Introduction
The impact of per- and polyfluoroalkyl substances (PFAS) on the environment and human health has spurred significant regulatory measures and technological innovations.
This article provides an in-depth exploration of the health implications of PFAS, proactive regulatory measures by the EPA, and the pivotal roles of water utilities, companies, and institutions in addressing PFAS contamination.
It also delves into a notable pilot study conducted in Rome, Georgia, aimed at identifying efficient treatment methods for eliminating PFAS from water systems.
Furthermore, the focus on reverse osmosis (RO) and nanofiltration membranes as promising approaches for addressing PFAS contamination and emerging contaminants is highlighted, along with insights from experts emphasizing the need for a comprehensive process involving both PFAS removal and destruction.
Dr. Graeme Pearce’s perspective on the twofold challenge of PFAS removal and destruction adds depth to the discussion, emphasizing the necessity of a combined approach to effectively address the PFAS challenge.
A Proactive Approach by EPA
The Environmental Protection Agency (EPA) has undertaken a series of significant regulatory measures to address the pressing issue of per- and polyfluoroalkyl substances (PFAS).
These measures include the establishment of drinking water health advisories for certain PFAS, the initiation of the PFAS Action Plan, and the proposal of regulatory determinations for PFAS under the Safe Drinking Water Act.
Additionally, the EPA has worked to expand monitoring and research efforts related to PFAS, aiming to better understand the extent of contamination and potential health risks.
These regulatory actions reflect the agency’s commitment to addressing the widespread presence of PFAS in the environment and their potential impact on human health, signaling a proactive approach to mitigating the risks associated with these persistent chemicals.
Roles of Water Utilities, Companies, and Institutions
Water utilities, companies, and institutions play a crucial role in addressing the treatment of per- and polyfluoroalkyl substances (PFAS) in water systems.
Many water utilities have been investing significant resources in upgrading treatment facilities to effectively remove PFAS from drinking water supplies.
This includes the adoption of advanced filtration technologies, such as activated carbon and ion exchange systems, designed to specifically target PFAS contaminants.
Moreover, some companies have taken proactive measures to address PFAS contamination in their operations, investing in on-site treatment systems to minimize the release of PFAS into the environment.
Institutions, including research organizations and regulatory bodies, have also allocated funding towards studying the behavior of PFAS in water systems and developing innovative treatment methods.
Collaborative efforts between these entities have led to the implementation of stringent monitoring programs and the development of best practices for PFAS treatment, reflecting a collective commitment to safeguarding public health and the environment from the impacts of PFAS contamination in water sources. ( Read more about PFAS Contamination )
Pilot Study on PFAS Treatment Methods: City of Rome, Georgia
Amid the evolving regulatory landscape and growing environmental concerns, several pilot projects have been initiated in the U.S. to address the pressing issue of PFAS contamination in water supplies.
A prominent illustration is the comprehensive pilot study conducted by the City of Rome Water and Sewer Division at the Bruce Hamler Water Treatment Facility in Rome, Georgia.
The primary objective of this initiative was to determine the most efficient and sustainable treatment method for eliminating PFAS from the water system.
Six distinct treatment processes were evaluated, showcasing notable PFAS reduction capabilities, although not achieving complete eradication of all compounds to non-detectable levels as initially intended.
Of particular significance, the implementation of reverse osmosis (RO) technologies consistently demonstrated the highest rates of PFAS removal.
After considering various factors such as PFAS elimination effectiveness, capital and operational expenses, performance of pilot equipment, and feedback from Rome WSD personnel, it was recommended to replace the existing treatment processes at the Hamler WTF with disk filter pretreatment followed by either closed circuit RO or cross flow reverse osmosis operating at a minimum 90% recovery rate.
Analysis of anticipated lifecycle costs further emphasized the feasibility of the RO approach, with flow reversal reverse osmosis (FR-RO), closed circuit reverse osmosis, and cross flow reverse osmosis technologies presenting estimated 20-year lifecycle costs of $142 million, $161 million, and $163 million, respectively.
RO and Nanofiltration Membranes for Addressing PFAS
The focus on reverse osmosis (RO) and nanofiltration membranes represents a promising approach not only for addressing PFAS contamination but also for tackling numerous other emerging contaminants. ( Read more about PFAS)
According to Alderman, RO has the capability to separate nearly all types of emerging contaminants to some extent, thereby producing permeate water suitable for drinking across various categories.
However, a significant challenge arises from the concentration of contaminants during the RO process, necessitating efficient management of the resulting concentrate. Typically, an RO system discards approximately 25% of water, leading to a fourfold increase in contaminant concentration.
Alderman highlights the advantageous approach of ROTEC, which returns 90% of the water, resulting in significantly reduced waste compared to traditional RO systems.
This approach minimizes the quantity of brine that needs to be managed for any subsequent destruction technology. Furthermore, he underscores the long-term cost-effectiveness of ROTEC’s high recovery RO solution, especially when compared to alternative treatments like granular activated carbon (GAC).
By utilizing RO as an initial step to eliminate various PFAS chains before employing GAC, the required carbon plant footprint could be substantially reduced, leading to more efficient long-term operations and decreased lifecycle costs.
Alderman also emphasizes the potential of RO to address emerging contaminants beyond PFAS, such as 1,4-dioxane and other substances. He concludes by highlighting the benefits of combining RO with carbon filtration, not only ensuring clean water but also providing the option to reuse wastewater, thereby creating an efficient and reliable solution that offers the best of both worlds.
Dr. Graeme Pearce, principal at Membrane Consultancy Associates, specializes in providing advice on membrane filtration technology. He emphasizes the need for a process that involves both PFAS removal and destruction.
Dr. Pearce explains that the PFAS challenge is twofold: firstly, the compounds need to be removed from treated water to a level acceptable for human consumption, and secondly, they need to be destroyed to prevent waste discharge that could lead to environmental buildup.
He stresses that a technology like RO is well-proven to meet the removal goals and highlights the benefit of reducing the volume of the waste stream requiring destruction of concentrated PFAS. Dr. Pearce believes that a combined approach will be necessary to effectively address the PFAS challenge.
Conclusion
The pervasive impact of per- and polyfluoroalkyl substances (PFAS) on both the environment and human health has prompted proactive regulatory measures and innovative technological advancements.
The EPA’s commitment to addressing PFAS contamination, alongside the pivotal roles played by water utilities, companies, and institutions, reflects a collective effort to safeguard public health and the environment.
Notably, the comprehensive pilot study in Rome, Georgia, has shed light on the efficacy of reverse osmosis (RO) technologies in addressing PFAS contamination, emphasizing the potential of advanced filtration methods.
Furthermore, the promising role of RO and nanofiltration membranes extends beyond PFAS, offering a versatile approach to tackling emerging contaminants.
Dr. Graeme Pearce’s insights underscore the necessity of a combined approach involving both PFAS removal and destruction, emphasizing the need for comprehensive solutions to effectively address the multifaceted challenges posed by PFAS contamination.
As such, the ongoing collaboration between regulatory bodies, industry stakeholders, and experts in developing and implementing innovative treatment methods holds promise for mitigating the risks associated with PFAS and ensuring the safety of water sources for future generations.
References
[4] ATSDR (Agency for Toxic Substances and Disease Registry). 2018. Toxicological Profile for Perfluoroalkyls. U.S. Department of Health and Human Services, Public Health Service.
[5]Shoemaker, J. A., & Grimmett, P. E. (2019). Removal of per- and polyfluoroalkyl substances from drinking water using granular activated carbon. Journal American Water Works Association, 111(3), 13-26.
