On-line biofouling monitoring and qualification based on local thermal and periodic excitation with MEMS sensor

Water and wastewater processing (cooling tower, heat exchanger, treatment, etc.) generate desirable or undesirable biofouling (mineral, organic, biological) which may affect equipment process performances. Fouling magnitude nature stand as critical parameters to be evaluated in-situ on-line control optimize the operation (production, cleaning). A fouling sensor based on a Micro-Electro-Mechanical Systems (MEMS) structure generating local periodic thermal excitation (PTR) was studied in order quantify qualify fouling. At lab scale, model deposit (PVC) were used simulate conditions. Limits of detection (LOD) quantification (LOQ) under steady regimes compared. Transposition industrial conditions investigated at pilot-plant scale. continuous bioprocess (PropellaTM reactor) fed with diluted controlled operating condition (temperature, mixing rate, flow rates, residence time) mimic realistic complex over six weeks. Thermal diffusivity, capacitive resistive components are extracted from spectrum response final factor is introduced. Results demonstrate ability information.