Search results for "Coal burning"
showing 2 items of 2 documents
Concentrations, optical properties and sources of humic-like substances (HULIS) in fine particulate matter in Xi'an, Northwest China
2021
Humic-like substances (HULIS) are ubiquitous in the atmospheric environment, which affects both human health and climate. We present here the mass concentration and optical characteristics of HULIS isolated from aerosol samples collected in Xi'an, China. Both mass concentration and absorption coefficient (Abs365) of HULIS show clear seasonal differences, with the highest average in winter (3.91 μgC m-3 and 4.78 M m-1, respectively) and the lowest in summer (0.65 μgC m-3 and 0.55 M m-1, respectively). The sources of HULIS_C and light absorption of HULIS were analyzed by positive matrix factorization (PMF) and four major sources were resolved, including secondary formation, biomass burning, c…
Origin of atmospheric lead in Johannesburg, South Africa
2006
International audience; The origin of lead in the atmosphere of Johannesburg, South Africa was investigated on the basis of elemental and lead isotopic analyses of coals, mine dumps, gasoline, and about 30 epiphytic lichen samples. Lead predominantly comes from automotive exhausts in urban and suburban areas, as leaded antiknock additives were still in use in South Africa at the time of the study. Although dust emissions from the numerous mine-tailing dumps were expected to contribute significantly to the heavy metal budget, the southern townships that are surrounded by the dumps (such as Soweto and other historically Black residential areas) do not appear to be more than partially influenc…