May 20, 2010

Chemistry and know-how in the fight against arsenic in drinking water - BU ION at international congress in Taiwan

Water is the most important substance of all to life. Specialty chemicals group LANXESS is highlighting the overriding importance of this substance with a variety of activities complementing its chemistry and know-how as part of its "Year of Water 2010" initiative. This includes the company’s contribution to the 3rd International Congress on Arsenic in the Environment, which takes place in Tainan, Taiwan, from May 17 to 21. 

In his congress presentation, Dr. Stefan Neumann, Manager Technical Marketing and Chemicals Purification at the Ion Exchange Resins (ION) business unit, showcases recent research using a new hybrid adsorber for treating drinking water. Plastic-based Lewatit® FO 36 grade hybrid adsorber, modified with a special, nanoscale iron oxide, allow highly efficient and selective removal of arsenic from drinking water. Arsenate and arsenite ions are attached via a covalent bond to the iron oxide surface and are thereby removed from the surrounding water. Product development was successfully completed in 2008 and the experts involved were honored the following year with the LANXESS innovation award in the ecology category. LANXESS is one of the world’s leading manufacturers of ion exchange resins and expects to see above-average growth in the future, particularly in water treatment.

 

“We have presented a technical concept in Taiwan to also remove arsenic from water containing large amounts of silica. This was previously only possible to a limited extent,” says Neumann, explaining one of the current research areas. Laboratory tests also showed that the hybrid adsorber can be used to fill filter cartridges and – as in standard cartridges for softening water – be deployed on a localized basis in the home or on the move. One single cartridge containing only around 0.1 liter of adsorber was used to treat around 1,200 liters of water over three months. This cut arsenic content from approximately 100 ppb (100 micrograms per liter) to less than 10 ppb.

 

As a dust-free, flowable substance with a standard grain size and excellent mechanical stability, the product is perfectly tailored to the requirements of industrial water treatment. After the saturation limit has been reached, it can be regenerated with lye, enabling it to be used repeatedly in an eco-friendly, cost-effective way. Lewatit® FO 36 is currently being used at a total of three facilities in Italy and Germany to remove arsenic from well water. This water can then be safely used as drinking water by several thousand people.  

Further information about the new hybrid adsorber Lewatit® FO 36 can be found in the _press release.