Screening of novel MBR fouling reducers: Benchmarking with known fouling reducers and evaluation of their mechanism of action

A novel fouling characterization method was applied for a first screening of two novel synthetic flocculants developed by BASF (BASF-1 and BASF-2) and benchmarking with six well-known products. Results showed that this MBR-VITO Fouling Measurement (VFM) was able to identify beneficial and adverse effects of different additives on the mixed liquor’s reversible and irreversible fouling and, in combination with supporting mixed liquor analyses, allowed to identify the additive’s main working mechanism. The first screening tests indicated that BASF-1 and BASF-2 reduced reversible and irreversible fouling to a similar extent as the known synthetic flocculants due to a charge neutralization mechanism, resulting in enhanced flocculation and SMP removal. Further testing at different additive concentrations provided a first indication of the optimal dosage and revealed a considerable risk of overdosing for BASF-2, rendering it less suited for fouling control. In contrast, such adverse effects were not observed for BASF-1. BASF-1 induced similar beneficial effects as the known MPE50 polymer at lower dosage and was therefore considered promising for application in MBRs.

► The MBR-VFM is a useful tool for evaluating additive’s fouling reduction potential.
► It allows a fast and economic first screening of products under development.
► It also gives a first indication on the working mechanism and the optimal dosage.
► The new flocculant BASF-1 induced similar effects as MPE50, but at a lower dosage.