For treating drinking water and wastewater, the ultrafiltration membranes developed by Arkema offer unrivaled performance in addressing a global challenge.
Ensuring everyone has access to high-quality water is one of the major challenges of the 21st century. Now one of the most common solutions for water treatment, ultrafiltration systems involve water flowing through membranes (hollow microporous fibers of 1 to 2 mm in diameter) that retain particles, bacteria and viruses. “These are purely mechanical solutions that require little energy,” explains Bernard Schlinquer, Manager, Kynar® Films & New Markets at Arkema. It is a vital market for which the Group is developing special grades of high- performance PVDF. “Membranes made from Kynar® DH 100, the latest to come out of our R&D department, stand out for their long-lasting hydrophilic property,” Schlinquer continues. “They retain more than 99% of bacteria and viruses, can filter larger volumes (20% more) with the same energy, and have double the lifespan of more traditional products.”
These Kynar® membranes are used in portable kits, developed in partnership with the module manufacturer Polymem, for drinking water solutions in developing countries.
More widely, drinking water processing plants, which must meet very high standards in terms of filtration, are the ideal application for Kynar PVDF® fibers. The latter are used widely in industry too, particularly for treating wastewater. “We work with many membrane bioreactor manufacturers in China, the United States, and Europe,” says Schlinquer. In 2019, the wastewater market represented two-thirds of sales of Kynar® ultrafiltration products.
A major issue in protecting water environments is the treatment of wastewater. Arkema’s acrylic monomers, which are used to produce flocculants, contribute to this process, as does hydrogen peroxide for desulfurization applications.
In a water treatment plant, flocculants play two essential roles. “They absorb materials suspended in the water, forming large flocs, which can then be filtered, and they are also used to thicken and dry sediment to make sludge for spreading,” explains Bernard Darricau, Director, Acrylic Monomers Europe at Arkema. These agents are based on acrylic monomers, of which Arkema is one of the world’s leading suppliers. In addition to state-run water treatment plants in developed countries, these products are essential in the treatment of industrial effluents around the world.
Hydrogen peroxide is another Arkema product that makes a valuable contribution to certain urban network configurations. “When water remains in the system too long, and in hot weather, bacteria can develop that lead to the formation of hydrogen sulfide (H2S), which is very damaging to the functioning of treatment plants,” explains Philippe Zydowicz, Hydrogen Peroxide Development Director. To protect the plant, materials and staff, one effective option is to inject incoming water with hydrogen peroxide, of which the Group is the world’s third biggest producer, under the Albone® brand. “When continuously injected at the levels corresponding with measured concentrations of H2S, it reacts instantly, generating byproducts of water and non-toxic sulfate,” says Julien Leroy, Business Manager, Oxygenated Products. This clean, rapid solution has been implemented by Veolia, for example, in various treatment plants in the south of France.