Performing Department
(N/A)
Non Technical Summary
Per and polyfluorinated alkyl substances (PFAS) are chemically and biologically resistant organic compounds that are persistent, bioaccumulative and highly toxic. Owing to their widespread contamination of public drinking water supplies, on April 10, 2024, the EPA established national drinking water standards for six PFAS compounds consistently detected in public drinking water systems. All regulated drinking water facilities must come into full compliance with the new national PFAS concentration standards by April 10, 2027.Beyond direct human consumption of PFAS-contaminated drinking water, the use of PFAS- impacted rural water resources to meet livestock drinking water demands has led to numerous cases of agricultural product contamination (e.g., tainted dairy products) as well as growing public concern over fish, meat and poultry quality. Similarly, use of PFAS-contaminated crop irrigation water has not only increased pollutant levels in rural public drinking water supplies (e.g., groundwater) but has also resulted in soil quality deterioration further exacerbating human exposure to these toxic pollutants.The focus of the current STTR Phase II scientific research program is the development and commercial deployment of the biochar-based electrochemical impedance PFAS detector technology. The ability to reliably measure PFAS levels at the picomolar concentrations using a portable, low-cost PFAS detection device facilitates actionable decision-making and allows rural water stakeholders to: 1) rapidly detect and quantify the concentration of PFAS chemicals in surface water, groundwater and reclaimed wastewater resources, 2) enhance protection of agricultural product quality from potentially PFAS-contaminated water supplies and 3) generate time-sensitive data needed to support PFAS-sensitive watershed management decisions.
Animal Health Component
50%
Research Effort Categories
Basic
25%
Applied
50%
Developmental
25%
Goals / Objectives
To date, our research group has achieved a number of important technical milestones including: 1) fabrication of a high-surface area biochar-based electrode, 2) synthesis of a first-generation fluorine molecular acceptor (FMA) electrode and 3) documented concentration-dependent changes in the measured surface capacitance of the FMA-coated electrodes in solutions containing 0.001 to 10 parts per million (ppm) perfluorooctanoic acid (PFOA). The following STTR Phase II project goals and supporting objectives are designed to complete the scientific inquiries necessary to pivot to product commercialization.Goal 1: Address the remaining key scientific questions associated with the practical use of FMA-biochar interfaces to detect and quantify aqueous PFAS concentrations.Objective 1A: Characterize the surface FMA layer attachment and coating uniformity of the biochar electrode surfaceObjective 1B: Optimize the applied bias and frequency conditions used for the impedimetric measurements in order to establish the lower PFAS concentration sensing limit Objective 1C: Establish the PFAS measurement reproducibility range for similarly constructed electrode surfaces Objective 1D: Determine the impact of aqueous conditions (i.e., pH, ionic strength, presence of dissolved organic non-PFAS species, etc.) on the sensitivity, accuracy, and reproducibility of the PFAS measurement Goal 2: Obtain national (i.e., Tier 3) regulatory approval of the portable PFAS detection technology as a legally recognized Alternative Test Procedure (ATP) for quantifying the aqueous concentrations of PFAS compounds by the US Environmental Protection Agency (EPA). Objective 2A: Develop an EPA-approved method validation plan that supports the collection of specific laboratory data required for comparing the performance of the portable PFAS detection technology with the current state-of-the-art analytical methods (i.e., EPA Methods 533 and 537.1)Objective 2B: Collect, analyze and statistically interpret the PFAS detection and quantification results from executing the method validation plan Objective 2C: Forward the internally reviewed method validation plan final report and accompanying petition to the EPA's Drinking Water and Wastewater ATP Program managers for an official approval recommendationGoal 3: Secure private sector STTR Phase III financing to support product manufacturing, marketing and sales distribution.Objective 3A: Develop a series of product design options that facilitate field deployment of the new PFAS detection technologyObjective 3B: Sign contractual agreements with reputable product manufacturing companies to develop a containerized version of the portable PFAS detection technology for commercial sale Objective 3C: Protect intellectual property (IP) through legal patent protection of key scientific concepts that define and support technology performanceObjective 3D: Utilize trade secrets and other legal means to protect the technology's manufacturing methodologies
Project Methods
The scientific methods employed during STTR Phase II efforts shall build upon those methods successfully developed and implemented during the STTR Phase I study. However, the overarching goal of STTR Phase II shall be to establish PFAS analyte sensitivity limits that are within the same order of magnitude as the current national regulatory limits (i.e., parts per trillion - ppt). Specifically, the previously verified scientific methods shall be employed to: 1) characterize the surface fluorine molecular acceptor (FMA) layer attachment and coating uniformity on the biochar electrode surface, 2) optimize the applied bias and frequency conditions used for the impedimetric measurements to determine the concentration lower limit for sensing regulated PFAS analytes, 3) establish measurement reproducibility ranges for similarly constructed electrode surfaces, and 4) determine the impact of aqueous conditions (i.e., pH, ionic strength, presence of dissolved organic non-PFAS species, etc.) on the sensitivity, accuracy, and reproducibility of the PFAS measurement.Enhanced selectivity and adsorption of regulated PFAS analytes are proposed to occur on the biochar electrode via the fluorophilic nature of the modified surface, which creates strong Van der Waals interactions. By improving its porosity and conductivity, the sensing performance of the lignin-derived mesoporous biochar electrode shall be enhanced to reliably and consistently respond to PFAS concentrations within the regulatory relevant (i.e., ppt) range.One of the unique challenges in commercializing the new portable PFAS analytical method is securing regulatory approval that the technology is "equivalent" to existing state-of-the-art methods. The official process by which an analytical method may be approved as an alternative test procedure (ATP) for PFAS quantification requires that the new method demonstrate in a multi-laboratory study that it can meet or exceed the quality control (QC) performance of currently approved methods.Once it has received regulatory approval, the new technology shall be made commercially available to a broad range of potential customers. The commercial availability of a rapid, low cost and portable PFAS detection system has the potential to fundamentally change the future scope of PFAS water monitoring programs. Agricultural producers, drinking water treatment plants, private well owners, public health officials and environmental regulators shall be able to monitor PFAS levels in water resources in nearly real-time. The ability to obtain reliable and instantaneous water quality data will allow rural water resource stakeholders to take immediate and decisive action to protect agricultural food safety, public health and/or the environment from PFAS contamination.Cache Environmental Laboratories, PC (CEL) has extensive experience in working with both national and regional US Environmental Protection Agency (EPA) offices as well as state regulatory authorities. CEL shall employ the EPA Quality System in designing a regulatory-approved multi-laboratory PFAS method validation program. The data collected from execution of the program shall include a statistical comparison of the aqueous PFAS concentrations reported by the new portable technology to those determined when employing the current state-of-the-art liquid chromatography-mass spectrometry (LC/MS) methods. The statistically validated data shall be used by the CEL technical staff in preparing an ATP petition for submission to the EPA for national regulatory approval.Obtaining regulatory approval of the portable PFAS detection system as an acceptable nationally recognized PFAS compliance verification method is the most important outcome of the STTR Phase II effort. Since verification of regulatory compliance is the overarching driver in technology sales, without securing the status of ATP method "equivalency", the target audience would not be inclined to purchase the new portable device.The evaluation of project success shall be determined by the ability of the research team to generate multi-laboratory verification data of sufficient quality that it may submitted to the EPA drinking water and wastewater managers as part of an ATP petition for technology equivalency approval. The project evaluation plan shall consist of the production and execution of an EPA-approved quality assurance project plan (QAPP) that provides the detailed steps of how aqueous PFAS analyte data shall be collected using the new portable technology as well as the data generated by the multi-laboratory participants. The QAPP shall incorporate explicit data quality objectives (DQOs) that establish the level of quality control necessary to support technology performance decisions. If the collected performance data satisfies the DQOs, it will be statistically analyzed and included as part of the ATP petition submitted by CEL to the EPA for approval consideration.To facilitate use of the new portable PFAS detection device, a user manual shall be developed that provides simple step-by-step instructions on how to calibrate the electrochemical sensor, load the biochar electrode and insert a water sample for analysis and reporting of the aqueous PFAS concentration. An accompanying YouTubeTM video that illustrates the operation of the new PFAS detection device in a typical field application is being considered for production. The impact of this outcome on the intended audiences shall be quantified by tracking the frequency and volume of new device sales following regulatory ATP approval of the technology.