The Potential Environmental Impact of PAHs on Soil and Water Resources in Air Deposited Coal Refuse Sites in Niangziguan Karst Catchment, Northern China

Abstract

Long-term deposition of coal spoil piles may lead to serious pollution of soil and water resources in the dumping sites and surrounding areas. Karst aquifers are highly sensitive to environmental pollution. In this study, the occurrence and release/mobilization of polycyclic aromatic hydrocarbons (PAHs) in coal waste and coal spoils fire gas mineral (CSFGM) were evaluated by field and indoor investigations at Yangquan city, one of the major coal mining districts in the karst areas of northern China. Field investigations showed that dumping of coal waste over decades has resulted in soil and water pollution via spontaneous combustion and leaching of coal spoil piles. Indoor analysis revealed that the 2-ring and 3-ring PAHs contribute to 65–80% of the total PAHs in coal spoils, with naphthalene (Nap), Chrysene (Chr), and Phenanthrene (Phe) as the dominant compounds. Based on a heating/burning simulation experiment, the production of PAHs is temperature-dependent and mainly consists of low-ring PAHs: 2-ring, 3-ring, and part of the 4-ring PAHs. The PAHs in the leachate are light-PAHs (Nap, 20.06 ng/L; Phe, 4.76 ng/L) with few heavy-PAHs. The distribution modes of PAHs in two soil profiles suggest that the precipitation caused downward movement of PAHs and higher mobility of light-PAHs.

Changes Induced by Self-Burning in Technosols from a Coal Mine Waste Pile: A Hydropedological Approach

“…The PAHs distribution varied significantly with depth, especially in the waste pile affected by self-burning, which can also be explained by the fact that the PAHs production was temperature-dependent. Similar results were observed by [42]. Several PAHs were identified in the leachates, specifically 2−3-rings PAHs (Nap, Acy, Ace, Flu, and Phe) and 4-ring PAHs (Flt, BaA, and Chr).…”

The Influence of a Fire at an Illegal Landfill in Southern Poland on the Formation of Toxic Compounds and Their Impact on the Natural Environment

“…2-ring naphthalenes were found to be significantly higher in combusted waste than in soil samples. This may be related to a study [ 64 ], in which, in laboratory conditions, controlled heating and burning of coal spoils was carried out to determine PAH emissions with full access and without access to oxygen. Increased 2-ring concentrations in the range of 200 °C were observed.…”

Distribution, sources and transport of polycyclic aromatic hydrocarbons (PAHs) in karst spring systems from Western Hubei, Central China

“…(1) PAHs can quickly enter karst aquifers via the vadose zone because the thin and uneven soil layer might not be sufficient to filter PAHs from the surface system ); (2) abundant precipitation in this area may also enhance the downward movement of PAHs (Li et al 2019); (3) the highly vulnerable karst area with numerous sinkholes, fissures and fractures acts as pathways and conduits for rainwater and surface runoff to enrich pollutants in the spring water (Qin et al 2021). Groundwater can have the optimum condition for long-term retention of organic pollutants.…”