In the sprawling landscape of the energy sector, where pipelines crisscross the earth and refineries hum with activity, the silent threat of oil pollution lurks beneath our feet. Soil contamination by oil and its derivatives is not just an environmental concern; it’s a geotechnical challenge that can compromise the stability of structures built on contaminated land. A groundbreaking study led by M. Arabani, Professor at the Department of Civil Engineering, Faculty of Engineering, University of Guilan, Rasht, Iran, has shed new light on how different types of oil pollutants affect the compressibility properties of clayey sand, a common soil type in many construction sites.
The study, published in the journal Civil Engineering Sharif, delves into the intricate dance between oil pollutants and soil particles. Using a one-dimensional consolidation test and scanning electron microscopy (SEM), Arabani and his team investigated how four types of oil pollutants—used motor oil, crude oil, diesel, and kerosene—alter the compressibility of clayey sand. The findings are both alarming and enlightening.
“Oil pollutants don’t just sit there; they actively change the soil structure,” Arabani explains. “They increase the pore space between particles and facilitate water movement by covering the soil particles.” This alteration in soil structure leads to a decrease in the soil’s specific surface area (SSA) and water absorption, causing water to drain faster and ultimately increasing the compaction coefficient (CC), consolidation settlement, consolidation coefficient (CV), and permeability coefficient (k).
The viscosity of the oil pollutant plays a pivotal role in this geotechnical drama. Higher viscosity means larger clots and increased surface energy at the oil-water interface, which can hinder water drainage. “The highest compressibility belonged to the samples contaminated with kerosene,” Arabani notes, “followed by those infected with diesel, crude oil, and used motor oil.” This hierarchy of impact is a crucial piece of information for engineers and planners working in areas prone to oil contamination.
The commercial implications for the energy sector are significant. Understanding how different oil pollutants affect soil compressibility can inform better site selection, remediation strategies, and structural design. For instance, knowing that kerosene has the highest impact on compressibility can guide decisions on pipeline routes and refinery locations, potentially saving millions in repair and maintenance costs.
This research opens up new avenues for future developments in the field. Engineers can now design more resilient structures by accounting for the specific type of oil contamination. Remediation techniques can be tailored to counteract the unique effects of different oil pollutants. Moreover, this study underscores the need for ongoing research into the geotechnical impacts of environmental pollutants, a field that is as complex as it is critical.
As the energy sector continues to evolve, so too must our understanding of its environmental footprint. Arabani’s work, published in the journal Civil Engineering Sharif, is a step forward in this direction, offering valuable insights that can shape the future of geotechnical engineering in oil-contaminated areas.
