Immobilization of P. stutzeri on Activated Carbons for Degradation of Hydrocarbons from Oil-in-Saltwater Emulsions

Abstract

Production water is the largest byproduct of the oil industry and must be treated before disposal, either by reinjection or shedding processes, with the purpose of eliminating emulsified crude oil and avoiding the operational and toxic problems associated with it. The objective of this work was to immobilize a hydrocarbon-degrading strain on activated carbons, to evaluate the biocomplex’s capacity for catalyzing hydrocarbons from Oil in Brine emulsions (O/W) simulating produced waters. Activated carbons were prepared and their chemical and porous properties were estimated by XPS, pHPZC and SEM, N2 adsorption, and mercury porosimetry. Biomaterials were synthesized and hydrocarbon removal tests were performed. The basic and neutral carbons immobilized Pseudomonas stutzeri by physisorption in the macroporous space and electrostatic interactions (108–109 UFC), while acid materials inhibited bacterial growth. Removal of aromatic hydrocarbons was more efficient using materials (60%–93%) and biomaterials (16%–84%) than using free P. stutzeri (1%–47%), and the removal efficiencies of crude oil were 22%, 48% and 37% for P. stutzeri and two biomaterials, respectively. The presence of minor hydrocarbons only when P. stutzeri was present confirmed the biotransformation process.