Browsing by Author "George, Maeti"

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    Assessment of Soil Degradation in a Palustrine Wetland and the Implication on its Water Purification Potential
    (journal of clean water air soil, 2021-09-24) George, Maeti; Ngole-Jeme, Veronica M
    This study determined the extent of degradation of soils in Khubelu wetland in Lesotho and the impact this may have on its water purification potential. Seventy-two soil samples were collected at different sites and depths around the wetland and characterised for different properties. The values of these properties were then used to determine the chemical degradation index (CDI) of the wetland soils. The soils were non-saline as reflected by the electrical conductivity (EC) values (<0.25 mS/cm), mostly acidic (4.5 < pH < 5.22) with moderate organic matter content (2.06–3.9 %). These soil properties varied with depth and from upstream to downstream of the wetland. Values for soil CDI were 3.42, 3.25 and 3.06 for soils from upstream, midstream and downstream of the wetland, respectively, indicating a decrease in soil degradation from upstream to downstream. The dominance of emergent vegetation in the Khubelu wetland may indicate a potential to get rid of sediments in influents into the wetland but the soil characteristics may present a challenge with regards to the removal of nutrients and organic and inorganic pollutants from these influents. The characteristics of the soils and the extent of soil degradation present some challenges in the performance of the Khubelu wetland as a water purification system especially with regards to nutrients and organic and inorganic pollutants.
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    Unravelling the Impact of Potentially Toxic Elements and Biochar on Soil: A Review
    (2022-04-29) George, Maeti
    Industrial activities, urbanization and mismanagement of toxic waste, have caused global environmental degra- dation. Biochar has lately gained considerable recognition and popularity for remediation of contaminated soil. Even though it is organic in nature, biochar may need further processing in order to safely remove contaminants, for soil augmentation and to enhance its treatment efficiency. In this study, areas that have been under-researched regarding safe precautionary measures in biochar preparation, and biochar safety towards soil environment, have been reviewed. The review has determined that, in order for biochar to have minimal negative impact on soil and its microorganisms, soil type and concentration of contaminants to be treated have to be pre-determined. Furthermore, the groups of microorganisms that are not tolerant to long-term application of biochar have to be known. Biochar itself may sometimes be a source of contaminants due to its substrate or method of its prepara- tion, therefore prior biological tests should be done. Variations in experimental and climatic conditions have to be considered prior to reporting on how soil behaves when conditioned or treated with biochar. Furthermore, long-term field research should also be considered in order to provide different insights on biochar suitability to soil amelioration. Further areas of research are also identified, for holistical reporting of biochar and impact on the environment.