Electrokinetic Remediation of Organic Soil Polluted with Petroleum Products in Temperate and Cold Regions

• Main Author: Ghanami, Shayan
• Format: Thesis
• Language: English
• Published: 2023
• Subjects: Ice; permafrost
• Online Access: https://spectrum.library.concordia.ca/id/eprint/992809/; https://spectrum.library.concordia.ca/id/eprint/992809/1/Ghanami_MASc_S2023.pdf

Global warming leads to the thawing of ice caps in cold regions like Canada's northern territories, which are predominantly covered with permafrost. Its active top layer contains different fractions of organic matter and clay. More frequent use of shipping routes increases the risk of northern soil pollution. One group of common pollutants, originating from pipeline spills or various leakage, are light hydrocarbons. Soil pollution affects the sensitive northern environment. Effective soil remediation necessitates a comprehensive understanding of soil properties to implement an appropriate remediation method tailored to the specific soil characteristics and the challenging climatic conditions in northern territories. A series of laboratory tests were conducted to evaluate the feasibility of electrokinetic (EK) soil remediation on organic soils in cold-tempered regions. The study involved four distinct soil compositions to determine the efficacy of EK transport within organic matter (3%, 16%, and 35% w/w) containing soil. The soil was polluted with toluene and exposed to a constant low DC voltage gradient. To optimize electrokinetic remediation, a daily injection of surfactant was conducted. The tests were carried out continuously over a period of four days without anolyte, and one day including electroosmotic discharge collecting both anolyte and catholyte. The study was conducted in ambient (20°C) and cold temperatures (7°C) to simulate temperate and cold environments. The results showed the feasibility of light hydrocarbons removal from organic soils, while EK transport was more effective under low temperatures. Soil changed properties and pH gradient was observed between the anode and cathode. Furthermore, extracted liquids indicated some dissolutions of humic substances present in organic soil.