Arduino and IoT-based direct filter observation method monitoring the color change of water filter for safe drinking water

Globally, the red water crisis continues to occur because of aging water pipelines, excessive water system conversion, and inadequate water tank management. Therefore, in this study, we have developed a monitoring system for water tank filters in apartment buildings by using Arduino and Internet of Things (IoT) technology to realize efficient water tank management. The proposed system uses grayscale, RGB color, and pressure sensors, and these sensors are connected to an Arduino. In the performance evaluation of the direct filter monitoring system using a color sensor, the system could effectively detect the turbid water inflow by the signal-to-noise ratio of derivative of color change. Moreover, the representative turbidity-causing minerals such as iron (III) oxide-hydroxide (FeO(OH)), iron (III) oxide (Fe₂O₃), manganese oxide (MnO₂) could be distinguished by a different color. A correlation analysis between pressure change and turbidity of filtered water yielded an R-square value of 0.9 or higher under most conditions. Based on the results obtained in the lab-scale test, a four-stage notification algorithm for safe filter operation was proposed. Finally, the developed direct filter monitoring system was installed in an apartment complex as a field demonstration, and it verified that the direct filter monitoring system can provide reliable notifications with high accuracy. Therefore, the direct filter monitoring system developed in this study can be widely used to manage water filter to ensure safe water supply in apartment complexes.