MBR Energy & Operating Cost Calculator
Aggregate process aeration, membrane air scour, pumping, ancillary loads, chemical consumption, membrane replacement, sludge disposal, labour, maintenance, and fixed allowances into a transparent preliminary annual-energy and direct-OPEX screen.
Membrane air-scour energy basis
When the derived source is selected, the time-weighted normal air flow from the membrane train-sizing calculator is converted to actual inlet flow at site elevation and temperature. The isentropic compression model then estimates average electrical scour-blower power. Because the imported air flow already includes membrane scour duty, annual energy uses the full calendar operating hours without multiplying the duty factor again.
Use a vendor or measured kW value when an equipment curve is available. The derived route is a preliminary thermodynamic screen, not final blower selection.
Source references
Aeration costs in MBRs [1] Calculating whole-life costs in MBRs [2]
Energy and operating-cost calculation basis
Documentation revision: 2026-10-02. This page documents the calculation basis so an engineer can trace the inputs, units, assumptions, and review needs. Results are preliminary screening estimates; they are not a permit determination, OEM guarantee, or construction/procurement approval.
Method and source basis
Annual energy is calculated as electrical power multiplied by operating hours and duty. Pump power uses rho-g-Q-head divided by overall efficiency. Derived membrane-scour power uses the entered SADm, air reference conversion, an isentropic compression screen, and wire-to-air efficiency; direct mode accepts supplier or measured power.
The sources below provide technical context or analytical/design methodology. They do not endorse this calculator's defaults, and any jurisdiction-specific requirement applies only where that authority has jurisdiction.
- U.S. EPA, Membrane Bioreactors Wastewater Management Fact Sheet (2007)
- Verrecht et al., An aeration energy model for an immersed membrane bioreactor, Water Research 42 (2008), DOI 10.1016/j.watres.2008.09.013
- Yamashita et al., Demonstration of energy-saving MBR systems, Water Science and Technology 79 (2019), DOI 10.2166/wst.2019.068
- WEF Manual of Practice No. 36, Membrane Bioreactors
Assumptions, limitations, and review actions
- The fallback train arrangement is illustrative; run and refresh the membrane train-sizing calculator before relying on imported area or scour values.
- Derived scour energy is a screening estimate, not a blower selection. Confirm standard-air convention, pressure rise, depth, manifold losses, blower curve, turndown, controls, and measured/vendor power.
- Direct OPEX excludes any loads not entered, such as screening, mixers, dewatering, HVAC/odour control, standby consumption, demand charges, taxes, financing, delivery, and disposal. Tariffs and prices are user assumptions.
Professional review checkpoint
Before using the result for specification or operation, reconcile it with representative site data, the applicable permit and design standard, the selected equipment or membrane supplier's current data, and a qualified wastewater/process engineer. Record the input basis, date, units, and any pilot, bench-test, or comparable full-scale evidence used to select the assumptions.