In many parts of the developing world and economies in transition, small-scale traditional brick kilns are a notorious source of urban air pollution. Many are both energy inefficient and burn highly polluting fuels that emit significant levels of black carbon (BC), organic carbon (OC) and other atmospheric pollutants into local communities, resulting in severe health and environmental impacts. However, only a very limited number of studies are available on the emission characteristics of brick kilns; thus there is a need to characterize their gaseous and particulate matter (PM) emission factors to better assess their overall contribution to emissions inventories and to quantify their ecological, human health, and climate impacts. In this study, the fuel-, energy-, and brick-based emissions factors and time-based emission ratios of BC, OC, inorganic PM components, CO, SO<sub>2</sub>, CH<sub>4</sub>, NO<sub>x</sub>, and selected volatile organic compounds (VOCs) from two traditional artisanal kilns and one MK2 kiln in Mexico were quantified using the tracer ratio sampling technique. Simultaneous measurements of PM components, CO and CO<sub>2</sub> were also obtained using a filter-based sampling probe technique. Additional measurements included the internal temperature of the brick kilns, mechanical resistance of bricks produced, and characteristics of fuels employed. The results show that both techniques capture similar temporal profiles of the brick kiln emissions and produce comparable emission factors, indicating that the tracer ratio technique can be an alternative option to the filter-based sampling probe technique in understanding the temporal profile of the chemical composition of brick kilns emissions. A more integrated inter-comparison of the brick kilns' performances was obtained by simultaneously assessing emissions factors, energy efficiency, fuel consumption, and the quality of the bricks produced. Overall, a well-designed and operated MK2 kiln produced lower PM<sub>2.5</sub>, BC, OC emission factors and higher energy efficiency than the traditional artisanal brick kilns. Average fuel-based BC emission factors ranged from 0.15&ndash;0.58&thinsp;g/kg-fuel whereas BC&thinsp;/&thinsp;OC mass ratios ranged from 0.9&ndash;5.2, depending on the kiln type. The results from this study contribute to the limited number of databases available on the emission characteristics of the informal brick production sector.
Zavala, M., Molina, L. T., Maiz, P., Monsivais, I., Chow, J. C., Watson, J. G., … Knighton, W. B. (2018). Black carbon, organic carbon, and co-pollutant emissions and energy efficiency from artisanal brick production in Mexico. Atmospheric Chemistry and Physics, 18(8), 6023–6037. https://doi.org/10.5194/acp-18-6023-2018