Abstract:
BACKGROUND:Sulfate-reducing bacteria (SRB) are considered to be themajor cause ofmicrobial-induced corrosion. It contributes to many environmental and other costly industrial problems in the petroleum industry. Thus there is always a great need for producing new efficient biocides and biocorrosion inhibitors. RESULTS: In this work, three Schiff base surfactants (coded Q12, Q14 and Q18) were synthesized and characterized using Fourier transform infrared and 1H-nuclear magnetic resonance techniques. A mixed culture of SRB was collected from an oil field production tank located at the North Bahrya Petroleum Company (NORPETCO), Egypt. The antimicrobial effect of the newly synthesized surfactants was studied against sessile and planktonic SRB over their different growth phases by various methods: viable cell count via most probable numbermethod,estimation ofbiogenic sulfideconcentrations, weight lossof iron coupons in microbial growthmediumandbiofilmexaminationoncouponsurfacesusingscanningelectronmicroscopy.Thesynthesized surfactants expressed a high inhibition effect on bacterial growth, recording a minimum inhibitory concentration of 750 mg L−1for Q18and1000 mg L−1for both Q12andQ14, with a considerable decline in biogenic sulfide productivity from a dose of 500 mg L−1 until complete suppression at a dose of 1000 mg L−1. Also the synthesized surfactants showed an effective metal corrosion inhibition at a concentration of 500 mg L−1. CONCLUSION:Schiffbasecationicsurfactantswithlonghydrophobicchainscanberecommendedasbiocorrosioninhibitorsfor industrial application in the petroleum sector. ©2020 Society of Chemical Industry (SCI)