Disclosed are embodiments of a reaction structure which has a gas phase electrode array integrated with defoamer, a container, a head space gas, bulk liquid, and a liquid phase electrode array with integrated gas bubbler, which emits process gas. There is a plasma discharge from the gas phase electrode array integrated with defoamer. The bulk liquid contains per- and polyfluoroalkyl substances (PFAS) chemicals, including short chain PFAS, which are degraded. In embodiments, a secondary plasma discharge can occur from the liquid phase electrode array with integrated gas bubbler. This secondary plasma discharge can be effective at degrading short-chain PFAS, which has a hard time gaining exposure to the plasma discharge formed from the gas phase electrode array integrated with defoamer. Also disclosed are embodiments of a process of use of the reaction structure to degrade PFAS.

A foam sensor device is used for monitoring foam within a vessel. The sensor (e.g. accelerometer) is encapsulated inside a water-tight, sterilizable, shell, which floats on a liquid contained. In one example, the foam sensor device includes an accelerometer for detecting and measuring rotation and movement of the foam sensor device and generates movement data based on the detected movement. During a learning or calibration process, sensor data (e.g., movement data) from the foam sensor device is analyzed and classified using machine learning and/or signal processing methods to extract features indicative of different possible foam statuses, including varying levels of foam, or no foam and generate models for the different statuses. During normal operation, the foam sensor device transmits sensor data to an analyzer containing the pre-calibrated models, which determines whether there is foam or not. Based on the foam status, a pump controller adds anti-foam solution.