Smog towers or smog free towers (see below for other names) are structures designed as large-scale air purifiers to reduce air pollution particles ( smog). This approach to the problem of urban air pollution involves air filtration, and removal of suspended mechanical particulates such as soot, and requires energy or power. Another approach is to remove urban air pollution by a chimney effect in a tall stack, or updraft tower, which may be either filtered or simply released at altitude as with a solar updraft tower, and which may not require operating energy beyond what may be produced by the updraft.

World’s first air cleaning tower

The world's first smog free tower was built by Dutch artist Daan Roosegaarde. It was unveiled in September 2015 in Rotterdam ^[1] and later similar structures toured in ^[2] Beijing and Tianjin, China, Kraków, Poland ^[3] and Anyang, South Korea. ^[4] The 7-meter (23 ft) tall tower uses patented positive ionisation technology and is expected to clean 30,000 m3 of air per hour. ^[2]

Gallery

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  Rotterdam
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  Beijing 1
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  Beijing 2
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  Beijing 3
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  Beijing 4
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  Beijing 5
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  Beijing 6
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  Beijing 7

World’s largest air cleaning tower

This section needs expansion. You can help by adding to it. (March 2023)

In 2016, ^{[5] [6]} a 100-metre (330 ft) tower has been built in Xi'an, Shaanxi to tackle the city's pollution. ^[7] It was funded by the provincial government and costs US$2 million. The running cost is $30000 per year. ^[8] It is under testing by researchers at the Institute of Earth Environment of the Chinese Academy of Sciences. ^[9]

The experimental demonstration urban updraft tower is cleaning the air in central China with little external energy input. ^{[10] [11]} A 60-metre urban chimney is surrounded by solar collector. This project was led by Cao Jun Ji, a chemist at the Chinese Academy of Sciences' Key Laboratory of Aerosol Chemistry and Physics. ^[8] This work has since been published on, with the performance data and modelling. ^{[12] [13]}

Other towers

India

As of 2022 ^[update], there are at least eight smog towers in India, some of which are smaller in scale:

• Connaught Place (around 80 ft; since Aug 2021) ^{[14] [15]}
• Anand Vihar (around 80 ft) ^[16]
• Lajpat Nagar Central market ^{[17] [18]} (20 ft; since Jan 2020)
• Gandhi Nagar market (12 ft) ^[19]
• Krishna Nagar market (12 ft) ^[20]
• Bangalore (15 more maybe installed later) ^[21]
• Chandigarh (24–25 m; water used to remove pollutants) ^{[22] [23]}
• Jaipur^{[ citation needed]}

Projects under development

In Delhi, India Kurin Systems is developing a 12-metre (40 ft) tall smog tower, called the "Kurin City Cleaner". ^[24] It is different from Daan Roosegaarde's Smog Tower in that it won't depend on the ionization technique to clean the air. The H14 grade HEPA Filter, known for being able to clean up to 99.99% of the particulate matter, will be used instead, together with a pre-filter and activated carbon. ^[25] It is claimed the tower will filter air for up to 75,000 people within a 3-kilometre (1.9 mi) radius. ^[26] and cleaning more than 32 million cubic metres of air every day. ^[27]

Reception

Some air pollution experts view smog filtration tower projects with scepticism. For example, Alastair Lewis, Professor of Atmospheric Chemistry at the University of York, Science Director at the National Centre for Atmospheric Science, and chair of the Air Quality Expert Group, has argued that static air cleaners, like the prototypes in Beijing and Delhi, cannot process enough city air, quickly enough, to make a meaningful difference to urban pollution. Instead, Lewis argues that "it is far, far easier to come up with technologies and schemes that stop harmful emissions at source, rather than to try to capture the resulting pollution once it's free and in the air". ^[28] Noting that the Delhi tower would be powered by (mostly) coal-fired electricity, Sunil Dahiya from India's Centre for Research on Energy and Clean Air has commented that "so we will only be adding to pollution elsewhere in the country". ^[29] According to The Times, environmentalists "decried" the Delhi project on the grounds that "given the city's size and the scale of its pollution, 2.5 million smog towers would be needed to clean its air". ^[30] As a refute, "The objective is not to clear entire Delhi's air, it is to create special zones where people can breathe," Anwar Ali Khan, the engineer in charge of the project said. ^[29]

See also

• Air-supported structure
• Biofilter
• CityTrees
• David Y. H. Pui
• Domed city
• Green building
• Green wall
• List of tallest buildings and structures
• Sustainable city

Other names

Other names for the structure include:

• anti-smog tower
• smog-filtering tower
• smog-sucking tower
• smog-eating tower
• smog-extracting tower
• smog removal tower
• smog control tower
• smog-alert tower
• air cleaning tower
• air-purifying tower
• air purifier tower
• air purification tower
• ambient air purifier
• pollution control tower
• SALSCS (Solar-assisted Large Scale Cleaning System)
• HSALSCS (Hybrid Solar-assisted Large Scale Cleaning System)

References

Further reading

• "Anti-Smog Building and Civil Engineering Structures".
• "Xi'an "internet celebrity", the 12 million smog removal tower debut". 18 April 2018. (machine translation, original page in Chinese)
• "Delhi AQI: CP Smog tower down due to DPCC, says minister Gopal Rai; official says running cost high". The Times of India. 5 Nov 2023. Retrieved 6 Nov 2023.
• "Smog tower reactivated in New Delhi". CBC. 8 Nov 2023. Retrieved 10 Nov 2023.
• Zhang, H.; Mao, S.; Wang, X. (2021). "How Much Are People Willing to Pay for Clean Air? Analyzing Housing Prices in Response to the Smog Free Tower in Xi'an". International Journal of Environmental Research and Public Health. 18 (19): 10210. doi: 10.3390/ijerph181910210. PMC  8508453. PMID  34639508.
• Guttikunda, Sarath; Jawahar, Puja (2020). "Can We Vacuum Our Air Pollution Problem Using Smog Towers?". Atmosphere. 11 (9): 922. Bibcode: 2020Atmos..11..922G. doi: 10.3390/atmos11090922.
• Qiu, Hong; Niu, Xin-Yi; Cao, Jun-Ji; Xu, Hong-Mei; Xiao, Shun; Zhang, Ning-Ning; Xia, Xi; Shen, Zhen-Xing; Huang, Yu; Lau, Gabriel Ngar-Cheung; Yim, Steve Hung-Lam; Ho, Kin-Fai (2022). "Inflammatory and oxidative stress responses of healthy elders to solar-assisted large-scale cleaning system (SALSCS) and changes in ambient air pollution: A quasi-interventional study in Xi'an, China". Science of the Total Environment. 806 (Pt 3): 151217. Bibcode: 2022ScTEn.806o1217Q. doi: 10.1016/j.scitotenv.2021.151217. PMID  34717999. S2CID  240109764.
• "Special Issues - Aerosol and Air Quality Research, in honor of Prof. David Y.H. Pui for his 50 Years of Contribution in Aerosol Science and Technology".
• "Curbing air pollution with purification towers, CSE professor leads international team in building purification towers".

External links

• "Filtration Solutions to Mitigate Coronavirus Aerosol and PM2.5 Pollutants" by Professor David Pui David Y. H. Pui talked about the smog free towers (SALSCS) in Xi'an and Delhi (video starts from 33:44)
• IFC Mall installs extra-large air purifiers to manage indoor fine dust (machine translation, original text in Korean)
• Development of Passive/Active integrated module device for fine dust free zone implementation (2nd year) | Bucheon City, Korea's first fine dust reduction device pilot operation (machine translation, original text in Korean)
• Nutan Labs Smog Towers, Nutan Labs is the producer of the tower in Bangalore
• This device can purify air over 500 sqm
• WAYU air purifiers on Delhi roads turn dustbins, spittoons
• Vast grid of filter towers proposed across Delhi to combat toxic smog
• Studio Symbiosis proposes Aũra towers to alleviate air pollution in Delhi