Air Pollution Monitoring and Control

The review paper "IoT Based Air Pollution Monitoring Using NodeMCU And MQ135 Gas Sensor" presents an innovative approach to air quality monitoring using the Internet of Things (IoT) technology. The study focuses on the utilization of the MQ135 gas sensor to measure pollution levels in the environment, with real-time data display on a webpage. The authors employ NodeMCU for data collection and transmission, interfacing with an LCD (16X2) to provide on-site pollution content visualization.The paper provides a comprehensive overview of the MQ135 sensor's internal circuit and explains the module format of the sensor, highlighting the connections necessary for implementation. Additionally, it elucidates the Arduino code used to handle the data from the sensor, connect to a local area network, and create a dynamic webpage for displaying pollution content.The operational workflow of the IoT air pollution monitoring system is outlined, with an emphasis on the threshold values for categorizing pollution levels as normal, medium, or dangerous. The authors demonstrate the system's practicality by showcasing its response to gas exposure, specifically using a lighter. This review paper serves as a valuable resource for researchers and enthusiasts interested in developing IoT-based air pollution monitoring systems, offering insights into the hardware components, code implementation, and real-time data visualization for effective environmental monitoring.