US 12,304,841 B2
PFAS remediation using high redox potential free-radicals
Daniel R. Griffiths, Denver, CO (US); and Akshay Chandrashekar Parenky, Syracuse, NY (US)
Assigned to Parsons Corporation, Centreville, VA (US)
Filed by PARSONS CORPORATION, Centreville, VA (US)
Filed on Jun. 23, 2023, as Appl. No. 18/340,433.
Application 18/340,433 is a continuation of application No. 17/344,129, filed on Jun. 10, 2021, abandoned.
Claims priority of provisional application 63/145,797, filed on Feb. 4, 2021.
Claims priority of provisional application 63/038,282, filed on Jun. 12, 2020.
Prior Publication US 2023/0348302 A1, Nov. 2, 2023
Int. Cl. C02F 1/72 (2023.01); C02F 1/02 (2023.01); C02F 101/36 (2006.01); C02F 103/06 (2006.01)
CPC C02F 1/725 (2013.01) [C02F 1/02 (2013.01); C02F 1/722 (2013.01); C02F 2101/36 (2013.01); C02F 2103/06 (2013.01); C02F 2209/003 (2013.01); C02F 2209/02 (2013.01); C02F 2303/16 (2013.01); C02F 2305/023 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for remediation of per- and polyfluoroalkyl substances (PFAS), the method comprising: forming an in-situ zone of treatment wherein forming includes measuring an initial groundwater fluoride concentration within the in-situ zone of treatment and verifying a thermal environment within the in-situ zone of treatment having a temperature >20 degrees centigrade;
dispersing an initial quantity of a transition metal catalyst into the thermal environment creating a catalyst rich thermal environment;
introducing to the catalyst rich thermal environment an initial quantity of an oxidant, wherein the initial quantity of the oxidant and the initial quantity of the transition metal catalyst within the catalyst rich thermal environment are at an initial molar ratio between 1:10-1:250, generating high redox potential free-radicals thereby oxidizing PFAS compounds by the high redox potential free-radicals producing, inter alia, fluoride;
calculating a rate of change of groundwater fluoride concentration within the in-situ zone of treatment;
monitoring the rate of change of groundwater fluoride concentration within the in-situ zone of treatment;
introducing an additional quantity of oxidant to the catalyst rich thermal environment if the rate of change of groundwater fluoride concentration in the catalyst rich thermal environment is not substantially zero until the rate of change of groundwater fluoride concentration in the catalyst rich thermal environment is substantially zero;
optionally adding an additional quantity of the transition metal catalyst in the catalyst rich thermal environment; and
responsive to the rate of change of groundwater fluoride concentration in the catalyst rich thermal environment being substantially zero upon introduction of the additional quantity of oxidant and replenishing of the transition metal catalyst, dispersing an additional quantity of the transition metal catalyst to the catalyst rich thermal environment until the rate of change of groundwater fluoride concentration in the catalyst rich thermal environment is substantially zero,
wherein the oxidant is a peroxy-based material or a sulfur-based material.