Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment.Bio-sorption of heavy metals by metabolically inactive biomass of microbial organisms is an innovative and...Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment.Bio-sorption of heavy metals by metabolically inactive biomass of microbial organisms is an innovative and alternative technology for removal of these pollutants from aqueous solution.The search of marine actinobacteria with potential heavy metal biosorption ability resulted in the identification of a novel alkalophilic Streptomyces VITSVK5 species.The biosorption property of Streptomyces VITSVK5 spp.was investigated by absorbing heavy metals Cadmium (Cd) and Lead (Pb).Physiochemical characteristics and trace metal concentration analysis of the backwater showed the concentrations of different metals were lead 13±2.1 μg L-1,cadmium 3.1±0.3μg L-1,zinc 8.4±2.6μg L-1 and copper 0.3±0.1μg L-1,whereas mercury was well below the detection limit.The effect of pH and biomass dosage on removal efficiency of heavy metal ions was also investigated.The optimum pH for maximal biosorption was 4.0 for Cd (II) and 5.0 for Pb (II) with 41% and 84% biosorption respectively.The biosorbent dosage was optimized as 3 g L-1 for both the trace metals.Fourier transform infrared absorption spectrum results indicated the chemical interactions of hydrogen atoms in carboxyl (–COOH),hydroxyl (–CHOH) and amine (–NH2) groups of biomass with the metal ions.This could be mainly involved in the biosorption of Cd (II) and Pb (II) onto Streptomyces VITSVK5 spp.The results of our study revealed Streptomyces metabolites could be used to develop a biosorbent for adsorbing metal ions from aqueous environments.展开更多
Marine copepods, Acartia erythraea, were exposed separately to aqueous Cu and Ag media and to a Cu＋Ag mixture in a series of experiments during which the metal body burden and partitioning in the exoskeleton and pola...Marine copepods, Acartia erythraea, were exposed separately to aqueous Cu and Ag media and to a Cu＋Ag mixture in a series of experiments during which the metal body burden and partitioning in the exoskeleton and polar and nonpolar parts of the animal cells were measured and the uptake and effiux rate constants for Cu and Ag were calculated. The metal uptake and effiux rate constants were 1.04×10^3±1.00×10^2 L·g^-1·d^-1 and 9.28× 102＋ 1.43×10-2 d^-1 for Cu and 1.60× 104＋1.78×10^3L·g^-1·d^-1and 9.23×10^2 -4- 9.1 1×10^3d^-1 for Ag, respectively. For both Cu and Ag, the uptake rate constants when the copepods were exposed to solutions of a single metal were generally higher than that when the copepods were exposed to metal mixtures. The results suggest an antagonistic interaction between waterborne Cu and Ag exists in marine copepods. The different distributions of Cu and Ag among the exoskeleton and polar and nonpolar parts of the copepods revealed that the metal bioavailability in copepods exposed to metal mixtures enhanced in some degree compared to copepods exposed to single metal solutions.展开更多
文摘Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment.Bio-sorption of heavy metals by metabolically inactive biomass of microbial organisms is an innovative and alternative technology for removal of these pollutants from aqueous solution.The search of marine actinobacteria with potential heavy metal biosorption ability resulted in the identification of a novel alkalophilic Streptomyces VITSVK5 species.The biosorption property of Streptomyces VITSVK5 spp.was investigated by absorbing heavy metals Cadmium (Cd) and Lead (Pb).Physiochemical characteristics and trace metal concentration analysis of the backwater showed the concentrations of different metals were lead 13±2.1 μg L-1,cadmium 3.1±0.3μg L-1,zinc 8.4±2.6μg L-1 and copper 0.3±0.1μg L-1,whereas mercury was well below the detection limit.The effect of pH and biomass dosage on removal efficiency of heavy metal ions was also investigated.The optimum pH for maximal biosorption was 4.0 for Cd (II) and 5.0 for Pb (II) with 41% and 84% biosorption respectively.The biosorbent dosage was optimized as 3 g L-1 for both the trace metals.Fourier transform infrared absorption spectrum results indicated the chemical interactions of hydrogen atoms in carboxyl (–COOH),hydroxyl (–CHOH) and amine (–NH2) groups of biomass with the metal ions.This could be mainly involved in the biosorption of Cd (II) and Pb (II) onto Streptomyces VITSVK5 spp.The results of our study revealed Streptomyces metabolites could be used to develop a biosorbent for adsorbing metal ions from aqueous environments.
文摘Marine copepods, Acartia erythraea, were exposed separately to aqueous Cu and Ag media and to a Cu＋Ag mixture in a series of experiments during which the metal body burden and partitioning in the exoskeleton and polar and nonpolar parts of the animal cells were measured and the uptake and effiux rate constants for Cu and Ag were calculated. The metal uptake and effiux rate constants were 1.04×10^3±1.00×10^2 L·g^-1·d^-1 and 9.28× 102＋ 1.43×10-2 d^-1 for Cu and 1.60× 104＋1.78×10^3L·g^-1·d^-1and 9.23×10^2 -4- 9.1 1×10^3d^-1 for Ag, respectively. For both Cu and Ag, the uptake rate constants when the copepods were exposed to solutions of a single metal were generally higher than that when the copepods were exposed to metal mixtures. The results suggest an antagonistic interaction between waterborne Cu and Ag exists in marine copepods. The different distributions of Cu and Ag among the exoskeleton and polar and nonpolar parts of the copepods revealed that the metal bioavailability in copepods exposed to metal mixtures enhanced in some degree compared to copepods exposed to single metal solutions.
