Development of a real-time algal biomass and health optical sensor

Abstract

Large-scale microalgae cultivation requires continuous monitoring of both biomass and health, yet existing real-time sensors are often prohibitively expensive or reliant on through-flow designs that demand constant maintenance. This presentation introduces an affordable, in-situ optical sensor capable of measuring algal biomass concentration and health without the need for pumping systems. The sensor employs near-infrared light to measure algal concentration while using absorbance at eight visible wavelengths for algal health. Operating in various lighting conditions, floating on the water surface, and correcting for background interference, it alleviates many constraints of conventional methods. Data from the sensor are wirelessly transmitted to local receivers and integrated into cloud-based databases, enabling remote access and continuous tracking of cultivation parameters. Because it supplies real-time information on growth patterns, effects of nutrient supply, and environmental influences such as pH or time of day variations, the system can detect small changes that can give new insights. When combined with nutrient sensors, the data provide comprehensive oversight of cultivation conditions, facilitating efficient harvesting strategies. By offering immediate feedback on biomass concentration and algal health, this optical sensing system facilitates cultivation adjustments to optimize growth and reduce resource waste. Its low cost, portability, and straightforward deployment make it an attractive alternative for large-scale operations, especially compared with limited manual measurements. With its robust design, this solution significantly advances cost-effective algae cultivation for commercial and research applications.