Distributions of Polycyclic Aromatic Hydrocarbons in Coal in China

Abstract

As China's main energy source, coal production and consumption account for 72% and 62%, respectively, of primary energy. The total output of raw coal was 3.41 billion tonnes (t) in 2016, down 9.0% from the same period a year earlier, and about 90% of coal comes from underground mines. In recent years, many coal mines have been closed because of the depletion of coal resources, resource integration, and coal mine production safety. Consequently, groundwater levels in these mines rise rapidly after the mine drainage systems stop working. Moreover, other aquifers are polluted with mine water through mining-induced fractures, faults, and poorly sealed drill holes. In northern China, the Ordovician or Cambrian aquifer, which is the main coal seam floor, is an important water source [1]. This water resource is at risk of being polluted when the groundwater above becomes polluted. For example, due to the influence of the coal mine water in Zibo mining area of Shandong Province, and Yangquan mining area in Shanxi Province, the karst groundwater has been polluted in different degrees [2-3]. Investigations show that around 40% of total groundwater in northern China

Polycyclic Aromatic Hydrocarbons in Surface Water from Wuhai and Lingwu Sections of the Yellow River: Concentrations, Sources, and Ecological Risk

“…It has been demonstrated that, in the process of coal mining, the treatment and storage of coal provided the basic conditions for the release of PAHs into the environment [4][5][6][7][8][9]. For example, PAHs in coal and coal waste could be leached into the mine water [10] and then enter into the aquatic environment with the discharge of mine water [11].…”

Determination of Polycyclic Aromatic Hydrocarbons in Coal from the Kuznetsk Coal Basin by Means of GC/MS and GC/GC-FID

“…The PAHs release from solid matrices is most frequently carried out using extraction with organic solvents (benzene, toluene, acetone, methanol, hexane, acetonitrile, dichloromethane, chloroform, and their mixtures) in Soxhlet apparatus or an ultrasonic bath; The methods of PAHs extraction from solid samples that can be applied to extract PAHs from coal include supercritical fluid extraction, liquid extraction under pressure, microwave extraction, extraction with hot water [21][22][23][24].…”

“…The distribution of 16 PAHs in coal mined in China and the factors affecting this distribution were analyzed in [12]. Results showed that the average concentration of PAHs in the samples of raw coal was 10.540±7.973 μg/g, and PAHs with low molecular mass had the largest content, comprising 44% of the total PAHs concentration.…”

“…The highest 16 PAHs content was observed in bituminous coal, then in lignite, and the lowest one was detected in anthracite. Analysis of the factors shows that the content of carbon, volatile substances, the ratios H/C and O/C have a substantial effect on PAHs content in raw coal [12]. Those studies were carried out by the authors to substantiate the sources of groundwater pollution with PAHs at the territories of abandoned coal mines.…”

Pollution Characteristics of Polycyclic Aromatic Hydrocarbons in Unsaturated Zone of the Different Workshops at a Large Iron and Steel Industrial Site of Beijing, China

“…), combustion condition and even burning stages of coal in the workshops. In the CP, the processes in the dry distillation of bituminous coals which have the highest concentration of 16-PAHs than lignite and anthracite [22] could yield PAHs emissions at a large scale and are the major contributors to the iron and steel industry. Coking wastewaters, oils and solid wastes produced during deep processing of tar and gas purification also contain high concentrations of PAHs.…”