Abstract: As an emerging approach for oily sludge treatment, ultrasonic technology demonstrates significant potential. Starting from the physicochemical properties of oily sludge, this paper analyzes the challenges posed by its stable emulsified structure and elaborates in depth the action mechanisms of ultrasonic cavitation and mechanical demulsification. It focuses on the synergistic application of ultrasonic technology combined with surfactants, extraction techniques and advanced oxidation processes to enhance oil-water-solid separation efficiency. Guided by the principles of “resource recovery, reduction and harmless treatment”, this study proposes optimization strategies to address the current bottlenecks of high energy consumption and scale-up, aiming to enhance crude oil recovery efficiency and facilitate efficient resource recycling and environmental remediation of oily sludge.

Key words: oil sludge, ultrasonic technology, combined process