Development of a Smartphone-Integrated Microalgae Photobioreactor for CO₂ Capture and Oxygen Generation in Indoor Air Purification Systems

Abstract

This study introduces an innovative microalgae-based air purification system designed to enhance indoor air quality by capturing carbon dioxide (CO₂) and generating oxygen (O₂). The system integrates a 1.5 L photobioreactor with advanced control and monitoring features accessible via a smartphone application. The photobioreactor employs RGB-LED lighting and an air pump to facilitate optimal microalgae growth. The system autonomously adjusts light and airflow based on real-time data, reducing the need for user intervention. A smartphone app allows additional manual control while providing visual feedback on microalgae growth through a six-stage color tracking method. Simulations were conducted to evaluate system performance, demonstrating a CO₂ capture rate of up to 0.55g/L/day and an O₂ generation rate of approximately 0.20g/L/day—improvements of 22% and 25%, respectively, over previous studies. The IoT control system showed high reliability with a precision of 93%, recall of 91%, and F1-score of 92%. The results indicate that the proposed system effectively enhances air purification efficiency and offers a user-friendly approach to indoor environmental management. © 2025 Elsevier B.V., All rights reserved.