Granulated Activated Carbon (GAC)

GAC is an established adsorption technology for removing PFAS from water, with particularly strong performance on long-chain compounds and broad use in drinking water treatment.

• Effective for long-chain PFAS treatment
• Proven in continuous-flow water treatment systems
• Well suited to lower contamination applications
• Familiar operating model for many owners and operators

GAC can remove more than PFAS alone, making it useful where treatment goals include a broader set of organic contaminants.

• Reduces volatile organic compounds (VOCs)
• Treats semi-volatile organic compounds (SVOCs)
• Supports removal of total petroleum hydrocarbons (TPH)
• Adds value where mixed contaminant profiles are present

GAC remains a practical choice in applications where water chemistry may limit other treatment approaches.

• Not adversely impacted by elevated chloride concentrations
• Can be integrated into broader treatment trains
• Supports modular deployment where needed
• Fits a range of flow rates and operating conditions

Strong GAC performance depends on more than vessel sizing. Media life, breakthrough timing and replacement strategy all influence long-term reliability and cost.

• Offsite regeneration can be incorporated into service planning
• Changeout intervals can be forecast through testing and modeling
• Operational planning can reduce disruption during media replacement
• Treatment strategies can balance performance, waste and cost

A granular activated carbon system passes water through a bed of porous carbon media with a high internal surface area. As water flows through the vessel, PFAS and other target contaminants adsorb to the carbon surface, lowering contaminant concentrations in the treated effluent.

This mechanism is especially effective for long-chain PFAS, which tend to adhere more readily to activated carbon. Over time, the media becomes saturated and treatment performance declines, which is why monitoring, breakthrough evaluation and planned changeout or regeneration are essential to maintaining reliable operation.

Key considerations before selecting GAC

GAC can be a strong treatment solution, but it should be selected with a clear understanding of both its strengths and its tradeoffs.

Advantages

• Effective on PFAS, especially long-chain compounds
• Not adversely impacted by elevated chloride concentrations
• Removes a range of co-contaminants, including VOCs, SVOCs and TPH
• Can be regenerated, typically offsite

Considerations

• Lower PFAS removal capacity than ion exchange resin
• Larger footprint than ion exchange systems
• Can foul more quickly than adsorptive clay in some applications
• Offsite regeneration requires vessel evacuation and transportation
• Breakthrough requires periodic media replacement