Beware China’s ‘Anti-Smog Tower’ And Other Plans To Pull Pollution From The Air
Alastair Lewis , 27 Jan 18
       

Artists impression of the purification tower. SCMP / handout

An air purifying tower the size of a small skyscraper has been built in the city of Xi'an, China. Reports from the scientists behind the project seem at first glance to be rather positive, offering a technological route to clean pollutants out of the air at the sort of scale that could help an entire city. But as there isn’t any hard data publicly available to support the claim, for now a dose of scepticism is likely in order.

This isn’t the first project to use a technological or natural intervention to try and clean up pollution from ambient air. In India water cannons have been used recently in an attempt to wash out particles, while in London NOx-eating paint has been promoted as a solution to harmful nitrogen oxides. And many cities have mooted the planting of more trees and shrubs as a route to cleaning up the air.

All of these, and indeed the purifying tower, are underpinned by at least some plausible science. A tower that filters the air no doubt will take tiny harmful particles out of the air, titanium oxide paints do react with NOx, and trees do act as sinks for air pollution. However, the more important but often neglected question is whether the effects really make a useful difference.

Pollution spreads far and wide

The biggest challenge in trying to take pollution out of air (rather than exhaust pipes) is that it is very diluted. Although humans live predominantly in the bottom couple of metres of the atmosphere, what we breathe is heavily influenced by a much deeper layer of air that runs from the surface up to around 1km in height, referred to in meteorological terms as the planetary boundary layer. Pollution is rapidly mixed in the boundary layer due to turbulence and thermals, and it is this much bigger volume of air that needs scrubbing and cleaning if pollution is really to be reduced on large scales.

Sign in to view full article

       
The Price of Connection: ‘Surveillance Capitalism’
Imagine, if you can, a period long before today’s internet-based connectivity. Imagine that, in that distant time, the populations of ...
Nick Couldry
Mon, 27 Feb 17
Fighting Online Trolls With Bots
The wonder of internet connectivity can turn into a horror show if the people who use online platforms decide that ...
Saiph Savage
Fri, 13 Jan 17
We Change Our Voice When We Talk to High-Status People, Shows New Study
Imagine going for a job interview and the employer sitting across from you is truly intimidating. He’s big, bold, loud ...
Viktoria Mileva, Juan David Leongómez
Wed, 5 Jul 17
How Hot-Deskers are Made to Feel Like the Homeless People of the Office World
If you work in an open-plan, hot-desking environment, you have probably at some point found yourself trudging through the office, ...
Alison Hirst
Thu, 16 Feb 17
Exploring the Complexities of Forgiveness
Friday, Jan. 27 is International Holocaust Remembrance Day – an annual day that honors the memories of the victims of ...
Yerachmiel Gorelik
Tue, 31 Jan 17
AcuSLIM - Acupuncture Weight Loss Programme
An Epoch Times Survey
An Epoch Times Survey
Sports Elements
BUCHERER
Sports Elements