This research will explore the innovative concept of capturing engine exhaust emissions and repurposing them into nutrient-rich water for agricultural use, which is a compelling waste-to-value proposition within the circular economy. The system will adopt the wet scrubbing principles to dissolve components like carbon and nitrogen into a liquid medium and offer a significant opportunity for reducing pollution. However, the advancement of this technology requires a standardised and scientifically rigorous methodology for performance validation. This research will introduce a comprehensive approach designed to address this critical gap. The proposed approach will provide a robust method for evaluating the capture efficacy, nutrient quality, and operational performance of a Wet Scrubber-based engine exhaust nutrient recovery system, based on a synthesised literature review of established principles in emissions control, analytical chemistry, and environmental engineering. This approach aims to accelerate the development and adoption of this promising technology by establishing a standardised process.