http://hdl.handle.net/10386/2801 2026-04-12T13:36:29Z 2026-04-12T13:36:29Z Masekela, Daniel Hintsho-Mbita, Nomso Charmaine Ntsendwana, Bulelwa Mabuba, Nonhlangabezo http://hdl.handle.net/10386/5102 2025-10-09T01:00:38Z 2022-01-01T00:00:00Z

Thin films (FTO/BaTiO3/AgNPs) for enhanced piezo-photocatalytic degradation of methylene blue and ciprofloxacin in wastewater Masekela, Daniel; Hintsho-Mbita, Nomso Charmaine; Ntsendwana, Bulelwa; Mabuba, Nonhlangabezo In this study, we investigate the ability of barium titanate/silver nanoparticles (BaTiO3/AgNPs) composites deposited on a fluorine-doped tin oxide (FTO) glass using tape-casting method to produce piezoelectric thin film (FTO/BaTiO3/AgNPs) for piezocatalytic, photocatalytic, and piezo-photocatalytic degradation of methylene blue (MB) and ciprofloxacin (CIP) in wastewater. The prepared piezoelectric materials (BaTiO3 and BaTiO3/AgNPs) were characterized using XRD, SEM, TEM, EDS, UV-DRS, TGA, PL, BET, EIS, and chronoamperometry. The UV-DRS showed the surface plasmon resonance (SPR) of Ag nanoparticles on the surface of BaTiO3 at a wavelength of 505 nm. The TEM images revealed the average Ag nanoparticle size deposited on the surface of BaTiO3 to be in the range of 10−15 nm. The chronoamperometry showed that the photoreduction of silver nanoparticles(AgNPs) onto BaTiO3 (BTO) resulted in a piezo- electrochemical current enhancement from 0.24 to 0.38 mA. The composites (FTO/BaTiO3/AgNPs) achieved a higher degradation of MB and CIP when the photocatalysis and piezocatalysis processes were merged. Under both ultrasonic vibration and UV light exposure, FTO/BTO/AgNPs degraded about 72 and 98% of CIP and MB from wastewater, respectively. These piezoelectric thin films were shown to be efficient and reusable even after five cycles, suggesting that they are highly stable. Furthermore, the reactive oxygen species studies demonstrated that hydroxyl radicals (·OH) were the most effective species during degradation of MB, with minor superoxide radicals (·O2 −) and holes (h+ ). From this study, we were able to show that these materials can be used as multifunctional materials as they were able to degrade both the dye and pharmaceutical pollutants. Moreover, they were more efficient through the piezo-photocatalytic process Journal article published in ACS Omega 2022, 7, 24329−24343

2022-01-01T00:00:00Z Ndwambi, Tikanani http://hdl.handle.net/10386/4936 2025-03-21T01:00:12Z 2023-01-01T00:00:00Z

Assessing the agro-environmental efficiency from electricity production of BRICS countries using desirable and undesirable inputs : the enhanced DEA approach Ndwambi, Tikanani The Data Envelopment Analysis (DEA) is a well-established non-parametric methodology for evaluating the relative efficiency of a set of comparable entities called decision making units (DMUs) with multiple inputs and output. In existing studies that benchmarked energy, the DEA has been widely used to study and compare the efficiency of energy industries, particularly in the electricity industry. Agro-environmental efficiency, as adopted by this study, is the ability of using the desirable and undesirable inputs in the electricity production, minimize them to obtain the desirable outcome of outputs (GDP and Income per capita) through the increased agricultural production. Agro-environmental efficiency refers to a kind of efficiency that considers both the economic and the agro-environmental factors in a system. This paper proposes two methods of data envelopment analysis (DEA) approach to assess the environmental efficiency of electricity production in BRICS countries namely, Brazil, Russia, India, China, and South Africa using desirable and undesirable inputs. The study aimed at assessing the Agro-environmental efficiency from electricity production of BRICS countries using desirable and undesirable inputs. The study has three objectives which are to estimate the Agro-environmental efficiency of BRICS countries from electricity production using desirable inputs, to measure the Agro-environmental efficiency of the BRICS countries from electricity production using undesirable inputs and to determine socio-economic factors that affect Agro-environmental efficiency from electricity production of the BRICS countries using desirable and undesirable inputs. The Data Envelopment Analysis (DEA) results in method 1 showed that the Agri-environmental efficiency (AEE) scores of the states in the BRICS countries had a mean of 47.12% with a minimum of 10% and a maximum of 100%. The implications are that BRICS countries were Agro-environmental inefficient on average. The use of the undesirable inputs should be minimized, as well as the undesirable outputs on average by approximately 52.88% and maximize the use of desirable inputs to obtain the same output level. The Agro-environmental efficiency scores in method 2 showed that the states of the BRICS countries had a mean of 54.06% with a minimum of 1% and a maximum of 100%. The AEE score in this method shows that the states in the BRICS countries are ii Agro-environmental inefficient. This implies that states are not minimizing undesirable inputs fully (Methane and CO2) to maximize the use of desirable inputs (Coal, diesel, and Gasoline) in electricity generation. The undesirable inputs in the electricity production could be decreased by approximately 45.94% on average to obtain the same level of output. The study also found that socioeconomic factors attributed to Agro-environmental efficiency in the BRICS countries were population, an agricultural area, industrial area, and rapid urbanisation. The population is significant towards the Agro-environmental efficiency of the BRICS countries at 5% significance level with a positive coefficient of 2.013. the agricultural area was found to positively influence Agro-environmental efficiency at a 1% significance level with a positive coefficient of 1.052. The industrial area was found to have the negative relationship with the Agro-environmental efficiency with a significance level at 10% and a coefficient of -2.001. the rapid urbanisation is significant towards the Agro-environmental efficiency at 5% significance level with a positive coefficient of 1.082. The study recommends the measures to improve efficiency in the electricity production in the BRICS countries. Such measure amongst others are to allow ecosystems to adapt naturally to climate change, ensure that food production is not threatened, and to enable economic development to proceed in a sustainable manner. Thesis (M.Sc. (Agricultural Economics)) -- University of Limpopo, 2023

2023-01-01T00:00:00Z Yamba, Siyanda Hintsho-Mbita, Nomso C. Yusuf, Tunde L. Moutloali, Richard Mabuba, Nonhlangabezo http://hdl.handle.net/10386/4736 2024-11-02T01:00:18Z 2022-01-01T00:00:00Z

Sulphate removal in industrial effluents using electrocoagulation sludge as an adsorbent Yamba, Siyanda; Hintsho-Mbita, Nomso C.; Yusuf, Tunde L.; Moutloali, Richard; Mabuba, Nonhlangabezo The high concentration of sulphates is detrimental to the infrastructure of wastewater treatment plants. Hence in this study, we present the application of electrocoagulation sludge as an adsorbent to remove sulphates from industrial effluents before they are released back to the environment. The sludge contains iron and aluminium cations and cationic complexes that precipitate sulphates in water. Corrugated iron sheet was used as a sacrificial electrode during electrocoagulation (EC) to generate sludge. FTIR, XRD, SEM, TEM, and Zeta Potential were used to characterize the sludge. The following parameters: contact time, pH, initial concentration, and adsorbent dosage were optimized to 120 min, 2, 100 mg/L and 150 mg, respectively. For the synthetic water, the sulphate removal was 99.1%, whereas for the real water it was found to be 98.7%. The adsorption capacity of the EC sludge was 66.76% for 2 h under acidic conditions. The Langmuir isotherm fitted better than the Freundlich isotherm. This confirmed the homogenous distribution of the active sites on the EC sludge. At different EC’s sludge, the pseudo-second order kinetic model produced the best fitting experimental results which confirmed the removal of sulphate ions by chemisorption. This approach (method) is useful for purifying industrial effluents before they are discharged into the environment. Journal article published in Journal of Sustainability 2022, 14, 12467. https://doi.org/10.3390/su141912467

2022-01-01T00:00:00Z Nyahunda, Louis Tirivangasi, Happy Mathew. http://hdl.handle.net/10386/4081 2023-02-11T01:00:09Z 2022-01-01T00:00:00Z

Adaptation strategies employed by rural women in the face of climate change impacts in Vhembe district, Limpopo province, South Africa Nyahunda, Louis; Tirivangasi, Happy Mathew. Purpose – This study documented adaptation strategies employed by rural women in Vhembe district as they reel with climate change impacts. Women are heavily plagued by climate change impacts than any other genders worldwide. This is attributed to their high dependence on the natural resources for survival, low adaptive capacity, illiteracy, social ascribed roles that limit their participation in climate change initiatives like men and high poverty levels. Despite the daunting fact of women’s vulnerability to climate change and its vagary impacts, women are agents of social change who have not remained passive victims to climate change and its impacts. Design/methodology/approach – This study adopted a qualitative methodology guided by multi-case study design. A sample of 25 participants was selected through simple random and purposive sampling techniques. Data were collected using Focus Group Discussions and individual interviews and analysed thematically. Rural women and traditional leaders served as key informants and participated in the study. Findings – The study established that the effects of climate change on rural women are real; however, there is a cocktail of strategies employed by women in Vhembe district in response to these effects. The strategies include livelihood and crop diversification, use of indigenous knowledge systems and harnessing of social capital among other household-based adaptation strategies. Originality/value – The study recommends that the best way of assisting rural women in adapting to climate change is through the amelioration of poverty, enhancing capacity building for women and elimination of all systems that serve as barriers to effective adaptation. Journal article published in Management of Environmental Quality An International Journal · March 2022

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