Wastewater Algae Explored as a Binder for Recycled Textile Materials

Researchers at UNSW Sydney are investigating whether algae used to treat wastewater could become a biobased binder for manufacturing. The project, developed with Sydney Water and Pacific Bio, explores how this biomass could combine with discarded textile fibres to create new composite materials.

The research remains at an early stage. Textiles provide the initial test case, but the team aims to understand whether algae-derived binders could replace fossil fuel-based alternatives across a wider range of applications.

Giving Wastewater Algae a Second Life

The project builds on an algae treatment trial at Sydney Water’s Picton Water Resource Recovery Facility. Pacific Bio’s RegenAqua technology uses native green macroalgae during the final treatment stage to remove nutrients, including nitrogen and phosphorus. This improves water quality before reuse or release into local waterways.

As the algae grow, they convert these nutrients into harvestable organic biomass. The UNSW team is exploring whether this biomass can become a natural binder, similar to a glue or resin, and testing its performance with discarded textile fibres and other materials.

Research officer Mariëtte van Bueren brings experience in seaweed research, design and economics to the project. Working with Associate Professor Anna Wang, she considers material chemistry alongside feedstock availability, processing requirements and potential applications.

Working With Mixed Textile Waste

More than 300,000 tonnes of clothing are sent to landfill or exported from Australia each year, according to the source article. Recycling garments presents challenges because they often contain blended fibres, dyes, buttons and zips.

Textile production can also involve chemicals such as PFAS, glues and dyes. Van Bueren highlights the need to remove these substances before recirculating materials.

The researchers are therefore investigating processing methods that could accommodate a broad variety of discarded textiles, rather than relying on carefully sorted feedstocks. Their work examines pathways for producing both the resin and new biocomposites.

For product and interior designers, the research could eventually offer another route for incorporating recovered textile fibres into manufactured materials. However, the binder’s properties and suitable applications still require investigation.

Processing Resources Locally

The team is also exploring processing at a local scale. Biomass supplies can be relatively small or vary in quality, making them less suitable for large centralised operations.

Smaller processing technologies could allow councils, utilities and remote communities to convert available biomass into useful materials closer to its source. This could reduce transport requirements and support local resource recovery. Pacific Bio is separately exploring RegenAqua biomass applications in agriculture, energy and building products.

Developing a Prototype Resin

As the project approaches its conclusion, the researchers aim to produce a prototype resin and examples demonstrating possible applications. Further funding would support collaboration with Sydney Water and a textile industry partner to develop functional products and processing technology.

The project received support through the UNSW Science Translational Impact Seed Fund, which funds early-stage collaborations between researchers and external organisations.

Source: UNSW Sydney
Photo: Pacific Biotechnologies