January 14, 2011

Lewatit resins driving environmental protection in India

It is new and unique

A new application for Lewatit® ion exchange resins successfully was implemented in India. The method is based on a special “chelating resin” produced by the Ion Exchange business unit (BU ION). The application ensures the removal of fluoride from waste water – leaving rest concentration below 1 ppm*. Such a low concentration can generally not be achieved by conventional methods such as lime precipitation – hence providing a big step forward in environmental protection technology.

Also looking at the method on larger scale – from a world wide perspective – the practical use of aluminium doped resins for selective fluoride removal is new. “Our unique approach was to use an ion exchange resin with an especially high affinity to bind both: the aluminium coating material as well as the fluoride. In various tests carried out in our application development laboratory in Leverkusen the resin Lewatit® MonoPlus TP 260 turned out to have the optimum properties”, explained Stefan Neumann, Manager Technical Marketing at Ion Exchange Resins business unit. “After clarification of basics in the laboratory we could successfully scale up and validate the process into technical scale by close cooperation with Sai Environmental Engineers Pvt. Ltd. in Hyderabad, India, and also by the strong support of our technically skilled Indian LANXESS colleagues".

Now, after successfully running a pilot plant in a major chemical manufacturing plant in Gujarat, India, for longer than one year it was decided to apply this technology to treat the joined waste water from the FAB-city industrial park located close to Hyderabad that was inaugurated in 2009. In total there will be nine semi conductor and nine solar cell production facilities on the premises of the industrial park once it is finished.

Together with his Indian colleagues Prakash Shanmugam, Kedar Oke and Rajesh Babu, Stefan Neumann visited the construction site in the beginning of December 2010. “Once the plant is in operation it will treat in total 1100 m³ of waste water per day. Several treatment steps including the selective fluoride removal by ion exchange insure the purified water will have the required quality to be used for watering of plants in the facility and/or will be recycled back to be used as industrial water,” said Neumann. The FAB-city project is a so-called zero emission site – the discharge of waste water is prohibited, since there is now river in the dry surroundings of Hyderabad where the recycled waste water could be discarded.

“Because of the same meteorological situation in other places, the overall booming computer and solar industry and the increased pressure from local authorities, we expect more projects of this kind in a short time” said Prakash Schanmugam, Head Marketing & Sales of ION in India.

Currently LANXESS researchers are further developing the application so that it can also be used for treatment of potable water. Several wells in India still contain fluoride in concentrations higher than the limit of 1.5 mg/L - this can damage teeth and bones and thus be hazardous for the health.

* parts per million = mg/L