As cities battle with the spiralling costs of healthcare–not least because of the variety of ailments brought about by smog–innovation is waiting to step in and help surmount the challenge of air pollution
Buildings in large cities rise vertically many storeys, as if attempting to touch the clouds. However what they manage to reach are clouds of smog.
Combustion from engines of vehicles results in carbon dioxide along with other harmful pollutants like nitrogen oxide and sulphur oxide. It is the dangerous cocktail of these noxious fumes that leads to smog.
As cities battle with the spiralling costs of healthcare–not least because of the variety of ailments induced by smog–innovation is waiting to step in and help surmount the challenge of air pollution.
Air pollution and suspended particulate matter harms people and infrastructure alike. Due to high pollution levels citizens suffer from ailments and life-threatening diseases. Airconditioning, electrical fittings and other equipment also do not last as long as they should due to the onslaught of the noxious fumes.
Buildings too bear the brunt of pollution by losing their finish and gleaming façade while developing micro cracks and sustaining other structural damage. The latest in futuristic building design is a building that is self-cleaning and one that will cut the smog while helping the building retain a sparkling façade.
An idea, that may sound far-fetched, has begun to take root. Building design experiments have begun around the globe–and in India too-to combat air pollution. This effort is not for nothing considering how particulate matter from vehicular emissions, construction activity, and factory output is a hazard that is endangering the health of city residents. The genesis of these experiments lies in the efforts by NASA to keep the space exploration environment clean.The technique adopted was photocatalytic technology.
Trying to mimic the ultimate pollution wipers–plants and green trees–whose leaves absorb dust and use photosynthesis to cut carbon dioxide and produce vital oxygen and energy, the new process flipped this natural process.Photocatalysis, which is a reverse process, utilizes energy or light to activate a mineral and produce carbon di-oxide and water. The building when coated with a layer of photocatalytic compound that is sprayed on can easily break down the organic atmospheric pollutants and reduce their impact and subsequent cost of façade maintenance. In addition, the process can also break down pollutants like nitrogen oxide in the surroundings, thereby limiting smog formation.
Titanium dioxide, the ubiquitous compound which is highly photocatalytic and present in many forms in suntan lotions and paints, is the real hero behind this smog-guzzling building.
In the presence of sunlight, the nano particles of titanium dioxide become charged and, using atmospheric water, release free radicals that break down organic pollutants as well as nitrogen oxide that can harm the façade. The pollutants then lose the power to stick to the building façade and are easily washed down with water or during rain. A secondary benefit is that this translates into a building that can guzzle smog and reduce pollution by nitrogen oxides, which is a key component of the smog.
The day is not far off when futuristic apartments sporting a coat of photocatalytic materials will be here in India as well. Self-cleaning buildings that retain gloss and finish with clean facades will be the norm.
Source: Times of India dated 26th Dec. 2015