An Emission Inventory-Based Study on Black Carbon Aerosols Produced During Biomass Burning

Source apportionment study at Madurai Kamaraj University was done to identify the possible sources of black carbon concentration (BC). It was found that the biomass burning resulted in the increase of BC mass concentration. As biomass was the primary source of fuel for most of the rural households around the educational site, a simple questionnaire-based bottom-up emission inventory was done to analyze the type of stove used, the number of combustion cycles performed and the type of biofuels used by them at two environments, namely indoor and outdoor. Emissions on an annual scale from the biofuels were estimated using the emission factors measured from real-time instruments such as Finch Mono-II for measuring carbon monoxide (CO), carbon dioxide (CO2) meter for CO2 and an Aethalometer AE-31 for BC. Due to the influence of external meteorological parameters and other sources, the emission factors of pollutants in the outdoor environment vary from the those in the indoor environment. The average emission factors of the pollutants from the fuel woods and dung were (1) indoor BC mass: 0.24 (0.03–1.19) and 0.06 (0.02–0.08) g kg−1, respectively; (2) indoor CO2: 224.57 (134.25–343.82) and 140.05 (135.59–148.74) g kg−1, respectively; (3) indoor CO: 88.17 (46.30–115.94) and 89.45 (90.28–92.04) g kg−1, respectively; (4) outdoor BC mass: 0.58 (0.00–1.70) and 0.94 (0.84–1.1) g kg−1, respectively; (5) outdoor CO2: 482.44 (215.94–894.93) and 491.60 (475.65–528.37) g kg−1, respectively; (6) outdoor CO: 101.64 (50.48–281.33) and 214.55 (200.16–232.64) g kg−1, respectively. From emission factors measured, the total emission from the biomass burning was estimated and it was found that a total of 32.62 ± 11.74 (ton year−1), 174.62 ± 62.86 (ton year−1) and 0.019 ± 0.006 (ton year−1) of CO, CO2 and BC, respectively, was emitted from an average single household. This study thus quantifies emissions from different biomass sources and lays the framework for the creation of a regional emission database on rural households.