Page 10 - trends in automation

“In 10 or 20 years, Europe could
well be following the example currently
being set by developing countries.”
Peter Cornel, IWAR Institute at TU Darmstadt
What can be done about this?
Cornel: These developments demand solutions that go beyond
the structures that exist in the Western world. Whereas we
generally use water only once and then dispose of it as
wastewater, megacities cannot allow water to be used in this
way. They cannot transport water over long distances, process
it in high-quality treatment plants and then use it only once.
Cen­trally organised concepts consisting of a large wastewater
treatment plant that feeds sewers are outdated as they cannot
keep pace with the growth of cities in Asia and don’t meet
current requirements with respect to resource conservation.
How can the new challenges posed by megacities for water
supply and wastewater disposal be dealt with?
Cornel: In China’s megacities, for example, new housing
developments are frequently built for tens of thousands of
residents by one investor. It therefore makes sense if the
facilities for water supply and wastewater disposal are built at
the same time. The slightly contaminated water from showers,
wash basins and washing machines – referred to as greywater –
can be re­cycled and then made available as reclaimed water for
flushing toilets. This can equate to drinking water savings of
between 30 and 40 per cent. The quality of reclaimed water is
perfectly adequate for use in toilets. It can be recycled with
minimal effort, which renders it colourless, odourless and
hygienic. Highly contaminated wastewater from toilets or
kitchens can be recycled for watering green spaces in inner
city areas. The same water can therefore be used not just
once, but as many as three times.
A big advantage of these semi-centralised plants is that
they have the flexibility to grow with cities. They offer much
greater scope when it comes to future planning for megacities
than large centralised supply and disposal solutions. Semi-
centralised plants are ideal for urban districts with 50,000 to
70,000 inhabitants.
Do such semi-centralised plants for water treatment
and consumption already exist?
Cornel: In Qingdao, the IWAR Institute is currently building a
model plant for 12,000 people in collaboration with our partner
university in Tongji as well as the city of Qingdao and the
organisers of the 2014 World Horticultural Exposition, with the
support of the German and Chinese research ministries. In
addition to water supply and wastewater recycling, the plant
also processes organic kitchen waste, for example. The energy
recovered allows the wastewater treatment plant to operate
self-sufficiently. In addition to water treatment, we are therefore
also making an important contribution in the area of waste
management.
At this point it is clear that the environmental solutions of
the future will incorporate multiple disciplines. Along with
wastewater and waste treatment, heat and energy management
also has an important role to play. Wastewater treatment
requires energy, which can be recovered from waste. Another
major contributing factor to the success of semi-centralised
solutions is the increasing degree of automation in areas such
as remote monitoring, where online measurement technology
simplifies and accelerates control and monitoring processes.
Added to this are efficient process automation solutions, which
reduce the amount of energy that the plants consume and
increase their reliability.
Are these developments also the way forward for the current
leading high-tech nations?
Cornel: The development currently taking place in megacities
is based on technological advances and experience in Europe and
the United States. However, as climate change will require a
rethink with regard to the way in which we use water, Europe
could well, in 10 or 20 years, be following the example currently
being set by developing countries.