Page 35 - EER-2-3

Explora: Environment
and Resource Air pollution mitigation technologies

thermal catalysis, photolysis, photocatalysis, and electrical (200–500℃). Stainless steel is affordable, widely available,
catalysis. For sulfate radical-based processes, both single- and its elemental compositions make it an effective support
catalyst and synergistic-catalyst approaches are possible, for VOC oxidation.
with the latter often achieving higher removal efficiencies For NO control, SCR with NH is the most effective
due to enhanced reaction pathways. Table 3 summarizes method for tail gas denitrification. N O, which has a
3
x
the reported pollutant removal efficiencies for SO , NO , global warming potential approximately 300 times greater
2
2
x
and mercury using different types of radicals.
than CO can be decomposed using monolithic stainless-
2,
3.4. Expansion of renewable energy use steel supports, which have been widely applied in N O
2
abatement. 16
The primary source of CO emissions is the combustion of
2
fossil fuels. Reducing fossil fuel use is therefore essential for 3.6. Biofiltration
mitigating air pollution. Transitioning to renewable energy
offers multiple benefits, including lowering the demand for Biofiltration is a low-cost biological process for air
17
fossil fuels, ensuring a sustainable clean fuel resource, and pollution control that requires minimal maintenance and
reducing greenhouse gas emissions. produces fewer hazardous byproducts compared to many
physicochemical techniques. It is also recognized for its
17
Previous research has examined hybrid power systems, potential to reduce atmospheric CO levels. It entails passing
2
such as one combining a lead–acid battery with renewable polluted air through a bed of solid media, often maintained
regeneration, and another applied in coastal regions of at a specific moisture level, where microorganisms degrade
Bangladesh. Both systems demonstrated effective results in methanotrophs, ammonia-oxidizing bacteria, oligotrophic
achieving sustainable electrification. From these studies, it bacteria, fungi, and algae. Bacteria play the primary role in
1
was observed that CO emissions decreased from 67% to contaminant removal during biofiltration, whereas fungi
2
64%. For instance, while a 1% increase in renewable energy aid in the degradation of complex compounds. 17
can reduce air pollution management costs in China by
17–35%, the same increase yields a reduction of more than Biofiltration can remove H S, odor, and VOCs, as well
2
two-thirds in India. Increasing renewable energy capacity as carbon disulfide, when combined with biotrickling
17
not only lowers CO emissions but also contributes to filtration. The efficiency of the process depends largely on
2
controlling NO and PM levels in China; however, it is less the concentration and activity of microorganisms, as well
x
effective in reducing SO emissions. 15 as environmental factors such as temperature, pH, and
2 moisture content. 17
3.5. Catalytic methods for air pollution control
3.7. NH emission reduction strategies
Catalysis, which encompasses catalytic oxidation and 3
catalytic reduction, is an effective and energy-efficient According to the GEOS-Chem model, decreasing VOCs
approach to air pollution mitigation that produces no and NO by 30% during winter leads to only an 8.6%
x
16
secondary pollutants. It has substantial emission- reduction in PM levels. In contrast, NH reduction is
3
reduction potential, making it an essential component the most effective strategy for lowering PM nitrate
2.5
of global air pollution control strategies. Stainless steel concentrations, especially during winter haze events. Even
16
catalysts have properties that make them suitable for small reductions in NH emissions are beneficial.
3
installation near diesel engines to control emissions. For A 50% reduction in NH emissions can lower nitrate-
3
example, Co–Ba–K/ZrO /AISI 314 foam catalysts can be containing PM by 25% and decrease haze days by 31%.
2
manufactured and utilized to remove both soot and NO . Such a reduction also lowers total PM by 13% in winter,
2.5
16
x
2.5
Catalytic combustion is particularly effective for oxidizing 18% on winter haze days, and 14% annually 8. Agriculture
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VOCs into CO and H O at relatively lower temperatures
2 2 is a major source of NH emissions, which can be reduced
3
through measures such as optimized fertilizer application
Table 3. Summary of multi‑pollutant removal efficiencies
using different radicals 7 and improved manure management practices.
Radical type SO removal NO removal Mercury removal 3.8. Traffic management and urban planning
2
x
efficiency (%) efficiency (%) efficiency (%) Two primary strategies can be applied to mitigate urban air
Hydroxyl radical 99–100 75–100 75–98 pollution: improving traffic systems and enhancing urban
Sulfate radical 99–100 72–100 85–99 planning efficiency.
Chlorine radical 99–100 77–98 90–95 Traffic systems can be improved by establishing low-
Ozone 97–100 91–97 82–91 emission zones and enforcing strict penalties for traffic
Volume 2 Issue 3 (2025) 5 doi: 10.36922/EER025210041