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resource. We have relied on massive engineering works and the relative resilience of the resource to ensure our survival… Our goal for the future is to change that; to eliminate the threat that our livelihood and our lives will be disrupted by scarcity.’ They believe this will require a different approach from these engineered solutions that will involve a combination of infrastructure, incentives and information – collaborative solution – to effect that change; what they have dubbed ‘Smarter water’, the right water for the right use. As the US Environmental Protection Agency has calculated around 50% of the potable water used residentially is not actually consumed by individuals but rather used for flushing lavatories, local irrigation such as watering lawns, washing cars, etc. Symmonds and Taylor believe that these are ideal applications for recycled water. The problem is how to deliver these separate streams of water; drinking and non- potable. Consumers also need to be able to make the judgement for themselves whether to use a certain amount of water for a particular task – and as the price of water rises with scarcity, just like oil, consumers will become more aware of the cost and look to increase the efficient use of water and make cost savings. But using recycled water does require


infrastructure changes at the residential level, but particularly at the larger scale. We are already encouraged to use so-called ‘grey water’, water used for bathing and laundry for watering our gardens, but as Symmonds and Taylor point out, in advanced recycling, the water must be supplied through a dual-plumbed, highly distributed network. This would allow all non-potable uses to be supplied separately, resulting in a 60% reduction in potable water consumption. Their company has already achieved this result at the Global Water – Santa Cruz Water Company, where the implementation of a recycled water plan reduced potable water consumption from 46.5m3


/month/connection customer to around 24m3 /


month by 2007 as the infrastructure advanced. But wastewater will increasingly be used for other applications, not just flushing lavatories and watering lawns, according to researchers at Japan’s Tottori University and the UN’s Canadian based Institute of Water, Environment and Health (UNU-INWEH). Water shortages, coupled with increasing global shortages of potash, nitrogen and phosphorus fertilisers, will result in a rapid increase in the use of treated wastewater for farming, for example, says the team. In North America, they calculate that around of wastewater is generated annually, but


85km3


only 75% is treated and of that just 3.8% is utilised. ‘From the earliest of times, most wastewater has truly been wasted, says UNU-INWEH director, Zafar Adeel. ‘However, it is a vast resource if we reclaim it properly, which includes the separation of municipal from industrial wastewater.’ Another approach is to turn undrinkable water, such as brackish or seawater, into potable water using


desalination, According to forecasts by Global Water Intelligence, some 14% of the world’s population will have its needs met by seawater desalination in 2015, up from just 1% today. Previously, it has been seen as an extremely expensive route that only suits those countries where freshwater is almost non-existent, such as in the Middle East. Today, there are around 13,000 desalination plants in operation or under construction in 150 countries, and the UK opened its first municipal plant in Beckton, east London, in June 2010. By 2050, the UK Institution of Chemical Engineers (IChemE) predicts the number of plants worldwide will have double with a further 18,000 plants coming on- stream, including at least a further four UK municipal facilities and up to 800 smaller units. But conventional thermal desalination plants


are energy intensive, utilising evaporative and condensation processes, while membrane systems, using reverse osmosis, for example, require high pressure pumps to force the water through the membrane; the energy needed for reverse osmosis being proportional to the salinity of the starting material. According to the IChemE, changes in technology, combined with population growth and unpredictable weather conditions exacerbated by climate change, are likely to make desalination more viable in the UK. ‘While improvements are continuously being made to RO membranes making desalination more chemical and energy efficient, some of the most exciting developments in desalination are with breakthrough technologies,’ says Martin Currie, an independent water consultant and member of the IChemE’s water special interest group. ‘Researchers are currently working to scale- up biomimetic membrane processes employing aquaporin proteins – found in our kidneys – that let water through much more efficiently than conventional membranes,’ he says. ‘Also UK universities and companies are at the forefront of forward osmosis (FO) – a technology now in commercial operation that uses osmosis to suck water through the membrane rather than just pumps to push it. Both technologies promise huge energy savings and FO plants are already seeing massive reductions in the amounts of chemicals required to maintain the membranes.’


So desalination is becoming a practical solution even in the UK – no longer will there be cause for apocryphal stories like the water that we drink having already passed through many bodies before reaching us. Or will there?


Of course, with limited resources, water is just one of many recycled substances that we currently, and will increasingly have to use, so why should we be squeamish about the water we drink, even the seawater has been recycled many, many times? And after all, it is just a simple molecule – albeit with some amazing properties.


Neil Eisberg – Editor Chemistry&Industry • November 2013 5


November 2013 Editorial Neil Eisberg


Editor neisberg@wiley.com


Deputy editor Cath O’Driscoll


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Design and production Simon Evans sevans@wiley.com


SCI Members’ News Simon Lightfoot slightfoot@wiley.com


contributors Maria Burke


Sarah Houlton Regular


Anna Jagger


Dede Williams


Kathryn Roberts


Kevin Burgess Emma Dorey


Nigel Freestone Michael Gross Anthony King A. Nair


Matt Pulzer


Richard Stephenson Mark Whitfield


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David Birkett James Bryce


Cynthia Challener Peter Chiyada Simon Cotton Michael Gross Catherine Joce


Michael de Podesta Lou Reade


Dennis Rouvray Ernie Salas


Brad Thompson Timothy Watling


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