RemBind Features Prominently in a New Report on PFAS Soil Treatment Processes Published by CONCAWE
PFAS Soil Treatment Processes – A Review of Operating Ranges and Constraints (Report 8/24, May 2024)
CONCAWE has released a new industry report titled PFAS Soil Treatment Processes – A Review of Operating Ranges and Constraints (Report 8/24, May 2024). RemBind is featured prominently throughout the report as a field-proven stabilization technology for the remediation of PFAS in soil.
Several full-scale RemBind projects in Sweden, Australia and the USA are cited, and references to published long-term stability data add further credibility to the RemBind technology. The report concludes that stabilization is increasingly being seen as a “pragmatic and cost-effective option compared with many other soil remediation technologies for PFAS”.
Full-Scale Projects
The report states that RemBind has been used to treat thousands of tonnes of PFAS soil at full-scale globally indicating “increased adoption/acceptance”. This includes using stabilization as a treatment for onsite reuse or as a pre-treatment for safer landfill disposal.
The following projects are mentioned:
- Treatment of 7,000 tonnes of soil at Melbourne International Airport with the addition of 1 – 2% RemBind to stockpiled soil with relatively low PFAS impacts using three different blending methods. PFOS and PFHxS were assessed with 95% to 99.9% reduction achieved enable on-site reuse.
- 1,500 tonnes of soil resulting from construction works at a Royal Australian Airforce Base in Townsville. Soil was treated prior to off-site disposal with a special treatment area also constructed at the landfill due to its high environmental sensitivity. 32 target PFAS assessed with 95% to 99.9% reduction achieved across all analytes tested.
- Stabilization treatment using 1 – 2% RemBind for around 1,000 tonnes of soil excavated as part of a new petroleum storage tank installation at an active military facility in Sweden.
- Around 3,000 tonnes of PFAS impacted soil required disposal as part of site redevelopment at the Markyard site in Sweden, but the landfills approached would not accept the material. Following laboratory trials, soil was stabilised with 3 – 5% RemBind to enable acceptance at landfill with stones and large gravel removed prior to stabilisation and reused. The case study states a similar approach was planned for around 60,000 tonnes of soil in future.
Long Term Stability
The report mentions ground-breaking independent work published by Kabiri and McLaughlin (2021) that considered the main environmental factors that would affect PFAS sorption over time were temperature extremes and ionic strength. RemBind showed little or no detrimental effects with temperature extremes or changes in ionic strength with effects of competing ions were also absent or minimal.
Another pivotal publication by Arcadis at a US field site (McDonough et al, 2021) was also heavily cited in the report. This involved the in-situ treatment of soil with RemBind and cement and the long-term stability is being monitored over time. After 3 years of monitoring, <0.1% of the PFAS has leached. Since the CONCAWE report was published, data presented by Theresa Guillette (Arcadis) on 4th June at the 2024 Battelle Chlorinated conference in Denver, showed that after 5 years of monitoring this treatment remains very robust.
Stabilization of Heavy Metals – Lessons Learned
Interestingly, the report also draws similarities between PFAS contaminants and other heavy metal contaminants such as arsenic and chromium in terms of their chemistry and went on to explain that, in the author’s experience, stabilization in general has been used in the US for more than 50 years with no reported major failures, including for contaminants such as heavy metals, PAHs, PCBs and dioxins.
References
McDonough, J.T.; Anderson, R.H.; Lang, J.R.; Liles, D.; Matteson, K.; Olechiw, T. Field‐Scale Demonstration of PFAS Leachability Following In Situ Soil Stabilization. ACS Omega 2022, 7, 1, 419‐429. https://doi.org/10.1021/acsomega.1c04789
Kabiri, S.; McLaughlin, M. J. Durability of sorption of per‐ and polyfluorinated alkyl substances in soils immobilized using common adsorbents: 2. Effects of repeated leaching, temperature extremes, ionic strength and competing ions. Sci. Total Environ. 2021, 766, 144718. https://doi.org/10.1016/j.scitotenv.2020.144718