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Anaerobic digestion has been identified as a feasible fragment of a bioeconomy, yet numerous factors hinder the adoption of the technology in South Africa. Apart from its energy recovery, other nonmarket advantages support the technology. Though it may be challenging to have a price tag, they provide clear added worth for such investments. With a growing energy demand and global energy transitions, there is a need to sustainably commercialise the biogas industry in South Africa. Most studies are at laboratory scale and under specific conditions, which invariably create gaps in using their data for commercialising the biogas technology. The key to recognising these gaps depends on knowing the crucial technical phases that have the utmost outcome on the economics of biogas production. This study is a meta-analysis of the optimisation of anaerobic digestion through methodological approaches aimed at enhancing the production of biogas. This review, therefore, argues that regulating the fundamental operational parameters, understanding the microbial community’s interactions, and modelling the anaerobic processes are vital indicators for improving the process stability and methane yield for the commercialisation of the technology. It further argues that South Africa can exploit water hyacinth as a substrate for a self-sufficient biogas production system in a bid to mitigate the invasive alien plants.
Obianuju Ilo; Mulala Simatele; S’Phumelele Nkomo; Ntandoyenkosi Mkhize; Nagendra Prabhu. Methodological Approaches to Optimising Anaerobic Digestion of Water Hyacinth for Energy Efficiency in South Africa. Sustainability 2021, 13, 6746 .
AMA StyleObianuju Ilo, Mulala Simatele, S’Phumelele Nkomo, Ntandoyenkosi Mkhize, Nagendra Prabhu. Methodological Approaches to Optimising Anaerobic Digestion of Water Hyacinth for Energy Efficiency in South Africa. Sustainability. 2021; 13 (12):6746.
Chicago/Turabian StyleObianuju Ilo; Mulala Simatele; S’Phumelele Nkomo; Ntandoyenkosi Mkhize; Nagendra Prabhu. 2021. "Methodological Approaches to Optimising Anaerobic Digestion of Water Hyacinth for Energy Efficiency in South Africa." Sustainability 13, no. 12: 6746.
The development and expansion of road networks have profoundly impacted the natural landscape and various life forms. Animals are affected by these roads in a myriad of ways, none as devastating as road mortalities. This article reviews the literature on the magnitude, spatiotemporal patterns, factors, and consequences of Animal-Vehicle Collisions (AVCs) and the subsequent road kills. Furthermore, the review paper briefly outlines the relationship between roads and animals in the surrounding landscape and later examines the nature and impacts of AVCs. This article evaluates the statistics on the number of road kills and a critical analysis of the spatiotemporal patterns of these mortalities is also evaluated. Subsequently, the review paper examines current mitigation measures and the challenges impeding their success. The paper then concludes with an evaluation of geospatial tools (GIS) and other technologies used in road kill studies. The relevant findings of this paper are that, (1) factors influencing road kill patterns interact with one another; (2) AVCs have serious environmental, economic and social consequences; (3) road kill mitigation strategies suffer several challenges hindering their success; and (4) specific geospatial tools and other technologies have been utilised in assessing AVC road kill patterns. The review, therefore, recommends including overall road kill clusters of all animals in mortality surveys, increasing the spatial coverage of road kill observations, consistent surveying, sufficient research on nighttime driving distances and speed, utilising citizen science in all road mortality studies and incorporating GIS into all apps used for recording road kills. An increased sufficiency in road kill data coupled with improved technologies can enable more effective mitigation strategies to prevent AVCs.
Ayrton Oddone Aquino; S’Phumelele Nkomo. Spatio-Temporal Patterns and Consequences of Road Kills: A Review. Animals 2021, 11, 799 .
AMA StyleAyrton Oddone Aquino, S’Phumelele Nkomo. Spatio-Temporal Patterns and Consequences of Road Kills: A Review. Animals. 2021; 11 (3):799.
Chicago/Turabian StyleAyrton Oddone Aquino; S’Phumelele Nkomo. 2021. "Spatio-Temporal Patterns and Consequences of Road Kills: A Review." Animals 11, no. 3: 799.
Seven disposable diaper brands that are commonly used in Clermont, Kwa-Zulu Natal (South Africa) and some frequently found along river bodies (due to illegal dumping) were characterised through proximate analysis, thermogravimetric analysis (TGA), ultimate analysis and analytical pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). A novel approach entailing separation of the diapers into two fractions, interior (constituting mainly biomass fibres) and exterior (mainly constituting non-biomass polyethylene), assisted in assessing thermochemical conversion of the disposable diaper’s potential as well as likely threats to the environment. In a comparison of the volatile matter between the two fractions, the exterior fraction is more combustible (due to a higher volatile fraction). Hence, it is more suitable for energy recovery. The present study investigates the use of pyrolysis to manage disposable diapers to potentially recover pyro-oil, pyro-gas and pyro-char. In this primary investigation, it was observed that each disposable diaper brand reacts differently to constant heating. However, the proximate and elemental analysis also highlights the likely negative environmental threats, such as that the high volatile content can potentially release dangerous permanent gases such as chlorine and cobalt into the atmosphere after the diaper is disposed of illegally and in landfill.
Asiphile Khanyile; Guy Caws; S’Phumelele Nkomo; Ntandoyenkosi Mkhize. Characterisation Study of Various Disposable Diaper Brands. Sustainability 2020, 12, 10437 .
AMA StyleAsiphile Khanyile, Guy Caws, S’Phumelele Nkomo, Ntandoyenkosi Mkhize. Characterisation Study of Various Disposable Diaper Brands. Sustainability. 2020; 12 (24):10437.
Chicago/Turabian StyleAsiphile Khanyile; Guy Caws; S’Phumelele Nkomo; Ntandoyenkosi Mkhize. 2020. "Characterisation Study of Various Disposable Diaper Brands." Sustainability 12, no. 24: 10437.
Globally, water hyacinth is a known invasive species that predominantly threatens the pillars of sustainability. The cost of controlling these invasive plants is high and many Southern African countries are barely equipped for this liability as the process has to be performed over time. Despite this challenge, there is valuable resource recovery from water hyacinth which can be used to make financial and environmental returns. The visible differences between the control and utilisation methods lie in the definition, recognition, and matching of costs and benefits. Using a rapid appraisal of existing literature, which was analysed using meta-analysis, the current paper is an attempt to discuss the beneficial use of water hyacinth. It is argued in the paper that the economic feasibility of control methods which, on one hand, are used to calculate the economic value of water hyacinth, mainly relies on assumptions whose reliability and sustainability are questionable, thus implying limitations on using this kind of control methods. On the other hand, the costs and benefits of utilising water hyacinth can be quantifiable, making them susceptible to changes associated with time value and sensitivity analysis of possible fluctuations in cashflows. In the context of these annotations, other scholars have argued for the consideration of other utilisation alternatives, among which is included biogas which has been identified as the most viable option because of its potential in diversifying the energy mix, reducing greenhouse gas emissions, and contributing to improved water quality. Given these observations, this paper aims to contribute to policy and research discussions on the fiscal understandings of the material recovery from water hyacinth to promote the adoption of biogas technology. These views are discussed within the broader discourse of the sustainable development goals (SDGs).
Obianuju Ilo; Mulala Simatele; S’Phumelele Nkomo; Ntandoyenkosi Mkhize; Nagendra Prabhu. The Benefits of Water Hyacinth (Eichhornia crassipes) for Southern Africa: A Review. Sustainability 2020, 12, 9222 .
AMA StyleObianuju Ilo, Mulala Simatele, S’Phumelele Nkomo, Ntandoyenkosi Mkhize, Nagendra Prabhu. The Benefits of Water Hyacinth (Eichhornia crassipes) for Southern Africa: A Review. Sustainability. 2020; 12 (21):9222.
Chicago/Turabian StyleObianuju Ilo; Mulala Simatele; S’Phumelele Nkomo; Ntandoyenkosi Mkhize; Nagendra Prabhu. 2020. "The Benefits of Water Hyacinth (Eichhornia crassipes) for Southern Africa: A Review." Sustainability 12, no. 21: 9222.
Disposable diapers have become a prominent feature of solid waste dumped in landfills. It is estimated that disposable diapers take anywhere between 300 to 500 years to decompose. Despite the associated environmental challenges, a plethora of studies show that disposable diapers have become a popular choice for parents when compared with cloth diapers. Disposable diapers are argued to be more convenient for parents because of their once-off use and super-absorbent ability, of which they are able to absorb 200-300 times the weight as compared to the cloth diapers. This study investigates thermal devolatilisation profiles of disposable diapers as well as their iso-conventional kinetic parameters, elemental and fractional composition. In this study, the two most dominant disposable diaper brands were sampled and analysed qualitatively and quantitatively. It was observed that the exterior fraction of both diapers showed a single peak devolatilisation at a temperature of around 500°C, while the interior fraction showed two distinctive devolatilisation peaks observed below 400°C and above 500°C. However, the pyrolysis heating rate produced no effect on the pyro-char fraction. Furthermore, the devolatilisation pathways of different types of disposable diaper fractions showed that there is a potential for conducting stepwise pyrolysis to promote fractional recovery of valuable products. Disposable diapers waste conversion can be better handled by separating the outer fraction (mainly fossil-based plastics and rubbery materials) from the inner fraction (mainly bio-based fibers and absorbents). It is further illustrated that the kinetic parameters, Ea and k0 are different for each disposable diaper fraction.
Asiphile Khanyile; Guy Cubitt Caws; S'phumelele Lucky Nkomo; Ntandoyenkosi Malusi Mkhize. THERMAL CHARACTERISATION STUDY OF TWO DISPOSABLE DIAPER BRANDS. Detritus 2020, 138 -149.
AMA StyleAsiphile Khanyile, Guy Cubitt Caws, S'phumelele Lucky Nkomo, Ntandoyenkosi Malusi Mkhize. THERMAL CHARACTERISATION STUDY OF TWO DISPOSABLE DIAPER BRANDS. Detritus. 2020; (9):138-149.
Chicago/Turabian StyleAsiphile Khanyile; Guy Cubitt Caws; S'phumelele Lucky Nkomo; Ntandoyenkosi Malusi Mkhize. 2020. "THERMAL CHARACTERISATION STUDY OF TWO DISPOSABLE DIAPER BRANDS." Detritus , no. 9: 138-149.
Road surface deterioration is one of the most common problems of unpaved road networks worldwide. It is a reduction in the performance of a road due to a decline in road surface material quality. Accumulated damage from vehicles, environmental and physical effects may contribute to a decline in the surface material quality and hence deterioration on an unpaved road surface. This study assesses the surface material quality of unpaved rural roads in four rural areas in the KwaZulu-Natal Province, South Africa in order to understand susceptibility to surface deterioration. The study further establishes other possible factors such as slope gradient and rainfall, that could determine the surface material quality. Soil samples were collected from R3, R4, and R5 road classes in four rural areas which are: Emazabekweni, Dukuza, Mkhunya and Mhlwazini Area. Laboratory analyses were conducted in order to determine the performance of the material as potential wearing course. Material performance was then determined using the Standard Methods of Testing Road Construction Materials (TMH 1:1976) classification method. The results obtained imply that there is a need for better material selection during the construction of unpaved road networks. All road classes in Mkhunya, Emazabekweni and Mhlwazini areas exhibited grading coefficient (Gc) values less than 16 and some of the shrinkage product (Sp) values in excess of 365, corresponding to a classification of Class D, A and B. These results indicate material that is susceptible to slippery conditions, easily erodible and prone to the formation of ravels and corrugations. Correlation analysis results conducted to assess the individual relationship between measured rainfall and slope with field shrinkage product and grading coefficient values in each area indicated that variation in slope better explains shrinkage product values in each area with an R2 of 0.62 when compared to rainfall producing a lower R2 of 0.57. For grading coefficient, slope and rainfall produced similar R2 of 0.65 and 0.67, respectively.
Lucky S'Phumelele Nkomo; Sumaiya Amod Desai; Khoboso Elizabeth Seutloali; Kabir Yunus Peerbhay; Timothy Dube. Assessing the surface material quality of unpaved rural roads to understand susceptibility to surface deterioration. A case study of four rural areas in KwaZulu-Natal, South Africa. Physics and Chemistry of the Earth, Parts A/B/C 2019, 112, 3 -11.
AMA StyleLucky S'Phumelele Nkomo, Sumaiya Amod Desai, Khoboso Elizabeth Seutloali, Kabir Yunus Peerbhay, Timothy Dube. Assessing the surface material quality of unpaved rural roads to understand susceptibility to surface deterioration. A case study of four rural areas in KwaZulu-Natal, South Africa. Physics and Chemistry of the Earth, Parts A/B/C. 2019; 112 ():3-11.
Chicago/Turabian StyleLucky S'Phumelele Nkomo; Sumaiya Amod Desai; Khoboso Elizabeth Seutloali; Kabir Yunus Peerbhay; Timothy Dube. 2019. "Assessing the surface material quality of unpaved rural roads to understand susceptibility to surface deterioration. A case study of four rural areas in KwaZulu-Natal, South Africa." Physics and Chemistry of the Earth, Parts A/B/C 112, no. : 3-11.