At this year’s IDA (International Desalination Association) World Congress, which is being held in Tianjin, China, 20-25 October, the specialty chemicals company is presenting the RO membrane elements in its Lewabrane series. Jean-Marc Vesselle, head of the Liquid Purification Technologies (LPT) business unit, said: “Our products meet the highest German and international production and quality standards. For quality assurance purposes, each individual Lewabrane element is checked before being delivered to the customers.”
The membrane elements for reverse osmosis (RO) are manufactured at Lanxess’ Bitterfeld site in Germany. The Lewabrane grades consist of spiral-wound polyamide composite membranes and are specially designed for industrial water treatment and the treatment of drinking water. The range currently includes products for the desalination of brackish and low-salinity waters. Main areas of application include the production of boiler feed water required in power stations, wastewater treatment and groundwater remediation and recharge. The technology is also used for demineralization and particle removal in microchip manufacture.
All Lewabrane membrane elements comply with the NSF/ANSI Standard 61 for health effects of drinking water system components. The US National Sanitation Foundation (NSF International) has thus certified that all membrane elements currently offered by Lanxess are safe for use in the treatment of drinking water, a market with strong potential for growth.
The Lewabrane product portfolio includes standard elements (HR and HF), low energy (LE) elements and fouling-resistant (FR) elements.
The HR elements are designed to provide extremely low salt transport in normal operation, with more than 99.7% salt rejection measured under standard conditions. The high rejection for troublesome compounds such as silica is also remarkable. The HF elements boast high flow rates and water productivity.
Special membrane elements are now also available for water with strong fouling potential. Dr Jens Lipnizki, head of Technical Marketing Membranes at LPT, explains: “Our membrane elements are characterized by a high degree of polymerization and a low surface charge, which in itself reduces the formation of particle deposits. In addition, the fouling-resistant (FR) elements have been equipped with a special feedspacer to generate greater turbulence in the feedwater channel, meaning that less solids accumulate on the membrane surface.”
Low energy (LE) elements were added to the product range in mid-2013. Their operating pressures are around 20-40% below those of the company’s standard elements. The pumps that use these elements exhibit corresponding reductions in energy consumption. Lewabrane LE membranes are particularly beneficial in any applications demanding a low energy consumption where slight compromises in terms of water quality are acceptable. The main areas of application include the desalination of brackish water for the industrial and municipal sectors and wastewater treatment.
In mid-2014, Lanxess plans to expand its BWRO (Brackish Water Reverse Osmosis) range to include new elements for seawater desalination.