用于市政水处理的离子交换树脂和氧化铁吸附剂

PFAS is a family of highly efficient surface active agents used in various applications such as firefighting foams, water repellent textiles, cook ware, galvanics, paints. When they are however, not handled and disposed thoroughly they can leach into the ground water where they persist due to their high chemical stability.

Even worse, PFAS bioaccumulate in humans, animals and plants and cause severe health issues including cancer. As a result, out of their hazardous potential, drinking water limits were set very strictly. Standard technologies such as activated carbon usually can not comply with the low effluent limits for short chain PFAS that represent the biggest challenge in remediation.

Reverse osmosis on the other hand generates large amounts of aqueous concentrates that have to be handled. LANXESS therefore developed a new family of selective ion exchange resins, that reduce PFAS reliably below the drinking water limits and which can safely be disposed after use.

Get more information about our solutions for the removal of per- and polyfluoroalkyl substances (PFAS) with Lewatit^® ion exchange resins.

Lewatit^® TP 106 is a new gel-type strong base anion exchange resin that is highly efficient for the removal of soft and toxic anions such as perchlorate (CIO₄^-), chlorate (ClO₃^-), bromate (BrO₃^-), and nitrate (NO₃^-). The special bead distribution of our novel product allows to operate at very high flow rates, which is crucial for a viable and efficient surface water and groundwater treatment.

Thanks to their very high surface area and adsorption capacity, Bayoxide^® iron oxide adsorbers can remove arsenic selectively and reliably below the limit value of 10 µg/l. Here, the efficiency is increased considerably if any As(III) present is converted into As(V) by means of oxidation. Compared with conventional adsorption media, the proven product for this application, Bayoxide^® E 33, enables significantly longer operating times for the filters due to higher capacity.

The arsenic is attached to the adsorbers In the form of arsenate via a covalent bond and can therefore be disposed of very simply as a solid. Due to the low As concentration that can be reached in the process at the beginning of the cycle (<< 5 ppb), the operating time of the adsorber can be extended significantly through dilution with the untreated water. The product types Bayoxide^® E 33 and Bayoxide^® E 33 HC are suitable for use in drinking water treatment and have the necessary certificates for this application.

Phosphate pollution in waste water frequently leads to problems in the outlet channels or the bodies of water into which the waste water is fed. Likewise, only a certain phosphate level can be tolerated in aquariums and aquacultures. Bayoxide^® IN 20 (fresh water) and Bayoxide^® IN 30 (salt water) are able to selectively remove phosphate from the water. For large-scale use, regeneration of the adsorber should be considered.

In addition to arsenic, Bayoxide^® E 33 and E 33 HC are able to remove metals from the water in the form of oxyanions (e.g. vanadate) or metal ions (Cu). The benefits here lie in the very simple handling (no regeneration), easy disposal (waste in solid form), and in the fact that both adsorbers can be used in the treatment of drinking water without any problems. Since the adsorbers are not regenerated, this application is especially recommended for a low feed concentration.