Advantages and disadvantages of the recent and emerging technologies used for the treatment of PFAS from wastewater
| Treatment technology . | Advantages . | Disadvantages . |
|---|---|---|
| Activated carbon adsorption | Technically simple process and adaptable to many existing treatment plants Can be applied for large-scale operations Inexpensive process Extensive range of available commercial products Highly effective process with fast adsorption kinetics High quality of the treated effluent | Nondestructive method Not effective for short-chain PFAS Efficiency reduces in the presence of other constituents Costly reactivation process Requirement of further disposal of the adsorbent if not reactivated |
| Ion-exchange resins | Technically simple operation Wide range of commercially available products Easy operation and maintenance Easy integration to other wastewater treatment processes Possibility of regeneration and reuse High quality of the treated effluent | Nondestructive method Economic limitations (high capital and maintenance cost of the selective resin and time-consuming regeneration process) Clogging of columns in the presence of particulates and organic matter, and may require a physicochemical pre-treatment Performance sensitive to pH Not very effective for short-chain PFAS Requirement of further disposal of the resin if not regenerated |
| Electrooxidation | Destructive technology High mineralization efficiency No need for addition of external chemicals in most cases Effective for many different types of PFAS including short-chain Relatively inexpensive operation cost Simple operation Rapid degradation | High initial cost of the electrodes Cost of the maintenance (depends on electrode inertness and stability) Anode passivation and sludge deposition on the electrodes which can reduce the process efficiency in continuous mode of operation Foam formation during wastewater treatment Possible toxic byproducts formation (chlorate and perchlorate) in the presence of chloride Mostly suitable for small- or medium-sized communities |
| Ultrasound | Destructive technology No need for addition of external chemicals No secondary pollution Simple operation No sludge production | High operational cost Management of generated heat energy Scale-up challenges Mostly suitable for small waste streams |
| Plasma-based technologies | Destructive technology Inexpensive operation cost High mineralization efficiency Effective for short-chain PFAS No need for addition of external chemicals | Scale-up is challenging Toxic byproduct formation Safety issues due to high voltage discharge for plasma generation |
| Photocatalysis using nanomaterials (Ga2O3 and In2O3-based) | In situ production of reactive radicals Little or no consumption of chemicals Mineralization of the pollutants No sludge production Rapid degradation | Separation of catalyst material from treated water Limited light penetration in solution for reaction to occur Mass transfer limitations Susceptible to inactivation from presence of NOM and ions |
| New generation adsorbents (COFs, MOFs, CNTs, and organically modified silica) | High chemical stability (COFs and MOFs) Pre-designable porous structure (COFs and MOFs) Effective for low concentrations Ease of operation High surface areas Tunable functionalities | Currently limited to laboratory scale Narrow pH range (MOFs)Relatively high synthesis cost (COFs and MOFs) Poor dispersibility in water (CNTs) Not effective for short-chain PFAS |
| Treatment technology . | Advantages . | Disadvantages . |
|---|---|---|
| Activated carbon adsorption | Technically simple process and adaptable to many existing treatment plants Can be applied for large-scale operations Inexpensive process Extensive range of available commercial products Highly effective process with fast adsorption kinetics High quality of the treated effluent | Nondestructive method Not effective for short-chain PFAS Efficiency reduces in the presence of other constituents Costly reactivation process Requirement of further disposal of the adsorbent if not reactivated |
| Ion-exchange resins | Technically simple operation Wide range of commercially available products Easy operation and maintenance Easy integration to other wastewater treatment processes Possibility of regeneration and reuse High quality of the treated effluent | Nondestructive method Economic limitations (high capital and maintenance cost of the selective resin and time-consuming regeneration process) Clogging of columns in the presence of particulates and organic matter, and may require a physicochemical pre-treatment Performance sensitive to pH Not very effective for short-chain PFAS Requirement of further disposal of the resin if not regenerated |
| Electrooxidation | Destructive technology High mineralization efficiency No need for addition of external chemicals in most cases Effective for many different types of PFAS including short-chain Relatively inexpensive operation cost Simple operation Rapid degradation | High initial cost of the electrodes Cost of the maintenance (depends on electrode inertness and stability) Anode passivation and sludge deposition on the electrodes which can reduce the process efficiency in continuous mode of operation Foam formation during wastewater treatment Possible toxic byproducts formation (chlorate and perchlorate) in the presence of chloride Mostly suitable for small- or medium-sized communities |
| Ultrasound | Destructive technology No need for addition of external chemicals No secondary pollution Simple operation No sludge production | High operational cost Management of generated heat energy Scale-up challenges Mostly suitable for small waste streams |
| Plasma-based technologies | Destructive technology Inexpensive operation cost High mineralization efficiency Effective for short-chain PFAS No need for addition of external chemicals | Scale-up is challenging Toxic byproduct formation Safety issues due to high voltage discharge for plasma generation |
| Photocatalysis using nanomaterials (Ga2O3 and In2O3-based) | In situ production of reactive radicals Little or no consumption of chemicals Mineralization of the pollutants No sludge production Rapid degradation | Separation of catalyst material from treated water Limited light penetration in solution for reaction to occur Mass transfer limitations Susceptible to inactivation from presence of NOM and ions |
| New generation adsorbents (COFs, MOFs, CNTs, and organically modified silica) | High chemical stability (COFs and MOFs) Pre-designable porous structure (COFs and MOFs) Effective for low concentrations Ease of operation High surface areas Tunable functionalities | Currently limited to laboratory scale Narrow pH range (MOFs)Relatively high synthesis cost (COFs and MOFs) Poor dispersibility in water (CNTs) Not effective for short-chain PFAS |