Removal of PFOA from waste water

PFOA (perfluorooctanoic acid) is a man-made chemical substance that does not occur naturally in the environment. It belongs to the PFAS group of substances, which has come under scrutiny in recent years. The substance PFOA is used to protect the surfaces of products, for example the treatment of carpets and clothing. PFOA can be released in the environment during production, by use of products and by waste from products containing PFOA. It can be detected in surface water, waste water and groundwater.

Contamination of surface water with these products should be avoided if at all possible, due to the potential environmental and health risks. Witteveen+Bos are working with others, performing research and tests to remove PFAS from the water. In this case, Witteveen+Bos worked together with Arcadis to remove PFOA from the waste water flow from a landfill site. We researched various techniques to see which yielded the best result.

An important requirement was that the technology could be implemented to achieve a feasible solution. A solution that is robust and cost-effective. The solution should also be suitable to the specific composition of the waste water from the landfill site in question. In addition, we also took into consideration the client’s request to develop a system that allows two suppliers to be compared simultaneously. In this project, Witteveen+Bos were responsible for drafting the technological recommendations for the removal of PFOA from this waste water flow.

Focus on high-performance purification system

To this end, we designed a water purification system consisting of two parallel activated carbon filters with their own pumps and buffering capacity. The advantage of this system is that it gives the client a very clear insight into the performance and this allowed the client to make an informed decision about the system. Following approval of the design, the system was installed on-site and extensive testing was conducted. The purified waste water complied with discharge requirements and could be safely discharged into the surface water.

In this part of the project, Witteveen+Bos monitored the removal efficiency for PFOA and the discharge via a monitoring programme.