Abstract:
Abstract: Coal fly ash, resulted from coal combustion in power plants, with relatively high
amounts of aluminium, iron, calcium, and magnesium oxides may modify the sorption capacity of
soils. A batch experiment was conducted to examine the capacity of reclaimed mining soils (RMS)
to adsorb organic carbon (OC) in response to coal fly ash application. Extraction of dissolved OC
was carried out from dried albizia shoot residue and reacted with the RMS at dissolved OC
concentrations varying from 0 to 175 mg C L−1 at pH 5.5. The results showed that the sorption
capacity of the RMS for OC increased significantly with coal fly ash application, which may relate
to increasing the contents exchangeable Ca and Mg, dithionite− and oxalate−extractable
aluminium and iron, and surface areas of soils. Desorption experiment indicated that only 5−23%
of the OC initially sorbed onto soil−coal fly ash interactions was freed using a single extraction
step, suggesting that most of the OC is strongly sorbed to the mineral surfaces. Results of the study
indicate an important role of fly ash in increasing OC sorption capacity of soils and reducing the
percentage of OC sorption from the RMS−coal fly ash association.
Keywords: mineralization, retention, sequestration, sorption, stabilization
