List of Titles

Authors: Olorundare, O F , Msagati, T A M , Okonkwo, J O , Krause, Rui W M , Mamba, Bhekie B
Date: 2015
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/125386 , vital:35778 , https://doi.org/10.1007/s13762-014-0645-5
Description: Polyurethane composite adsorbent polymeric material was prepared and investigated for selected solid-phase extraction for metal ions, prior to its determination by inductively coupled plasma optical emission spectrometry. The surface characterisation was done using Fourier transform infrared spectroscopy. The separation and preconcentration conditions of the analytes investigated includes influence of pH, sample loading flow rate, elution flow rate, type and concentration of eluents. The optimum pH for the highest efficient recoveries for all metal ions, which ranged from 70 to 85 %, is pH 7. The metal ions were quantitatively eluted with 5 mL of 2 mol/L HNO3. Common coexisting ions did not interfere with the separation. The percentage recovery of the metal ions ranged between 70 and 89 %, while the results for the limit of detection and limit of quantification ranged from 0.249 to 0.256 and 0.831 to 0.855, respectively. The experimental tests showed good preconcentration results of trace levels of metal ions using synthesised polyurethane polymer adsorbent composite.
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Date Issued: 2015

Authors: Olorundare, O F , Msagati, T A M , Okonkwo, J O , Krause, Rui W M , Mamba, Bhekie B
Date: 2015
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/125331 , vital:35773 , https://doi.org/10.1007/s11356-014-3742-6
Description: The determination and remediation of three phenolic compounds bisphenol A (BPA), ortho-nitrophenol (o-NTP), parachlorophenol (PCP) in wastewater is reported. The analysis of these molecules in wastewater was done using gas chromatography (GC) × GC time-of-flight mass spectrometry while activated carbon derived from maize tassel was used as an adsorbent. During the experimental procedures, the effect of various parameters such as initial concentration, pH of sample solution, eluent volume, and sample volume on the removal efficiency with respect to the three phenolic compounds was studied. The results showed that maize tassel produced activated carbon (MTAC) cartridge packed solid-phase extraction (SPE) system was able to remove the phenolic compounds effectively (90.84–98.49 %, 80.75–97.11 %, and 78.27–97.08 % for BPA, o-NTP, and PCP, respectively) . The MTAC cartridge packed SPE sorbent performance was compared to commercially produced C18 SPE cartridges and found to be comparable. All the parameters investigated were found to have a notable influence on the adsorption efficiency of the phenolic compounds from wastewaters at different magnitudes.
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Date Issued: 2015

Authors: Olorundare, O F , Okonkwo, J O , Msagati, T A M , Mamba, Bhekie B , Krause, Rui W M
Date: 2014
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/125233 , vital:35748 , https://doi.org/10.1007/s11270-014-1876-2
Description: This paper reports on the effect of activating agents such as the impregnation ratio of phosphoric acid (1:1–1:5) at constant activation temperature on the performance of porous activated carbon from waste residues (maize tassel). The variation in the impregnation ratio of the produced activated carbon (AC) from 1:1 to 1:5 enabled the preparation of a high surface area (1,263 m2/g) and a large pore volume (1.592 cm3/g) of AC produced from maize tassel (MT) using a convectional chemical activating agent (phosphoric acid). Impregnation ratios (IR) of the precursors were varied between 1:1 and 1:5 in which it was found that the ratio of 1:4 was optimal based on the high surface area, while 1:5 has the optimal pore volume value for the produced activated carbon.
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Date Issued: 2014

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