https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41368 Tue 02 Aug 2022 14:59:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26716 27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) spectroscopy. The XRD patterns indicated preservation of the crystalline structure of palygorskite following all the treatments. These findings were supported by the Al (IV) and Al (VI) coordination peaks (chemical shift ~ 55 and 2.9 ppm, respectively) which were unaltered in the ²⁷Al MAS NMR spectra of the samples. The acid-thermal activated palygorskite exhibited the highest specific surface area (152.7 m² g^-1) and pore volume (0.2137 cm³ g^-1) which respectively were 3-fold and 69% greater than the raw palygorskite. The potentiometric titration analyses highlighted the possible role of Al derivatives towards development of the surface charge of the activated palygorskites. Electrokinetic studies described the stability of the activated products (zeta potential values ranging from - 5 mV to - 32 mV) at different electrolyte (NaNO₃) concentrations. Combined acid-thermal activated palygorskite displayed a stronger specific adsorption of multivalent cations, and held a direct relevance to environmental remediation. Findings of this study will assist in the development of palygorskite-based adsorbents for heavy metal contaminants remediation.]]> Sat 24 Mar 2018 07:26:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24988 max) (mg g⁻¹) of the soil clay fractions (SCF) maintained the order: Allo > Smec > Kaol-Ill. A similar order was also observed when the adsorption capacities were normalized to the specific surface area (SSA) of the SCFs (mg m⁻²). DOC adsorption showed a positive relationship with SSA, and sesquioxides and allophanic minerals provided the largest contributions to the SSA in the SCF. Removal of sesquioxides from the SCF resulted in a decrease in SSA and thus DOC adsorption, whereas removal of native OC increased the SSA and subsequent DOC adsorption. Because this study used pedogenic SCFs which represented soils formed in different environments instead of processed clays from geological deposits, it provided realistic information about the interaction of DOC with SCF in relation to their native OC and sesquioxide contents. It also revealed the importance of Ca2+ in enhancing the carbon adsorption capacities of these SCFs.]]> Sat 24 Mar 2018 07:09:55 AEDT ]]>