Water treatment for removing PFAS
AssigneeThe Water & Carbon Group Pty, Ltd.
InventorsCliff Alexander DuckWorth, James Patrick Hunter
Life of this patent
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Abstract
An above-ground low-energy method of dewatering highly contaminated waste e.g. leachate contaminated with at least a first group of contaminants and PFAS is described. The method comprises the step of removing the PFAS before removing the first group of contaminants. The removal of PFAS is undertaken by actively aerating the contaminated waste comprising PFAS to produce a waste stream comprising a concentration of PFAS and a liquid stream having at least some of the first group of contaminants. The one or more liquid streams are separated from the waste streams so as to dewater the contaminated waste. Optionally, the liquid streams are treated to remove the first group of contaminants.
Claims20
An above ground low energy method of dewatering waste contaminated with at least a first group of contaminants and PFAS, the method comprising the steps of:
- (a) removing the PFAS before removing the first group of contaminants;
- (b) removing the first group of contaminants;
- in step (a) the removal of PFAS is undertaken by:
- actively aerating the contaminated waste comprising PFAS in a first vessel to produce a first waste stream comprising a concentration of PFAS and a first liquid stream having at least some of the first group of contaminants;
- subjecting the first waste stream to a second process comprising actively aerating the waste stream in a second vessel to further concentrate the PFAS in a second waste stream, and also to generate a second liquid stream having at least some of the first group of contaminants;
- subjecting the second waste stream to a further process to further concentrate the PFAS in the waste stream, and also to generate a third liquid stream having at least some of the first group of contaminants;
- wherein one or more of the first, second and third liquid streams having at least some of the first group of contaminants are separated from the waste streams so as to dewater the contaminated waste;
- and
- in step (b) the removal of at least some of the first group of contaminants is undertaken by treating the first, second and or third liquid streams either separately or together.
An above ground low energy method of generating a highly PFAS concentrated waste stream from a waste, the waste comprising at least one of sewage, leachate, contaminated surface water, municipal wastewater and industrial wastewater, the waste contaminated with a first group of contaminants and having a TOC level greater than about 5 mg/L and the waste contaminated with PFAS, the PFAS including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (conjugate base perfluorooctanesulfonate) (PFOS), the method including the steps of:
- actively aerating the waste in a first vessel to produce a waste stream having a first PFAS concentration, and a first stream having at least some of the first group of contaminants;
- actively aerating the waste stream having a first PFAS concentration in a second vessel to produce a second waste stream having a second PFAS concentration, and a second stream having at least some of the first group of contaminants;
- passing the second waste stream having a second PFAS concentration through a further process to produce a third waste stream having a third PFAS concentration, and a third stream having at least some of the first group of contaminants;
- wherein the third PFAS concentration is higher than the second PFAS concentration
- further wherein, at least one of the first, second and third streams having the first group of contaminants is treatable so as to remove at least some of the first group of contaminants.
Dependencies are inferred from the claim text.