QE437 : Mobility and speciation of heavy mextals in coal astes of Alborze-Sharghi coal washing plant
Thesis > Central Library of Shahrood University > Geosciences > MSc > 2019
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Abstarct: In this study the concentration and speciation of heavy mextals in coal wastes around the Mehmandost Coal Washing Plant were investigated. For this purpose, 4 reprehensive composite samples of coal wastes were collected and analyzed by standard methods. After preparation of the samples, the total concentration elements (Cr, As, Zn, Cu, Ni, Cd, Pb) and their mineralogy were determined. A six-stage method according to Zheng’s was used to fractionate of mextals in coal wastes samples. The results showed that chromium, on average, had the highest concentration (184.2 mg / kg) and arsenic showed the lowest concentration (11.6 mg / kg). The concentration coefficient in the studied samples showed moderate enrichment regard to arsenic and lead and low enrichment of copper and cadmium, nickel zinc and chromium. The results of sequential extraction showed that the highest percentage of trace elements occurred in the sulfide-bound phase and the lowest percentage of trace elements related to the exchangeable, carbonate and organic matter fractions. According to X-ray diffraction analysis, the minerals found in the coal wastes include quartz, illite, kaolinite and calcite, siderite, pyrite, gypsum and chlorite. The calculated mobility factors for the studied heavy mextals showed that zinc, copper, nickel and lead had the highest mobility coefficient while chromium had the moderate mobility. The results of risk assessment also showed that Pb, As, Cr, Cu posed low nearly 97.11%, indicating repeatability and reliability of the obtained results.
Keywords:
#sequential extraction #mobility #coal #environmental Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
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