RemBind featured in the May/June 2025 edition of Inside Water Magazine, where Founder, Dr Richard Stewart shares how PFAS (per- and polyfluoroalkyl substances) can be safely stabilised in biosolids – enabling sustainable agricultural reuse while protecting the environment and reducing long-term contamination risk.
With tightening PFAS regulations and growing scrutiny around PFAS in wastewater and sewage sludge, this article offers practical, science-based guidance for councils, water utilities, and environmental professionals looking to reduce contamination risk and support the beneficial reuse of biosolids.
PFAS, officially known as per- and polyfluoroalkyl substances and often referred to as ‘forever chemicals’, are a group of synthetic chemicals that persist in the environment and accumulate in living organisms. Evidence links a subset of these compounds to toxicity in human health and the environment. PFAS have been widely used in firefighting foams (AFFF), non-stick cookware, waterproofing agents, food packaging, and many industrial applications.
Biosolids are nutrient-rich organic materials produced during wastewater treatment processes. While biosolids offer genuine agronomic value and have been beneficially reused on agricultural land for decades, wastewater treatment processes also concentrate environmental contaminants — including heavy metals and PFAS. The detection of elevated PFAS concentrations in biosolids has attracted significant regulatory and media attention, as the associated PFAS loads applied to land and pastures have historically been largely uncontrolled.
Stabilisation — also known as immobilisation — involves adding inert mineral sorbents to biosolids to bind and ‘lock up’ PFAS contaminants, preventing them from leaching into groundwater or being taken up by plants, where they could cause harm to human health and the environment.
This immobilisation process is relatively cost-effective and practical, and critically, treated biosolids can still be applied to agricultural land for beneficial reuse. The technology can also be deployed in-situ to reduce PFAS bioavailability and limit uptake into crops and food sources.
Recent independent research has demonstrated that the application of RemBind® sorbents significantly reduced the uptake of PFAS into grass grown in biosolids-amended agricultural soil. The study validated the use of sorbents applied in-situ to lower PFAS bioavailability in crops, decrease PFAS leaching to groundwater, and reduce PFAS movement to vulnerable biota and water systems.
The latest version of the PFAS National Environmental Management Plan (NEMP), publicly released in March 2025, specifically mentions biosolids for the first time. The PFAS NEMP provides nationally agreed guidance on managing PFAS environmental contamination, including strategies for preventing its spread across soil, groundwater, and water systems.
While the NEMP’s reuse criteria are based on total PFAS concentrations, reducing leachable PFAS concentrations through stabilisation represents a viable, risk-based approach for the safe and beneficial management of biosolids. It is essential to continue exploring innovative technologies and strategies that ensure environmental safety while supporting the sustainable reuse of vital agricultural resources.
RemBind® delivers proven, science-based PFAS remediation solutions for contaminated soils, groundwater, and biosolids. Key advantages include:
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