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INTRODUCTION
Different brick kiln technologies contribute to air pollution at varying levels due to differences in combustion efficiency, fuel use, and design. Fixed Chimney Bull's Trench Kilns (FCBTKs) emit significant amounts of pollutants such as PM2.5, sulfur dioxide (SO2), and carbon dioxide (CO2), primarily due to inefficient fuel combustion. Studies highlight that adopting Induced Draught Zigzag Kilns (IDZKs) can reduce PM2.5 emissions by 20-40% and black carbon emissions by around 30-55% compared to FCBTKs (Raza et al., 2023; MDPI, 2019).
Additionally, Vertical Shaft Brick Kilns (VSBKs) are among the cleanest technologies, producing the least amount of atmospheric pollutants. These kilns consume less energy and emit significantly lower amounts of PM10, CO, and NO compared to conventional kilns. Tunnel kilns, which are often more energy-efficient due to continuous firing processes, rank slightly below VSBKs in emission reduction potential but still outperform older FCBTKs and clamp kilns (Longdom, 2023).
Transitioning from older technologies like FCBTKs to more efficient designs, such as zigzag and VSBKs, plays a crucial role in mitigating the environmental impact of brick manufacturing. Such shifts also align with sustainable development goals by reducing fuel consumption and greenhouse gas emissions (MDPI, 2019; Longdom, 2023).
Brick kilns are significant sources of air pollution, emitting various harmful pollutants depending on the technology and fuel used. Traditional technologies like Fixed Chimney Bull's Trench Kilns (FCBTK) are prevalent in many developing countries, including Pakistan. These kilns typically burn low-grade coal, bagasse, or wood, resulting in emissions of particulate matter (PM2.5), black carbon, sulfur dioxide (SO2), and carbon monoxide (CO). The inefficient combustion in these setups leads to significant environmental degradation and health impacts in nearby communities.
Recent research suggests that switching to more modern technologies, such as Induced Draught Zigzag Kilns (IDZK), can reduce pollution significantly. IDZKs improve combustion efficiency by altering the airflow within the kiln, resulting in approximately 30% lower CO2 emissions and up to 35% reductions in PM2.5 emissions compared to FCBTKs. Additionally, emissions of black carbon, a potent climate forcer, can be reduced by 80% with this technology. Cleaner kilns also contribute to a decline in acidification and photochemical pollutants, reducing local environmental impacts such as smog formation and soil degradation.
A study conducted in Nepal and Pakistan found that the adoption of zigzag technology...