http://hdl.handle.net/11189/1891 Tue, 01 Sep 2026 16:02:28 GMT 2026-09-01T16:02:28Z http://hdl.handle.net/11189/10769 Title: Poultry slaughterhouse wastewater treatment using nanobubble technology Authors: Kaskote, Ephraim; Basitere, Moses; Mshayisa, Vusi; Sheldon, Marshall Sheerene Abstract: This study investigates the enhancement of aerobic treatment of poultry slaughterhouse wastewater (PSW) using nanobubble (NB) technology. Three aeration methods, i.e. air-NB, ozone-NB, and air-NB combined with Ecoflush enzymes were evaluated for removing chemical oxygen demand (COD), total suspended solids (TSS), NH3-N, total nitrogen, and fats, oil, and grease (FOG). Air-NB and ozone-NB achieved over 80% COD removal within 2 h, while NBs with Ecoflush enzymes initially showed lower removal rates but reached 99.5% FOG removal after 6 h. TSS removal efficiency remained steady across all methods after 4 h, with ozone-NBs performing best. Ammonia removal was most effective with NBs and Ecoflush enzymes, achieving 99% removal after 6 h. Both ozone-treated NBs and NBs with Ecoflush enzymes showed notably high FOG removal. The findings demonstrate that NBs can enhance mass transfer in wastewater treatment, making them an effective method for improving pollutant degradation in PSW. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10769 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10768 Title: Ternary Fe-Zn-Al layered double-hydroxides for interactive removal of cd and pb from aqueous solutions: Isotherms, kinetics and application to real samples Authors: Phogole, Ramatsobane Rosy; Mpungose, Philani Perfect; Nyaba, Luthando; Mnguni, Mthokozisi; Nomngongo, Philiswa Nosizo Abstract: The ongoing influx of trace elements in our water systems from industrial wastewater poses a need for water decontamination. In this study, Fe-Zn-Al LDH was synthesised via the co-precipitation method as an adsorbent in the decontamination of Cd and Pb from surface and groundwater. The synthetic technique was used because it is simple and effective. The synthesised Fe-Zn-Al LDH was characterised by instruments including X-ray powder diffraction (P-XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope-energy dispersive spectroscopy (SEM-EDS). The FTIR showed that the dominant characteristic groups of Fe-Zn-Al LDH were Osingle bondH, CO32-, NO3-, M-O and M-O-M, which are the expected functional groups. The SEM-EDS confirmed the elemental composition of the material, and XRD also confirmed the lamellar structure of Fe-Zn-Al LDH by having characteristic peaks of LDH. Under optimum conditions, adsorption kinetics and equilibrium studies were conducted to investigate possible adsorption mechanisms involved during the removal process. The kinetics data fitted the Elovich and pseudo-second-order models, with the relatively highest correlation coefficient for both analytes compared to the pseudo-first-order model. It was also observed that the Langmuir and the Freundlich models show the best agreement with adsorption equilibrium data. The maximum adsorption capacities for Cd and Pb were calculated using the Langmuir model equation and were 11.9 and 280 mg/g. Moreover, because of its high adsorption affinity and fast adsorption kinetics, the Fe-Zn-Al LDH proved to be a suitable adsorbent material for Cd and Pb removal from water samples, with removal efficiencies ranging from 80–98 %. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10768 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10767 Title: Algoa Bay sediment metal distribution and potential ecological riskassessment Authors: Gumede, Xolani; Masikane, Ntuthuko F.; Jonnalagadda, Sreekantha; Hendricks, Nokwanda; Mpungose, Philani; Gumbi, Bhekumuzi P. Abstract: The study assessed the heavy metal distribution and ecological risk in marine sediments across three depths (10, 20 and 30 m) in Algoa Bay, South Africa. The concentration of heavy metals varied between depths, ranging from 0.8 to 124.5 mg/kg at 10 m depth contour, 0.5–96.7 mg/kg at 20 m depth contour and 0.7​​​​–113.3 mg/kg at 30 m depth contour determined using X-ray fluorescence (XRF). Higher concentrations were reported both at 10 and 30 m depths. The sediment quality was evaluated against the threshold effect concentration (TEC), probable effect concentration (PEC), effect range low (ERL) and effect range medium (ERM) guidelines. Pollution indices, including geoaccumulation (Igeo), the enrichment factor (EF), the pollution load index (PLI) and the potential risk index (PERI), consistently demonstrated anthropogenic accumulation of As, Ag, Cd and Hg. The PERI demonstrated the ecological risk from low to significantly high across all depths; 10, 20 and 30 m had PERI of 4013, 5391 and 5051, respectively. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10767 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10766 Title: Synthesis of Fe-Zn-Al Layered double oxide for effective adsorptive removal of trace metal(loid)s: optimisation, isotherms, kinetics and application to real water samples Authors: Phogole, Ramatsobane Rosy; Mpungose, Philani Perfect; Nyaba, Luthando; Mnguni, Mthokozisi; Nomngongo, Philiswa Nosizo Abstract: The layered double oxides (LDO) have gained attention as sorbets for decontaminating metal (loid)s for wastewater treatment. These materials are prepared from LDH by thermal treatment, whereby LDHs are calcined to remove interlayer anions. This study synthesised Fe-Zn-Al-LDO from Fe-Zn-Al LDH via thermal treatment to decontaminate As, Cd, and Pb in wastewater. The synthesised Fe-Zn-Al LDO was characterised using various analytical characterisation techniques. The transmittance electron microscopy (TEM) results showed that Fe-Zn-Al-LDO had spherically shaped particles with an average size of 12.1 ± 1.7 nm. The Brunauer–Emmett–Teller (BET) surface area and pore volume of the Fe-Zn-Al LDO material were 88.1 m2/g and 0.35 cm3/g. Under optimum conditions, Fe-Zn-Al LDO adsorbent had an excellent adsorption efficiency for As, Cd and Pb, with maximum adsorption capacities of 233 mg/g, 204 mg/g and 256 mg/g, respectively. The kinetics and isotherm studies revealed that the adsorption process of the analytes onto Fe-Zn-Al LDO adsorbent followed pseudo-second order and Freundlich isotherm models. The Fe-Zn-Al LDO materials were utilised as an adsorbent to remove As, Cd and Pb from groundwater and surface water spiked with 1000 µg/L of analytes, and the results showed that the adsorbent reduced the concentrations of these analytes to levels below the acceptable contamination levels. With the systematic study of adsorptive removal of trace metal(loid)s using Fe-Zn-Al LDO adsorbent, a promising adsorption technology was developed to address pollution of drinking water sources. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10766 2025-01-01T00:00:00Z