synthesis and characterization of zero-valent iron nanocomposites based on granular activated carbon using walnut leaf extract reducer

Nanoscale zero-valent iron (nzvi) is one of the most effective materials recently used to remove heavy metals from water# however, their tendency to aggregation and rapid oxidation reaction is one of the major drawbacks reported in the literature# in other words, the rapid reduction of impurities, especially cations in water, is an important feature of zero valent iron# in order to revive iron particles during synthesis, sodium borohydride is usually used to as a strong reducer# due to the problems of this chemical matter, green synthesis method was used in this study# walnut leaf extract is capable of easily reducing iron cation to zero-valent iron due to its polyphenolic materials# therefore, in this study, nzvi particles were produced using walnut leaf extract as a green reducer and stabilizer# then nzvi particles were stabilized on the granular activated carbon (wl-nzvi/gac)# the characteristics of wl-nzvi/gac synthesized by (fe-sem) and (ftir) were studied# the main purpose of the production of this nanocomposite is to remove heavy metals present in contaminated water and wastewater# also, in this study, the isoelectric point of the nanocomposite was investigated# the results showed that the size of the produced iron nanoparticles was about 16#72-27#77 nm# it can be seen from the ftir spectrum that the polyphenols present in walnut leaf extract are responsible for the formation of wl-nzvi/gac# the ph at the zero charge point (phpzc) is 6#1-6#2, indicating that the adsorbent level of wl-nzvi/gac at ph lower than phpzc positive and at ph higher than phpzc negative#