Using Microscreens as Clarification Technology Downstream of a Moving Bed Biofilm Reactor (MBBR)

Many pilot tests and a number of full-scale plants show that discfilters can be used very efficiently as an alternative clarification process after an MBBR process. Depending on the MBBR configuration (whether secondary or tertiary biological treatment, IFAS or pure MBBR) the design of the downstream filtration can be adapted to combine good removal performances and high filtration velocity. Examples of design adaptations include: varying the media pore size (e.g., from 10 to 40 microns) and the configuration of chemical addition between the MBBR and the discfilters (e.g., without any chemical addition, with flocculation only, or with both coagulation and flocculation). Comparison with more conventional clarification technologies show that for similar removal performances, the discfilters can be much more compact, more energy efficient, and have a lower carbon footprint.