FO1000 Forward Osmosis system for high contaminant rejection, 1000 GPD production. Uses osmotic pressure. | AMPAC USA
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Ampac USA Forward Osmosis 500 GPD systems offer high contaminant rejection and low back diffusion using osmotic pressure. | AMPAC USA
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How does forward osmosis differ from reverse osmosis in terms of driving force?
Reverse osmosis uses hydraulic pressure, typically 150-1,200 psi depending on feed salinity, to push water through a membrane against the osmotic gradient. Forward osmosis uses a concentrated draw solution on the permeate side to create an osmotic pressure differential that pulls water naturally through the membrane, requiring little to no applied pressure. The tradeoff is that FO requires an additional step to recover clean water from the draw solution.
What draw solutions are used in AMPAC USA forward osmosis systems?
Our FO systems use ammonia-carbon dioxide draw solutions for applications where thermal regeneration is feasible, and sodium chloride or proprietary organic draw solutions where low-temperature operation is required. Draw solution selection depends on the application: food and pharmaceutical clients often prefer food-safe draw solutes, while industrial brine concentration projects tolerate a wider range of chemistries. We engineer the full draw solution recovery loop, not just the membrane stage.
What feed water TDS levels can forward osmosis handle compared to conventional RO?
FO membranes can process feed streams up to 70,000-100,000 mg/L TDS, well beyond the practical limit of high-pressure seawater RO membranes at roughly 45,000-50,000 mg/L. This makes FO useful for concentrating produced water from oil and gas operations, landfill leachate, and pharmaceutical process streams where conventional pressure-driven membranes fail or foul rapidly. AMPAC USA sizes FO systems based on feed osmotic pressure and target volume reduction ratio.
In what industries does AMPAC USA deploy forward osmosis systems?
We build FO systems for food and beverage concentration including juice, dairy, and coffee, pharmaceutical process water recovery, brine minimization in industrial wastewater, and fertilizer-drawn FO for irrigation. Each application uses a different draw solution and recovery scheme, and we engineer the full system rather than supplying membranes alone. Contact our engineering team with your feed water chemistry and product specification for a preliminary design.
How resistant are FO membranes to fouling compared to RO membranes?
FO membranes foul less severely than RO membranes for the same feed water because the absence of applied hydraulic pressure means foulants are not compacted against the membrane surface. Fouling is also more reversible under low-pressure osmotic conditions. That said, FO is not immune to scaling or biofouling, and our system designs include periodic osmotic backwashing, which can restore flux without chemical cleaning in many cases.