Short answer

When designing products or processes that involve PFAS, consider that cationic and zwitterionic forms will be more persistent in soil, requiring more robust waste management and end-of-life strategies.

Field: Resource Management
Source: UND Scholarly Commons (University of North Dakota) (2019)
Method: Experimental study with laboratory analysis
Evidence: Strong effect

The chemical structure of Per- and Polyfluoroalkyl Substances (PFASs), specifically whether they are cationic or zwitterionic, significantly influences their retention in soil environments compared to their acidic forms. This resource management research insight is drawn from a 2019 study published in UND Scholarly Commons (University of North Dakota). Using Experimental study with laboratory analysis, researchers explored how this design variable affects real-world outcomes. The key design takeaway: When designing products or processes that involve PFAS, consider that cationic and zwitterionic forms will be more persistent in soil, requiring more robust waste management and end-of-life strategies.

Study

Resource ManagementHigh ImpactStrong effect

Cationic and Zwitterionic PFAS Exhibit Higher Soil Sorption Than Their Acidic Counterparts

UND Scholarly Commons (University of North Dakota) · 2019

Key Findings

01Distribution coefficients (Kd) for zwitterionic (PFOAB) and cationic (PFOAAmS) PFAS precursors were significantly higher than for the acidic PFOA.
02The order of sorption affinity was PFOAAmS > PFOAB > PFOA.
03Soil properties, including organic matter, cation exchange capacity, and BET surface area, were identified as key factors influencing PFAS adsorption.
04Sorption-desorption hysteresis was observed for the zwitterionic PFAS (PFOAB) in soils with low organic matter content.

Application

Design takeaway

How to apply

When assessing the environmental impact of products containing PFAS, differentiate between various PFAS chemical forms and their known soil sorption behaviors. Prioritize materials with lower soil affinity or develop containment strategies for those with higher affinity.

Project actions

01When researching materials, look for data on their environmental persistence and interaction with common environmental media like soil.
02Consider how the chemical structure of a material might influence its behavior after disposal or during use in outdoor environments.

Method & Evidence

AimTo investigate the sorption and desorption mechanisms of perfluorooctanoic acid (PFOA) and its cationic and zwitterionic precursor compounds in various soil types.

MethodExperimental study with laboratory analysis

ProcedurePFAS compounds (PFOA, PFOAB, PFOAAmS) were introduced to five different soil samples. Sorption and desorption processes were measured, and the data was fitted to the Freundlich model to calculate distribution coefficients (Kd). Soil properties like organic matter content, cation exchange capacity, and surface area were analyzed for their influence on PFAS sorption.

ContextEnvironmental chemistry and soil science, focusing on industrial and consumer chemical contaminants.

Variables

IVChemical form of PFAS (acidic, cationic, zwitterionic)

DVSorption/desorption coefficient (Kd)

CVSoil properties (organic matter, CEC, surface area), PFAS concentration, contact time

Strengths & Limitations

Strengths

+Investigated multiple PFAS forms and their interaction with diverse soil types.
+Utilized established modelling techniques (Freundlich model) to quantify sorption behavior.

Limitations

The specific soil types and PFAS compounds studied might not represent all real-world scenarios. The study did not cover the full range of environmental conditions or degradation processes.

Reliability & validity

The use of established models and controlled laboratory conditions likely enhances reliability. Validity is supported by the correlation with soil properties, but generalizability to all soil types and PFASs may be limited.

Think critically

How might the observed differences in soil sorption for various PFAS types influence the design of filtration systems or remediation technologies for contaminated water or soil?

Design Principles

"Chemical structure dictates environmental interaction and persistence."

Understanding how different PFAS compounds interact with soil is crucial for assessing their environmental persistence and potential for contamination. This knowledge informs strategies for managing industrial waste, designing remediation technologies, and developing safer chemical alternatives.

What This Means for Your Design

Some man-made chemicals called PFAS stick to soil more strongly than others, depending on their electrical charge. This means some PFAS will stay in the ground longer.

How to use in your project

1.Use this research to justify the selection of materials with lower environmental persistence or to inform the design of waste management strategies for materials containing PFAS.

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Quick Cite

Paragraph starter

Research indicates that the chemical structure of Per- and Polyfluoroalkyl Substances (PFASs) significantly impacts their environmental behavior, with cationic and zwitterionic forms exhibiting considerably higher sorption to soil compared to their acidic counterparts (Jin, 2019). This differential binding, influenced by soil properties such as organic matter content, suggests that products containing these more persistent PFAS forms require more rigorous end-of-life management to prevent environmental accumulation.

Source

UND Scholarly Commons (University of North Dakota)

Per- And Polyfluoroalkyl Substances In The Soil Environment: Sorption, Bioaccumulation And Biotransformation

journal · 2019

View source

Questions About This Research

What does the research say about cationic and zwitterionic pfas exhibit higher soil sorption than their acidic counterparts?: When designing products or processes that involve PFAS, consider that cationic and zwitterionic forms will be more persistent in soil, requiring more robust waste management and end-of-life strategies. Evidence: UND Scholarly Commons (University of North Dakota) (2019).
Why does "Cationic and Zwitterionic PFAS Exhibit Higher Soil Sorption Than Their Acidic Counterparts" matter for design?: Understanding how different PFAS compounds interact with soil is crucial for assessing their environmental persistence and potential for contamination. This knowledge informs strategies for managing industrial waste, designing remediation technologies, and developing safer chemical alternatives.
How can designers apply this research?: When designing products or processes that involve PFAS, consider that cationic and zwitterionic forms will be more persistent in soil, requiring more robust waste management and end-of-life strategies.
What were the main findings?: Distribution coefficients (Kd) for zwitterionic (PFOAB) and cationic (PFOAAmS) PFAS precursors were significantly higher than for the acidic PFOA.. The order of sorption affinity was PFOAAmS > PFOAB > PFOA.. Soil properties, including organic matter, cation exchange capacity, and BET surface area, were identified as key factors influencing PFAS adsorption.. Sorption-desorption hysteresis was observed for the zwitterionic PFAS (PFOAB) in soils with low organic matter content.
What research method was used?: Experimental study with laboratory analysis.
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2019 journal from UND Scholarly Commons (University of North Dakota).
What should I do differently in my next project?: When assessing the environmental impact of products containing PFAS, differentiate between various PFAS chemical forms and their known soil sorption behaviors. Prioritize materials with lower soil affinity or develop containment strategies for those with higher affinity.
What are the limitations?: The study focused on specific PFAS compounds and soil types; results may vary with different PFAS chemistries and diverse soil compositions. Long-term environmental fate and transformation pathways were not fully explored.