ORCID Profile
0000-0001-9190-4264
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Publisher: Copernicus GmbH
Date: 26-03-2022
DOI: 10.5194/EGUSPHERE-EGU22-812
Abstract: & & Bauxite residues (BR) from the Bayer process to produce alumina are highly alkaline and saline, containing high-level toxic elements (such as vanadium (V)), which are soluble in water under the alkaline pH condition. Ecological engineering of the BR can significantly improve physicochemical, mineralogical, and biological conditions, leading to the productive growth of pioneer plants. However, it remains unknown the fate of vanadium in response to the eco-engineering-driven changes of mineralogy, geochemistry, and organic matter decomposition.& & & & The primary distribution of V in the BR-technosols will be characterized in sequential extraction and fractionation. The results of sequential extraction over show that the main vanadium pools in BR-technosols are in the iron oxide and organic matter phases, which provoked an investigation into the controlling mechanisms and specific sorbents, through microstructural and spectroscopic analysis combined with multivariate analysis. The alkaline environment was found to be the main controlling factor leading to elevated bioavailable vanadium in the bauxite residue. Within the iron oxide phase, amorphous iron oxides are expected to play an important role in sorption and therefore the conversion of crystalline iron-bearing minerals to the amorphous phase during weathering will be a direction of concern during long-term rehabilitation. Organic matter under natural soil conditions is an important vanadium sorbent, and additional additions of organic matter did not observe a significant improvement in this study s le, but when combined with P additions, a significant reduction in pH occurred, as did water-soluble vanadium. More investigation needs to be stimulated in terms of the role of P in promoting the addition of organic matter.& & & & The expected results will aid the risk assessment of the eco-engineered BR-technosols and necessary intervention to mitigate the identified risks of V pollution in seepage and surface runoff in the future.& & &
Publisher: Elsevier BV
Date: 2022
Publisher: University of Queensland Library
Date: 2022
DOI: 10.14264/B884F23
Publisher: No publisher found
Date: 2019
Publisher: Society of Exploration Geophysicists
Date: 08-2019
Abstract: The pore structure and fractal characteristics of the Lower Cambrian marine organic-rich shale in southern China were comprehensively studied using low-pressure [Formula: see text] adsorption and organic geochemical experiments, X-ray diffraction, petrophysical property tests, and scanning electron microscope observations. The results indicate that the total organic carbon (TOC) content of the study shale varies between 0.45% and 8.50%, with an average value of 3.97%. The adsorption isotherm of the shale s les belongs to type IV, and slit-type pores are the predominant pore type in these shales. The shale has a Brunner–Emmet–Teller specific surface area ranging from 1.83 to [Formula: see text], a pore volume ranging from 0.00398 to [Formula: see text], and an average pore diameter ranging from 3.61 to 15.19 nm. Organic matter pores (OMPs) are the main contributors to the specific surface area and the pore volume. The organic matter is closely symbiotic with the epigenetic quartz. We have obtained two fractal dimensions ([Formula: see text] and [Formula: see text]) of the shale using the Frenkel-Halsey-Hill method. It was found that [Formula: see text] is suitable for the quantitative characterizing of the pore structure of nanopores inside the shale due to its good correlation with the TOC content and pore structure parameters. When the TOC content of the shale exceeds 4%, the main pore type inside the shale is OMP and the [Formula: see text] value mainly reflects the fractal characteristics of OMP. Moreover, we analyzed the seepage characteristics of different types of pores. It was found that the parallel plate-like pores and the slit-type pores are more favorable for fluid seepage than the ink bottle-like pores. The shale with [Formula: see text] and [Formula: see text] type pore structures should be the key exploration targets for the target shale in the study area.
Publisher: Springer Singapore
Date: 2017
No related grants have been discovered for Chengyao Ren.