Macrolepiota-mediated synthesized silver nanoparticles as a green corrosive inhibitor for mild steel in re-circulating cooling water system.

A simple, cost effective and eco-friendly silver nanoparticle (AgNPs) was synthesized by wild edible Macrolepiota mushroom. Nanoparticles were characterized by UV-visible, FTIR, XRD analysis and TEM analysis. The characterized studies confirmed the spherical shape of AgNPs with 20-50 nm size. Biocorrosion efficacy of myco-synthesized AgNPs and the mushroom extract were tested against mild steel by corrosive bacteria Bacillus thuringiensis EN2, Terribacillus aidingensis EN3 and Bacillus oleronius EN9. Weight loss analysis, EIS, and surface analysis were used to evaluate the corrosion inhibition efficiency of mild steel in various experimental systems. Reduced corrosion rate (0.07 mm/y, 0.14 mm/y), reduced weight loss (0.006 ± 2, 0.011 ± 2) and increased corrosion inhibition efficiency (59%, 18%) were identified in both system II and system IV. Peak intensity was reduced in both surface analysis studies (FTIR and XRD) in the presence of mushroom extract and AgNPs. EIS studies reveal that the mushroom extract and AgNPs act as a corrosive green inhibitor and adsorbs on the mild steel surfaces in cooling water tower system, which are responsible for corrosion protection.