The Biocidal Efficacy of Tetrakis-hydroxymethyl Phosphonium Sulfate (THPS) Based Biocides on Oil Pipeline PigRuns Liquid Biofilms

Abstract

The biocidal efficacy of THPS on oil pipeline biofilms was determined by direct MPN counts of SRB and APB after incubations at various concentrations of THPS for 14 days and also by its inhibitory effects on functional group activities of some oil field microorganisms. THPS was unable to drastically inhibit SRB growth at lower concentrations (0.1–0.3%) but its selective action on the activities of the hNRB and so-NRB further inhibits SRB growth and prevents sulfide formation at lower concentrations (0.2–0.3%). It was also observed that sulfide formation occurred at relatively high concentration of SRB (>10⁶ cells/mL) at 0.1% THPS concentration.

Keywords:

• THPS
• biofilms
• biocidal efficacy
• SRB
• APB
• hNRB
• soNRB