Exploration of the reactivity of nanoscale zero-valent iron (NZVI) associated nanoparticles in diverse experimental conditions

Abstract

The bimetallic nanoparticles have been used to improve the reactivity of Nanoscale Zero-Valent Iron (NZVI) during environmental contamination remediation. The main objective of this research was to determine the reactivity of the metal-doped NZVI (bimetallic) nanoparticles in aqueous solutions. In this study, FeCu, FeNi and FeAg bimetals were synthesized through the chemical reduction of ferric chloride with sodium borohydride then deposition of 1% (wt/wt) of the corresponding metal. The reactivity of these bimetallic nanoparticles in specific reaction conditions being; temperature, oxygen supply, pH, dosage and interferences (nitrate and phosphate) was studied. The results revealed that more iron dissolution was in acidic pH, high dosage (3 g/L) and continuous oxygen supply. Furthermore, nitrate was removed more in alkaline pH due to co-precipitation whereas phosphate was adsorbed more in acidic pH due to the positively charged surface that attracts negatively charged species. FeCu, FeNi and FeAg showed the best dissolution of iron in 90 °C, 5 °C and 25 °C respectively. Loaded metals (Cu, Ni, Ag) catalyzed NZVI reaction, promoted electrons’ transfer and minimized oxidation.