Follow-Up Application of Spondias Mombin Modified Nano-Sorbent for Trace Metals Remediation
Ayomide Blessing Olusegun,
Obi Chidi,
Obuzor Ukalina Gloria
Issue:
Volume 12, Issue 1, March 2023
Pages:
1-6
Received:
13 January 2023
Accepted:
2 February 2023
Published:
14 February 2023
Abstract: Environmental pollution, specifically soil contamination by trace metals, is a significant problem that has caused widespread concern around the globe due to its grave negative effects on the fragile ecosystem. Zero-valent iron nano-compound modified with Spondias mombin leaves extract was employed in the removal of Zinc (Zn), Chromium (Cr), Lead (Pb), and Nickel (Ni) from contaminated soil. The metal compositions in both plant and soil were evaluated using Atomic Absorption Spectrophotometer (AAS). The result showed that the pH conditions for optimum removal efficiency (%) of Zn (70.53%), Pb (98.89%), and Ni (99.99%) were in the range of 7 < pH ≤ 12 while Cr (98.67%) was in the range of 3 < pH ≤ 7. The result revealed that the adsorbent dosage for optimum removal efficiency (%) was 0.2 g for Cr (99.99%) and Pb (98.89%) while 0.8 g for Zn (57.51%), and Ni (99.99%). The optimum contact time was 15 min for Cr (99.99%) and Pb (86.38%) while 120 min for Zn (52.43%) and Ni (99.99%). The modified nano-compound showed higher removal efficiency (%) for Ni (99.99%) under the same condition. This study has revealed that the modified adsorbent can serve as an effective and efficient eco-benign matrix for soil remediation.
Abstract: Environmental pollution, specifically soil contamination by trace metals, is a significant problem that has caused widespread concern around the globe due to its grave negative effects on the fragile ecosystem. Zero-valent iron nano-compound modified with Spondias mombin leaves extract was employed in the removal of Zinc (Zn), Chromium (Cr), Lead (...
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Photocatalytic Epoxidation of Propylene with Bi2WO6-Based Catalyst Supported on Glass Beads
Emmanuel Alhassan Kamba,
Qiao Chen
Issue:
Volume 12, Issue 1, March 2023
Pages:
7-16
Received:
6 September 2022
Accepted:
29 October 2022
Published:
31 March 2023
Abstract: The photo activities of some photo-catalysts including TiO2, Bi2WO6 and Bi2WO6-TiO2 (in various mixing ratios) were evaluated for photo-epoxidation of propylene. The photocatalytic epoxidation reaction was performed in gas-phase under atmospheric pressure. Typical reaction mixture of C3H6:O2:N2 corresponding to the ratio 1:1:18, afforded PO (PO) in addition to other products such as acetone, acetaldehyde and propanal as observed by the FTIR-GCMS tandem analysis. It was established from the results that Bi2WO6-TiO2 photo-catalysts were more preferable for selectivity of PO peaking at 49%. The highest formation rate of PO achieved was 111μmol g cat-1 h-1 over 12mol% Bi2WO6-TiO2 ratio in a typical flow reaction for 1h at 345 K under UVA illumination. Under this condition the selectivity of products was also observed to be very stable. Further study on the effect of light intensity revealed that increasing the light intensity from 0.1 to 0.3mWcm-2 significantly increased the selectivity of PO by 5%. Higher intensity depreciated the PO selectivity. In order to study the effect of temperature on the photocatalytic epoxidation reaction, a systematic approach was followed. As raising the reaction temperature influences the distribution of products significantly, a temperature range of 335-355 K was used in the optimised reaction condition. At 355 K, it was observed that the formation of propanal was favoured which was attributed to its inhibition to be transformed into propionic acid. However, raising the reaction temperature was observed to affect the rate of reaction in two ways: first, the adsorption of PR on to the photo-catalyst which causes a decrease in the reaction efficiency was reduced and secondly, the desorption of products of reaction which in turn reveals more active sites, was improved.
Abstract: The photo activities of some photo-catalysts including TiO2, Bi2WO6 and Bi2WO6-TiO2 (in various mixing ratios) were evaluated for photo-epoxidation of propylene. The photocatalytic epoxidation reaction was performed in gas-phase under atmospheric pressure. Typical reaction mixture of C3H6:O2:N2 corresponding to the ratio 1:1:18, afforded PO (PO) in...
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