Estimation of gaseous products and particulate matter emission from garden biomass combustion in a simulation fire test chamber

Air quality in many of the cities in India is gradually deteriorated due to various activities. One of such activities is open burning of garden biomasses in cities. This study was aimed to estimate the emissions from various types of garden biomasses, namely grass, leaves, twigs and mixtures of these three in a controlled SIFT chamber. Though the particulate emission (1.51 g kg−1) was the lowest from grass, the particle size distribution indicates that the emission contains 10% of fine particulates (<2.5 μm) and significant quantity (70%) of respirable fraction (<10 μm). On the other hand, leaves, though generating 32.3 g kg−1 particulate matter, contained major portion in non-respirable range (around 40%). CO2 emission from leaves (1064.6 g kg−1) and twigs (897.3 g kg−1) are significantly lower than the emission from a mixture (1423 g kg−1) of equal proportion of these two. Similar trend is followed in case of carbon monoxide and nitrogen oxide emissions. However, hydrocarbon emission followed a reverse trend of emitting high emission load (11.4 g kg−1) in the mixture of leaves and twigs than their individual type (2.4 g kg−1 (leaves) and 0.2 g kg−1 (twigs)). The toxicity indices for all categories were very low (0.06–0.12). However, out of the five categories, grass was found to have the lowest toxicity index (0.06) and followed by the mixture (1:1:1), having 0.07. The particulate matter emission load computed for the cities of India shows that the leaves and grass contribute 97 and 4.5 tons day−1, respectively. Among the gaseous pollutants, CO2 emission was the highest, as the computed values were 3212 tons day−1 from leaves and 92 tons day−1 from grass.