Spreadsheet-based MBR design ...

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Spreadsheet-based MBR design software? No.

'Conventional' software to support design of MBRs? Yes.

Capable of predicting likely effluent quality? Somewhat.

All the models of which I am aware require that you specify the retention of particulates by the membrane - none of them can predict that from first principles. Other particulate-associated components are then calculated assuming that the retention is pro-rata to that of particulates, and that all soluble material will pass through the membrane.

I am not aware that any have any meaningful estimate of pathogen removal; that is relegated to out-of-simulation engineering expertise. If it was included it would again be that the user specifies a likely value for coli/viruses in the effluent.

Now we come to the nasty part: flow handling.

The simplest approach assumes that the membrane is always adequately sized and controlled for the flows; so flow limits do not come into the modelling output.

Then there is jump where you specify membrane resistances, expected cake resistances, cleaning frequencies, and the model has various parameters for fouling. This will give you a better prediction of the likely fall-off in performance with time, and the limits to flow that can be expected through a membrane for a given pressure drop. But the models are still in their infancy, and should be treated cautiously, and you need to continue to use vendor information to support the output. Fouling is the Achilles heel of membrane systems, and can mean that you will be unable to accommodate the peak flow.

Software products with membranes: as far as I know, all can support the'simple approach.' I haven't seen all the software products, so while I know that GPS-X and WEST support some aspects of the more detailed models, I cannot be sure that Biowin, SIMBA# and SUMO do not also support them. STOAT, which I develop, has an unreleased version that has the more detailed membrane model - I think we are approaching the time when I can make that model available if needed.

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