Fe₃O₄@SiO₂ Core-Shell Magnetic Nanoparticles as a Potential Novel Platform for Removal of Cadmium (II) from Aqueous Solution

Fe3O4@SiO2-NH2 core-shell magnetic nanoparticles were developed by a rapid one-step precipitation route followed by reverse microemulsion and amine functionalization. In this study, an Fe3O4@SiO2-NH2 nanoparticle was used to evaluate its adsorption efficiency for the treatment of a synthetic solution of Cd(II) ion. The structural and physicochemical properties of Fe3O4@SiO2-NH2 nanoparticles were characterized by XRD, SEM-EDAX, TEM, FTIR and TGA. From the TEM analysis, the morphology of Fe3O4@SiO2-NH2 was found as 100–300 nm. In TGA, the first weight loss was noticed between 373 and 573 K, the second was between 673 and 773 K and the final weight loss took place above 773 K. Batch experimental tests, such as pH, dosage of Fe3O4@SiO2-NH2, Cd(II) ion concentration, temperature as well as interaction time, were conducted and evaluated. Experimental study data were used for the non-linear forms exhibited by isotherms and kinetics of the sorption procedure. The equilibrium adsorption observations were adequately combined with pseudo-first-order kinetics as well as Freundlich isotherm. Monolayer maximum adsorption capacity was found to be 40.02 mg/g, recorded at pH 6 with an interaction time of 30 min, temperature of 303 K and sorbent dose of 2.0 g/L. The thermodynamic study indicated that the adsorption process was an exothermic, spontaneous reaction (−∆oo = −15.46–7.81 (kJ/mol)). The as-synthesized sorbent had excellent recyclability, and its adsorption efficiency was maintained after five cycles of reuse. The findings of the study exhibited the magnetic Fe3O4@SiO2-NH2-nanoparticle as an alternative effective adsorbent in eradicating Cd(II) ions from aqueous solution