Meet China’s mist cannons – A unique approach to shoot down smog from sky
A couple of months ago, China was the highlight of global media for their ingenious solution to tackling environmental issues, more specifically smog. In November 2016, many reports suggested that smog had reached over 25 times off safe levels in Beijing. To tackle this problem on immediate priority, the relevant authorities enabled two (mobile) dust suppression systems. Designed to control dust and particulate matter (subject to the quality of DSS), these cannon-like machines are used at industrial units, coal deposits, and construction sites to control dust and other pollutants.
The fog cannons used in Beijing consist of a high power turbine ventilator, which is capable of spraying light rain to a distance of 120 meters and a height of 60 meters and also be rotated up to 270 degrees via remote control. According to Beijing Morning Post, the air becomes temporarily bright and feels cleansed after the dust fighter has passed by.
What is Smog?
Before we move on to discuss the topic in question in detail, I believe it is important to give some details on what is smog. Conventional definition of smog dictates that it is formed by a mixture of smoke, fog and other pollutants in the air. This phenomenon was first witnessed in the early years of industrial age, where fog would capture the smoke from coal factories and would trap it. However, in today’s age smog is mostly seen in cities as the yellow cloud covering the horizon. This smog cloud is also known as bad ozone, as it is toxic in nature. This phenomenon (as mentioned) earlier is the result of contact between nitrogen oxides and volatile organic compounds with sunlight. In case you are wondering what are these volatile compounds? Then look no further, as they are pollutants, created by human inventions – industries, vehicles, crop/wood burning etc. It is harmful for lungs, skin and eyes.
How does Dust Suppression System work and what are its applications?
With many cities around the world smothered by smog, the use of facemasks and air purifiers comes as no big surprise. And as mentioned earlier, China has been at the forefront of employing unique solutions to tackle this problem head-on. Remeber the reference to the use of (Mobile) Dust Suppression System in the first couple of lines of this article; the company which introduced these cannons for city use goes by the name of Hunan Jiujiu Mining Safety Equipment. The company was founded in 2011 and is based in Hunan Province of China, an area long known for coal mines.
The Dust Suppression Systems work by nebulizing water into ultra-fine droplets and spraying them into the air, where they combine with dust particles and fall to the ground, thus effectively clearing out the air from the majority of pollutants. Foreseeing a potential new market, Hunan Jiujiu Mining Safety Equipment started developing and their subsequent marketing in late 2013 and early 2014 to various government departments involved in infrastructure development, demolition, and environmental projects.
As per sources, the mobile unit of dust suppression that can be mounted on a vehicle starts at about $93,000 and a stationary unit can be bought for a starting price of $80,000. The company claims that these specialized machines consume less electricity and water to deliver smaller particles -down to 10 microns, as compared to its conventional brethren capable of producing water droplets with 30 microns. For information’s sake, a ‘micron’ is a measurement unit. (For reference, a grain of table salt is around 100 microns in diameter and sand is around 50 microns. The human eye can see an object down to approximately 50 microns. So, an individual fog droplet that is 1- 10 microns is invisible to the human eye, but in mass quantities, it appears as fog.)
Can DSS effectively curb all pollutants?
Not necessarily. As mentioned, even the most sophisticated DSS systems are capable of producing water droplets up to 10 microns which do not particularly spell any solution for the most troublesome pollutants PM2.5 (2.5 microns and below) & PM10 (10 microns and below.) In a statement to Quartz, company’s Office Director Lu Huang remarked; although these machines cannot catch everything, but they are effective and efficient. Two of these (mobile) DSS units eliminated dust from a six-story building’s explosive demolition in about five minutes.
Why are these machines being used in China and not someplace else?
Because China is notorious amongst various international circles for its very severe Air Quality Index and heavy smogs. For a lot of outsiders, smog may not hold appeal but some experts have summed up the pollution in China’s capital as ‘Similar to that of a Nuclear Winter’.
Don’t believe me? Here’s an experiment of a Chinese Artist – Nut Brother. Where the majority of Beijing residents tend to stay indoors to escape city’s recurring cloud of pollution (smog), Nut exposed himself to the toxic air for four hours a day, 100 days in a row. With the aid of his industrial-strength vacuum Nut collected the dust and turned it into a brick. You can read more on this endeavor, by clicking here!
What’s the relevance with Pakistan?
In November 2016, Lahore and its surrounding regions were engulfed with heavy clouds of smog, which lasted for quite a while and resulted in numerous crashes and health issues. With rapid deforestation, increasing temperatures and lack of any effective policy to address the changing climate; Pakistan is susceptible to random bouts of smog and other out-of-season weather trends. Last year, NASA branded the widespread crop burning in India as the chief tormentor of this anomaly.
More insight into this issue by New York Times, revealed that the farmers in those areas burn the left over straw instead of getting rid of it through proper means. Reports suggest that this left over straw weighed somewhere around 32 million tonnes, creating massive amounts of smoke. While many would argue and resort to pointing fingers, the fact remains that rapid urbanization and deforestation has led to severe climate changes in Pakistan. A fact highlighted in a recent article reported by one of Pakistan’s most reputed media outlets. Following is the visual depiction of how bad things have gotten in various regions of Pakistan. The map is a 3D visualization highlighting flow of air and the amount of particulate matter in any selected spot.
The WHO says that air pollution (PM 2.5) needs to reduce to an annual average of no more than 10 μg/m³, or a 24-hour average of 25 μg/m³ in order to significantly reduce the risks for acute and chronic health effects. As far as the color coding on the map is concerned, the map shows areas with very low levels of particulate matter in blue, and areas with the most pollution in dark red.
You can check this map with live data by clicking here
It’s not like the concept of cleansing the ambient air is new, scholars have been taking on this challenge for years – Google Scholar is full of these researchers. The highlight of this statement is the Dutch Artist – Daan Roosegaarde and his successful endeavors.
- A couple of years ago, Daan co-designed a seven-meter high tower to suck in dirt air like a mega vacuum cleaner. This tower employed Ion technology to filter this air, before releasing smog free air through its vents. And as per some reports, this tower can clean 30,000 cubic meters of air in one hour. The first tower was installed in the Dutch city of Rotterdam in 2015. Lauded as a breakthrough technology for clean air, this tower is just a part of Dan Roosengaarde’s Smog-Free Project. It is prudent to mention the man behind this tower’s cleaning filter – Bob Ursem, a nanoparticles expert at the Delft University of Technology. Several reports highlight that this filter has cleaned the air by 60% in outdoor tests. While nothing concrete has been released on this tower’s final cost, TheGuardian in one of its post has revealed that the filter used in this project has been developed in the price range from €1,600 to more than €118,000.
- Daan Roosegaarde’s second step in his smog-free project is the advent of Anti-smog cycles, a bike that sucks in polluted air and releases purified air. Bikes have always served as a symbol of energy friendly and congestion reducing living around the globe, so to use them as a means to purify air will surely contribute to the collective effort to battle smog. For now, China is the main attraction for various smog-removal projects as the more than 300 cities of China have failed in air quality tests in 2015, as reported by Greenpeace. A fact which is further augmented by the happening of ‘Airpocalypse,’ an event which led to the imposition of ‘red alert’ in more than 24 cities of China.
Although Pakistan does not come near China in terms of air pollution; the rapidly changing landscape and deforestation will have severe repercussions for both the country and its population. A foggy season always merits heightened safety precautions from motorists and add ‘off-season’ smog into this mix and you will end up with loads of extra troubles. Apart from environmental issues and human safety, the increasing chances of smog has also highlighted the glaring need for an authority to improve emission and fuel standards and hopefully get Pakistan closer to stringent yet environment-friendly euro V & VI standards. With CPEC en-route towards its deadlines, Pakistan is already seeing an influx of investors in its auto-industry; a feat which is only strengthed by the launch of six cars in six months. The use of globally obsolete fuels (namely diesel) and less than efficient measures to phase out two-stroke vehicles leaves much to be desired. Last but not the least, it is our duty to save the natural beauty of Pakistan. As per common logic, the relevant departments and policy makers of government can:
- Take initiatives by importing these ‘Mist Cannons’ and be ready to tackle smog in big cities like Karachi, Lahore etc.
- Discuss, draw and deploy long-term policies against rapid deforestation and urbanization to save the landscape, economy, and agriculture of Pakistan.
- Engage local auto manufacturers (Honda Atlas, Indus Motor Company, Pak-Suzuki etc) to add forestation in their Corporate Responsibility Program as a means to contribute positively to the ecosystem of Pakistan.
Last but not the least I will leave you with some questions to think on
- What role has Pakistan Environmental Protection Agency, Ministry of Climate Change, Board of Investment and Ministry of Industries & Production have played to ensure the safety of Pakistan’s ecosystem with its prospering economy in various development policies such as Auto Development Policy etc.?
- Where is an active authority to revamp vehicle fitness & emissions and spearhead the nationwide phase-out of 2-stroke engines? and if there is then why aren’t their progress being highlighted?
- The role of diesel engines and diesel fuel is very important in any country’s economy, so why is Pakistan still living on globally obsolete diesel fuels (and globally obsolete diesel engines in the majority of cases : old busses, Bedford trucks & industrial plants etc), which not only reduces performance but emits huge amounts of (particulate matter) PM 2.5 & 10?