About 97 per cent of water on earth’s surface is seawater. The remaining three per cent which is fresh water is fragmented in the form of frozen ice-caps, rivers, lakes, and water found underground in the Earth’s crust (also known as groundwater). Of this, less than one per cent is easily accessible for consumption, making only a fraction of water supply in the world available for human use[1].
The shortage of clean water for both industrial and personal consumption is thus a complex issue for governments, corporations and individuals. Many governmental and non-profit organisations in the world today run multiple awareness programmes to address the prevailing and increasingly crucial issues surrounding this topic. In fact, since 1993, the United Nations (UN) has officially designated an annual ‘World Water Day’ on March 22 to raise international awareness of key water-related issues faced by the world’s population. This year, ‘Water and Energy’ is the main focus.
According to the UN Global Compact-Accenture CEO Study 2010, corporations and the public alike in emerging economies see sustainability in very personal, local and immediate terms—e.g., access to clean water, more direct dependence on the natural environment—and therefore perceive their future success to be more directly threatened by environmental degradation.
It is, hence, no surprise that there are many organisations that abide by sustainable water management systems, made possible through various technological innovations and improvements.
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It has been estimated that approximately 500 liters of water is used to produce one kilogram of paper, while some 10,000 to 20,000 liters of water is consumed to build a car, and as much as six metric tons of water is needed to manufacture one metric ton of steel!
Responsible water usage is not the lone responsibility of industries that have obvious water source needs. It is the responsibility of all organisations, as water is often used as a direct or indirect source in almost all aspects of manufacturing and industrial processes.
‘Virtual Water’ – a term coined by British scientist John Anthony Allan – refers to the ‘embedded’ water used in the production of agricultural and industrial goods. For example, about 1,000 liters of water is used to produce one kilogram of wheat. For the same amount of meat, approximately five to ten times more water is needed[2]. The water sources which are required to support these industrial processes are often not visible upfront and are thus often not taken into consideration, and forgotten in the process of managing water resources, hence the term ‘embedded’.
Apart from food production, it has been estimated that approximately 500 liters of water is used to produce one kilogram of paper, while some 10,000 to 20,000 liters of water is consumed to build a car, and as much as six metric tons of water is needed to manufacture one metric ton of steel! Globally, over 20 per cent of all the water extracted from the earth’s surface sources such as rivers, lakes, and groundwater is used for industrial purposes. In highly developed regions such as Europe, this figure is as high as 60 per cent, whereas in developing countries it is just under eight per cent.
The importance of water has never been more amplified than now with increased attention in the international arena placed on ‘virtual water’.
Water treatment for safe energy generation
Despite its importance, the link between clean water and global rise in energy demands has rarely been made a subject in public discussion. However, for a long time, the chemical industry has been working to contribute positively to this global issue.
Complex chemical and mechanical treatment is needed for a multitude of water treatment processes, which includes water cooling, processing water and water desalination at power stations. In most cases, ion exchange resins are used to soften and desalinate the feed-water. This is essential because high temperatures at the power stations would otherwise cause the salts and alkaline earths present in water to build up on the heating surfaces as the boiler scales and forms an insulating layer that would prevent heat transfer.
For example, in power generation turbines, this can lead to thermal stress cracks or even cause the boiler to burst and give rise to corrosion, abrasion and imbalance among components on the steam side. If the water contains a high proportion of organic substances after this initial stage, a second downstream step is sometimes required. This second step is called reverse osmosis.
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In Singapore, desalination is becoming an important component for augmenting and diversifying available national water resources
LANXESS, a water treatment solutions provider, has complementary technologies – ion exchange and reverse osmosis – that are often combined to obtain optimal efficacy in industrial water treatment. Further enhancing this dual treatment functionality is the company’s LewaPlus software, which enables planning and designing of complex water treatment plants. This proprietary software combines the two technologies into one single planning tool to offer water treatment plant designers significant added value in water analysis and aids their selection of the most effective treatment solution for their manufacturing plants.
At the Chemnitz combined heat and power station in Germany, these membrane filter elements from LANXESS significantly lower the degree of fluctuation in water quality and, in particular, filter out organic substances. In addition to this, reverse osmosis can be used to desalinate brackish water or seawater to produce drinking water.
Closer to home, here in Singapore, desalination is becoming an important component for augmenting and diversifying available national water resources. In late 2005, the Tuas Desalination Plant – Singapore’s first municipal-scale seawater desalination plant was opened. Reverse osmosis treatment was the process used for water treatment in this plant which had an output capacity of 30 million gallons per day (mgl) [3].
It has been estimated that by 2060, desalinated water will contribute to about 30 per cent of Singapore’s water demand[4].
Conserving resources through recycling
Thanks to numerous changes in production processes and ongoing optimization of water treatment, it has been possible to steadily reduce the consumption of water by using it several times – that is, by recycling it. Here too, products from the chemical industry have played a key role.
The number of times water is recycled in the paper industry has risen from 2.4 times in the 1950s to about 12 times in present day. In the chemical industry, water is now recycled an average of 28 times before it is channeled downstream through the sewage clarification system and then allowed to re-enter the water cycle as purified water.
More developments in water recycling is expected in the future, especially in the chemical industry which heavily relies on water both as a raw material and a source of energy generation. The chemical industry not only offers innovative approaches for the efficient use of water as a raw material but also provides solutions for resource-saving, sustainable energy generation.
Beyond World Water Day, let’s acknowledge what we tend to take for granted – clean water and a reliable supply of energy – because the two will continue to be inextricably linked in the future.
Jean-Marc Vesselle is Global Head of Liquid Purification Technologies (LPT) business unit at LANXESS. To learn more about LANXESS’ water treatment solutions, visit their booth at the upcoming Singapore International Water Week from June 2 to 4 at the Marina Bay Sands Expo and Convention Centre.
