Tech Innovations For Clean Air: Preventing Air Pollution

Air pollution is a pressing issue that affects countries worldwide, and the development of new technology is key to improving air quality. Technological solutions are being used to monitor and reduce air pollution, with smart technology emerging as a powerful tool in the fight against pollution. From catalytic converters to low-emitting consumer products, there are many methods for preventing air pollution both indoors and outdoors. For example, scrubbers are a valuable tool for pollution control, preventing harmful air pollutants from damaging communities near industrial centres. In addition, the increasing popularity of electric vehicles is helping to reduce air pollution in urban areas.

Electric vehicles

However, EVs are not without their drawbacks. For instance, the electricity used to charge EVs needs to be generated, and this can create carbon pollution, depending on the energy source. If renewable energy sources like wind or solar power are used, then the carbon pollution is negated. In 2020, renewable energy sources became the second-most prevalent source of electricity in the US, which bodes well for the environmental impact of EVs.

Another concern is the potential for increased pollution from brake, tyre, and road wear. This is particularly true for heavier EVs, which may produce more tyre wear and road dust pollution. However, regenerative braking in EVs can reduce particulate emissions from brake wear, and overall, EVs produce less brake wear than gasoline cars.

The manufacturing process of EVs has also been called into question, with some studies suggesting that the additional energy required to produce an EV battery results in more carbon pollution than manufacturing a gasoline car. Nevertheless, over the lifetime of the vehicle, the total GHG emissions associated with an EV are typically lower due to the absence of tailpipe emissions.

Despite some drawbacks, EVs are an important step towards reducing air pollution. As technology improves, and renewable energy sources become more prevalent, the environmental benefits of EVs will only increase.

Low-emitting consumer products

The development of new technology offers a promising solution for improving air quality. Low-emitting consumer products are an important innovation in this regard, particularly for reducing indoor air pollution.

Many everyday products, such as paints, cleaning agents, adhesives, sealants, furniture, and flooring, release volatile organic compounds (VOCs) that can accumulate in enclosed spaces without proper ventilation. VOCs are known to have adverse effects on human health and the environment. In recognition of these concerns, there has been a growing trend towards developing and certifying low-emitting or VOC-free consumer products and building materials. Guidelines provided by entities like the California Department of Public Health and ASTM help determine whether a product is low-emitting.

Building standards are increasingly incorporating the use of low-emitting materials and products as part of indoor air quality strategies. This is particularly crucial in residential and commercial construction, where the use of low-emitting paints, adhesives, and sealants can significantly reduce indoor air pollution. Additionally, the strategic placement of windows, insulated walls, and reflective roofs can reduce the demand for space heating in cooler climates, further lowering emissions.

Low-emission biomass stoves are another example of low-emitting consumer products. These stoves, equipped with features like secondary combustion, insulated combustion chambers, and fans, can enhance combustion efficiency and significantly reduce emissions. While not all "improved" biomass stoves meet WHO guidelines, they can still serve as a transitional technology towards cleaner alternatives. Pairing these stoves with cleaner fuels, such as biogas, ethanol, and liquefied petroleum gas, can further minimize the health risks associated with household air pollution.

To facilitate the adoption of low-emitting consumer products, various initiatives have been implemented. These include microfinance schemes that provide loans for entrepreneurs and small businesses selling cleaner technologies, as well as consumer credit/lease arrangements that offer rent-to-own options for expensive clean energy products. Additionally, pay-as-you-go schemes, utilizing smart meters and mobile banking, enable consumers to pay for clean energy in smaller, more manageable increments.

Air quality monitoring

Smart air quality monitoring devices and systems can provide real-time data on various aspects of air quality, including carbon dioxide levels, carbon monoxide, noxious gases, and other pollutants. These devices use stationary or mobile IoT-enabled sensors to map and monitor air quality in diverse geographical areas, from small to large regions. The data collected is transmitted to a central management dashboard, enabling enhanced visibility, improved situational awareness, and the ability to predict maintenance and repurchasing schedules. Such systems can also provide early indications of pollution hotspots and send instant alerts if an air quality risk is detected, facilitating a faster response in emergency situations.

Several organizations, such as Smarter Technologies, Aeroqual, and Airly, offer advanced air quality monitoring solutions. These solutions can be tailored for specific contexts, such as construction sites, industrial hygiene, and mining operations, where they can detect the levels of numerous gases and surface conditions that may increase risk.

On a global scale, the United Nations Environment Programme (UNEP) has established the Global Environment Monitoring System for Air (GEMS/Air) to empower governments and stakeholders in developing countries to make evidence-based decisions through improved access to air quality data. GEMS/Air employs a strategic approach that includes the use of low-cost sensors, satellite surface estimates for pollution hotspots, and the Global Consortium for Better Air Quality Data (CBAQd) to facilitate collaboration between various sectors and promote scalable solutions.

Scrubbers

Wet scrubbers use a liquid, usually water, to absorb particles or gases from a stream of air. They vary in energy level, with spray towers being a common low-energy option. In a spray tower, the exhaust is passed through an open vessel with sprayers that distribute the liquid, which then picks up floating particles or absorbs the target gas. Wet scrubbers can also use other solvents to target specific compounds, such as hydrochloric acid or ammonia. Venturi scrubbers are the most efficient type of wet scrubber, achieving efficiencies of more than 98% for particles larger than 0.5 μm in diameter.

Dry scrubbers, on the other hand, do not saturate the flue gas stream with moisture. Instead, they spray dry reagents into the flue stream to neutralize gases. Dry scrubbing systems are used to remove acid gases, primarily from combustion sources, and can be designed as dry sorbent injectors (DSIs) or spray dryer absorbers (SDAs). Dry scrubbers are often used for the removal of odorous and corrosive gases from wastewater treatment plant operations. They can also be used to remove mercury, a highly toxic element found in coal and municipal waste, from exhaust gases.

Both wet and dry scrubbers are effective tools for minimizing environmental impact and reducing the health and safety risks associated with air pollution. They are essential for industries that produce air pollutants, helping to control airborne fumes, vapors, and gases that can cause environmental disruption and adverse health effects.

Biofiltration systems

The process of biofiltration can be applied to air filtration and purification in a variety of settings, including industrial processes, composting, and waste stabilisation. During the biofiltration process, contaminated air passes through the filter media, where pollutants are transferred to a liquid medium and biologically consumed by the microorganisms. This results in the complete decomposition of the pollutants, producing energy, biomass, and metabolic end products such as CO2 and H2O.

One of the key advantages of biofiltration systems is their ability to treat a wide range of pollutants, including VOCs such as toluene, benzene, and xylene, which have been linked to negative health consequences. Additionally, biofilters are effective in treating poorly soluble pollutants in water due to the increased surface area available for mass transfer. They are also useful in reducing water-borne diseases, dissolved organic carbon, turbidity, and colour in surface water, thereby improving overall water quality.

Overall, biofiltration systems offer a sustainable and eco-friendly approach to air pollution prevention, with low operating costs and minimal hazardous by-products. By utilising biological processes and microorganisms, these systems provide an effective and adaptable solution for removing pollutants from the air and improving environmental quality.

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