Micropollutants are man-made chemicals that occur in the environment due to human activities but with concentrations at trace levels (i.e. up to the μg/l range). Thousands of chemicals fall into this category and consist of purely synthetic chemicals, such as per- and polyfluoroalkyl substances (PFAS), or pharmaceutical compounds, such as antibiotics or oestrogens. PFAS come from manufacturing processes for coatings and foams used for controlling fires and are now ubiquitous in the environment and especially water sources. They have been shown to pose severe health risks to exposed populations and have been linked to thyroid disease, reproductive abnormalities, cancer, and suppressed immune responses. The EU-funded CGM project developed a customisable, selective, nanocellulose-based solution called CustoMem Granular Media (CGM) that deals with micropollutants. “The media are bioengineered to capture and remove PFAS and other micropollutants, including the fraction that cannot currently be eliminated,” states Henrik Hagemann, project coordinator and CEO of Puraffinity, Ltd. (formerly CustoMem).
More efficient alternative
Conventional water treatment methods cannot currently treat broad classes of PFAS efficiently. Existing water treatment removes 99.96 % of contaminants but does not remove the 0.04 % that comprises micropollutants. This is due to their exceptional chemical properties and stability in water - necessitating the development of novel treatment methods. Those absorbents that are currently available at an affordable price to capture PFAS are not selective enough. Furthermore, “the advanced oxidation processes that exist on the market capable of dealing with these substances are not a good option, since they increase operating costs when tackling highly recalcitrant compounds and their use generates other toxic chemicals,” Hagemann explains. The research team addressed this challenge by developing a practical, low-cost, low-energy solution using biological materials. “We developed granular media (CGM) to specifically bind the target hazardous micropollutants in water, such as pesticides, pharmaceuticals and high-performance chemicals,” comments Hagemann.
Friendlier to the environment
CGM is also superior to other solutions, like advanced oxidation processes, adsorption resins, ultraviolet treatment, and carbon nanotubes, in several key parameters. For example, it captures over 90 % of micropollutants in approximately 10 s, reducing concentrations to parts per trillion levels. “It operates like an industrial-scale, Brita-type water filter, as a drop-in to existing steel tank infrastructure and requiring a smaller footprint than conventional granular-activated carbon infrastructure,” Hagemann points out. The nano media are designed and manufactured through a sustainable biological production process that produces much lower amounts of hazardous chemicals and reduces energy consumption. CGM production and treatment operations are low energy and support a circular economy and reduce the greenhouse gas footprint by more than 50 % upon implementation. “Our goal is to reach proof of concept of CGM for removal of PFAS at a client’s site whilst scaling manufacturing of the granular media,” adds Hagemann. Beneficiaries of CGM are diverse and include water companies and utilities, industrial manufacturing facilities, airports, military bases and the general population. “Customers will benefit from a simple, low maintenance, low-cost, low-energy solution that removes high impact micropollutants to give clean water,” Hagemann concludes.
CGM, micropollutants, PFAS, water treatment, Polyfluoroalkyl substances, nanocellulose, circular economy