This study describes the development and evaluation of an economical, portable online monitoring system (OMSys) based on ESP32 Wi-Fi/Bluetooth technology, commercial sensors, and electronic measurement modules. The OMSys was designed for real-time evaluation of parameters such as the flow rate, temperature, and pH in a filtration/photocatalysis reactor used to degrade contaminants in treated water. The developed system allows simultaneous acquisition of all studied parameters at 2 s intervals and facilitates real-time data transmission via Wi-Fi, automatic storage, and real-time control (on/off) of other devices connected to the reactor, such as an LED irradiation source and a peristaltic pump, via a smartphone. The OMSys was evaluated in the degradation of venlafaxine (VEN) and used as a test model. Thanks to its performance, the OMSys facilitates the study of parameters that directly influence the degradation of emerging contaminants in real time, identifying critical stages in the water treatment process such as membrane stability (leaching). This enables real-time adjustments and improves the study’s final performance, demonstrating an approximately 80% reduction in VEN concentration within 120 min, a response influenced by changes in pH and temperature throughout the experiment. This system can be integrated with other recirculating loops for a variety of applications. The versatility of the OMSys is also evident, as it allows the addition of new sensors to monitor other parameters of interest. Easy upgrades with the addition of modern components improve performance, reduce problems such as obsolescence, and minimize environmental impact.
Rojas-Mantilla et al. (Fri,) studied this question.