Why does the planet have to recycle its waste water
Not only in the highly
parched Middle East or North Africa.
In Europe, about a third of the landmass and
about 11 percent of the population suffer from water shortages.
Access to water is increasingly a source of tension, and
scientists warn that climate change is likely to worsen water scarcity.
It is becoming important
to secure supplies.
And that might mean getting
over the squeamishness of the wastewater.
"There is no question that the capacity for water recovery is
very high," said Steven Eisenreich, a geochemist at the University of Brussels.
"How high, we
don't know yet."
Normally, wastewater treatment includes washing, extracting nutrients
and adding them to rivers and streams.
However, in order to make it safe for
immediate re-use, wastewater must be treated even more thoroughly.
This is already happening in
countries like the US and Australia.
Approximately one third of treated wastewater is used for agricultural irrigation
and 20% for irrigation of landscapes such as lawns and golf courses.
Overall, however, very little wastewater
is being treated to this degree.
Approximately 7 cubic kilometers of wastewater is reused worldwide in
2011 – less than 1% of total global water usage.
The majority of
the capacity remains untapped.
"The effective use of wastewater decreases the
amount of groundwater used for irrigation," Eisenreich said.
"In addition, the rivers become less polluted if less pollution is returned to
them. It also has benefits for both the quantity and consistency of the water."
The President of the World Water Council, Benedito Braga, also sees
"recycling and reusing wastewater as an effective tool for resolving water shortages
often reused as drinking water.
But public recognition
Water treatment in Namibia — one of the
few countries to convert wastewater into drinking water.
is no funding for it," Eisenreich said.
"And it is not foreseeable that
this will happen in the future."
Wastewater can be a real alternative,
particularly in regions suffering from water scarcity.
Water-stressed Israel, for example,
recycles 90% of its wastewate
There is an increasing
Belgium, for example, has
a significant water shortage.
Bulgaria is also suffering from water shortages,
but has made little use of its wastewater.
Wastewater should theoretically stages until it
is free of nutrients that could interrupt the water cycle.
However, wastewater must be treated
Approximately 40% of Europe's wastewater treatment
plants handle wastewater in all three stages.
This implies, ideally, that they have the capacity to handle
wastewater thoroughly enough for irrigation of green areas , for example.
"It is clear that European countries have been storing more wastewater and treating it to
now," said Caroline Whalley, Project Manager at the European Environment Agency.
Wastewater treatment has now been a priority for
the European Union since the
Since then, several European countries
have been investing in wastewater facilities.
In Greece, only 10% of
wastewater was treated extensively in 2005.
A decade later,
89% received tertiary care.
Countries like Romania have ambitions
to follow the example of Greece.
Malta recycles about
90% of its wastewater.
However, there are
no EU-wide guidelines.
"There are already European countries
that are reusing water," Eisenreich said.
"They follow criteria
The European Commission introduced an initiative
for minimum quality standards in 2016.
However, the proposals are not yet binding and
it is used.
If the environment heats up, more and more countries
will have to make decisions in favor of recycling.
But we're still a long
way from all over the world.
Globally, 80% of wastewater is now returned to the atmosphere without being treated
at all – let alone at a stage where it can be reused.
We may not be able to
afford such a valuable resource much longer. By JLF