A novel approach for textile dye degradation by zinc,iron–doped tin oxide/titanium moving anode

The present contribution reports a moving iron (Fe), zinc (Zn)–doped tin oxide/titanium (SnO₂/Ti) anode-based system designed and operated for the electro-oxidation of methyl orange dye effluent. Electrochemical oxidation of the dye was carried out at a current density of 1.8 A/dm² for 120 min. Similar experiments were repeated with pure SnO₂-based static and moving anode-based systems and the Fe, Zn-doped SnO₂ static anode-based electro-oxidation system. Post oxidation, the surface of the electrodes was critically examined by scanning electron microscopy. Dye samples were analysed at regular intervals during the electro-oxidation process by chemical oxygen demand and colour removal measurements and characterized by UV–Vis spectroscopy and Fourier transform infrared spectroscopy at the end of the oxidation process. The obtained results elucidate the superiority of Fe, Zn-doped SnO₂/Ti moving anode-based system for methyl orange dye effluent electro-oxidation. The moving anode prevents passive layer formation and decreases polarization resistance. Doping of Fe and Zn provides the anode-enhanced mechanical strength and electrocatalytic activity. The combined effects of axial anode movement and doping are responsible for improved performance of the moving anode system reported in this contribution.     

Antibiotic resistant pathogens versus human impacts: a study from three eco-regions of the Chennai coast, southern India

We assessed the occurrence of pollution indicators and antibiotic resistant bacterial isolates from water and sediment samples of three different eco-regions of the Chennai coast between March - May of 2010. Total of 960 bacterial strains belonging to four genera were isolated which show the highest frequencies of resistance to vancomycin (53.6%) and penicillin (52.6%) (except Enterococcus sp., which is highly resistant to erythromycin) and lowest frequencies of resistance to chloramphenicol (3.43%), ciprofloxacin (3.95%), gentamicin (4.68%), and tetracycline (6.97%). The E. coli, Vibrio sp., Salmonella sp. and Enterococcus sp. show high frequency of resistance to 2-5 antibacterials of 60.4%, 45.83%, 69.16% and 46.6%, respectively. High pollution indices (PI - 6.66-14.06) and antibiotic resistance indices (ARI - 0.29-0.343) indicate that the coastal environment is highly exposed to antibiotic sources that suggesting to avoid direct contact.