http://hdl.handle.net/10386/2798 2026-04-12T15:03:57Z 2026-04-12T15:03:57Z Mpai, Semakaleng Mokganya, Lerato M. Raphoko, Lerato Masoko, Peter http://hdl.handle.net/10386/4698 2024-10-22T01:00:14Z 2022-01-01T00:00:00Z

Untargeted metabolites and chemometric approach to elucidate the response of growth and yield attributes on different concentrations of an amino acid based biostimulant in two lettuce cultivars Mpai, Semakaleng; Mokganya, Lerato M.; Raphoko, Lerato; Masoko, Peter The study aims to underpin biochemical mechanisms induced by the application of different concentrations of an amino-acid based Phytostim® biostimulant on growth and yield attributes. Different concentrations of Phytos- tim® biostimulant: 0 (untreated), 1, 3, and 6% were foliar applied on lettuce cultivars (‘Lara’ and ‘Elisa’). After 45 days of transplanting, analysis growth and yield attributes, biochemical analysis and LC-MS untargeted metabolites profile were performed. Application of 3% dose improved both growth and yield parameters in both cultivars in comparison to the 6% dose which inhibited growth. Similar trend was observed for biochemical and antioxidant analysis (phenolic, flavonoids, carotenoids, chloroplyll a and b and scavenging activity). The PCA and OPLS-DA score-plot clustered the metabolome profile of biostimulant treated vs untreated samples with major heterogeneity distinction observed in the untreated samples. Obtained results validate the use of bio- stimulants in agriculture while giving information on the effects of the treatments towards changes in the chemical composition within the studied cultivars. Journal article published in Scientia Horticulturae 306 (2022) 111478

2022-01-01T00:00:00Z Maponya, Thabiso C. Makgopa, Katlego Somo, Thabang R. Tshwane, David M. Modibane, Kwena D. http://hdl.handle.net/10386/4259 2023-07-15T01:00:16Z 2023-01-01T00:00:00Z

Highly adsorptive removal of palladium and platinum ions from wastewater using novel ethylenediamine-glutaraldehyde-grafted metal organic framework Maponya, Thabiso C.; Makgopa, Katlego; Somo, Thabang R.; Tshwane, David M.; Modibane, Kwena D. Herein, a metal–organic framework (MIL-101(Cr)) was synthesized and functionalized with ethylenediamineglutaraldehyde (ED-GA for removal of palladium (Pd2+) and platinum (Pt4+) from wastewater. The chemical structure, surface properties, morphology, and adsorption energy of the prepared materials, MIL-101(Cr) and MIL-101(Cr)/ED-GA were analyzed using several analytical techniques and density functional theory (DFT). The prepared MIL-101(Cr)/ED-GA was efficient in removing Pd2+ and Pt4+ from aqueous solution with the percentage removal reaching 95% for Pd2+ and 85% for Pt4+. Furthermore, the adsorption data demonstrated a good fit to the Langmuir isotherm model and gave the maximum adsorption capacity values of 416.17 mg g􀀀 1 for Pt4+ and and 322.6 mg g􀀀 1 for Pd2+ ions. Kinetics data obeyed a pseudo-second-order model and revealed the rapid adsorption of Pd2+ and Pt4+ ions by MIL-101(Cr)/ED-GA which reached equilibrium within 10 and 40 min, respectively. Lastly, DFT studies revealed that the adsorption of Pd2+ ions by the composite forms a more thermodynamically stable compound than adsorption of Pt4+, suggesting that the material easily interacts with Pd and high selectivity is thus expected. This was indeed confirmed by experimental selectivity test results. Owing to their high affinity for PGMs, N atoms depicted large adsorption energy values compared to other adsorption sites. The MIL-101(Cr)/ED-GA could act as an efficient and cost effective adsorbent for removal of platinum group metals from wastewater. Journal article published in the journal Environmental Nanotechnology, Monitoring & Management 20 (2023) 100805

2023-01-01T00:00:00Z