Multi-stage RO reduces biofouling and chemical consumption in seawater desalination, which extends membrane life by up to 30% and minimizes CIP- and replacement-related downtime.
This works by balancing system flux, reducing concentration polarization (membrane beta) by up to 40%, and increasing cross flow velocity by up to 80%.
The table below illustrates how multi-stage RO delivers more favourable membrane conditions in Gulf seawater, compared to single stage RO.
Design attribute |
Single stage RO |
BiTurboTM |
Biofouling risk |
Severe |
Moderate |
First membrane replacement |
2 years |
3 years |
2nd pass RO |
Essential |
Optional |
Permeate TDS (mg/L) |
707 |
440 |
Annual salt passage increase and flux decrease |
7% |
5% |
Maximum membrane beta |
1.15 |
1.09 |
Minimum cross flow (m3/hr) |
5.1 |
7.7 |
Maximum flux (lmh) |
31.3 |
21.6 |
Average flux (lmh) |
12.7 |
11.9 |
Feed pump pressure (bar) |
65 |
35 |
Maximum system pressure (bar) |
65 |
66 |
FEDCO's patented BiTurbo design uses a multi-stage RO design with two turbochargers for feed and interstage boosting for optimal pressure distribution and membrane performance.
This design can either be used to extend membrane life by improving cross-flow velocity and reducing concentration polarization, or to maximize permeate production without increasing pretreatment or intake requirements.
For more information on the design, download the BiTurboTM White Paper, or contact our sales team.
For the past 20 years, the desalination industry has focused on bringing down the energy consumption of low recovery, single stage RO systems. However, direct and indirect capital costs represent around 50% of the total cost of desalinated water.
By transitioning to a high recovery, two-stage SWRO design we can reduce capex by as much as 20%, while maintaining highly competitive energy consumption. Increasing recovery reduces both the cost and environmental impact of desalination by reducing plant footprint, intake & outfall size, and chemical consumption.
To find out more about how increasing recovery could impact the total cost of water in your upcoming project, download the BiTurboTM White Paper, or contact our sales team.
Introducing the BiTurbo: a Revolution in RO Technology
The next generation of desalination will rely on multi-stage, high recovery reverse osmosis, delivering a lower cost of water and improving membrane...
FEDCO presents optimized RO approaches at IDA World Congress, Sydney
On October 8-11 the global desalination industry convened in Sydney for the International Desalination Association World Congress. Following delays...