Browsing by Author "Ncube, L.K."

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    Development and Characterisation of a Nanocomposite Membrane Using Polyethersulphone and Graphene Oxide-Magnetite Nanoparticles for Rejection of Chromium Hexavalent Ions from Tannery Wastewater
    (2018) Gadlula, S.; Ndlovu, L.N.; Ncube, L.K.
    Polyethersulphone (PES) polymer blended with Graphene Oxide (GO) and magnetite ( nano-composite was synthesized using an immersion precipitation process for the filtration of chromium hexavalent ions from leather processing waste water. PES is a synthetic polymer with good chemical resistance, wide pH range (2-13) as well as good mechanical and thermal properties. However, it is hydrophobic and prone to fouling hence its limitations in aqueous separation processes. In order to improve hydrophilicity, porosity, permeability and strength properties of the polymeric membrane, GO was synthesized from coal via a modified Hummers Method and then blended with anhydrous ferrous chloride to form Graphene oxide/ magnetite () hybrid nano-particles. To assess the performance of the membrane pure water flux, Equilibrium Water Content (EWC) and tensile strength test was measured. Structural analysis involved porosity measurement. The filtration efficiency of the membranes was found by testing the waste water for chromium ion concentration before and after filtration. It was established that both the physical properties and chromium ion rejection improved with increase in polymer concentration and addition of hybrid nano-particles.
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    Enhanced technique for removal of methylene blue dye from water using Luffa microcrystalline cellulose
    (South African Journal of Chemistry, 2024-02-11) Ngwenya, V.; Ndebele, N.R.; Ncube, L.K.; Nkomo, N.Z.; Gadlula, S. and Ndlovu, L.N.; Ndlovu, L.N.
    Methylene blue, a toxic and carcinogenic azo dye, is being discharged as industrial effluent to the environment posing a threat to human health and marine life. Different methods have been developed to alleviate these problems associated with methylene blue. In this work, the adsorption of methylene blue dye was studied using Luffa microcrystalline cellulose (Luffa MCC) under different physicochemical conditions. Luffa MCC was synthesized through a hydrolysis process which entails the extraction of alpha-cellulose from Luffa cylindrica fibers followed by acid treatment for microcrystallisation. The α cellulose extraction was achieved through a pretreatment process of Luffa fibers in NaOH followed by bleaching with H 2 O 2 and finally hydrolysis of α-cellulose using HCl. Different methods were used to characterize the properties of Luffa fibers and Luffa MCC. The morphological structure was studied through the use of Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDS), and Thermogravimetric Analyzer (TGA). Adsorptive removal of methylene blue was studied at different pH, initial dye concentration, adsorbent dosage, temperature and contact time. Maximum adsorption efficiency of 99.69%. of methylene blue was achieved at pH 10 in 180 min. The adsorption kinetics suggests a chemisorption process since it was favoring the pseudo-second-order reaction while the isotherm was best described by Langmuir model which suggests that it was monolayer sorption at a homogenous surface. It can be concluded that adsorption properties were significantly improved after the modification of Luffa fibers.