What FMs need to know about water treatment to advance water conservation
With technology advancing water conservation, the scope for the private sector to get involved in the debate is widening.
The technology behind water treatment is more complex than the average facility manager needs to understand. However, in a world where water is a depleting commodity and its use is being increasingly regulated and questioned, the average facility manager could do with understanding the basics, including the technology. With countries such as Australia hit by drought there has been enormous innovation in this area, although much of it has been in small buildings in suburbia and remote areas where some local councils have even stopped connecting people to the reticulated water supply.
In many parts of Asia this is not an option offered by the state to begin with. A representative from Thames Water notes that given, the difficulty of completing infrastructure work in many of these countries, “It’s a miracle that they have a reticulated water supply at all.” In Asia (and Australia) there has been further controversy where large industries are largely immune from shortages because of separate binding contracts with water supply companies.
Technology such as Siemens Water Technologies are positionedbetween governments and industry, explains Jagannath Rao of Siemens. They do this by providing water treatment, installation commissioning and operations and maintenance of the various technologies that improve water management processes.
Re-use, Recycle
Despite the fact that Singapore imports its water, average use per person in is 165- 170 litres per day compared to 130 in many European countries. Understandably, the Singapore government is committed to water conservation and reuse. They have launched “ABC: Active, Beautiful, Clean” campaign aimed at educating people about the benefits of water, and waste water is required by law to be reused. This by definition requires the advanced use of water treatment technologies. However, in Rao’s personals view, before long this will be the rule, not the exception: “Waste water will be the commodity of the future”.
In order to convert waste water into potable water several steps must be taken. First comes micro filtration, followed by a two stage reverse osmosis process. By this point the water is usually drinkable. In some cases an ultraviolet treatment is required to kill any remaining bacteria. Recycled water consumption is still at a developmental stage in most countries, says Rao. While most people are still reluctant it is becoming more accepted, especially where there are shortages. Other alternatives such as desalination are also becoming more viable. For example, Siemens is working hard on a breakthrough desalination technology that uses less energy than current methodology.
Many agricultural and industrial processes produce what is known in the industry as “sludge”, says Rao. Water treatment companies dispose of this by a process of ‘dewatering’ so that it can be sent to landfill. Though, says Rao, there are technologies that can turn the by-products into building materials such as bricks. Various new bio treatment schemes can reduce sludge by 40-60 percent. Municipal waste water is generally organic in nature so, says Rao, the number of chemicals in it is few. A lot of “mucky waste” comes from the production of biofuels, for example, but the resulting gas can be stored and used to run a small power plant.
Drinking Water
In Hong Kong, most offices and homes elect not to use tap water for reasons of taste and to counter negative perceptions that the water is not clean. “Hong Kong water is not going to kill you”, says Blake Ireland, Managing Director, Life Solutions, a company that supplies reverse osmosis (RO) and other water treatment and filtration services in commercial and residential buildings around the region. From a corporate perspective the filter is installed for reasons of cost saving — much cheaper than buying bottled water but also no stacks of water cooler bottles taking up expensive real estate.
Where tap water is not potable, many offices resort to using distilled bottled water. Ireland points out that while this might appear to satisfy a thirsty staff, it is not the most environmentally friendly method of doing so. Distilling water requires a lot of energy and plastic bottles are detrimental on a number of levels: they use huge amounts of water when they are washed, they use energy and polluting technology to create, they are transported by road. “Qualifying comparative data is hard,” he says, but bottles seem to come off worse than most filtration techniques on many levels.
Hotels again provide an example of buildings with complex water requirements. Ireland is currently working on many of the big hotel projects currently under construction and finalising stages in Macau. Of the many types of filtration available, hotels have to use some of the most rigorous because of stringent health and safety requirements. One large filtration plant might send water to numerous devices, from post-mix guns to anything involved in food preparation. Distances of up to 50 yards from the original filter plant coupled with infrequent use, mean that an ultra-violet filter needs to be installed just before the delivery apparatus to catch bacteria forming in the pipes. UV and carbon however will not filter out heavy metals such as arsenic, lead and mercury, which are generally invisible yet highly toxic.
Another technique be used in new building construction projects is the separation of grey water for non-drinking or washing purposes. While many developers still overlook the cost benefits of this during planning stages, new commercial buildings in Asia’s more developed markets are more likely to use grey or sea water where possible.
For example, One Island East is one of the latest Hong Kong buildings to pump in sea-water for use in the airconditioning system.
No One’s Perfect
There are down sides to all systems. RO technology for example, while very safe and effective at treating water for drinking, can result in water wastage. In some cases up to 50 percent of water that goes through the system will be flushed away with the impurities. As Ireland says, “It’s carbon neutral but it’s not perfect”. In his view the only way to get closer to a perfect system is to stop polluting and, a sentiment echoed by everybody in the water business, “Make an impact at the source”.
As developed companies drive the use and innovation in water treatment technologies, the hope must be that eventually these advances get rolled out where they are needed the most. According to UN statistics About 90 percent of sewage and 70 per cent of industrial wastes in developing countries are discharged into water courses without treatment, often polluting the usable water supply. Tom Palakudiyil who head’s Asia operations for NGO WaterAid, notes that in developing countries the situation in urban areas is “mush grimmer than in rural areas”.
Sanitation in urban slums is generally “more neglected” says Palakudiyil than water supply both politically and by the general population, however, the good work done to improve drinking water quality can be undone by poor sanitation. Apart from in Bangladesh where naturally occurring arsenic pollutes the ground water, most water treatment and purification is designed to mitigate effects of other human activities. Ireland says there are lots of alternatives to where we get our drinking water, but the best solution would be to get it straight from the tap without having to treat or process it further. After all, he concludes: “No one can argue that bottled water is a better alternative.”
