SideStroem Nano-selective Forward Osmosis (FOns)

Sidestroem Water Technologies is a Singapore membrane company incorporated on 17 March 2021. It develops membranes that selectively recover water and salts from industrial effluents, aiming to cut the high energy and equipment cost of zero liquid discharge (ZLD) and to enable continuous industrial fermentation. It was selected for the fourth cohort of the Imagine H2O Asia accelerator.

Its core technology, nano-selective forward osmosis (FOns), combines the low fouling and scaling tendency of forward osmosis with the higher permeability and salt selectivity of nanofiltration. In wastewater, FOns can be inserted at primary, secondary or tertiary stages to reduce load, produce high-quality recycled brine and remove costly tertiary equipment. A two-stage FOns plus nanofiltration train targets dye concentration and desalting, and the same membranes can gently extract inhibitory by-products from fermentation broths. The beachhead market is India's textile industry, where ZLD is mandatory for larger dischargers.

• Nano-selective forward osmosis: membranes combining forward osmosis fouling resistance with nanofiltration permeability and salt selectivity.
• ZLD integration: can be applied at primary, secondary or tertiary treatment to cut load and remove tertiary equipment.
• Brine recovery: produces high-quality recycled brine so salts used in textile dyeing can be recovered.
• Dye concentration and desalting: a two-stage FOns plus nanofiltration train that limits irreversible fouling at high dye concentrations.
• Fermentation extraction: removes inhibitory by-products from fermentation broths to allow continuous production.
• Pilot-ready elements: 4-inch FOns elements developed with Singapore's START Centre and validated in an industrial pilot.

Textile dyeing mills in Vietnamese industrial parks can pilot FOns to concentrate dye-laden effluent and recover salt for reuse. Industrial park wastewater operators can add a forward osmosis stage before evaporators to cut ZLD energy costs. Fermentation-based producers of enzymes, ethanol or bio-ingredients can test continuous extraction of inhibitory by-products.

The company states that FOns can deliver up to 55% OPEX savings and 50% CAPEX savings in greenfield ZLD systems. Forward osmosis tolerates a wide range of feedwater with limited pretreatment and is less prone to fouling than pressure-driven membranes. Recovered brine and salts can be reused, and in fermentation the company says continuous operation can raise productivity up to 20-fold.

Textile, dyeing and tannery hubs in South and Southeast Asia face stricter discharge rules and rising water demand, while the company notes that industrial water reuse in the region remains below 8%. Conventional ZLD based on evaporators is energy intensive, so membrane-based brine concentration and salt recovery are attracting interest as a cheaper path to compliance and circularity.

Sidestroem Water Technologies Pte. Ltd. (UEN 202109449G) was incorporated in Singapore in March 2021 and is based at 61 Robinson Road. It was part of Imagine H2O Asia's fourth cohort. Its first industrial-scale pilot with Lexcru Water Tech was featured in Everything About Water in November 2025, and in August 2026 it signed a contract manufacturing agreement with Levigas Water Tech for FO membranes.