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Open Access
Approaches to the Evaluation of Teaching and Learning Methods at a University: Evidence from South Africa
(2017) Gumbo, Jabulani R.
An increasing number of students drop out of university in South Africa and throughout the world. The South African Council for Higher Education has introduced strategies to deal with high dropout rates, which include the improvement of teaching and learning through the Quality Enhancement Program. I hereby document and evaluate my teaching and learning methods. The data collection for this research involved student informal evaluation, formal evaluation and peer evaluation. The formative evaluation data was grouped in 14 themes with numbers in brackets representing the number of counts of student expression of [their free form]: good lecturer (51); stop pointing (12); request for softcopy of lecture notes (7); speak with a loud voice (5); time to write notes (4); field work/practicals (2);; do not understand lecture notes (2); lecturer coming late (2); lots of lectures notes and case studies are long (2); update notes (1); no double class on Friday (1); timetables are clashing (1); require a small tests (1); revision of lecture (1). The concerns for summative evaluation were: I was a good lecturer; issues on hard copies of lecture notes and feedback on assignments. With regard to peer evaluation, a fellow academic attended one of my lectures to make observations and review the teaching and learning procedures. I was able to observe that I ended my lectures too abruptly. As a result, the suggested approach was that gradually end the lectures with a series of questions that invoke a critical response from students and ask any student to summarize the lecture in three sentences. I have since implemented the student concerns.
Open Access
Asessing the Quality of Traditionally Manufactured Ceramic Water Filters, Limpopo, South Africa
(2017-11-28) Gumbo, Jabulani R.; Munarini, Asivhanzhi I.; Khangale Ndishavha
The traditional clay pot can be modernized by including sawdust to produce a ceramic water filter. Ceramic water filters are known to improve the quality of drinking water by inactivating waterborne pathogens. Here we report on the quality of traditionally manufactured ceramic water filter in improving the chemical and microbial quality of drinking water. The sources of drinking water were Mambedi dam and the Luvuvhu River. The water from Luvuvhu River was then filtered with ceramic water filter (CWF). The mean pH values of Luvuvhu River and purified water ranged from 6.20 to 6.56 and 7.79 to 7.91 respectfully. The electrical conductivity of Luvuvhu River and purified water ranged from 210 to 224 μS/cm and 229 to 284 μS/cm respectfully. The temperature of Luvuvhu River and purified water ranged from 21.3 to 23.5 °C and 23.1 to 25.5°C respectfully. The turbidity mean value of Luvuvhu River and purified water ranged from 1.67 to 4.38 NTU and 0.31 to 0.64 NTU respectfully. The CWF was effective in the removal of some metals Cr, Sr, and Ba and there was no leaching of metals As and Ni. The total coliforms and faecal coliforms in the purified water were 3 cfu/100 ml and 36 cfu/100 ml respectfully. Thus at household level, the ceramic water filter may be used to improve the chemical and microbial safety of the Luvuvhu river.
Open Access
Assessing environmental factors structuring populations and movement dynamics of the invasive snail Tarebia granifera in a subtropical Austral reservoir
(2022-07-15) Makherana, Fhatuwani; Dalu. Tatenda; Cuthbert, Ross N.; Dondofema, Farai
Invasive alien species continue to spread and proliferate in waterways worldwide, but environmental drivers of invasion dynamics lack assessment. Understanding alien species ability to self-disperse via locomotion following arrival to new environments is also critical for prediction of invasion success. The study assessed: (i) the distribution and abundance of Tarebia granifera and the potential drivers of population structure in Nandoni reservoir; and (ii) compared movement traits between two widespread invasive alien snails, T. granifera and Physa acuta, to assess their net distance and velocity and determine dispersal potential. Tarebia granifera was widespread at sites invaded, with abundances exceeding 500 individuals m-2 at impacted areas. Tarebia granifera was significantly associated with sediment (i.e., chlorophyll-a, Mn, sediment organic carbon (SOC) and organic matter (SOM)) and water (i.e., pH, conductivity, total dissolved solids (TDS)) variables. Tarebia granifera seemed to exhibit two recruitment peaks in November and March, identified via size-based stock assessment. Tarebia granifera displayed a significantly greater velocity and covered a significantly larger net distance than Physa acuta. The exploratory behaviour (i.e., mean, or absolute turning angles and straightness index) did not differ significantly between the two alien species; both species showed a slight tendency to turn counter clockwise. Overall, the study shows that there was higher snail abundance during the summer season, furthermore, sediment and water variables were found to be important in structuring T. granifera populations. The present study suggests a more rapid capacity to self-disperse in T. granifera than P. acuta, but a similar level of exploratory behaviour between the two species. The study provided autecological information and insights on the distribution and extent of spread of T. granifera, given the often-overlooked role of animal behaviour in promoting invasion, this information can help inform and predict the invasion pattern of invasive alien freshwater snail. This information can also help in the development of invasive alien snail management action plans within the region and elsewhere.
Open Access
Assessing the environmental context of hand washing among school children in Limpopo, South Africa
(Tandonline, 2017) Bulled Nicola; Poppe Kara; Ramatsitsi Khuliso; Sitsula Londolani; Winegar Geoffrey; Gumbo Jabulani; Dellingham Rebecca; Smith James
Despite its simplicity and efficacy, the promotion of hand washing for disease prevention remains a challenge, particularly in resourcelimited settings. This article reports on a quasi-experimental schoolbased study that aimed to improve habitual hand washing. Significant increases in hand washing occurred following improvements in hygiene and sanitation facilities (School A: t = 13.86, p = 0.0052). Smaller increases in hand washing occurred following education (School A: t = 2.63; p = 0.012; School B, no infrastructure improvements: t = 1.66, p = 0.239). Health policy and programming need to pay greater attention to the interplay of the structural, social and individual dimensions of unique contextual environments that influence habitual behaviours.
Open Access
Assessment of As and Hg in mine tailings and indigenous grass : a case study of non-functional New Union Gold Mine, South Africa
(2015) Mundalamo, Tsedzuluso; Gumbo, Jabulani R.; Muzerengi, Confidence; Dacosta, Francis
The present study was carried out to assess the uptake of toxic metals, arsenic (As) and mercury (Hg), by Cynodon dactylon grass species at New Union gold mine tailings, Limpopo Province, South Africa. The samples were collected from New Union Gold Mine tailings and from Ka-Madonsi Village (control), and concentrations of As and Hg in soil and plant material were determined by ICP-MS. The average dry weight concentrations of As and Hg in mine tailing dam A were 2.53 and 1.18 µg/g, respectively, and 2.24 and 0.91 µg/g, respectively, in mine tailings B. The average dry weight of As and Hg in the control soil samples were 0.30 and 0.05 µg/g, respectively. The C. dactylon, on average dry weight, absorbed 5.45 µg/g of As, and 1.72 µg/g of Hg from mine tailings A, and 4.29 µg/g of As; and 1.55 µg/g of Hg from mine tailings B. The control grass, on average dry weight, absorbed 0.53 µg/g and 0.01 µg/g of As and Hg, respectively. In most cases, significant differences were observed between bioaccumulation of Hg and As in plant tissue from mine sites and control sites. The study showed that the bioconcentration factor was less than 1 for the acidic mine tailings, with exception of the root and rhizome system which was greater than 1. This contrasted sharply with the control site where the pH was alkaline, and As and Hg levels were low. The pH values were significantly different (p <0.05) between the soils originating from mine tailings and the control site. The electrical conductivity (EC) of soil at mine tailings A and B were 1847.35 and 1777.5 µS/cm, respectively. The EC for the control site was significantly different (p < 0.05) at 543.3 µS/cm. C. dactylon was found to be capable of bioaccumulation of As and Hg, effective at soil stabilization, and grew well under the acidic conditions. The control grass was healthy and thrived under the alkaline conditions.
Open Access
Assessment of Microbial Quality of Surface Water Sources of Luvuvhu River Catchment, South Africa
(2017-11-28) Mailula, M. A.; Gumbo, J. R.
The majority of global rural communities, including South Africa, rely on untreated surface water for human consumption. The consumption arises partly from the local municipalities’ erratic supply of treated drinking water to its residents. Here we report on the microbial load of surface water sources and after simple water treatment using hand dug wells in Vhembe District, South Africa. The results of the pH were in the range 6.90 to 8.86 with the water temperature ranging from 16 to 25 ºC. The turbidity values were in the range 2.53 to 393.67 NTU which shows problem of soil erosion, rainfall runoff and wastewater discharge by upstream sewage works. The faecal coliform counts varied between 0 cfu/100 ml to > 300 cfu/100 ml, E. coli counts varied between 0 cfu/100ml and >300 cfu/100 ml, and faecal Streptococci counts between 1.5 cfu/100 ml to >300 cfu/100 ml. The microbial load in the hand dug wells was considerably lower than that of the Nandoni reservoir (due to soil filtering capacity). The existence of a high microbial load that exceeded acceptable regulatory guidelines render these water sources unsafe for human consumption. Physical conditions, such as water temperature, also enable bacterial propagation. Thus, the advent of climate change and especially the warming of surface waters may exacerbate the current condition of the use of untreated surface water sources.
Open Access
Biosynthesis of Ultrasonically Modified Ag-MgO Nanocomposite and Its Potential for Antimicrobial Activity
(Hindawi, 2018-08-29) Ayinde, Wasiu B; Gitari, Mugera W.; Muchindu, Munkombwe; Samie, Amidou
This study reports a green synthesis route for a bilayered Ag-MgO nanocomposite using aqueous peel extract of Citrus paradisi (grapefruit red) under an accelerated uniform heating technique and its antibacterial potency against Escherichia coli. Surface modifications and composition of the nanocomposite were examined using a UV-visible spectrophotometer, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray (EDX) analyzer. (e efficiencies of the as-synthesized Ag-MgO nanocomposite against Escherichia coli were examined. (e synthesized Ag-MgO nanocomposite showed characteristic synergetic bands at 290nm for MgO nanoparticle and at around 440nm for Ag nanoparticle which blue-shifted to 380nm in the composite. A spherically dispersed nanocomposite with cubical crystal lattice network with a diameter of about 20–100nm comprising Ag nanoparticle embedded within MgO nanoparticles was obtained. (e nanocomposite produced stronger antibacterial activity against Escherichia coli as compared to MgO nanoparticle, indicating a higher interaction between Ag and MgO ions. (e nanocomposite was successfully synthesized via an efficient modified method by bioreductive agents with an improved synergistic antibacterial property towards water purification.
Open Access
Contamination of Soil due to Leakages of Polychlorinated Biphenyls (PCBs) at a Vandalized Electrical Transformer Site
(2017) Nedzamba, R. M.; Gumbo, J. R.
Worldwide and including in South Africa, the use of polychlorinated biphenyls (PCBs) has been banned as these have been implicated in the destruction of the ozone layer. The lack of the protective ozone layer has been widely blamed for increase in global warming. Here we report on impact of PCBs from a human vandalized electrical transformer on the soil environment at the Rietvlei farm in Louis Trichardt. The particle analysis showed that the soil was sandy followed by loam and then clay. The soil pH was in the range 6.79 to 10.15. The soil moisture content was on average below 6.8%. The analysis of Mg, Al, Ca and K for Cation Exchange Capacity (CEC) was carried out to determine the fertility of the soil. The average CEC of the soil sample was 7.48 meq/g and therefore the soil was fertile and but lacked organic nutrients. However at this site where the transformer oil was spilled it was observed that no grass was growing. The analysis of samples by the GC-MS and GCECD at Waterlab and SABS showed that there were ultra-traces of PCBs in the soil samples. Probably the absence of grass growing at the contaminated site was due to presence of the ultra-trace levels of PCBs. Thus there is a need to improve plant growth at the contaminated site in order to prevent easy water infiltration that might contaminate groundwater supplies. Makhado local municipality draws some of its water supplies from borehole just 1 m from the contaminated site.
Open Access
Defluoridation of groundwater using diatomaceous earth : optimization of adsorption conditions, kinetics and leached metals risk assessment
(Taylor and Francis, 2015-08-27) Izuagie, Anthony A.; Gitari, Wilson M.; Gumbo, Jabulani R.
In Sub-Saharan Africa, many rural communities depend on boreholes as the most appropriate source of water supply. Sadly, water from some of the boreholes contains ﬂuoride above the WHO guideline of 1.5 mg/L. Hence, deﬂuoridation is necessary. The aim of this study is to investigate the ﬂuoride uptake capacity of diatomaceous earth (DE), a natural resource at optimized conditions by batch method. X-ray ﬂuorescence analysis showed that the major component is silica (83.1%), while Al2O3 is the main minor component. XRD shows it is an amorphous material. For 8 mg/L ﬂuoride spiked water, the highest per cent ﬂuoride removal at optimum adsorption conditions (contact time: 30 min, adsorbent dosage: 8 g/L, pH 2, temperature: 298 K and shaking speed: 200 rpm) was between 23.4 and 25.6%. PO3 4 in tested ﬁeld water was observed to reduce the ﬂuoride uptake capacity of ﬂuoride. The sorption data ﬁtted better into Freundlich isotherm than Langmuir isotherm. Fluoride sorption process was found to be a second-order kinetic. Inductively coupled plasma-mass spectrometer analysis of treated water revealed that metal and non-metal species were released at trace levels. Modiﬁcation of DE would be necessary to enhance the ﬂuoride adsorption capacity
Open Access
Effect of hysteresis on water flow in the vadose zone under natural boundary conditions, Siloam Village case study, South Africa
(2017-10-17) Arrey, I. A.; Odiyo, J. O.; Makungo, R.; Kataka, M. O.
A one-dimensional vadose zone model was used to simulate flow under natural boundary conditions. The effects of hysteresis and temporal variability of meteorological conditions were evaluated. Simulations were performed in HYDRUS-1D code for the period April 2013–January 2014 (6601 hours) at three different locations in a delineated portion of the sub-quaternary catchment A80A of Nzhelele with different soil textures. Soil hydraulic characteristics were estimated in a Rosetta library dynamically linked to the HYDRUS-1D model which is based on the numerical solution of a one-dimensional Richard’s equation. Analysis of the simulation results suggests that ignoring hysteresis for soils of similar textural class does not lead to any significant deviation of the model predicted soil moisture, unlike for soils with different textural classes
Open Access
Effects of calcination temperature and solution pH on the defluoridation potential of Al/Fe oxide-modified diatomaceous earth: metal leaching and sorbent reuse
(IWa Publishing, 2017) Izuagie, Anthony A.; Gitari, M.; Gumbo, Jabulani R.
An evaluation of the effects of calcination temperature and solution pH on the fluoride removal capacity of Al/Fe oxide-modified diatomaceous earth was carried out. The sorbent was observed to be most effective and stable within the pH range 6.70–8.12, where the lowest concentrations of Al and Fe (<1 mg/L) in treated water were recorded. Thus, sorbent loss was minimal at that pH range. It was observed that the sorbent lost its efficiency and stability at calcination temperatures above 600 WC. Inductively coupled plasma-mass spectrometer analysis of metals in supernatants and thermogravimetric analysis of the sorbent showed that there was substantive loss of Al and Fe from the sorbent at temperatures above 600 WC because of evaporation. K2SO4 solution proved to be the best regenerant for spent sorbent compared to NaOH and Na2CO3, which caused sorbent loss owing to high solution pH. The CO2 3 from Na2CO3 bound to regenerated sorbent so much that it could not be displaced by fluoride during subsequent defluoridation experiments. Sorbent regenerated with 0.1 M K2SO4 solution could reduce 10 mg/L fluoride in artificial water at a dosage of 0.8 g/100 mL by 81.8% and 67.2% at the second and third cycles, respectively.
Open Access
An evaluation of the effects of climate change on flood frequency in the Luvuvhu River Catchment, Limpopo Province, South Africa
(WIT Press, 2014) Kundu, P. M.; Singo, R. L.; Odiyo, J. O.; Nkuna, R. N.
Climate change poses a great risk to natural resources and agriculture in the Luvuvhu River Catchment. The catchment has experienced floods resulting from higher than normal rainfall associated with the Intertropical Convergence Zone and cyclones, which have caused enormous damage to property and impacted negatively on fauna and flora and human livelihoods. In order to understand the dynamics involved in the effects of climate change in the catchment, annual maximum flow data was used to evaluate flood frequencies. The distribution models used in the study included the Generalized Extreme Value distributions, the Gumbel Extreme Value type I distribution, the Log-normal distribution and the Log Pearson type III distribution. The extreme value analysis showed that the Log-normal and Log-Pearson type III distributions provided the best fit, which could be used to derive the probability of occurrence of flood events. The results showed a general increase in the frequency of extreme events, accompanied by floods of higher magnitude.
Open Access
An evaluation of the performance of tourism at Mapungubwe National Park, South Africa
(2015) Sinthumule, Ndidzulafhi I.
Mapungubwe National Park is one of the parks that were created to conserve both biodiversity and cultural heritage in South Africa. It has also been awarded the status of a World Heritage Site by the United Nations Educational, Scientific and Cultural Organization (UNESCO). This study evaluates the performance of tourism at the park and the cultural landscape. Data on visitations and lodging occupancy after the Park was declared as a World Heritage Site were examined. In order to understand possible causes of tourism trends, visitation data was supplemented by social survey data. The study established that there is no sharp increase on the tourist numbers to the Park. In addition, bed occupancy is below 50% since the Park was declared a World Heritage Site. Potential barriers contributing to low bed occupancy are discussed. The study concludes that the World Heritage Site status did not trigger an increase in tourism in Mapungubwe National Park. Contributing factor is newness of Mapungubwe as a national park in South Africa.
Open Access
Flood Frequency Analysis of Annual Maximum Stream Flows for Luvuvhu River Catchment, Limpopo Province, South Africa
(2012) Singo, L. R.; Kundu, P. M.; Odiyo, J. O.; Mathivha, F. I.; Nkuna, T. R.
Luvuvhu River Catchment (LRC) is one of the regions in South Africa where floods have caused enormous damage and impacted negatively on fauna and flora. Over the years, the catchment has experienced floods resulting from heavy rainfall associated with the ITCZ. Annual maximum flow data from 8 stations with 50 years hydrological data were used to analyze flood frequencies in the catchment. To derive the probability of occurrence of flood events, the frequency distributions which could best describe the past characteristics and magnitudes of such floods were tested. This involved the determination of the best flood frequency models, which could be fitted to the available historical recorded data. The distribution models used included the Generalized Extreme Value, Gumbel or Extreme Value type 1, Log-Normal and the Log Pearson type III distributions. The extreme value analysis showed that the Gumbel and Log Pearson type III distributions provided the best fit.
Open Access
Geochemical and Mineralogical Characterization of Gold Mine Tailings for the Potential of Acid Mine Darinage in the Sabie-Pilgrim's Rest Goldfields, South Africa
(2017-11-28) Lusunzi, Rudzani; Gumbo, Jabulani Ray; Yibas, Bisrat; Novhe, Obed
The environmental hazards arising from active and abandoned mine tailings are a cause for concern. We report on the presence of mineral-related environmental hazards in both Glynn Lydenburg and Nestor mine tailings, approximately 6 km apart and located in the Mpumalanga Province of South Africa. Based on XRD, shows a wide range of minerals: pyritic sulphide, quartz and mica. The XRF results showed that quartz was the dominant oxide in both the mine tailings; followed by Fe2O3 and Al2O3. Furthermore, trace elements, such as As, Cr, Cu, Pb, V and Zn, were also found which are hazardous to the environment.
Open Access
Impact of land use change on surface runoff and stream discharges in Luvuvhu River Catchment
(2016) Singo, L. R.; Kundu, P. M.; Odiyo, J. O.
Luvuvhu River catchment in Limpopo Province of South Africa experiences floods resulting from heavy rainfall of intensities exceeding 15 mm per hour associated with the Intertropical Convergence Zone. The generation of runoff is triggered by the rainfall intensity and soil moisture status. Runoff was calculated as a product of the net precipitation and a curve number coefficient. It was then routed using the Muskingum-Cunge method through the basin along flow paths determined by the topography using a diffusive wave transfer model that enabled the calculation of response functions between start and end point, depending upon slope, flow velocity and dissipation characteristics along the flow lines. Results showed that the simulated discharges closely compared with the measured discharges without the need for model optimization. It was concluded that simulation techniques had the potential to determine the influence of changes in land use to the hydrologic response of the catchment.
Open Access
Impact of Tea Processing Water Wastes on Phytoplankton Composition of Tshinane River, Limpopo Province
(2017-11-28) Sinthumule, H.; Mokgoebo, M. J.; Gumbo, J. R.
The discharge of industrial waste water on freshwater resources is on the increase worldwide, including in South Africa. The study aimed at assessing the response of phytoplankton upon exposure to high levels of nutrients along the Tshinane River Limpopo Province. The study showed different phytoplankton assemblages with different changes in physico-chemical levels. Environmental factors do have a noticeable effect on phytoplankton abundance as it was shown by statistical analysis. Results computed by the Czekanowski coefficient showed that various environmental factors components contributed to the different composition and types of phytoplankton abundance (p<0.05). When environmental factors showed fluctuation (Increase or decrease) a different type of plankton was found to be tolerant to those levels. A total of 64 species were identified upstream and 103 species identified downstream. Phytoplankton spectrums were recorded from six taxonomic groups namely Chrysophyta, Dinophyta, Chlorophyta, Bacillariophyta, Cyanophyta and Dinophyta. The dominant taxonomic group was Chlorophyta (Downstream) and Bacillariophyta was the dominant phytoplankton upstream. The results supports the assumption that an increase in nutrients lead to a diverse phytoplankton species even if all the other parameters are within the South African Water Quality Range for Aquatic ecosystems. This shows that tea processing waste has a minimal impact on the ecosystem health of Tshinane River and the river is able to recover from the nutrient enrichment.
Open Access
Impact on water quality of Nandoni Water Reservoir Downstream of municipal sewage plants in Vhembe District, South Africa
(2016-06-24) Gumbo, Jabulani R.; Dzaga, Ratshilumela Aaron; Nethengwe, Nthaduleni Samuel
Open Access
Impacts of Land Management on Water Resources in the Crocodile River Catchment, Mpumalanga
(2022-07-15) Nkosi, Mary; Mathivha, F. I.; Odiyo, J. O.
Land use/land cover (LULC) have a “cause and effect” relationship with the hydrology of catchment areas. The Crocodile River Catchment (CRC) has been reported to be fully utilised and at its limit. Due to its ecological and socio-economic importance, it is therefore imperative to quantify the changes in the river’s water resources. Using remote sensing (RS), QSWAT and Quantum GIS (QGIS) this study analysed and evaluated the long-term effects of LULC changes on the hydrology of the CRC between 1981 and 2020. LULC was classified into 8 major classes (cultivation land, forest plantation, water, grassland, built-up areas, bush/savannah and natural forest) for 1980/81, 2000/01 and 2020 to demonstrate the changes in land-use for the past 40 years. The study found that natural forests and grassland decreased by 12.8% and 1%, respectively. There was an increase in cultivated lands, forest plantations and built-up by 2.5%, 3.1% and 2.3%, respectively. Built-up areas, cultivated lands and forest plantations were identified as the major land-use activities and the hotspots for these were further mapped and analysed per quaternary catchment. The overall NDVI value for all LULC ranged between -0.3 and 0.9. The LULC maps were used as input data to the QSWAT model to evaluate LULC impacts on water resources. The model performance evaluation showed an NSE value between 0.41 to 0.79, PBIAS -4.44 to 44.7 and RSR 0.54 to 0.75 between simulated and the observed streamflow. For this study, these findings on model performance showed acceptable results. The results further showed a decreasing trend in streamflow from1981-2020. The decreasing trends were attributed to the increase in forest plantation and cultivation with built-up areas found to have minimum impacts on the catchment’s hydrological response because they occupied a small percentage of the catchment. The distribution of ET and surface runoff also varied with the LULC, however, climate was shown to have an influence on streamflow and the distribution of LULC in the catchment area, thus affecting the hydrological regime.
Open Access
International Conference on Sustainable Management of Natural Resources (ICSMNR) : Proceedings of the First International Conference in Sustainable Management of Natural Resources: 15th - 17th October 2018, Bolivia Lodge, Polokwane, South Africa
(School of Environmental Sciences, 2018-10-17) Edokpayi, Joshua; Gitari, Wilson M.; Stam, Eduard M.; Mhlongo, Sphiwe E.