Characterization of acidity and sulfate in dust obtained from the Wuda coal base, northern China: spatial distribution and pollution assessment

• Published in: Environmental science and pollution research international 2021-07, Vol.28 (25), p.33219-33230
• Main Authors: Hong, Xiuping, Yang, Kang, Liang, Handong
• Format: Article
• Language: English
• Subjects: Acidity; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Calcium carbonate; Coal; Contamination; Dust; Earth and Environmental Science; Ecotoxicology; Environment; Environmental assessment; Environmental Chemistry; Environmental Health; Environmental risk; Environmental science; Fires; Industrial areas; Industrial parks; Industrial plants; Industrial pollution; Parks; Parks & recreation areas; pH effects; Pollution; Pollution levels; Research Article; Spatial analysis; Spatial distribution; Urban areas; Waste Water Technology; Water Management; Water Pollution Control; Wind direction
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-12897-8

The coal fire in Wuda, Inner Mongolia of China, is one of the most serious coal fires in the world with a history over 50 years and endangers the neighboring downwind urban area. A lack of effective measures to control coal fires in this region can aggravate environmental pollution. In this study, the levels and spatial distributions of acid (pH) and SO 4 2− in dust in the Wuda coalfield and its surrounding areas in Inner Mongolia, North China, were reported to identify the potential acid and SO 4 2− pollution in the local environment with an area of 270 km 2 . The mean pH and SO 4 2− content was to found to be 7.44 and 5981 μg·g −1 , respectively. Through the analysis of the spatial distribution of pH and SO 4 2− concentrations, it was found that most of contaminated areas are mainly distributed in coalfield and its affiliated industrial parks, and the Wuda urban area also suffered from pollution. Based on chemical equilibrium, the surface acid pollution might have resulted in the change of the dust type from the original weakly alkaline CaCO 3 type to the CaSO 4 type in coalfield and industrial parks. Finally, the pollution assessment revealed that the coalfield and industrial parks are both at heavy pollution levels, and the urban area is mostly moderately polluted, followed by farm and peripheral region with a certain pollution risk. The results indicated that the long-term release of acidic gas from the coal fires and industrial parks can led to significantly elevated acidity and SO 4 2− levels in the dust of the local environment, while coal fires can aggravate surface pollution in industrial parks, but the extent of contamination was also closely related to the terrain and wind direction in the study area.