https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34060 Tue 05 Feb 2019 14:14:59 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30779 2+ and Cu²⁺ on the oxidative degradation of Amoxicillin (AMX) by heterogeneous Fenton-like oxidation using nanoscale zero-valent iron (nZVI) as a catalyst was investigated. It was found that about 90.0% and 54.7% of AMX was degraded in the presence of 1 mM Cu²⁺ and 1 mM Mg²⁺ ions respectively, while 60.2% of AMX was removed by the control sample. Scanning electron microscopy (SEM) indicated that nZVI aggregated visibly after degradation of amoxicillin. X-ray photoelectron spectrometer (XPS) confirmed the reduction of Cu²⁺ to Cu⁰ by Fe⁰ on nZVI’s surface to form similar Fe/Cu bimetal to accelerate the degradation of AMX, and magnesium oxides or hydroxides formed on the surface of nZVI to restrain the removal of AMX. X-ray diffraction (XRD) demonstrated the existence of Fe⁰ in fresh nZVI and the corrosion aggregation of nZVI to form iron oxides or hydroxides after reaction. Kinetics studies demonstrated a pseudo first-order kinetics model for the oxidative degradation with the observed maximum K_obs as 0.0867 min⁻¹ in the presence of 1 mM Cu²⁺. The reason for this enhanced bimetallic catalytic activity is discussed.]]> Sat 24 Mar 2018 07:37:52 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26611 Bacillus fusiformis and Fenton oxidation of their degraded metabolites using nanoscale zero-valent iron (nZVI). A 99.0% naphthalene was biodegraded by B. fusiformis in 96 h, while only 59.4% chemical oxygen demand (COD) was removed, indicating that the degraded metabolites existed in solution. To further degrade the metabolites, nanoscale zero-valent iron (nZVI) was used as heterogeneous catalyst for Fenton-like oxidation of the metabolites after biodegradation lasting 40 h. Results showed that the total the removal COD increased from 36.4% to 91.6% at pH 3.0, 1.0 g L⁻¹ nZVI, 10.0 mM L⁻¹ H₂O₂ and temperature of 35 °C. Scanning electron microscopy (SEM) showed the aggregation and corrosion of nZVI. X-ray diffraction (XRD) confirmed the existence of Fe⁰ and the presence of iron oxide (Fe(II)) and iron oxohydroxide (Fe(III)). A possible degradation pathway was proposed since two naphthalene metabolites (1-Naphthalenol and 1,4-Naphthalenedione) were detected by GC–MS.]]> Sat 24 Mar 2018 07:33:58 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24555 Eisenia fetida, and the soil health was investigated. C-nZVI at concentration level of 3 g kg^-1 soil showed no effect on the survival of E. fetida in the three soil types. However, varying effects such as concentration-dependent increase in tissue iron concentration, lipid peroxidation, and damage to DNA molecules by C-nZVI were observed. C-nZVI at an exposure concentration of 60 mg kg^-1 soil induced oxidative stress in E. fetida. Tissue Fe concentration appeared correlated to the DNA damage. Oxidative stress and DNA damage may explain the toxicity mechanisms of nZVI to E. fetida.]]> Sat 24 Mar 2018 07:11:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47494 Mon 23 Jan 2023 11:47:24 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34738 0.96). The As(V) removal capacity was higher using Z-nZVI than nZVI both in the single and multi-component systems, suffering minimal differences in removal in both cases. The results suggested that Z-nZVI had more specific surface sites for As(V) than nZVI and zeolite, which makes Z-nZVI a more effective adsorbent than nZVI for the removal of As(V) from aqueous solutions in the presence of other oxyanions.]]> Mon 15 May 2023 10:14:02 AEST ]]>