Changes in soil chemical composition caused by self‐heating of a coal‐waste dump

Abstract

The paper presents soil features and chemical composition in a self-heating coalwaste dump. The investigations were carried out in the Upper Silesian Coal Basin.A fire zone in which the soil temperature exceeded 50 C was selected for our study.Soil analyses were carried out for three grain sizesd > 1 mm, 0.063 mm < d ≤ 1 mm, and d ≤ 0.063 mmenabling identification of the diversity of the chemical composition in soil fractions. The highest concentration of heavy metals is represented by Mn (212-6972 mg kg -1 ), Zn (127-3283 mg kg -1 ), Pb (33.6-1344.7 mg kg -1 ), Cu (38.9-101.4 mg kg -1 ), and major elements by Fe (14,300-117,400 mg kg -1 ) and Ca (900-63,600 mg kg -1 ). Soil chemistry showed variations within individual studied sites. The soil reaction ranges from acidic (4.3 in KCl and 5.26 in H 2 O) to moderate alkaline (7.96 in H 2 O and 7.31 in KCl), whereas TOC ranges from 1.21% to 14.60% and TN from 0.023% to 0.291%. The distribution of n-alkanes clearly showed a low degree of transformation of organic matter and characteristic high values of Pr/Ph ratio for humic coals and coal waste in the region. Grains with diameters greater than 1 mm exhibited completely different features than those of fractions smaller than or equal to 1 mm. High organic carbon content (14.60) was detected in the samples along with PAHs. The influence of fire on the chemical composition of all samples was identified using geochemical indicators. PCA analysis showed that the values of the variables were more closely correlated in finer grains than in the coarsest fraction.

The Properties of Black Locust Robinia pseudoacacia L. to Selectively Accumulate Chemical Elements from Soils of Ecologically Transformed Areas

“…All of this has led to massive soil degradation in the Silesia Upland. The most common transformations are soil contamination with heavy metals, acidification, and, in extreme cases, destruction of the soil cover [7][8][9]. Currently, there have been actions to rehabilitate degraded areas by reintroducing vegetation and restoring soil in areas such as dumps, landfills, etc.…”

Unmanned Aerial Vehicle (UAV)-Based Vegetation Restoration Monitoring in Coal Waste Dumps after Reclamation

“…Coal gangue contains different calorific carbon, residual coal, pyrite, and other flammable substances. It is easy to react in low-temperature oxidation processes and releases a lot of heat when exposed to air and water, leading to spontaneous combustion of coal waste dumps [7,8]. The risk of spontaneous combustion remains even after land reclamation [6,9,10].…”

Element Cycling at Thermally Active Coal-Waste Dumps: A Case Study of Calamagrostis epigejos and Solidago canadensis

“…There are cases where extreme phenomena such as selfheating and uncontrolled smoldering underground fires occur in many older, long-existing Resources 2024, 13, 73 2 of 17 coal-waste dumps [16]. These processes can completely change the bio-and geochemical situation in these objects and their vicinity [17][18][19]. High temperatures intensify, among others, element mobility, gas emissions, and dust [20][21][22].…”

“…The enrichment factor is used to assess the degree of anthropogenic influence on ecosystems. The results determine five classes: deficiency to minimal enrichment (<2), moderate enrichment (2-5), significant enrichment (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), very high enrichment , and extremely high enrichment (>40). • Translocation factor (TF): TF = C n R n , where C n is the element content in the aboveground parts of the plant, and B n is the concentration of the same element in the roots [58,59].…”