Air pollutant monitoring in different brick kiln technologies: a step towards the implication of emission inventory development of Punjab, Pakistan

Abstract

The inefficiency of fixed chimney bull’s trench kilns (FCBTKs) leads to high emissions of smoke, particulate matter, and gaseous pollutants, impacting local air quality and nearby populations. Given the lack of air quality data on the brick kiln sector, this study aims to assess gaseous pollutants emissions to support the formulation of an emissions inventory for the brick kiln industry, providing a basis for pollution reduction policies. To achieve this, the present study was conducted in four districts of Punjab (Attock, Chakwal, Rawalpindi, and Mianwali) to compare emissions from FCBTKs and induced draught zigzag brick kilns (IDZZKs). Emission rates were measured to evaluate the performance of both kiln technologies, and the results showed a reduction in emissions of 35%, 26%, 17.6%, and 4% for CO, CO₂, SO₂, and NOx, respectively, in IDZZKs. To further assess the impacts of IDZZKs, emission inventories were made based on emission factors including emission rate (ER), mass-based-emission factors (EFm), energy-based factors, (EFe) and production-based factors (EFp). The emission inventories depict a 10% decrease in fuel consumption, while brick production increased by 42% in IDZZKs compared to FCBTKs. These findings show the benefits of adopting IDZZKs, which are the basis of proposed policy guidelines. The guidelines recommend: effectively communicating the benefits of IDZZKs to kiln owners, offering financial support for kiln retrofitting, and implementing strict monitoring and penalties to ensure compliance with emission standards. Overall, the study concluded that IDZZKs technology offers significant environmental benefits by reducing emissions and fuel consumption, improving air quality, and contributing to sustainable brick production.