Remediation of Oil Field Effluents Using Acid Base Foams
Cherukupally Pavani (1)*
(1) University of Toronto - Ontario - Canada
Separation of toxic organic pollutants from industrial effluents is a great environmental challenge.
Herein, an acid−base engineered foam is employed for separation of micro-oil droplets from an
aqueous solution. In acidic or basic environments, acid−base polymers acquire surface charge due
to protonation or dissociation of surface active functional groups. This property is invoked to
adsorb crude oil microdroplets from water using polyester polyurethane (PESPU) foam. The
physicochemical surface properties of the foam was characterized using X-ray photoelectron
spectrosco- py, inverse gas chromatography, electrokinetic analysis, and micro-computed
tomography. Using the surface charge of the foam and oil droplets, the solution pH (5.6) for
maximum separation efficacy was predicted. This optimal pH was verified through underwater
wetting behavior and adsorption experiments. The droplet adsorption onto the foam was governed
by physisorption, and the driving forces were attributed to electrostatic attraction and Lifshitz−van
der Waals forces. The foam was regenerated and reused multiple times by simple compression.
The lowest trace oil content in the retentate was 3.6 mg L−1
, and all oil droplets larger than 140
nm were removed. This work lays the foundation for the development of a new class of engineered
foam adsorbents with the potential to revolutionize water treatment technologies.