Theme: 07. Per- and Polyfluorinated Alkyl Substances (PFAS)

Topic Area: 7p. PFAS: Groundwater Treatment Case Studies

Formatted Title:

PFAS: Case Study and Limitations of the Brazilian Market/Regulators

Background/Objectives:

An industrial plant producing specialty chemicals operating since 1954 in the state of São Paulo has an environmental liability composed mainly of metals, especially manganese, and concentrations of perfluoroalkylated acids (PFAS) on the banks of a river that is strategic for the urban development of the region. Although this is a case of management of a long-standing contaminated area and already at an advanced stage of knowledge/conceptual model, the PFAS theme arises from the review of the preliminary assessment of the area in the guidelines of CETESB Board Decision No. 038/2017, which presents indications of the use of raw materials with PFAS in the production of foam-generating liquids (AFFF). After evaluation by the responsible environmental agency and demand for monitoring the concentrations of these compounds in the network of existing wells, and the input of the São Paulo Public Ministry in the case due to the existence of the river, the search for potential solutions for treatment, disposal and destination of the compounds PFAS has been hampered by technological development and incipient legislation on the subject in the Brazilian market. That said, this study aims to illustrate a case study of PFAS on Brazilian soil, as well as the existing limitations on the topic in Brazil.

Approach/Activities:

The origin of the occurrences of metals and PFAS currently known and delimited in the industrial area is linked to usual transport mechanisms, such as leaks and infiltrations from the production area and the plant's existing effluent treatment station. Although recent studies on risk assessment to human health, numerical modeling and mass flow calculations have mischaracterized potential risks through the concentrations identified in groundwater, there is a latent demand for the implementation of intervention measures to treat the manganese present in groundwater and which consequently it contributes to the river. It should be noted, however, that as mentioned, there are also concentrations of PFAS above North American environmental references (EPA) – used due to the absence of national standards – in groundwater, and, therefore, EBP Brasil understands that such compounds should also be object of treatment in this case.

With this scenario under discussion, the implementation of a pump and treat hydraulic barrier presents itself as a viable and reliable alternative for the treatment of manganese, where the level of knowledge regarding the usual treatment methods is high. For PFAS, however, the scenario is different; 1) Treatment techniques restricted to adsorption (CAG), ion exchange resin (IX Resin) and reverse osmosis, with little or no development on national soil; and 2) Lack of information regarding the capacity of existing materials on the market to act with PFAS. Furthermore, even if the technical gaps that still exist in Brazil are equalized for the design and implementation of a system that acts in the treatment of PFAS, there is a legal gap to be discussed, since there is currently no legislation that address treatment standards and/or disposal, which can guide the definition of project goals.

Results/Lessons Learned:

EBP Brasil is developing internal studies and in partnerships with suppliers of activated carbon and resin to design breakthrough curves and isotherms, seeking the best solution for national customers. In parallel, the Brazilian technical contaminated site management community has the mission of promoting the issue with regulatory bodies, so that in the near future the national market is prepared to deal with PFAS.

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Victor Sorze

Biography