Using Porous Nanofilters for Removal of Environmental Pollutants

Electrospinning is the most clear-cut and flexible method for 1D nanostructure production compared to other techniques. The most prominent feature of this method is formation of nanofibers with diameters down to tens of nanometers. In electrospinning method compared with other methods, due to the formation of very thin nanofibers, the surface-to-volume ratio of adsorbent increases greatly. In this study, high performance nanofilters were fabricated based on functionalized porous nanostructures with polyacrylonitrile (PAN) and polyvinylpyrrolidone (PVP) polymers using electrospinning method and theirs applications for removal dyes and metallic ions were investigated in aqueous solutions. Various parameters for the synthesis of nanofilters, such as precursor and adsorbent concentration, molecular mass of polymers, type and amount of additives, pH of solution, electrospinning distance, feed rate and voltage were optimized. The influence of effective factors on the filtration process, such as initial concentrations of dye and metallic ion, pH solutions and the amount of nanofilters were investigated. The nanofilters were characterized using scanning electron microscopy (SEM), Thermo Gravimetric-Differential Thermal Analysis (TG/DTA), FTIR, EDX and XRD analysis. Also UV-VIS spectrophotometer for investigating of dyes removing and Flame atomic absorption spectroscopy (Flame-AAS) for metallic ions removing were used. The results showed nanofilters had antibacterial properties and could minimize the dye pollutions associated with potassium permanganate and methylene blue; nanofilters recycling also indicate more than 90% removal of dyes. By investigating the filtration heavy metals in aqueous solutions, these nanofilters were able to remove more than 90% of heavy metals pollution . Filtration advantages with these nanofilters in comparison to other methods are: high speed in responsiveness, reproducibility, scalability, and high power of elimination of pollutions.