Sift harmful pollutants from water with LANXESS

Water is not only the source of all life, the only alternative to water, is water. Thus, the importance of responsible management of water cannot be emphasised more, and that includes industrial production as well.

Industrial production accounts for almost a quarter of water consumption globally, and the volume of wastewater produced is as high. With wastewater as the subject this year’s United Nations World Water Day coming up on Wednesday, March 22, the goal is to avoid and recycle the wastewater instead of disposing of it through conventional means. To that end, LANXESS is spearheading the way in this area, and the enterprise has kick-started the effort with its very own production facilities. The Group’s wastewater production relative to its product yield has dropped six per cent over the past half decade.

Water, or “blue gold”, is becoming more and more precious to man, due to the lack of availability of clean drinking water. Reports by the World Health Organisation (WHO) and the United Nations International Children’s Emergency Fund (UNICEF), an estimated 1.8 billion people around the world turn to contaminated water in order to quench their thirst. As a result, almost 850,000 people die from the unsanitary living conditions and imbibing the polluted water. In the coming decades, the issues might be aggravated by climate change, environmental pollution, and continued population growth.

Minimising wastewater and using processed water sustainably is an area of boundless possibilities in the water industry. Particularly, the chemical industry has much to bring to bear in water responsibility and management, especially as it can provide vital answers to many issues. Now, LANXESS is confronting the challenges at full-speed, using its years of experience in product innovation, water treatment, and technologies to its advantage. Notably, ion exchange and reverse osmosis in water treatment have taken on important roles in realising the company’s goals.

Presently, the market for ion exchange resins is slated to increase by an average of four per cent a year, and reverse osmosis membrane elements are projected to rise 10 per cent annually – an above-average rate of growth – in the coming three years.

Lewatit ion exchange and specialty adsorber resins are what make LANXESS’ effective technology for treating the water so effective. Among many other useful functions, ion exchange resins are capable of eliminating contaminants like borate, hydrocarbons, nickel, nitrate, and perchlorate from potable water.

During the ion exchange procedure, the tainted water gushes through a vessel suffused with ion exchange resin. This sifts through and removes the impurities, binding the contaminant ions and leaving harmless ions in its place. An assortment of resins will be deployed based on the contaminant.

In the case of wastewater treatment, the ion exchange resins will take out heavy metals like cadmium and mercury. Additionally, copper and platinum – precious metals – can be separated from the mixture and then used for other production purposes.

In industry, the water treatment can be extended to industrial processes and procedures in power plants. For instance, huge, expensive plants require large volumes of process and cooling water that have to be demineralised in order to safeguard the systems against limescale.

Pharmaceutical and microchip manufacturers need unusually pure water, and Lewatit is commonly utilised for the production of the ultra-pure water required – a crucial resource for the manufacturing.

The membrane components found in LANXESS’ Lewabrane products are thin-film, spirally-wound composite membranes. They go through the water and sift out the unsavoury and unwelcome elements like bacteria, herbicides, pesticides, salts, and viruses. The product line also includes the components needed for reverse osmosis use, as well as for desalination of seawater, brackish water, and low-salinity water. Areas where the product can be applied include not only the treatment and production of potable water, but also for the treatment of wastewater, other industrial water, and process water.

The reverse osmosis membranes can be applied for the production of potable water from both seawater and brackish water. Already, this process is being used in both municipalities and metropolises in a large scale, and in cruise ships, hotels and restaurants on a smaller scale. The membranes are often combined with the ion exchange resins to create a system not only capable of reducing the content of salts and particles in the water, but also with a highly effective and impressive demineralisation system.

The Lewabrane membrane elements are manufactured and produced in a fully-automated, high-tech production facility in Bitterfeld-Wolfen, Germany. The chemistry found in the membrane is reliant on a durable cross-linked polyamide layer that comes highly resistant to chemical cleansers, and has an even higher rate of rejection of intricate salt combinations with a low surface charge, all of which contribute to the reduction of a tendency to clog. Since the introduction of this technology to the market in 2012, tens of thousands of Lewabrane filter components have been set up in more than 70 countries around the world.

The Lewabrane range of membrane components were first introduced to the market in 2012. The components lower the salt and particle content in water and are usually used along with ion exchange resins to realise a highly-effective and efficient demineralisation system. Photo credit: LANXESS AG

But one of the most deadly contaminants in drinking water is arsenic, scentless and tasteless, and slowly accumulated in the body. High concentrations of arsenic have been found in the groundwater in many locations in Asia, Europe, South America, and the United States of America (USA), a natural occurrence. An estimated 100 million people globally drink water laced with an arsenic content upwards of 50 micrograms (0.05 milligrams) a litre. Recently new legislation in both the USA and the European Union (EU) took up the WHO’s recommended limit of 10 milligrams a litre of water.

A semi-metal that occurs naturally in the form of minerals under certain conditions, highly poisonous arsenic elements can be washed out from the surrounding stones and dissolved into the groundwater. Multiple medical studies have documented the never-ending illnesses people who have imbibed the tainted water for extended periods of time suffer, ranging from carcinomas to skin disorders.

The adsorber Lewatit FO 36 is combined with the iron oxide adsorber Bayoxide E33 to create a hybrid devised especially to extract arsenic from both wastewater and water. A solid, stable bed of iron oxide beads makes up the core of the Bayoxide system, constituting of finely-structured surfaces that adsorb the dissolved contaminants when the polluted water gushes over it. The beads are very durable in water, and will not break down due to water erosion. Comprised of tiny particles that cannot be seen with the naked eye, the beads are visible when placed under a high-resolution electron microscope. One gram of these beads is capable of selectively adsorbing around 150m² of arsenic.

The Lewatit FO 36, as featured above, is a highly-effective ion exchange resin for the selective removal of arsenic from water. Photo credit: LANXESS AG

Treating water for drinking is not the only thing the LANXESS’ Bayoxide E33 is capable of doing. The Bayoxide E33 can be turned to wastewater treatment in mining, and it can also be used to treat polluted groundwater located near industrial facilities.