Water pollution problem such heavy metal pollution and oil spill in water ecosystems causing significant damage to living things and the environment. The demand for technology and devices to handle water pollution is increasing due to the frequent occurrence of the pollution. This research presents the utilization of metal oxide nanomaterials for water treatment (heavy metal removal and oily water separation), along with the development of an IoT-based automatic water treatment device. Emerging nanotechnology with IoT system would improve operational effectivity and efficiency by providing excellent performance, real-time data, alerts, and notifications through monitoring systems. Additionally, the automatic device is developed with IoT pairing with a website application for an online monitoring system. It is of interest to explore this further since it offers an effective and implementable method to solve water pollution problems in real-world applications.