Questão 545408

Texto 4 para responder às questões 22 e 23.

The new water technologies that could save the planet

1-----------The well was a transformative invention, though it isThe well was a transformative invention, though it is

often overlooked. This source of freshwater, vital for the

expansion of inland communities, dates back nearly 10,000

4--years — 3,000 years before the wheel was ever imagined.years — 3,000 years before the wheel was ever imagined.

The well is but one of a long list of innovations in

water technology that have enabled human development to

7--continue apace. Sophisticated pipeline networks and

treatment plants today furnish us with this elixir of life and

industry. As intense pressure is placed on the planet's

10--limited water supplies, businesses are again turning to

technological innovation. New and emerging inventions

should see human civilisation through the 2Ist century and,

13--with any luck, the next 10,000 years.

Nanotechnology in filtration:

According to the World Health Organisation, 1.6

16--million people die each year from diarrhoeal diseases

attributable to lack of safe drinking water as well as basic

sanitation. Researchers in India have come up with a

19--solution to this perennial problem with a water purification

system using nanotechnology.

The technology removes microbes, bacteria and other

22--matter from water using composite nanoparticles, which

emit silver ions that destroy contaminants. "Our work can

start saving lives," says Prof Thalappil Pradeep of the Indian

25--Institute of Technology Madras. "For just \$2.50 a year you

can deliver microbially safe water for a family." It is a sign

that low-cost water purification may finally be round the

28--corner – and be commercially scaleable. Unlike other

solutions, in being inexpensive, this new process brought

about a real fix for an increasingly growing problem.

31----Seawater desalination:

Another innovative stride in terms of solutions for the

increasing concern surrounding access to drinking water has

34--to do with making brackish water and even seawater safe for

consumption. Although holding much: promise for the

future, seawater desalination is still extremely expensive,

37--with reverse osmosis technology 'consuming a vast amount

of energy: around 4 kilowatt hours of energy for every cubic

metre of water.

40---------One solution being studied in Singapore, whichOne solution being studied in Singapore, which

opened its first seawater desalination plant in 2005, is

biomimicry - mimicking the biological processes by which

43--mangrove plants and, curyhaline fish (fish that can live in

fresh briny or salt water) extract seawater using minimal

energy. Another new approach is to use biomimetic

46--membranes enhanced with aquaporin: proteins embedded in

cell membranes that selectively shuttle water in and out of

cells while blocking out salts.

49---------Harry Seah, chief technology officer for PUB,Harry Seah, chief technology officer for PUB,

Singapore's national water agency, says: “If science can find

a way of effectively mimicking these biological processes,

52--innovative engineering solutions can potentially be derived

for seawater desalination. Seawater desalination can then be

54--transformed beyond our wildest imagination.”

Hanley Will. The new water technologies that could save the planet.

The Guardian. 2013. Adapted from:

<https:/Awww.theguardian.com/sustainable-business/new-water-

technologies-save-planet>. Accessed on: May 26^th 2022.

Considering what was said about the use of nanotechnology in the filtration of water in the article, choose the correct alternative.