IoT-Based Smart Air Purification and Real-Time Environmental Monitoring System Using ESP8266 and MQ135 Sensor

Air pollution is a major environmental challenge that creates a need for affordable and intelligent air quality monitoring and purification systems. This research presents an Internet of Things (IoT)-based smart air purification and environmental monitoring system using an ESP8266 NodeMCU microcontroller and an MQ135 gas sensor. The proposed system collects air-quality-related sensor readings and transmits the data through Wi-Fi for remote monitoring. A threshold-based control mechanism can be used to activate an air purification fan when sensor readings exceed a predefined threshold. The system is designed to support real-time monitoring and provide accessible information about changing environmental conditions. The proposed architecture can be extended with cloud-based data storage, historical data visualization, and automated alerts. The system aims to provide a practical and affordable approach to developing an IoT-based environmental monitoring prototype. Further testing, sensor calibration, and comparison with reference instruments are necessary to establish measurement accuracy and evaluate the effectiveness of the air purification mechanism under different environmental conditions.