In a significant breakthrough in environmental science, researchers from Monash University in Melbourne have developed a new water filter capable of effectively removing smaller perfluoroalkyl and polyfluoroalkyl substances (PFAS) from water. These so-called "forever chemicals" are notoriously difficult to eliminate due to their persistent nature and the challenges they pose in water treatment.
PFAS, a group of thousands of synthetic chemicals, have been linked to various health issues, including cancer and developmental delays in children. According to estimates, more than 20% of Americans may be exposed to PFAS-laced tap water. In Australia, most individuals have detectable levels of PFAS in their blood, as reported by the government's PFAS Taskforce.
The new filter developed by the Monash team utilizes a beta-cyclodextrin modified graphene oxide membrane featuring nanoscale channels. This innovative design allows the filter to selectively retain PFAS while permitting water to flow through, significantly outperforming traditional polyamide membranes, which typically manage to remove only about 35% of short-chain PFAS.
“PFAS are difficult to manage because they dissolve easily in water and can spread far from their original source, making contamination challenging to contain and remediate,” said Eubert Mahofa, the study's first author. He emphasized that removing small PFAS molecules has been a major hurdle for existing filters.
In addition to the Monash University development, a team from the University of Illinois has also made strides in this area, finding a method to remove the full spectrum of PFAS from water in a single process. However, the focus remains on the Monash filter due to its advanced capabilities.
Health officials have raised concerns about the implications of PFAS exposure. The U.S. Environmental Protection Agency has linked these chemicals to a range of negative health outcomes, including an increased risk of certain cancers and cardiovascular diseases, particularly in postmenopausal women. Research indicates that PFAS exposure can also alter gene expressions within the brain, further complicating the health risks associated with these substances.
While the timeline for the implementation of this new PFAS-removing technology remains unclear, researcher Sally El Meragawi believes that their approach could set the stage for future membrane technologies designed to target specific contaminants in both drinking and wastewater. “It also retains key nutrients in water, making it an attractive method for use alongside traditional nanofiltration systems,” she added.
In a separate initiative, efforts are underway to clean the Hindon River, a tributary of the Yamuna, which has suffered from severe pollution due to industrial discharges and sewage. Once considered a “dead” river, the Hindon is now the focus of an ambitious restoration project led by Raman Kant, President of the Bhartiya Nadi Parishad, a non-governmental organization based in Uttar Pradesh.
The restoration plan involves constructing in-situ wetlands on the drains that feed into the Hindon River. These wetlands will utilize natural filtration methods, employing large boulders, cut stone ridges, and microbes found in wetland plants' roots to purify the water before it enters the river.
The Hindon River flows through several key districts, including Muzaffarnagar, Meerut, Shamli, Baghpat, and Ghaziabad, before merging with the Yamuna. Along its route, the river collects significant amounts of human waste and toxic discharge from various industries, including tanneries and dyeing units. Sewage accounts for nearly 80% of the river's pollution.
Kant's vision includes building wetlands capable of handling drains that carry between 0.5 to 2 million liters of water per day. He believes that these natural filters can significantly improve the water quality of smaller rivers, which often struggle with pollution during dry months when larger rivers swell and can carry away waste.
“When there’s no rain, how do you clean a drain entering smaller rivers at every nook and corner?” Kant asked, highlighting the challenges faced in managing water quality. His solution involves creating a series of in-situ wetlands that can act as effective barriers against pollution.
The design of the wetlands includes multiple sections of large boulders enclosed in mesh, forming the first line of defense against incoming water. As water flows over these rock walls, it slows down, allowing for greater oxygenation, which is often depleted by sewage. The water then passes through layers of cut-stone ridges, each lined with local aquatic plants like arbi, keli, and jhund, which further enhance aeration and promote microbial activity to break down organic matter.
Having refined the design of this living filtration system, Kant's team is set to commence construction of the first in-situ wetland on the Sardhana drain in Meerut district, a major conduit for waste entering the Hindon network. Starting Monday, May 5, 2025, Kant will conduct training sessions in Baghpat for local leaders and community members to mobilize grassroots efforts in the restoration project.
“These workshops are designed to show them exactly how to kick off the restoration work,” Kant explained. Once the pilot wetlands prove successful, similar structures will be implemented across all seven districts bordering the Hindon, potentially delivering irrigation water that is up to 90% pure.
The dual efforts of developing advanced PFAS filtration technology and restoring the Hindon River highlight a growing recognition of the need for innovative solutions to tackle water pollution. These initiatives not only aim to improve public health but also seek to restore the natural environment, ensuring cleaner water for future generations.
