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The future for water cleaning31st of October 2012
Many companies are coming up with cleaning systems that use water only, claiming these to be sustainable since they remove the need for chemicals. But as water supplies dwindle, are such claims justified? Ann Laffeaty looks at arguments for and against water-based and chemical-based cleaning systems.
Products and systems were once considered to be environmentally-friendly if they minimised the use of potentially harmful chemicals. Manufacturers then began coming up with new, eco-friendly chemicals said to be less aggressive and kinder to the environment. Soon chemicals were dispensed with altogether in certain applications, and systems that used water alone - such as water-fed poles, microfibre cloths and high pressure cleaning machines – began to gain ground.
But the world is now facing a water crisis. A UN report issued this summer claimed that water supplies are falling while demand is growing at an unsustainable rate. In fact the average supply of water per person worldwide is expected to drop by a third over the next 20 years.
So does this mean that water-based cleaning systems are no longer sustainable?
Water-fed pole window cleaning is one of the services offered by facilities management services company OCS. Regional operations manager Michael Chambers admits that such systems require more water than traditional window cleaning methods using a ladder and squeegee.
“However I think the advantages of water-fed pole window cleaning outweigh the disadvantages, both from a financial and sustainability point of view,” he said. “For one thing this method allows you to clean windows 60 ft up, which is much better for the safety of staff than using ladders. Access equipment often runs on diesel, too, which can cause pollution. And traditional cleaning methods use chemicals whereas water-fed systems of course use only water.”
He adds that the extra water used for window cleaning is not wasted in any case. “All the run-off goes into the drains and ends up back in the system,” he said. “The fact that the water is pure means it is more or less equivalent to rainwater.”
High pressure cleaning also uses large quantities of water to remove dirt from indoor and outdoor surfaces. However this is still an eco-friendly cleaning method according to Karcher environmental PR David Wickel.
“The narrow diameter of a high pressure nozzle reduces water consumption considerably in comparison with an ordinary hose,” he said. “Furthermore, mechanical cleaning is an environmentally-friendly alternative to using chemicals, and in many cases leads to better cleaning results in a much shorter time.”
He argues that high pressure cleaning keeps chemical use to a minimum since detergent consumption can be reduced under higher pressure. “Pressure cleaners also have dosing devices that enable detergent to be added precisely and in minimal quantities.”
He claims Kärcher’s high pressure cleaners save up to 50 per cent more water, electricity and time than most other high pressure systems. In some cases, too – particularly in car-washing applications - the water can be recycled.
“With our WRH 1200 eco it is possible to recycle the oily waste water arising from washing engines and vehicle under-bodies with a high pressure cleaner,” he said. “Using this method, fresh water consumption can be reduced by as much as 85 per cent.”
Wickel adds that the company’s scrubber dryers can also be adapted to save water. “When using scrubber dryers with disk brushes, aquamisers –or aprons fitted behind the disks on the brush head - confine the cleaning solution to the area being cleaned,” he said. “This makes it possible to reduce water and detergent consumption by up to 30 per cent.”
PHS Washrooms offers a number of products designed to save water including flush control systems for toilets and urinals, and a water saver system for taps. When attached to a siphon in the toilet cistern, the Flush-wiser WC Flush Control can reduce the amount of water flushed by up to three litres according to marketing manager Keri Reynolds. “This can be adjusted to suit each cistern, taking into account cistern size and performance in order to make optimum
savings without compromising on hygiene,” she says.
Reduction in wastage
The PHS SaverTap is designed to make existing taps work more efficiently by preventing them from being allowed to be left to run. “This reduces water wastage by up to 80 per cent,” says Reynolds. “Using water more efficiently is a smart way for businesses to save energy and money, while also delivering on commitments to cut energy and resource wastage.
“The washroom is somewhere that energy-saving schemes can easily be put into action by installing products that are economical with water, yet still deliver the best performance and hygiene standards. As well as the financial benefits, by demonstrating your company’s water efficiency you may attract new, more environmentally-aware customers and employees.”
Nilfisk-Advance has developed a cleaning system said to cut water consumption by 50 per cent and reduce the need for detergents by between 35 and 100 per cent. The company’s Ecoflex System allows the operator to vary the quantity of detergent used and also to switch between chemical-free cleaning and water-only cleaning.
“The Ecoflex System enables the operator to select the right blend of pad pressure, water and detergent for any given task,” says group corporate responsibility manager Ulla Riber. “This means the decision on how to balance the use of detergent and water is managed at the point of cleaning which allows the operator to achieve the best possible results.”
The company also offers the Nilfisk-Advance Cyclone 4500 system which collects and filters waste water. All contaminants are removed and contained and the clean water is recycled and reused.
“Water is a main component for delivering the highest standards of effective cleaning - but it is a natural resource and we all need to protect it,” says Ruber.
“There is no doubt that water will be high on the agenda in our industry in years to come. Both we and our customers see potential in developing products that provide equal or enhanced cleaning efficiency while using less energy, less water and less detergent. We want to take a key position in this development.”
Ecolab also aims to reduce the use of water during cleaning. However senior marketing communications manager Nick Burchell feels that water alone is rarely a substitute for chemicals in any case.
“If you want to remove limescale you will need an acid-based product, and if you want to disinfect a surface you will require a QAT-based or chlorine bleach product,” he said.
Chemicals are also sometimes required even when cleaning with microfibre, according to Burchell. In a 2005 laboratory study carried out by Ecolab, two surfaces were charged with pathogens and cleaned using different methods - one with microfibre plus chemicals and one with microfibre and
“There was a significant log reduction when chemicals were used,” said Burchell. “Also the fresh smell associated with a chemical clean is often important. Patient studies in the UK have shown that if a hospital smells clean, patients feel that it must be clean. Cleaning methods that use water alone do not generate this clean smell.”
Ecolab offers a mop impregnation system for hospitals designed to be ergonomic for the cleaner while minimising the use of water and chemicals. The Vario Maxx Healthguard system is said to reduce water and chemical consumption by up to 80 per cent while also facilitating the task of hospital cleaning.
“We design our trolleys around the workforce and take into account how people use them,” said Burchell. “A calculation is made as to how many microfibre mops are required to clean each bay and ward, and these mops are then lined up in a box on the trolley ready for use.
“The mops are then moistened in a bucket that contains a powerful concentration of detergent plus two litres of water at most. This solution is absorbed by the mops so that they become only damp, with no wringing required.”
Ecolab also offers a rinse-free product for manual and machine cleaning that is said to save water. Magic Maxx contains a blend of active cleaning agents to create what Ecolab calls 'super-wetting technology'.
Diversey corporate communications director Rafael Echevarria agrees that besides any sustainability issues, water alone is not always an effective cleaning medium. “With a chemical-free system it is not necessarily the amount of water that is the issue,” he said. “The water will need to be hotter which gives rise to safety and environmental issues. Also more abrasion may be required which could lead to damage to the cleaning surface or the user. And when using water alone it may take significantly longer to clean which will lead to productivity and cost issues.”
He argues that chemicals play an important role in hygiene-critical environments such as kitchens and washrooms. “Although water alone could be used in these areas, the germs would have to be physically removed by microfibre or through thermal disinfection,” he said.
“Very few microfibre systems have been scientifically assessed for their ability to remove harmful bacteria. As regards thermal disinfection, you would have to use either very high temperatures for relatively long contact times, or steam. This may be fine in a closed system such as a laundry machine, but elsewhere there will be some environmental impact regarding how the water is heated, damage to materials and personal safety.”
He says it is misleading to categorically claim that water-only systems are more sustainable than those that use chemicals. However he adds that a sustainable cleaning regime should successfully balance both water and chemical use.
“Around 1.5 billion people live in river basins where water is physically scarce, while another billion live in river basins where water is economically scarce,” he said. “Water management and conservation is critical to any regime - cleaning or not. The water-only/chemical balance can be extremely complex and the only certain answer is: whatever the answer, it doesn’t apply to everyone.”