Abstract
Microbiologically influenced corrosion (MIC) is caused by problematic biofilms in many industries, especially the oil and gas industry. In this work, a novel peptide (labeled as “Peptide A”) was used to enhance tetrakis hydroxymethyl phosphonium sulfate (THPS) biocide to treat the corrosive sulfate reducing bacterium (SRB) Desulfovibrio vulgaris and a tough field biofilm consortium (labeled as “Consortium II”) on C1018 carbon steel coupons. This peptide was synthesized based on the active sequence derived from an anti-biofilm protein produced by a sea anemone. Only 10 nM Peptide A or 18 ppb (w/w) was used in the biofilm prevention test and 10 – 100 nM was tested in the biofilm removal test. The cocktail of 50 ppm THPS + 10 nM Peptide A achieved 2 extra log reduction of SRB sessile cell count in the 7-day biofilm prevention test compared with 50 ppm THPS treatment alone. In the 3-hour biofilm removal test that started with mature biofilms, the combination of 50 ppm THPS + 100 nM Peptide A achieved 2 extra log reduction compared with 50 ppm THPS treatment alone. Peptide A alone showed no log reduction in the mitigation of biofilm Consortium II. However, in the D. vulgaris biofilm removal test, 10 nM Peptide A achieved 1-log reduction and 100 nM achieved 2 logs.
