Lanxess' Liquid Purification Technologies (LPT) business will present its ion exchange resins and reverse osmosis membrane elements at IFAT in Munich on 14-18 May.
Lanxess LPT believes efficient processing and recycling methods will be essential in order to meet the demand for water in the future. Dr Jens Lipnizki, head of Technical Marketing Membrane at LPT, will discuss an example of efficient wastewater treatment resulting in the almost complete avoidance of wastewater at an Indian textile dyeing factory as part of a presentation at a joint event by the German Water Partnership (GWP) and the Federal Ministry for Environment, Nature Conservation and Nuclear Safety (BMU) on 15 May. His presentation, Successful water management in India – challenges and opportunities, illustrates how practical, sustainable solutions can be developed based on expertise and experience.
Lanxess IPT reports that numerous examples from the municipal and industrial sectors show how ion exchange resins (IX) and reverse osmosis (RO) membranes complement one another to achieve optimal results in water treatment. Ion exchange resins can be installed in front of an RO unit to remove organic impurities through adsorption, which would otherwise enable fouling on the membranes. Previous partial softening of the feed water with weak acidic ion exchange resin can also reduce both scaling on the membrane elements and the salt content of the feed with practically stoichiometric application of the regeneration agent. This enables more efficient operation of the RO plant. This procedure is recommended for highly carbonated, industrial process water.
Ion exchange resins can selectively remove heavy metal cations or complex anions during the water purification process. At IFAT, Lanxess LPT will present Lewatit TP106, which binds oxyanions such as perchlorate, chlorate, bromate, and nitrate with high selectivity. It complements a series of ion exchange resins, including Lewatit TP 107 and Lewatit TP 207. The former, a strong basic, macroporous resin based on an interlaced polyacrylate, enables the efficient removal of various types of polyatomic oxyanions. It is notable for its high capacity for chromate, as well as vanadate and molybdate, during the treatment of drinking water. Similar to Lewatit TP 106, it is certified according to NSF/ANSI standard 61.
The weak acidic, monodisperse chelating resin Lewatit TP 207 exhibits high selectivity for bivalent heavy-metal ions in a neutral solution. It can be used to selectively remove copper ions, as well as lead, nickel, or zinc, for example, even in the presence of complexing amines, polyvalent carboxylic acids, or phosphates. With its Bayoxide product line, LPT also offers iron oxide adsorbents specially developed for the separation of arsenate and phosphate.
The gel-like, strong basic Lewatit S 5128 will also be presented at IFAT. This acrylate-divinylbenzene-copolymer enables highly effective adsorption and desorption of naturally occurring organic substances and is approved for use in food applications.
Membrane elements from the Lewabrane RO ULP (Reverse Osmosis – Ultra-Low Pressure) series are Lanxess' new standard with regards to energy efficiency. They are designed for a test pressure of just 7.6 bar. Compared with standard elements, a 40% reduction in operating pressure is therefore sufficient and energy and operating costs are reduced accordingly.
The ULP membrane has the highest surface hydrophilicity of all Lewabrane types, Lanxess reports. A thin, protective water film on the surface of the membrane prevents the adsorption of organic substances, or organic fouling. The ASD feed spacers used in the elements, which create more space for the flowing water between the membrane surfaces, also reduce fouling.
