Water, Sewage & Effluent March April 2019 | Page 42

temperature with ambient sunlight, and
with no additional energy input, you
can collect water in the desert. This
laboratory-to-desert journey allowed us
to really turn water harvesting from an
interesting phenomenon into a science,”
says Yaghi.
From seawater
Smart grids
While not exactly a means of sourcing
or creating fresh water, smart grids
and smart agriculture techniques,
which use the Internet of Things to
create highly data-driven and efficient
systems, promise to reduce water use
and waste across the largest water
users on the planet.
From big agriculture to poorly
maintained or monitored infrastructure,
countless millions of gallons of water
are wasted due to inefficiencies in
current systems. Smart grids pinpoint
leaks faster, identify improper water use
during periods of water restrictions, and
funnel water to agricultural purposes
with more specificity than was ever
previously possible.
Avoiding water crises
through technology
While promising breakthroughs such
as MOF and water recycling systems
like those being developed by NASA
for space stations bring us closer to
the science fiction ability to create
and gather water from thin air or from
plants’ perspiration (seriously), humanity
still faces serious water issues as the
population swells and the climate trends
hotter and more arid.
The latest generation of technology
brings us closer to sustaining our
water habits than we were before, but
the need for innovation surrounding
potable water is very real and far more
The ocean has long been considered
the Holy Grail for the water-scarcity
crisis around the world. Dating back
decades, scientists have worked on
desalination projects aimed at creating
an efficient, reliable means of turning
salty ocean water into potable water
for drinking and other processes that
require clean, fresh water.
However, even as some large-scale
operations have been implemented
to varying degrees of success,
no desalination plant has made a
meaningful contribution to a given city’s
water supply.
The main reason is that the two
primary desalination processes —
steam distillation and reverse osmosis
— are both incredibly energy- and cost-
intensive and create large amounts of
waste by-products.
Whether it’s salt and other minerals
or used filters contaminated with
dissolved solids, the waste by-products
plus the massive amount of energy
required (an average gallon of potable
water produced by desalination
costs three times what a gallon of
more traditionally sourced fresh
water does to produce) means that
desalination plants remain a tempting
but impractical solution.
Given that renewable energy is nearly
as large a concern as fresh water,
creating large-scale systems that derive
drinking water from the ocean is going to
require radical new breakthroughs that
enable faster, more efficient filtration.
Gariep Dam in South Africa — where three provinces meet.
40
Water Sewage & Effluent March/April 2019
urgent than most people realise. Only
2.5% of the world’s water is fresh water,
and roughly half of that is frozen in polar
ice caps.
These striking numbers drive home the
scarcity and urgency populations across
the world are facing, and technology and
research are poised to provide solutions
to a complex and natural problem.
Resources
• http://news.berkeley.
edu/2018/06/08/in-desert-trials-
next-generation-water-harvester-
delivers-fresh-water-from-air/
• http://www.sciencemag.org/
news/2017/04/new-solar-powered-
device-can-pull-water-straight-
desert-air
• http://news.berkeley.
edu/2017/04/13/device-pulls-water-
from-dry-air-powered-only-by-the-
sun/
• https://phys..org/news/2017-04-
device-air-powered-sun.html
• https://techcrunch.com/2018/03/22/
water-abundance-xprize-finalists-
compete-in-gathering-water-from-
thin-air/
• https://www.theguardian.com/
environment/2015/mar/08/how-
water-shortages-lead-food-crises-
conflicts
• http://www.bbc.com/future/
story/20170412-is-the-world-
running-out-of-fresh-water
• https://www.inquisitr.com/3046643/
world-will-run-out-of-fresh-water-
in-2050-says-leaked-report-earth-
faces-catastrophic-fate/
• https://www.bbc.com/news/
world-42982959
• https://www.cnbc.com/2018/04/11/
cape-town-water-crisis-cities-
should-prepare-for-water-scarcity.
html
• http://news.mit.edu/2017/MOF-
device-harvests-fresh-water-from-
air-0414
• https://www.theguardian.com/
environment/2013/aug/11/texas-
tragedy-ample-oil-no-water
• https://www.huffingtonpost.com/
entry/water-scarcity-study_
us_56c1ebc5e4b0b40245c72f5e
• https://gizmodo.com/5909889/
awesome-picture-perfectly-shows-
how-little-water-there-is-on-earth
• https://www.worldwildlife.org/
threats/water-scarcity
• http://theeconomiccollapseblog.
com/archives/25-shocking-facts-
about-the-earths-dwindling-water-
resources 
www.waterafrica.co.za