Sharif Digital Repository

This research demonstrates the feasibility to enhance solar disinfection (SODIS) treatment by addition of peroxymonosulfate (PMS) and peroxydisulfate (PDS) by the generation of sulfate (and hydroxyl) radicals through different activation routes. The different promoters were i) sunlight irradiation, ii) mild heat (40 °C), and iii) μM amounts of Fe2+, all present during actual field SODIS experiments, or voluntarily added alongside PMS/PDS. In a first approach, the promoters were studied separately, in pairs and finally all together in a combined process (CP). In all the cases, PMS showed a higher efficiency than PDS in E. coli removal, requiring lower concentration and a faster reaction time... 

Bacterial toxicity of graphene nanosheets in the form of graphene nanowalls deposited on stainless steel substrates was investigated for both Gram-positive and Gram-negative models of bacteria. The graphene oxide nanowalls were obtained by electrophoretic deposition of Mg2+-graphene oxide nanosheets synthesized by a chemical exfoliation method. On the basis of measuring the efflux of cytoplasmic materials of the bacteria, it was found that the cell membrane damage of the bacteria caused by direct contact of the bacteria with the extremely sharp edges of the nanowalls was the effective mechanism in the bacterial inactivation. In this regard, the Gram-negative Escherichia coli bacteria with an...