Electrically induced displacement transport of immiscible oil in saline sediments

Sibel Pamukcu; Reena A Shrestha; Alexandra B Ribeiro; Eduardo P Mateus

doi:10.1016/j.jhazmat.2016.04.005

Electrically induced displacement transport of immiscible oil in saline sediments

J Hazard Mater. 2016 Aug 5:313:185-92. doi: 10.1016/j.jhazmat.2016.04.005. Epub 2016 Apr 4.

Authors

Sibel Pamukcu¹, Reena A Shrestha², Alexandra B Ribeiro³, Eduardo P Mateus⁴

Affiliations

¹ Department of Civil and Environmental Engineering, Lehigh University, Bethlehem, PA 18015, USA. Electronic address: sp01@lehigh.edu.
² Department of Civil and Environmental Engineering, Lehigh University, Bethlehem, PA 18015, USA; Department of Chemistry, Towson University, Towson, MD 21252, USA.
³ CENSE-Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
⁴ Department of Civil and Environmental Engineering, Lehigh University, Bethlehem, PA 18015, USA; CENSE-Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.

PMID: 27064863
DOI: 10.1016/j.jhazmat.2016.04.005

Abstract

Electrically assisted mitigation of coastal sediment oil pollution was simulated in floor-scale laboratory experiments using light crude oil and saline water at approximately 1/10 oil/water (O/W) mass ratio in pore fluid. The mass transport of the immiscible liquid phases was induced under constant direct current density of 2A/m(2), without water flooding. The transient pore water pressures (PWP) and the voltage differences (V) at and in between consecutive ports lined along the test specimen cell were measured over 90days. The oil phase transport occurred towards the anode half of the test specimen where the O/W volume ratio increased by 50% over its initial value within that half-length of the specimen. In contrast, the O/W ratio decreased within the cathode side half of the specimen. During this time, the PWP decreased systematically at the anode side with oil bank accumulation. PWP increased at the cathode side of the specimen, signaling increased concentration of water there as it replaced oil in the pore space. Electrically induced transport of the non-polar, non-conductive oil was accomplished in the opposing direction of flow by displacement in absence of viscous coupling of oil-water phases.

Keywords: Coastal contamination; Crude oil; Electro-kinetics; Electroosmotic pumps; Environmental mitigation; Mass transport.