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"Oberholster, Paul"
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Assessment of water, sanitation, and hygiene target and theoretical modeling to determine sanitation success in sub-Saharan Africa
2023
Accessing the status of clean drinking water, sanitation, and hygiene remains a challenge in sub-Saharan Africa (SSA). The current article contributes to the progress made by the WASH initiatives in ten SSA countries in eliminating open defecation by 2030, using theoretical data from 2017 to 2019. The authors used regression trend estimation to observe that rural and urban population growth had a statistically significant detrimental influence on the elimination of open defecation by 2030. According to the predicted data model, by 2030–2035, the urban population of SSA would be 65, 25, and 10 million in all the three categories of income groups. An increase in the number of modern pit users (C1) shows no improvement at the annual rate of change. The unimproved toilets and open-pit latrines (C2 and C3) show a linear growth rate, which expanded over time. Population growth, higher unemployment, and teen pregnancies contribute to this increase. Under current conditions, the curve of modern pit latrine users will increase linearly. Nigeria has the most significant number of spread pit latrine users, which has decreased linearly from 25 to 20% since 2017. It was evident that the power-law trend in Nigeria would increase the usage of unimproved pit latrines and open-pit latrines. Ghana had the highest rate (50%) of open-pit latrine users, while the data show that this situation remained stable (2001–2017). In the Democratic Rep. Congo, annual rates increased linearly from 25 to 33% (2000–2017), while Burundi was one of the countries in the region with the lowest number of open-pit latrine users, although the annual rate has increased from 6.13 to 11.75% since 2017 to 2019.
Journal Article
Potential Toxic-Element Pollution in Surface Water and Its Implications for Aquatic and Human Health: Source–Pathway–Receptor Model
by
Oberholster, Paul
,
Schoeman, Yolandi
,
Belle, Gladys
in
Agriculture
,
Analysis
,
Aquatic ecosystems
2023
This study focused on assessing the extent of pollution in both flowing and non-flowing surface water within the Matjhabeng mining area of South Africa, with particular emphasis on the substantial impact of gold mine tailings. A comprehensive analysis of physical water-quality attributes, including potentially toxic elements (PTEs), and relevant pollution risk indices was undertaken. To comprehensively elucidate the potential risks to aquatic organisms and human health, a risk assessment framework predicated upon the source–pathway–receptor model was developed. Principal Component Analysis (PCA) was employed as a multivariate statistical tool to discern the potential origins of PTE contamination within the environment. The results substantiate pronounced pollution manifestations within the surface water milieu of the Matjhabeng mining area. Specifically, concentrations of critical PTEs, such as arsenic, cobalt, copper, iron, selenium, and zinc, exhibited transgressions of the regulatory thresholds stipulated by both the South African Department of Water Affairs and Forestry (DWAF) and the Canadian Council of the Ministers of the Environment (CCME). Additionally, concentrations of the aforementioned elements exceeded the stipulated DWAF guidelines for irrigation water usage. Pollution indices, encompassing the Single-Factor Pollution Index and the Nemerow Integrated Pollution Index, discerned moderate contamination stemming from As, while remarkably elevated pollution levels were identified for selenium. PCA elucidated 94.5% of the aggregate variance, revealing cobalt, copper, nickel, and zinc as coalescing within PC1, indicative of a common anthropogenic provenance that is conceivably linked to historical gold mine tailings. PC2 exhibited an aggregation of chromium, iron, and lead, reaffirming this shared anthropogenic etiology. The third PCA component was characterized by selenium, followed by arsenic and magnesium in the fourth. The resultant PTE contamination underscores a profound ecological and public health risk, impacting both the aquatic ecosystems and the local community within the precincts of the Matjhabeng Local Municipality (MLM) area, with consequential amplification of susceptibilities to deleterious health consequences. Urgent and concerted interventions are imperative to ameliorate the emergent decline in surface-water quality within the MLM locale. The adoption of nature-based remediation paradigms holds promise for efficaciously elevating water quality, ameliorating community health, and underpinning the long-term economic viability of the region.
Journal Article
Modified Biopolymer (Chitin–Chitosan Derivatives) for the Removal of Heavy Metals in Poultry Wastewater
2020
In the meat production industry, large volumes of wastewater are generated containing great quantities of organic matter that requires y safe disposal or utilization. As a result, management of poultry wastewater is of great concern worldwide. However, problems associated with wastewater disposal are a well-known phenomenon. Nevertheless finding solutions to treat different waste types are not always an orderly method to solve and this have cause a lot of adverse effects on the receiving environment. In the current study, chitosan was synthesized from shrimp chitin to determine its usefulness in removing heavy metals from meat wastewater. Factors for example yield, moisture and ash content and deacetylation (DDA) were tested as well and results showed that chitosan was a source from shrimp chitin. Structural properties such FTIR, SEM and XRD were used to determine the structural morphology, and the final results implies successful isolation of chitosan. Modification of chitosan product was then accomplished via cross-linked chitosan with a series of cross-linking agent; glutaraldehyde, epichlorohydrine, p-benzoquinone s-methylbutylamine and 1,3-dichloroaceone adsorbents. Satisfactory percentages were obtained from shrimp chitosan cross-linked s-methylbutylamine, glutaraldehyde and epichlorohydrine (63–72%) whereas lower yield was observed from chitosan starch cross-linked p-benzoquinone (57%). The usefulness of the chitosan modified products were then investigated in purifying wastewater effluent using HG-AAS. Results of qualitative and quantitative analysis on the elemental content showed the presence of the following elements present in different concentrations: Pb, Cr, Cu, Fe and Zn in the meat wastewaters. Lower concentration ranges (0.01–0.9 mg/L) of these heavy metals were observed for Pb(II), Cr(VI), Cu(II), Fe(II) and Zn(II) after testing the different chitosan cross-linked products (A–E). Among all the metals tested, shrimp chitosan cross-linked with 1,3-dichloroacetone was found to be the most effective product for heavy metals removal. These results also revealed that there is a decrease in the amount of heavy metals present in meat wastewater effluent.
Journal Article
Assessment of the Impact of Coal Mining on Water Resources in Middelburg, Mpumalanga Province, South Africa: Using Different Water Quality Indices
by
Oberholster, Paul
,
Magagula, Mndeni
,
Atangana, Ernestine
in
acid mine drainage
,
Coal
,
Coal mining
2024
The objective of this study was to assess the water quality status of the surface water and groundwater resources in the Middelburg area, South Africa. The assessment was addressed using combined water quality indices, investigating selected chemical parameters over four different seasons for a period of five years from 2017 to 2021. A combination of the Canadian Council of Ministers of the Environment water quality index and the comprehensive pollution index was used to analyze the water quality status of surface water and groundwater of the town of Middelburg, situated near coal mining activities in Mpumalanga, South Africa. The combination of the indices indicated that some surface water monitoring sites ranged between poor to fair water quality. Groundwater monitoring points also showed a poor to fair ranking. The comprehensive pollution index confirmed that some sites showed very poor water quality in the summer seasons, exceeding expected limits for the period 2017 to 2021. The principal component analysis further showed that both surface water and groundwater sites had high levels of contamination with increased chemical parameters. The results were compared against the different water quality guidelines. In an extensive monitoring program, water management systems must be properly implemented to mitigate impacts on water resources.
Journal Article
A bibliometric analysis of water-energy-food nexus approach to wastewater treatment and reuse
by
Sei, Louis Kimbi
,
Mshelia, Zacharia
,
Dirwai, Tinashe
in
Agriculture
,
Aquatic Pollution
,
Bibliometrics
2025
Wastewater contains water, energy, and nutrients that can be recovered to reduce pressure on available resources and promote food security. This potential is often neglected partly because of the lack of understanding of the synergies and tradeoffs between the three resources. Integrating the wastewater treatment process into the water-energy-food (WEF) nexus framework can strengthen the understanding between these three resources. This study used bibliometric analysis to explore the trends in publication and thematic evolution between 2000 and 2024 from the Scopus database. The bibliometrics R-package and VOSviewer software were used for bibliometric analysis and science mapping. Findings suggest that the wastewater treatment process has evolved from eliminating and disposing of organic matter and nutrients to recovering resources, suggesting a sustainable and environmentally friendly approach. Despite these transitions, the study found that the integration of the wastewater treatment process into the WEF nexus framework was not seriously investigated by researchers in South Africa, suggesting a potential gap in the literature that needs to be addressed. More studies are required to understand the ramifications and chain value of WEF resources to strengthen the WEF implementation in South Africa.
Journal Article
Assessment of Effluent Wastewater Quality and the Application of an Integrated Wastewater Resource Recovery Model: The Burgersfort Wastewater Resource Recovery Case Study
2024
Rivers in Africa have experienced dire pollution as a result of the poor management of wastewater effluent emanating from water resource recovery facilities (WRRFs). An integrated wastewater resource recovery model was developed and applied to identify ideal wastewater resource recovery technologies that can be used to recover valuable resources from a mixture of wastewater effluents in a case study in the Burgersfort WRRF in the Limpopo province, South Africa. This novel model incorporates the process of biological nutrient removal (BNR) with an extension of conventional methods of resource recovery applicable to wastewater. The assessment of results of effluent quality from 2016 to 2022 revealed that ammonia, chemical oxygen demand, total coliform, fecal coliform, and Escherichia coli levels were critically non-compliant with the permissible effluent guidelines, indicating a stable upward trend in terms of concentrations, and scored a very bad wastewater quality index rating. All variables assessed showed a significant loading, except for orthophosphates, and significant correlations were observed among the variables. The results of the integrated wastewater resource recovery model revealed a high probability of reclaiming recoverable resources such as nutrients, sludge, bioplastics, biofuel, metals, and water from wastewater, which have economic, environmental, and social benefits, thereby improving the effluent quality of a WRRF.
Journal Article
The environmental feasibility of low-cost algae-based sewage treatment as a climate change adaption measure in rural areas of SADC countries
2019
Employing specific algae treatment to treat municipal domestic wastewater effluent presents an alternative practice to improving water quality effluent of existing rural pond systems in Southern Africa. In the present study, domestic wastewater was treated by using existing infrastructure and inoculated specific selected algae strains in a pond system treatment plant. The objective was to determine through a field pilot study if algae nutrient treatment efficiencies in current traditional water-stabilisation ponds can be optimised by manipulating the existing natural consortium of algae through mass inoculation of specific algae strains of Chlorella spp. The reduction of total phosphorus in the unfiltered water (contain algae) after specific algae treatment was 74.7 and 76.4% for water-stabilisation ponds 5 and 6, while total nitrogen removal was 43.1 and 35.1%, respectively. Chlorella protothecoides was the dominant algal species in ponds 4, 5 and 6 after specific algae treatment. The maximum algae abundance (4.6 × 106 cells mL−1 in pond 4 and 6.1 × 106 cells mL−1 in pond 5) were observed in August 2016, while the maximum chlorophyll-a concentration of 783 μg L−1 was measured in pond 5 after 2 months of specific algae inoculation. Although the present study showed that inoculation of specific algal strains can potentially enhance the treatment efficiencies of existing rural domestic sewage pond systems, it was also evident from the algae-treated effluent analysis that the algae biomass in the upper surface water layer must be harvested for maximum treatment results.
Journal Article
Using Multiple Indices for the Water Resource Management of a Monomictic Man-Made Dam in Southern Africa
by
Mnyango, Samkele S.
,
Oberholster, Paul J.
,
Truter, Christoff J.
in
Climate change
,
Dams
,
Decision making
2022
This study employed different indices, namely the weighted arithmetic water quality index (WQI), Carlson Trophic State Index (TSI), van Ginkel TSI, and Trophic Level Index (TLI) to determine the water quality status of a man-made dam for the needs of sustainable water resource management in Southern Africa. The selection of indices for the study was based on the impacts of anthropogenic activities on the dam. The Roodeplaat Dam exhibited the spatial variation of physicochemical characteristics, indicative of influence by point-source pollution. Although the dam was classified as being eutro-hypertrophic, it was evident that water clarity was not a limiting factor but was P-limited, which was an indication of limiting conditions on primary production. Moreover, the WQI calculated for the dam with an average of 93.94 demonstrated very poor water quality that could be used for crop irrigation purposes only. As such, continued nutrient enrichment must be mitigated to sustain fitness for irrigation, at least. However, strategic goals should involve widening fitness for use. The selected indices were found to be effective for water resource management and could be applied to dams impacted by point-source pollution in Southern Africa. Thus, this study recommends the implementation of an integrated management approach, which needs to prioritize nutrient management to retain societal resource value.
Journal Article
A Comparative Study of Improvement of Phycoremediation Using a Consortium of Microalgae in Municipal Wastewater Treatment Pond Systems as an Alternative Solution to Africa’s Sanitation Challenges
by
Oberholster, Paul J.
,
Botha, Anna-Maria
,
Steyn, Maronel
in
Air temperature
,
Algae
,
Aquatic microorganisms
2021
The reuse of wastewater has been observed as a viable option to cope with increasing water stress in Africa. The present case studies evaluated the optimization of the process of phycoremediation as an alternative low-cost green treatment technology in two municipality wastewater treatment pond systems that make up the largest number of domestic sewage treatment systems on the African continent. A consortium of specific microalgae (Chlorella vulgaris and Chlorella protothecoides) was used to improve the treatment capacity of domestic wastewater at two operational municipality wastewater pond systems under different environmental conditions in South Africa. Pre- and post-phycoremediation optimization through mass inoculation of a consortium of microalgae, over a period of one year under different environmental conditions, were compared. It was evident that the higher reduction of total phosphates (74.4%) in the effluent, after treatment with a consortium of microalgae at the Motetema pond system, was possibly related to (1) the dominance of the algal taxa C. protothecoides (52%), and to a lesser extent C. vulgaris (36%), (2) more cloudless days, (3) higher air temperature, and (4) a higher domestic wastewater strength. In the case of the Brandwag pond treatment system, the higher reduction of total nitrogen can possibly be related to the dominance of C. vulgaris, different weather conditions, and lower domestic wastewater strength. The nutrient reduction data from the current study clearly presented compelling evidence in terms of the feasibility for use of this technology in developing countries to reduce nutrient loads from domestic wastewater effluent.
Journal Article