14th International Conference on Remediation of Chlorinated and Recalcitrant Compounds banner

14th International Conference on Remediation of Chlorinated and Recalcitrant Compounds

May 31 – June 4, 2026

134 Articles 180 Sessions

180 Session Types

A1.: PFAS Stabilization in Soil and Solid Wastes (Platforms)

A1.: PFAS Stabilization in Soil and Solid Wastes (Posters)

A2.: In Situ PFAS Soil Treatment Approaches (Platforms)

A2.: In Situ PFAS Soil Treatment Approaches (Posters)

A3.: PFAS Human Health and Ecological Risk Assessment and Toxicity (Platforms)

A3.: PFAS Human Health and Ecological Risk Assessment and Toxicity (Posters)

A4.: PFAS: Sampling and Analytical Methods Challenges in Different Environmental Matrices (Platforms)

A4.: PFAS: Sampling and Analytical Methods Challenges in Different Environmental Matrices (Posters)

A5.: PFAS Fate and Transport at Contaminated Sites (Platforms)

A5.: PFAS Fate and Transport at Contaminated Sites (Posters)

A6.: Ex Situ PFAS Destruction Technologies: Field Demonstrations (Platforms)

A6.: Ex Situ PFAS Destruction Technologies: Field Demonstrations (Posters)

A7.: PFAS and Bugs: The Search Continues (Platforms)

A7.: PFAS and Bugs: The Search Continues (Posters)

Presentation Title: Competing Cascade Modules of Fluorotelomer PFAS Biotransformation under Anaerobic and Aerobic ConditionsFormatted Title: Competing Cascade Modules of Fluorotelomer PFAS Biotransformation under Anaerobic and Aerobic ConditionsBackground/Objectives: Fluorotelomer carboxylic acids (n:3 FTCAs) are significant PFAS precursors largely found and persisted in landfill leachates and other environmental matrices. Here we used 5:3 FTCA as a representative molecule and compared its biotransformation potentials under varying redox conditions. We discovered two cascading pathways , including “enoyl-hydration cascade” and “hydroxylation cascade” that are involved across anaerobic and aerobic conditions based on the detection of transient and accumulating transformation metabolites by Nano-ESI-HRMS. The discovery of previously unreported keto-FTCA intermediates enabled to complete the biotransformation step of two cascades, and quantify how anaerobic versus aerobic operation partitions flux between the two cascades. Approach/Activities: Bench-scale microcosms were assembled using biosolids collected from a local WWTP in northern New Jersey. Two parallel treatments were prepared, including long-term anaerobic incubations over 5 months, including nitrate-reducing, sulfate-reducing, and methanogenic conditions, and short-term aerobic incubations through 12 days. Parent FTCA loss and products were tracked by both targeted LC-QQQ and non-target nano-ESI-HRMS with CID-based structural interpretation. Redox conditions were monitored using IC and GC-FID. We apportioned interval fluxes to cascade families and generating cumulative cascade shares by different redox conditions.Results/Lessons Learned: Here we identified keto-FTCA as an early and important intermediate under both aerobic and anaerobic conditions supporting by MS1 and MS2 confirmation. The intermediate provided missing mechanistic bridge for FTCA biotransformation (i.e., from hydroxylated FTCA to downstream products).  Anaerobic operation favored the“enoyl-hydration cascade", while aerobic operation expressed both cascades . Rapid formation of initial OH-FTCA and keto-FTCA formation was observed, together with the significant formation of downstream chain-shortening FTCA intermediate s and PFCA series with different chain length. Time-series data supported two FTCA biotransformation cascades initiated by Michael-type hydration or direct hydroxylation. Quantitative cascade apportionment, time-series kinetics, CID spectra for key metabolites confirmation, and fluorine mass recovery are investigated to reveal the contributions of individual processes to 5:3 FTCA biotransformation under varying redox conditions.

A8.: Expedite Site Closure: Innovative Strategies and Approaches (Platforms)

A8.: Expedite Site Closure: Innovative Strategies and Approaches (Posters)

A9.: From Data to Dialogue: Modern Tools and Practices for Stakeholder Communication (Platforms)

A9.: From Data to Dialogue: Modern Tools and Practices for Stakeholder Communication (Posters)

B1.: Advances in the Analysis of Non-Target PFAS (Platforms)

B1.: Advances in the Analysis of Non-Target PFAS (Posters)

B2.: Ex Situ PFAS Destruction Technologies (Platforms)

B2.: Ex Situ PFAS Destruction Technologies (Posters)

B3.: Ex Situ PFAS Treatment: Soils/Solids and Other Waste Streams (Platforms)

B3.: Ex Situ PFAS Treatment: Soils/Solids and Other Waste Streams (Posters)

B4.: Ex Situ PFAS Treatment Approaches (Platforms)