Toray Industries has developed a high-removal ultrafiltration (UF) membrane. This new offering maintains high water permeability of UF membranes while reducing the reverse osmosis (RO) membrane load to stabilize long-term production of high-quality water in wastewater reuse.

With global water demand rising, the use of hybrid UF and RO membranes to recycle wastewater and industrial effluent is fast expanding. Efforts have started around the globe to harness reused water for drinking and produce ultrapure water that is vital to manufacture semiconductors. Conventional UF membranes are poor at removing biopolymers commonly found in wastewater. RO membranes thus have to be cleaned more frequently with chemicals, increasing water production costs and carbon dioxide emissions.

Toray overcame that challenge by quantitatively analyzing the formation process of sub-10-nanometer nanopores in designing a high-removal UF membrane. It leveraged observations using the SPring-8 large synchrotron radiation facility (see glossary) and simulations to carefully assess the membrane structure. It drew on its findings to precisely control the polymer materials and manufacturing process to simultaneously create finer pores and increase the number of nanopores. This effort culminated in a high-efficiency UF membrane that can deliver unprecedented removal performance and high water permeability.

Tests confirmed that the new UF membrane reduces biopolymer transmission, a prime factor in RO membrane contamination, to less than one-third of the levels of current offerings from Toray, providing excellent removal performance, including for sewage and industrial wastewater. Pilot operations at a sewage plant linked UF and RO membranes and demonstrated that the high-removal UF membrane maintained water permeability while reducing the decline in RO membrane permeability by one-third.

This advance should reduce the need for RO membrane cleaning in wastewater reuse applications, including for sewage treatment and industrial wastewater recycling in the chemical, steel, textile, and other sectors. It should also help minimize chemical cleaning, reduce operational problems, and extend RO membrane lifespans, thus cutting water treatment costs and lowering carbon dioxide emissions from replacing and disposing of RO membranes by more than 30%. Toray is preparing to mass produce this new offering, launching it in mid-2025 in North America, where wastewater reuse is rising, and then rolling it out in Japan and other markets.

The company will unveil the technology behind this product at the Membrane Technology Conference, one of the world’s largest such events, which will open in the United States on February 24.

Toray will continue to innovate technologies that contribute to a sustainable economy in line with its corporate philosophy of contributing to society by creating new value with innovative ideas, technologies, and products.