Monash University advances ozone nanobubble and GAC technology for PFAS remediation

The Evolution of Catchment-Wide PFAS Regulations

The ongoing evolution of international and domestic environmental regulations is placing unprecedented pressure on Australian land developers, councils, and industries to manage per- and polyfluoroalkyl substances (PFAS) with greater precision. This pressure is driven by a fundamental shift in regulatory focus, transitioning from end-of-pipe drinking water treatment to comprehensive, catchment-wide source control. A notable example of this global trend is the Council of the European Union’s recent adoption of a directive tightening PFAS limits across surface and groundwater ecosystems, cementing an ecosystem-based framework that addresses how these persistent compounds cycle through entire catchments.

To meet these stringent standards, the remediation sector requires technologies that are both highly efficient and economically sustainable over long operational life cycles. Addressing this need, a research team at Monash University, led by Dr. Arash Zamyadi and Professor Mainak Majumder, has developed a treatment method integrating ozone nanobubble platforms with enhanced granular activated carbon (GAC). Their work provides a practical engineering pathway to improve the efficiency of adsorption-based PFAS treatment, offering a timely solution for practitioners designing groundwater remediation strategies under increasingly strict regulatory regimes.

For Australian environmental consultants, site auditors, and legal advisors, this scientific advancement addresses one of the most persistent bottlenecks in contaminated land management: the high operational cost of carbon media replacement. By extending the operational life of filtration media, this combined technology lowers long-term management costs and mitigates risks associated with long-term groundwater liabilities. It represents a mature step forward in aligning site-scale remediation with the ecological objectives of modern environmental frameworks.

How Ozone Nanobubbles Extend GAC Filtration Lifespans

Traditional water treatment systems rely heavily on granular activated carbon (GAC) because of its proven ability to adsorb a wide range of organic contaminants, including PFAS. However, when deployed in complex environmental matrices, the performance of standard GAC columns degrades rapidly. The primary driver of this degradation is not the PFAS load itself, but the presence of competing background organics. Natural organic matter (NOM), humic acids, and other co-contaminants compete directly with PFAS molecules for available active adsorption sites on the carbon surface, rapidly exhausting the media. This competition results in frequent media saturation, requiring expensive media change-outs, transport, thermal reactivation, or hazardous waste disposal.

The Monash University research addresses this operational bottleneck by introducing a selective ozone nanobubble pre-treatment stage prior to GAC filtration. Nanobubbles are extremely small gas cavities, typically measuring between 10 and 200 nanometres in diameter, which exhibit unique physical properties. Unlike macro-bubbles, nanobubbles remain suspended in liquid for long periods, possess a high gas-transfer efficiency, and generate highly reactive hydroxyl radicals at their interface due to their high zeta potential. When ozone is introduced via these nanobubbles, it acts as a highly targeted oxidant.

It is chemically critical to distinguish the function of the ozone nanobubbles in this treatment train. The ozone pre-treatment stage does not mineralise, destroy, or cleave the highly stable carbon-fluorine bonds of the PFAS compounds themselves. Instead, the ozone selectively targets, oxidises, and breaks down the NOM and competing organic load within the raw groundwater before it enters the carbon vessels. By destroying these competing organic compounds upstream, the pre-treatment stage preserves the adsorption capacity of the subsequent GAC media specifically for the targeted PFAS compounds.

This engineered configuration results in a highly efficient treatment train. The GAC media is shielded from premature organic fouling, which measurably extends the operational lifespan of the carbon bed and decreases the frequency of media replacement. By optimising the adsorption efficiency of the GAC without requiring continuous, high-volume carbon replacement, the technology addresses the critical economic challenges of high-volume groundwater pump-and-treat systems.

Australian context

The practical application of this dual-stage technology is highly relevant to the Australian regulatory environment. The management of contaminated sites in Australia is governed by a comprehensive framework, primarily structured around the National Environment Protection (Assessment of Site Contamination) Measure (NEPM 2013) and the PFAS National Environmental Management Plan (PFAS NEMP), which is currently transitioning into PFAS NEMP 3.0. Under these guidelines, regulators have established extremely low ecological trigger values for PFAS compounds. For instance, the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZG) specify a freshwater 99% species protection guideline value for perfluorooctane sulfonate (PFOS) of just 0.00023 micrograms per litre (µg/L). Meeting these near-zero detection limits during groundwater discharge is a significant technical challenge for standard remediation systems.

Furthermore, state environmental protection agencies, including the New South Wales Environment Protection Authority (NSW EPA) and the Victorian Environment Protection Authority (EPA Victoria) under the Environment Protection Act 2017, enforce strict compliance regimes regarding groundwater contamination and waste classification. In Victoria, the General Environmental Duty (GED) requires duty holders to eliminate or reduce risks to human health and the environment so far as reasonably practicable. If a site owner is discharging treated groundwater to a receiving environment, they must demonstrate that the treatment process consistently meets the relevant guideline values, and that ongoing operational practices reflect the best available technology to manage residual risk.

References and related sources

• Primary source: lens.monash.edu
• PFAS National Environmental Management Plan (NEMP)

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This is an iEnvi Machete news summary. Prepared by iEnvi to summarise the source article for contaminated land, groundwater, remediation, approvals and site risk professionals.

Published: 17 Jun 2026

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