An MBR replaces the secondary clarifier with membranes. Set the flow, the high MLSS,
HRT and design flux — get the bioreactor volume, permeate flow, required membrane area and module
count, and the transmembrane pressure / permeability that decide cleaning frequency.
1Duty & membrane
MBR runs high MLSS (8–12 g/L) at short HRT; flux 15–30 LMH; recovery 90–98 %.
Results — reactor & membrane
Bioreactor V
—m³
Membrane area
—m²
Modules
—ea
Item
Value
Basis
2Permeability & cleaning
Permeability K = J / TMP drops as fouling builds — that is what CEB and the cleaning interval manage.
Parameter
Value
Note
Order note
Quote the MBR instruments at factory price
An MBR is the most instrument-dense unit on the plant: TMP per rack, permeability trend, DO, MLSS,
permeate turbidity and level. We supply them at the manufacturer's ex-works price — margin from the
export rebate only.
Full derivation and worked example: MBR-Calculation-Sheet.md. An MBR is the clarifier-replacing biological variant — size it, then carry the sludge into the thickening tool.
