MECHANISTIC MODELING OF ANAEROBIC THPS DEGRADATION IN SEAWATER UNDER VARIOUS CONDITIONS

摘要

Microbially influenced corrosion (MIC) is increasingly becoming a major problem in the oil and gas industry as well as in the water treatment industry. Currently, MIC mitigation mostly depends on biocides. THPS (Tetrakis Hydroxymethyl Phosphonium Sulfate) is one of the commonly used biocides because it is degradable and non-bioaccumulative in the environment. Usually a minimum of 50 or 100 ppm THPS is needed to prevent planktonic bacterial growth and biofilm establishment. A much higher concentration is needed to remove established biofilms. THPS degradability, however, shortens its effectiveness in time. Prediction of THPS degradation is essential in proper dosing for operations such as hydrotesting. THPS degradation may be affected by many factors such as temperature, pH, O_2, light, presence of microbes and presence of mild steel. This work presents a mechanistic model, based on experimental data, to predict THPS degradation as a function of time, temperature and pH.