Azadirachta indica leaves extract as inhibitor for microbial corrosion of copper by Arthrobacter sulfureus in neutral pH conditions-A remedy to blue green water problem

Abstract

Copper corrosion by the action of aerobic A. sulfureus in neutral medium was investigated. The bacteria form biofilm and colonize on the copper metal surface resulting in corrosion leading to blue green colour water. A. indica (neem) leaf extract was found to be effective in inhibiting the growth of the bacteria and thus help in preventing the corrosion. The copper coupons immersed for different durations in media with and without neem leaf extract were tested for their weight loss to study the corrosion rate. The copper biocorrosion was also investigated using electrochemical impedance spectroscopy and potentiodynamic polarization studies. The morphology of the films formed on the metal surface in different media at different immersion times were studied using scanning electron microscopy. © 2016 Taiwan Institute of Chemical Engineers.