Viraj deSilva, PE

PFAS Treatment and Remediation - What's New in Destruction  

Dr. Viraj deSilva, PE, BCEE, Senior Treatment Process Engineer and PFAS Expert, Freese & Nichols, Inc.

After clearing the hurdles of identifying and removing PFAS, water and wastewater utilities must then figure out what to do with it. Removal of PFAS is a widespread  challenge because public-owned treatment works are refusing to accept PFAS sources for example from industries and landfills. A case study will examine PFOA and  PFOS leachate data from 4 landfills in North Carolina and how one landfill is currently removing and managing these contaminants.  EPA is currently considering multiple disposal techniques, including incineration of PFAS materials, thermal treatment of PFAS in biosolids and managing PFAS in landfill  leachate. If PFAS waste can be broken down at high temperatures with less harmful compounds, this may be one way to manage PFAS when options such as GAC, IX, or  RO only do separation and ending up with concentrated product with original PFAS content.   This presentation will provide an overview of ongoing PFAS destruction research funded by USEPA and progress on each technology, along with expected destruction  efficiencies and timeline for completion and producing commercially available systems. Most these projects are in the final stages with some promising results. The  presentation will cover technologies such as electrochemical oxidation, mechanochemical degradation, pyrolysis/gasification, and supercritical water oxidation.    Learning Objectives: Options for PFAS destruction technologies that are under development through EPA-funded research.

Dr. deSilva has more than 29 years of experience on water and wastewater treatment projects across the U.S. and 12 other countries, including PFAS management and treatment projects in five states working with airports, landfills, and other contaminated sites. He has been published in or presented at over 170 industry journals and conferences; authored EPA, WEF, ASCE and AWWA manuals of practice; and his recent PFAS work is cited in AWWA and EPA publications.  Dr. deSilva currently serves on the WEF PFAS Task Force and works closely with the national EPA Council on PFAS and state agencies for development of the new PFAS regulations. Dr. deSilva’s AWWA’s paper Managing and treating PFAS in membrane concentrates has been selected as the 2021 AWWA Membrane Treatment Best Paper AWARD.