Posters

Posters are sorted by presenters last name.

PFAS - Are We Closer to Closing the Data Gap?

Dr. Kesavalu Bagawandoss, Ph.D., J.D., Industries & Environment Technical Director, SGS North America, Inc.

Abstract:

The complexity and diversity of per- and polyfluoroalkyl substances (PFAS) continue to challenge environmental scientists, regulators, and public health professionals. With thousands of known and unknown PFAS compounds in circulation, the question remains: are we closer to closing the data gap?  This presentation explores the evolving analytical landscape of PFAS detection and quantification, highlighting how integrated approaches are expanding our understanding of PFAS occurrence and behavior. Targeted LC/MS/MS analysis, the cornerstone of PFAS monitoring, offers high sensitivity for a defined list of legacy and emerging compounds. The Total Oxidizable Precursor (TOP) Assay reveals hidden precursor burdens by transforming them into measurable terminal PFAS.  To address the limitations of targeted or compound-specific methods, techniques have been developed and promulgated that provide a bulk measure of organic fluorine as a proxy for PFAS impact and help quantify the “dark matter” of PFAS.  Special attention will be given to the analysis of ultra-short chain PFAS, such as trifluoroacetic acid (TFA), which evade conventional methods, yet pose unique mobility and toxicity concerns. Finally, non-targeted high-resolution mass spectrometry (HRMS), a powerful tool for discovering novel PFAS structures and transformation products in complex environmental matrices will be explored.  By comparing these complementary techniques and showcasing recent applications, this session will present how far we've come and perhaps, how far we still need to go to fully characterize PFAS in the environment. The presentation will afford a clearer picture of the analytical toolbox available today and the strategic pathways to bridge remaining data gaps.

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Leveraging Electron Upconversion to Improve Energy Efficiency of PFAS Degradation in a Nonthermal Plasma Reactor 

Kimberley Christopher, Ph.D. Candidate, Department of Chemistry and Biochemistry, Florida State University

Abstract:

Electrons are often treated as stoichiometric reagents in PFAS remediation, yet can act catalytically when coupled to electron upconversion, i.e., in situ the generation of stronger reductants from mild electron donors. Here, we develop a comprehensive computational framework showing how electron upconversion enables energy-efficient degradation of perfluorosulfonic acids (PFSAs), among the most recalcitrant PFAS. We identify radical anions of sulfonic acids as previously unrecognized intermediates where C–F bonds are weakened by up to 80 kcal/mol, opening pathways inaccessible to neutral or deprotonated PFSAs. Electrons and hydrogen atoms emerge as the dominant agents of defluorination, while hydroxyl radicals play a secondary role. Crucially, radical/anion cross-reactions can recycle electrons, establishing catalytic defluorination cycles. Experiments support this framework, showing up to four-fold enhancement of fluoride release.  These findings unify plasma, photoredox and electrochemical approaches through a shared electron-catalytic principle and point toward broadly applicable, greener strategies for destroying persistent pollutants.

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 Aqueous PFOA and PFOS Degradation: The Role of Hydrated Electrons in Advanced Photochemical Reduction

Pranesha Dangol, Undergraduate Student Researcher, Texas State University

Abstract:

Advanced photochemical reduction processes, such as the UV/sulfite process, have shown good remediation potential for per- and polyfluoroalkyl substances (PFAS) that are highly resistant to typical biological, thermal, and oxidative degradation processes. Hydrated electrons are known to be responsible for the advanced reduction of PFAS. However, due mainly to the lack of standard methods for measuring hydrated electrons, its role as a reductant has been indirectly proved by adding substrates with a fast bimolecular rate constant for hydrated electrons (e.g., oxygen and nitrate). However, the operating and experimental conditions, such as the concentrations of PFAS and hydrated electron scavengers and the reaction pH and temperature, affect the role and performance of hydrated electrons in advanced reduction processes. In this study, the UV/sulfite advanced photochemical reduction process was first optimized for the concentration of UV sensitizer (sulfite), pH, and temperature, and then was tested for the effect of the initial concentrations of PFOA and PFOS as the model PFAS and nitrate as the hydrated electro scavenger to understand the role of hydrated electrons in the UV/sulfite advanced reduction process under varying operating and experimental conditions. Reductive chain cleavage of C-C and C-F bonds was also evaluated by tracking the occurrence of shorter-chain PFAS and fluoride ions. We envision that the findings from this study provide technical insight into the UV/sulfite advanced photochemical reduction process to remediate water contaminated with PFAS.

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Adopting Emerging PFAS Destruction Technologies: The Orlando Case Study for Supercritical Water Oxidation 

Dr. Raj Melkote, Ph.D., Chief Technology Officer, 374Water, Inc.

Abstract:

Introduction  The rate at which organic contaminants of emerging concern (CECs), such as per- and polyfluoroalkyl substances (PFAS) are being introduced into the environment is rapidly outpacing our ability to treat them with conventional water/wastewater treatment technologies. Since PFAS have are highly diverse in their physico-chemical properties, emerging technologies, such as supercritical water oxidation (SCWO), that broadly treat PFAS are warranted as a catch-all solution to PFAS destruction.  SCWO is a physical thermal process that eliminates organic compounds indiscriminately. During SCWO, a waste with an appropriate water:waste:oxygen ratio is fed into a reactor, where temperature and pressure conditions are elevated above the critical point of water (374°C and 221 bar) so that the water in the feed becomes supercritical. The high solubility of organics and gases (e.g. oxygen) in supercritical water allows for the rapid exothermic oxidation of any organic compound, yielding only inert inorganics, recoverable heat, and clean vent gas as the final products. Since 1982, SCWO was popularized and applied by various researchers and companies to municipal and industrial sludges, military waste, and organic industrial chemicals (Svanström et al., 2005; Bermejo & Cocero, 2006) and have shown a positive environment impact as measured by life-cycle assessment (Svanström et al., 2004).  The City of Orlando, Florida’s Water Reclamation Division has been investigating technologies such as SCWO for biosolids management. Their current biosolids management strategies - land application or landfill – are currently limited by wet weather restrictions (SB 712) and lower acceptance of the biosolids at landfills. The City is simultaneously seeking solutions to address per- and polyfluoroalkyl substances (PFAS) to safeguard water sources potentially impacted by biosolids disposal. After evaluating various management strategies, including composting, incineration, and drying, the City identified 374Water’s SCWO system as a viable candidate for biosolids volume reduction and contaminant elimination.  Methodology  374Water’s commercial scale AirSCWO 6 system was used for this demonstration study (Figure 1.1), with a design capacity of 6 wet tonnes of sludge (at ~10-20% dry solids (DS) content) per day. The sludge is stored in a feed hopper with a homogenization tank and internal recirculation to keep slurry in suspension. A high-pressure pump transfers the homogenized waste to the SCWO reactor via a heat exchanger, which preheats the incoming slurry. A high-pressure compressor compresses pre-heated ambient air, before the air is fed into the plug flow once-through SCWO reactor. The reactor output is sent through a series of heat exchangers and depressurizing equipment to bring the outputs to near ambient conditions.  The system is typically run for 12-36 hours per test run, with a typical residence time for sludge in the reactor of 5-10 seconds. Grab samples were between the end of sludge handling and the AirSCWO 6 inlet and at the effluent of the AirSCWO 6 unit. Grab samples from each sampling point were analyzed for various parameters including flowrate, chemical oxygen demand, and PFAS (via EPA Method 1633).  PFAS analyses were conducted by a third-party accredited lab. Most operating parameters were monitored in real-time, while others, such as trace and emerging contaminants, were analyzed offline.  Results  The facility secured funding ($812,000) through an awarded State Revolving Fund (SRF), after which the AirSCWO system was mobilized, installed, and commissioned by September 2024. The project is currently ongoing and is in the operations phase.  Results of sludge volume reduction are immediately apparent post-treatment via the AirSCWO 6 system. WAS obtained at ~0.5% DS and pre-treated prior to SCWO was treated and discharged from the AirSCWO 6 system as an effluent with a small fraction of settleable inorganic solids (Figure 1.2). Once dried, the solid fraction became a manageable inert ash. The AirSCWO 6 system performed exceptionally well at eliminating a broad range of PFAS. Across the seven (7) PFAS detected in the AirSCWO influent (WAS at 8% DS), the lowest destruction and removal efficiency (DRE) was ~96.5%. DREs ranged from 96.5 to >99.5%, with no distinct hindrance from PFAS chain length or classification (Figure 1.3). The system also demonstrated the ability to eliminate the precursor NetFOSAA with >96.5% DRE, which confirms previous mass balance studies by 374Water that illustrate near complete mineralization of PFAS with no transformation of precursors.  Discussion & Conclusions  This demonstration of 374Water’s AirSCWO 6 technology at the Iron Bridge Water Reclamation Facility provides encouraging results for adopting SCWO at scale in the municipal water/wastewater field. To accelerate the implementation of SCWO in the field, technology providers, such as 374Water, and municipalities should continue to pursue joint projects that leverage federal and state funding opportunities (such as the EPA’s SRF). Integration with and/or funding support from industrial dischargers can further promote efforts to increase the scale (throughput) of SCWO to align with utility sizes for which SCWO is in budget at current pricing, and/or circumvent water/wastewater treatment plants by installing SCWO on industrial dischargers’ sites. Additionally, this demonstration validates previous studies from 374Water, across various scales, that show broad spectrum PFAS destruction of over 95%. Continued testing in this demonstration will mirror previous studies to pseudo-identify the final fate of PFAS via fluorine mass balance analysis and increase the frequency of PFAS emissions analyses.   The teams at 374Water and the City are continuously working to complete this pilot study successfully and on-schedule. The performance results will be shared with the FDEP and EPA to aid them in their development of databases and tools. At the conclusion of the pilot study, the City will receive the second part of the grant to support the design, construction, and installation of an AirSCWO 30 system. Additionally, a long-term partnership with the City has been established to continue operating the AirSCWO 6 unit for treatment of other PFAS-contaminated materials. The AirSCWO 30 will be built and tested at Iron Bridge before being relocated to Orlando’s Water Conserv I facility, the smallest of the city’s three treatment plants, which processes an average of 5.5 million gallons per day. The AirSCWO 30 system should be capable of handling all sludge produced at Conserv I for the foreseeable future. We thank Alan Oyler at the City of Orlando Public Works, who has advocated for and enabled this innovation to be tested, further developed, and demonstrated at their facility. 

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Advancing PFAS Data Management and Regulatory Tracking Using an Integrated Digital Framework

Heather Nunn, Sr. Data Management Lead, Langan Engineering

Abstract:

The rapidly evolving regulatory landscape for per- and polyfluoroalkyl substances (PFAS) presents significant challenges for site investigation, compliance evaluation, and risk management. Variations in federal and state criteria, coupled with increasing public concern and complex site conditions, require approaches that can integrate diverse data sources while supporting timely, defensible decision-making.  This presentation describes the development and implementation of an integrated digital framework designed to centralize PFAS regulatory criteria, site data, and project workflows. Built on EQuIS Enterprise and a firmwide environmental database, the system incorporates an interactive regulatory mapping component to provide current access to Maximum Contaminant Levels (MCLs), health advisories, and state-specific action levels. This approach supports consistent compliance evaluation across multiple jurisdictions and enables project teams to respond efficiently as regulatory standards evolve.  The framework has been applied to a range of use cases, including due diligence, site assessments, sampling program design, and data review and reporting. Implementation results demonstrate improvements in the efficiency of regulatory evaluations, standardization of PFAS data integration across projects, and coordination between field teams, data managers, and risk assessors.  The presentation will also discuss lessons learned during system development, including considerations for long-term maintainability, regulatory updates, and the importance of collaboration between regulatory, technical, and data management subject matter experts. Examples from multi-state PFAS investigations will be used to illustrate both the benefits and practical challenges of deploying a scalable PFAS data management and regulatory tracking solution.

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Mitigation Strategies for PFAS in Stormwater: A Collection of Case Studies

Jenny Olmsted, P.E., Environmental Engineer, CDM Smith

Abstract:

Per- and polyfluoroalkyl substances (PFAS) present a persistent and complex challenge in urban stormwater systems, necessitating innovative management strategies to mitigate environmental and public health risks.  PFAS can enter stormwater systems through multiple pathways including industrial discharges, airport operations, urban surface runoff, and atmospheric deposition, making it challenging to pinpoint and manage sources effectively. PFAS comprise thousands of compounds with varying fate and transport properties. Monitoring and treating such a diverse group requires specialized analytical methods and tailored treatment technologies. Conventional stormwater structures, such as detention basins and vegetated retention areas, are not equipped to remove PFAS and may inadvertently facilitate their migration into soil and groundwater. Due to their environmental persistence and unique fate and transport characteristics, PFAS that accumulate on both paved and unpaved surfaces can continue leaching into stormwater systems for decades, serving as a long-term source of contamination. Treatment technologies developed for PFAS removal in drinking water and groundwater often face challenges when applied to stormwater due to elevated levels of suspended solids, organic carbon, and other co-contaminants. Many states have yet to establish definitive standards for PFAS concentrations in stormwater, and those that have typically address only a limited subset of compounds. This regulatory void creates uncertainty in setting design goals and determining appropriate treatment targets.  Mitigating PFAS in stormwater requires a tiered approach that balances effectiveness, feasibility, and cost. The first and most proactive strategy is source control, which involves preventing stormwater from contacting PFAS-contaminated media—such as soils, pavement, or industrial materials—through isolation, containment, or diversion techniques. This method minimizes downstream contamination and is often the most cost-effective long-term solution, however successful implementation requires a robust PFAS conceptual site model. The second strategy focuses on optimizing existing stormwater infrastructure, such as retrofitting detention basins or bioretention systems with PFAS-targeted amendments like activated carbon or specialized media. This approach leverages existing assets while enhancing their ability to capture and retain PFAS. The third option is to install dedicated PFAS treatment systems such as advanced filtration units designed specifically for PFAS removal. While these systems can offer targeted performance, they are typically expensive to implement and may be less efficient when dealing with the variable water quality and flow conditions characteristic of stormwater. An integrated strategy that prioritizes source control and infrastructure optimization, with selective use of treatment systems, offers the most practical path forward.  This presentation highlights findings from four case studies on practical strategies for managing PFAS in stormwater systems. Approaches include in situ soil mixing with commercial amendments to reduce PFAS leaching from soil to stormwater and enhancements to existing stormwater control measures using passive sorptive media. It also showcases CDM Smith’s recent work on aerosol and foam enhanced PFAS capture, along with a review of PFAS dynamics in plant-based stormwater systems, all aimed at advancing treatment train implementation. These strategies contribute to a broader multi-stage treatment approach, offering scalable, site-specific solutions for PFAS mitigation. 

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Advanced PFAS Destruction Through Custom Reactivation of Spent Granular Activated Carbon (GAC)

Benjamin Pepper, Business Development Manager, Norit Americas

Abstract:

As regulatory pressure increases and disposal options for spent granular activated carbon (GAC) become more limited, water utilities must seek sustainable and effective methods for PFAS mitigation. This study presents the findings of Norit Americas’ custom reactivation trial conducted at its Pryor, OK facility, demonstrating the complete destruction of PFAS in spent GAC through high-temperature thermal reactivation.  The reactivation process utilized advanced process controls, including kiln processing at temperatures exceeding 1750°F, an afterburner for emissions treatment, and a caustic scrubber for fluorinated byproduct neutralization. Comprehensive mass balance analysis confirmed >99.98% PFAS destruction, with rigorous emissions and water quality monitoring ensuring zero detectable PFAS release into the environment.  Furthermore, performance testing confirmed that reactivated GAC maintains its PFAS adsorption capacity, proving to be a viable, cost-effective alternative to virgin carbon for water treatment applications. These findings highlight custom GAC reactivation as a practical circular economy solution, offering utilities a sustainable, regulatory-compliant approach to PFAS management.  

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Verralize: A Portable, Battery-Powered 16-Channel Carbon-Nanomaterial PFAS Screening Kit with Single-Use Sensor Cartridge and US EPA Method 533 LC-MS/MS Benchmarking

Kiruthiga Ramakrishnan, Lead Engineer, Verralize (Formerly 12-15 Molecular Diagnostics)

Abstract:

Per- and polyfluoroalkyl substances (PFAS) monitoring programs often require rapid screening to guide sampling decisions and prioritize confirmatory testing, yet laboratory turnaround times can delay field actions. We have developed Verralize, a portable, battery-powered, compact standalone PFAS screening kit that delivers qualitative presence/absence calls and quantitative concentration estimates in <15 minutes from drinking-water samples. The system consists of a 16-channel Verralize reader/analyzer and a single-use, carbon-nanomaterial-based 16-sensor cartridge, enabling rapid on-site field screening without dependence on benchtop laboratory infrastructure or highly trained personnel.  The workflow is designed for simplicity and speed. A single universal (class-selective) ligand is mixed directly with the water sample and briefly vortexed to promote rapid ligand–PFAS association. The mixture is then applied to the disposable sensor cartridge, where interactions with the carbon-nanomaterial sensing interface are transduced into a measurable conductive electrical signal captured by the Verralize reader/analyzer. The universal ligand is designed based on the chemical surface properties towards PFAS targets, which are differentiated using property-driven response behavior, where signal magnitude and response characteristics vary with chain length, functional group chemistry, ionic/charge behavior, and concentration-dependent interaction strength.  The platform targets PFOA, PFOS, PFNA, PFHxS, HFPO-DA (GenX), and PFBS. To improve sensitivity and confidence, the disposable cartridge implements two replicate sensing channels per target (12 analyte channels total) with replicate aggregation and outlier flagging. The remaining channels provide internal QA/QC, including two negative controls (blank/matrix blank) to quantify baseline and nonspecific response and two positive controls (defined PFAS mixture spike) to verify assay function and sensor responsivity each run.  Water samples collected across the Tri-State region (Connecticut, New Jersey, and New York) were measured using Verralize and benchmarked against LC-MS/MS using US EPA Method 533. Across tested drinking-water samples, the system demonstrated ppt-level sensitivity down to ~1.5 ppt, supporting highly sensitive, rapid field screening at low concentrations and enabling fast prioritization of samples for confirmatory laboratory analysis. This work demonstrates a practical pathway toward higher-throughput PFAS monitoring by combining a rapid universal-ligand workflow, carbon-nanomaterial signal transduction, disposable 16-sensor cartridges, embedded controls, and orthogonal laboratory corroboration.  Keywords: PFAS; rapid field screening; Verralize; portable sensor; battery-powered reader; disposable cartridge; carbon nanomaterial; conductometric array; universal ligand; EPA 533 validation  

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