Smart Water Safety: An Integrated IoT Framework for Microplastic and Chemical Contamination Detection

Safe water is crucial for health and requires effective monitoring of not only chemical contaminants, but also emerging contaminants like microplastics. Existing IoT solutions that monitor pH, turbidity, and TDS (Total Dissolved Solids) to assess the quality of drinking water do not consider the presence of microplastics or combine the two detection methods. Here, we propose an intelligent IoT-based water monitoring system that can assess chemical pollution for drinking water quality and microplastic contamination for overall water quality. The proposed system incorporates an ESP32-based microcontroller and pH, TDS, turbidity sensors, and optical microplastic detection mechanism. The microplastic detection is achieved using a blue LED and a Light Dependent Resistor (LDR) at 90° angles, along with Nile Red dye-based fluorescence and light scattering. Model microplastics of size in the range of 500-1000 μm made of Expanded Polystyrene (EPS) were used to test the system. The sensor signals are converted into voltage signals, where microplastics are detected by voltage thresholds. A live web interface presents all metrics and a Water Quality Index (WQI), indicating water as safe, caution or unsafe. The system has a bigger picture of the safety of drinking water (chemicals) and pollution (microplastics).