https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43671 Wed 28 Sep 2022 14:55:48 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38044 2PO₄) (10 %, w/w) at 300 ℃, 500 ℃ and 700 ℃ to evaluate their potential lead [Pb(II)] adsorption. Effects of pH, contact time, and initial Pb(II) concentration on the Pb(II) adsorption capacity of the biochars were investigated. The physico-chemical, morphological, porous structure, crystallinity and spectroscopic characteristics of pre- and post-Pb-adsorbed biochars were analyzed to unravel the Pb(II) adsorption mechanism. Results showed that KH₂PO₄ reacted with biomass carbon to form stable C–P and/or C–O–P groups in BCP, and increased carbon retention and aromaticity of BCP. However, the addition of KH₂PO₄ led to an adverse effect on porous structure, e.g. surface area of biochars produced at 300 ℃, 500 ℃ and 700 ℃ were decreased by 41.53 %, 80.32 %, and 59.74 %, respectively. Adsorption experiments displayed that BCP produced at 300 ℃ exhibited the highest Pb(II) adsorption capacity (q_max = 154.7 mg g⁻¹), which was almost 6 times higher than the pristine biochar (q_max = 24.3 mg g⁻¹). Potassium polymetaphosphate [(KPO₃)_n] particles were attached on the surface of BCP, which facilitated the precipitation of Pb(II) to form [Pb(PO_3)2]n, Pb5(PO₄₎₃OH and PbHPO₄. This study thus demonstrated the effect of pyrolysis temperature on the enhancing removal capability of P-modified biochar for Pb(II) from aqueous solutions.]]> Wed 28 Jul 2021 15:18:58 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47725 2 emission into the atmosphere along with the soil respiratory CO₂ fluxes but is comparatively less studied than the organic C mineralisation processes. This study aims to understand how soil available carbonates influence the soil C dynamics under different tillage, mulching and temperature regimes. A 90-day incubation experiment was conducted by adding calcite nodules to soils (10% w/w) collected from an agricultural field maintained with or without 5 t ha⁻¹ mulching under no-till (NT) or conventional tillage (CT) systems. Environmental Scanning Electron Microscope (ESEM) examination indicated greater morphological changes in the calcite nodules incubated with CT than NT soils. Soil samples incubated with calcite and mulching recorded 6.3% greater CO₂ evolution than the un-mulched condition. Under the CT system, the overall CO₂ emission rate was higher in the control treatment (43%), followed by a combined treatment of 5 t ha⁻¹ mulch + CaCO₃ (10% w/w) (29.2%), 5 t ha⁻¹ mulch only treatment (27.9%), and 10% CaCO₃ (w/w) (16.5%) treatment, with a rise in incubation temperature from 22 °C to 37 °C. Kinetic model calculations for CO₂ emission indicated a greater half-life of easily mineralisable C pools in the NT system at 22 °C. Microbial biomass carbon (MBC) results further verified that the high temperature and disturbed soil conditions limit the availability of soil MBC under the CT systems, indicating a higher decomposition rate. Eventually, these results indicated that agricultural management practices, including tillage shift, explicitly influence the different functional components of soil organic matter (SOM).]]> Wed 28 Feb 2024 14:56:49 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39627 Wed 28 Feb 2024 14:54:32 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39789 Wed 28 Feb 2024 14:54:28 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45147 −1) and high (50 and 5000 mg kg⁻¹) concentrations of Cd and Pb, respectively, in an artificially contaminated soil. In a laboratory incubation experiment, bio-available and potentially bio-available metal concentrations, selected soil properties (pH, electrical conductivity, total organic carbon and total nitrogen), and microbial parameters (microbial activity as basal respiration, microbial biomass carbon (MBC) and microbial functional groups) were determined at two sampling occasions (7 and 49 days). Metal contamination had no effect on the selected soil properties, while it significantly inhibited both microbial activity and MBC formation. Contaminated soils had higher microbial quotient (qCO₂), suggesting there was higher energy demand with less microbially immobilized carbon as MBC. Notably, the efficiency of microbial carbon use was repressed as the metal concentration increased, yet no difference was observed between metal types (p > 0.05). Based on the microbial phospholipid fatty acids (PLFA) analysis, total PLFAs decreased significantly under metal stress at the end of incubation. Heavy metals had a greater negative influence on the fungal population than bacteria with respective 5–35 and 8–32% fall in abundances. The contaminant-driven (metal concentrations and types) variation of soil PLFA biomarkers demonstrated that the heavy metals led to the alteration of soil microbial community compositions and their activities, which consequently had an adverse impact on soil microbial carbon immobilization.]]> Wed 26 Oct 2022 13:44:24 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:55185 Wed 24 Apr 2024 09:55:21 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46733 0.90) and Langmuir isotherm models (R2 > 0.97) quite well described the adsorption of Sb(V) on Y-based MOFs, revealed that the uptake of Sb(V) on Y-based MOFs were followed by a monolayer chemical adsorption process. The maximum adsorption capacities of Sb(V) calculated from the Langmuir model were 161.3 and 151.5 mg/g for MOF-Y and NH2-MOF-Y, respectively. The Y-based MOFs exhibited strong water and chemical stability, it could be utilized for removal Sb(V) under wide pH range and various concentration of Sb(V). The spent adsorbents could be successfully regenerated by NaCl (5 mol/L) solution for further utilization without damaging the crystal structure of Y-based MOFs. X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS) results revealed that the formation of inner-sphere Y-O-Sb complex between Y-oxo-clusters and Sb(V) was the dominant adsorption mechanism, while the co-precipitation of Y3+ and Sb(V) was also partially contributed the Sb(V) adsorption. High stability together with high Sb(V) adsorption capacity and excellent recyclability endow the Y-based MOFs as promising adsorbents for Sb(V) removal from wastewater.]]> Wed 22 Mar 2023 18:38:30 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38847 −, SO₄²⁻, NO₃⁻, SiO₃²⁻ and PO₄³⁻. The adsorption affinity increased from 0.0047 to 0.0915 and 0.0053 to 0.4091 for As(V) and Sb(V), respectively. X-ray photoelectron spectroscopic investigation demonstrated a reductive conversion of As(V) to As(III) during the adsorption process with sulfide-modified α-FeOOH, but with no obvious variation of Sb(V) speciation. While the removal mechanism for As(V) was reduction followed by adsorption via hydroxyl groups, mainly surface complexation was involved in the removal of Sb(V). This study presented a simple strategy to enhance the adsorption capacity and adsorption affinity of α-FeOOH toward As(V)/Sb(V) via sulfide-modification.]]> Wed 16 Feb 2022 10:55:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47171 in-situ Fe-oxide precipitation process modified the active surface sites of the imogolite. The Fe–oxide, mainly magnetite, favored the contaminants’ adsorption over the pristine imogolite. The adsorption kinetics of these pollutants were adequately described by the pseudo-second order and intraparticle diffusion models. The kinetic models showed that surface adsorption was more important than intraparticle diffusion in the removal of the pollutants by all the adsorbents. The Langmuir-Freundlich model described the experimental adsorption data, and both nanocomposites showed greater adsorption capacity than the imogolite. The adsorption of Cu and Cd was sensitive to cationic competition, showing a decrease of the adsorption capacity when the two cations coexisted, while their adsorption increased in the presence of arsenate.]]> Wed 14 Dec 2022 15:49:11 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45846 Wed 11 Jan 2023 10:20:44 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:53697 Wed 10 Jan 2024 10:48:46 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39613 Wed 10 Aug 2022 11:41:40 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47158 Wed 07 Feb 2024 18:00:55 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43096 Wed 07 Feb 2024 17:17:32 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39503 −1) and lead (Pb = 736.2 mg kg⁻¹). Soil properties, microbial activities, and the geochemical fractions and potential availabilities of As and Pb were determined in the non-treated (control) and biochar-treated soil. Modification of PB (pH = 10.6) and GWB (pH = 9.3) with Fe caused a decrease in their pH to 4.4 and 3.4, respectively. The application of PB and GWB significantly increased soil pH, while Fe-PB and Fe-GWB decreased soil pH, as compared to the control. Application of Fe-GWB and Fe-PB decreased the NH₄H₂PO₄-extractable As by 32.8 and 35.9%, which was more effective than addition of GWB and PB. However, PB and GWB were more effective than Fe-PB and Fe-GWB in Pb immobilization. Compared to the control, the DTPA-extractable Pb decreased by 20.6 and 21.7%, respectively, following PB and GWB application. Both biochars, particularly PB significantly increased the 16S rRNA bacterial gene copy numbers, indicating that biochar amendments enhanced the bacterial abundance, implying an alleviation of As and Pb bio-toxicity to soil bacteria. The results demonstrated that pristine pig carcass and green waste biochars were more effective in immobilizing Pb, while their Fe-engineered biochars were more effective in As immobilization in co-contaminated soils.]]> Wed 07 Feb 2024 16:39:44 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46503 Wed 07 Feb 2024 16:39:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45684 Wed 07 Feb 2024 16:37:32 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46172 –1, respectively), while the highest P was found in biosolid biochar (40.5 g kg^–1). The specific surface area of biochars ranged from 96.06–110.83 m2 g^–1. Hierarchical analyses of the chemical compositions of feedstocks and biochars enabled grouping of the materials respectively into four and five distinguished clusters. Three principal components (PC) explained 86.8% and 83.3% of the variances in the feedstocks and biochars, respectively. The PC1 represented the content of the major nutrients (N, P and K), whereas PC2 and PC3 represented other nutrients (secondary and micronutrients) contents and physicochemical properties (pH and EC). The results of this study suggested that biochars produced from different manures and biosolids may potentially be a source of soil nutrients and trace elements. In addition, different biochars may be applied to different nutrient-deficient soils to avoid plausible nutrient and potentially toxic element contamination.]]> Wed 07 Feb 2024 14:49:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47440 Wed 07 Feb 2024 14:39:59 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37953 VI and As^V from water in mono- and binary-adsorbate systems. The adsorption kinetics and isotherm data for Se^VI and As^V were adequately described by the pseudo-second-order (PSO) (r²>0.94) and Freundlich (r²>0.93) equations. Results from scanning electron microscopy showed that the dimension of the NZVI immobilized on the Mt was smaller than pure NZVI. Using 0.05 g of adsorbent and an initial 200 mg L⁻¹ As^V and Se^VI concentration, the maximum adsorption capacity (q_max and partition coefficient (PC) for As^V on NZVI-Mt in monocomponent system were 54.75 mg g^-1 and 0.065 mg g^-1·μM^-1, which dropped respectively to 49.91 mg g^-1 and 0.055 mg g^-1·μM^-1 under competitive system. For Se^VI adsorption on NZVI-Mt in monocomponent system, q_max and PC were 28.63 mg g^-1 and 0.024 mg g^-1·μM^-1, respectively. Values of q_max and PC were higher for NZVI-Mt than NZVI and montmorillonite, indicating that the nanocomposite contained greater adsorption sites for removing both oxyanions, but with a marked preference for As^V. Future research should evaluate the effect of different operational variables on the removal efficiency of both oxyanions by NZVI-Mt.]]> Wed 06 Dec 2023 09:51:50 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38109 Wed 04 Aug 2021 09:52:45 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35640 Tue 24 Sep 2019 16:19:55 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:53312 Tue 21 Nov 2023 12:36:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37099 Tue 18 Aug 2020 09:55:43 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47998 Tue 14 Feb 2023 16:22:00 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39474 Acacia inaequilatera, Acacia pyrifolia, Acacia stellaticeps, Banksia seminuda, Chloris truncata, Hakea prostrata, Hardenbergia violacea, and Triodia wiseana were transplanted in a soil contaminated with diesel and engine oil as TPH at pollution levels of 4,370 (TPH1) and 7,500 (TPH2) mg kg^-1, and an uncontaminated control (TPH0). After 150 days, the presence of TPH negatively affected the plant growth, but the growth inhibition effect varied between the plant species. Plant growth and associated root biomass influenced the activity of rhizo-microbiome. The presence of B. seminuda, C. truncata, and H. prostrata significantly increased the TPH removal rate (up to 30% compared to the unplanted treatment) due to the stimulation of rhizosphere microorganisms. No significant difference was observed between TPH1 and TPH2 regarding the plant tolerance and rhizoremediation potentials of the three plant species. The presence of TPH stimulated cluster root formation in B. seminuda and H. prostrata which was associated with enhanced TPH remediation of these two members of Proteaceae family. These results indicated that B. seminuda, C. truncata, and H. prostrata wild plant species could be suitable candidates for the rhizoremediation of TPH-contaminated soil.]]> Tue 09 Aug 2022 14:32:31 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42866 Tue 06 Sep 2022 09:17:31 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34057 in situ by embedding magnetite into the palygorskite structure through co-precipitation method. The physico-chemical characteristics of Pal-IO and their pristine components were examined through various spectroscopic and micro-analytical techniques. Batch adsorption experiments were conducted to evaluate the performance of Pal-IO in removing Pb(II) from aqueous solution. The surface morphology, magnetic recyclability and adsorption efficiency of regenerated Pal-IO using desorbing agents HCl (Pal-IO-HCl) and ethylenediaminetetraacetic acid disodium salt (EDTA-Na₂) (Pal-IO-EDTA) were compared. The nanocomposite showed a superparamagnetic property (magnetic susceptibility: 20.2 emu g^-1) with higher specific surface area (99.8 m² g^-1) than the pristine palygorskite (49.4 m² g^-1) and iron oxide (72.6 m² g^-1). Pal-IO showed a maximum Pb(II) adsorption capacity of 26.6 mg g^-1 (experimental condition: 5 g L^-1 adsorbent loading, 150 agitations min^-1, initial Pb(II) concentration from 20 to 500 mg L^-1, at 25 °C) with easy separation of the spent adsorbent. The adsorption data best fitted to the Langmuir isotherm model (R² = 0.9995) and pseudo-second order kinetic model (R² = 0.9945). Pb(II) desorption using EDTA as the complexing agent produced no disaggregation of Pal-IO crystal bundles, and was able to preserve the composite's magnetic recyclability. Pal-IO-EDTA exhibited almost 64% removal capacity after three cycles of regeneration and preserved the nanocomposite's structural integrity and magnetic properties (15.6 emu g^-1). The nanocomposite holds advantages as a sustainable material (easily separable and recyclable) for potential application in purifying heavy metal contaminated wastewaters.]]> Tue 05 Feb 2019 12:51:19 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35244 Tue 02 Jul 2019 16:24:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35243 Tue 02 Jul 2019 16:10:45 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41368 Tue 02 Aug 2022 14:59:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33758 3 showed higher correlations (r = 0.91 and 0.96, respectively) with plant K uptake values. Both the chemical and biological methods were able to extract only a portion (12–20%) of total K present in the mineral powder. The results indicated that the mineral powder could be used as a slow release K fertilizer in soils. Further studies in long term applications with exhaustive crops under field conditions are needed to assess its feasibility as a source of K in agriculture.]]> Thu 30 Jan 2020 11:19:11 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46441 Thu 24 Nov 2022 14:07:36 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33595 Thu 22 Nov 2018 13:41:25 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29473 Thu 21 Oct 2021 12:52:02 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39592 Thu 21 Jul 2022 08:39:46 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38611 Thu 18 Nov 2021 14:12:30 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:49463 Thu 18 May 2023 13:01:04 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32950 −1; 45% reduction) in Soil 2 (pH 5.5). The modified biochars enhanced Cr(VI) reduction by 55% (SM-BC-M) compared to manure (29%, SM) and manure-derived biochars (40% reduction, SM-BC). Among the modified biochars, SM-BC-M showed a higher Cr(VI) reduction rate (55%) than PM-BC-M (48%) in Soil 2. Various oxygen-containing surface functional groups such as phenolic, carboxyl, carbonyl, etc. on biochar surface might act as a proton donor for Cr(VI) reduction and subsequent Cr(III) adsorption. This study underpins the immense potential of modified biochar in remediation of Cr(VI) contaminated soils.]]> Thu 16 Aug 2018 13:28:48 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38586 Thu 11 Nov 2021 13:58:36 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31377 14C labelled malic acid confirmed the trend of the bulk respiration results. The allophanic soil showed the lowest amount of carbon mineralisation under all experimental conditions. A strong inverse correlation (R² = 0.90 at p < 0.05) was observed between CO₂ emission rate and total sesquioxides (Fe and Al oxides) content. As evidenced by the pore size distribution, micromorphologies and thermogravimetric analyses, the microporous structure and microaggregate formation in the allophanic soil enhanced carbon sequestration. This study indicated that soil carbon stabilisation was related more to the sesquioxides content than to the clay types or their relative specific surface areas]]> Sat 24 Mar 2018 08:44:09 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27868 2+). Two kinds of clays were used. One was an acid-treated bentonite that had a specific surface area (SSA) of 395 m²/g and the other was natural palygorskite with a SSA of 87 m²/g. The materials were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption and Fourier transform infrared spectroscopy (FTIR). The materials' ability to remove NH₃ was investigated using NH₃ breakthrough dynamic test while the strength of NH₃ retention was characterised by Thermogravimetric Analysis (TGA) coupled with FTIR. The results indicate that clay/poly-acrylic acid composites are highly efficient adsorbents of NH₃ after binding with Cu²⁺. Trapping NH₃ on such adsorbents can lead to colour change and this makes it possible to predict the lifetime of the adsorption bed visually. In addition, the result of NH₃ release from the material following adsorption showed that majority of the adsorbed NH₃ desorbed at temperature above 180°C. The clay/polymer composites can potentially be used in air filters. They may provide an effective and cheap way for removing NH₃ from contaminated air.]]> Sat 24 Mar 2018 07:41:12 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27865 Sat 24 Mar 2018 07:41:11 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29856 Mycobacterium gilvum VF1 in the presence of a palmitic acid (PA)-grafted Arquad® 2HT-75-based organobentonite in cadmium (Cd)-phenanthrene co-contaminated water. The PA-grafted organobentonite (ABP) adsorbed a slightly greater quantity of Cd than bentonite at up to 30 mg L^{− 1} metal concentration, but its highly negative surface charge imparted by carboxylic groups indicated the potential of being a significantly superior adsorbent of Cd at higher metal concentrations. In systems co-contained with Cd (5 and 10 mg L^{− 1}), the Arquad® 2HT-75-modified bentonite (AB) and PA-grafted organobentonite (ABP) resulted in a significantly higher (72–78%) degradation of phenanthrene than bentonite (62%) by the bacterium. The growth and proliferation of bacteria were supported by ABP which not only eliminated Cd toxicity through adsorption but also created a congenial microenvironment for bacterial survival. The macromolecules produced during ABP–bacteria interaction could form a stable clay-bacterial cluster by overcoming the electrostatic repulsion among individual components. Findings of this study provide new insights for designing clay modulated PAH bioremediation technologies in mixed-contaminated water and soil.]]> Sat 24 Mar 2018 07:40:45 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30131 Sat 24 Mar 2018 07:39:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26339 Sat 24 Mar 2018 07:35:55 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29515 A. pycnantha was grown under greenhouse condition in six different soils collected from abandoned copper mine at Kapunda in South Australia. Among the six soil samples, soil-1 with the highest copper concentration produced 2.05 mmol g⁻¹ tissue of proline. Proline expression was prominent in more saline soils (1, 5 and 6) having electrical conductivity (EC) 1184, 1364 and 1256 μS, respectively. Chlorophyll a, b and carotenoid levels in plants showed a gradually decreasing trend in all the soils as experiment progressed. The plants grown on soil sample-1, containing 4083 ± 103 mg kg⁻¹ of copper resulted in 18 ± 2 mg kg⁻¹ accumulation in its leaf. The calcium accumulation was significant up to 11648 ± 1209 mg kg⁻¹ in leaf. Although pore water samples showed higher Cu concentration in soils, an increased mobility of arsenic and lead was observed in all the soil samples. Our experiment points out the need for proper monitoring of revegetation processes to avoid revegetation and reclamation failure.]]> Sat 24 Mar 2018 07:32:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30893 14C-labelled phenanthrene and a model bacterium Burkholderia sartisoli, we studied the mineralization of phenanthrene on the surface of a moderately heat-treated (up to 400 °C) palygorskite. The heat treatment at 400 °C induced a reduction of binding sites (e.g., by the elimination of organic matter and/or channel shrinkage) in the palygorskite and thus imparted a weaker sequestration of phenanthrene on its surface and within the pores. As a result, a supplement with the thermally modified palygorskite (400 °C) significantly increased (20–30%; p < 0.05) the biomineralization of total phenanthrene in a simulated soil slurry system. These results are highly promising to develop a clay mineral based technology for the bioremediation of PAH contaminants in water and soil environments.]]> Sat 24 Mar 2018 07:30:39 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30891 14C-tracing study showed that the mild acid/alkali-treated clay products increased the PAH biodegradation (5–8%) in the order of 0.5 M HCl ≥ unmodified > 3 M NaOH ≥ 0.5 M NaOH for smectite, and 0.5 M HCl > 0.5 M NaOH ≥ unmodified ≥ 3 M NaOH for palygorskite. The biodegradation was correlated (r = 0.81) with the bioavailable fraction of PAHs and microbial growth as affected particularly by the 0.5 M HCl and 0.5 M NaOH-treated clay minerals. These results could be pivotal in developing a clay-modulated bioremediation technology for cleaning up PAH-contaminated soils and sediments in the field.]]> Sat 24 Mar 2018 07:30:38 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30892 Sat 24 Mar 2018 07:30:38 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26717 Burkholderia sartisoli. The mineralogical and physico-chemical properties were characterised in detail, and the bacterial adhesion to the substrate and their growth were observed in relation to these properties. The major variation in the cation exchange capacity (CEC), surface area, water content and the elemental dissolution in the aqueous medium occurred in the palygorskite products heated at extreme temperature (700-900 °C). These changes significantly influenced the bacterial growth and attachment. The maximum viability was imparted by the palygorskite product obtained at 400 °C. Dissolution of Al from products heated above 500 °C also posed inhibitory effect on bacterial growth in the aqueous media. This study provided valuable information about the mechanisms of bacterial viability as affected by modified clay minerals, which is important for developing a novel clay-modulated-bioremediation technology.]]> Sat 24 Mar 2018 07:26:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26716 27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) spectroscopy. The XRD patterns indicated preservation of the crystalline structure of palygorskite following all the treatments. These findings were supported by the Al (IV) and Al (VI) coordination peaks (chemical shift ~ 55 and 2.9 ppm, respectively) which were unaltered in the ²⁷Al MAS NMR spectra of the samples. The acid-thermal activated palygorskite exhibited the highest specific surface area (152.7 m² g^-1) and pore volume (0.2137 cm³ g^-1) which respectively were 3-fold and 69% greater than the raw palygorskite. The potentiometric titration analyses highlighted the possible role of Al derivatives towards development of the surface charge of the activated palygorskites. Electrokinetic studies described the stability of the activated products (zeta potential values ranging from - 5 mV to - 32 mV) at different electrolyte (NaNO₃) concentrations. Combined acid-thermal activated palygorskite displayed a stronger specific adsorption of multivalent cations, and held a direct relevance to environmental remediation. Findings of this study will assist in the development of palygorskite-based adsorbents for heavy metal contaminants remediation.]]> Sat 24 Mar 2018 07:26:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26579 −1) under CO₂ environment (200 mL min⁻¹) (Composite 2). A uniform dispersion of nano-scale carbon spheres was formed on partially destroyed palygorskite structures. Composite 2, which indicated the formation of graphitised carbon nanoparticles, generated a 17-fold greater specific surface area than Composite 1 and also created micro- and mesopores in its structure. The nanocomposites, especially in Composite 1, contained organic surface functional groups (C⎯H, C=C, C=O) and indicated variable affinity to cationic and anionic dye compounds. While Composite 2 adsorbed a larger amount of anionic orange II dye (23 mg g⁻¹), Composite 1 adsorbed more cationic methylene blue (46.3 mg g⁻¹). Isothermal and kinetic modelling of the adsorption data indicated that in addition to electrostatic attraction for methylene blue adsorption on both nanocomposites, a pore diffusion mechanism was involved and the boundary resistance was greater for orange II than methylene blue adsorption. Being a material developed from green biomass (starch) and an abundant natural resource (palygorskite), these nanocomposites have immense potential for application in environmental remediation including in situ immobilisation of contaminants in soil.]]> Sat 24 Mar 2018 07:26:11 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30526 Sat 24 Mar 2018 07:25:05 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30028 Sat 24 Mar 2018 07:24:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25140 Sat 24 Mar 2018 07:17:12 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24310 2+ ions. The element was taken up by the mineral through ion exchange mechanism; and the formation of a lead carbonate hydroxide (hydrocerussite) also occurred. Al-bentonite adsorbed a smaller amount of Pb than Na-bentonite. XRD data indicated that the totality of clay interlayers was occupied by the pillaring agent that led to decrease in Pb uptake. The amount of Pb taken up by Na-bentonite decreased with increasing concentration of citric acid both when Pb and organic acid were added together as a mixture, and when citric acid was added 2 h before the metal ions. Possible reasons for this were the formation of Pb-citrate complexes which had less affinity to Na-bentonite, and also hydrocerussite dissolution at acidic pH. Citric acid, however, did not change Pb uptake by Al-bentonite. Addition of lysine together with Pb did not have any effect on Pb uptake by Na-bentonite and Al-bentonite, which indicated occupation of different adsorption sites by Pb and lysine compared to citrate. However, lysine addition at 1:1 ratio 2 h before Pb decreased the metal uptake, which again may be explained by the effect of lysine in hydrocerussite dissolution. Uptake of Pb in the presence of lysine was also higher when using Na-bentonite compared to Al-bentonite.]]> Sat 24 Mar 2018 07:14:40 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23888 −1 soil) followed by PM (124.2 mg kg⁻¹ soil) and DAP (99 mg kg⁻¹ soil). Ammonia volatilization was reduced by approximately 70% with PL-BC and MS-BC. The decreased NH3 volatilization with biochars is attributed to multiple mechanisms such as NH₃ adsorption/immobilization, and nitrification. Moreover, biochar increased wheat dry weight and N uptake as high as by 24.24% and 76.11%, respectively. This study unravels the immense potential of biochar in decreasing N volatilization from soils and simultaneously improving use efficiency by wheat.]]> Sat 24 Mar 2018 07:13:40 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24988 max) (mg g⁻¹) of the soil clay fractions (SCF) maintained the order: Allo > Smec > Kaol-Ill. A similar order was also observed when the adsorption capacities were normalized to the specific surface area (SSA) of the SCFs (mg m⁻²). DOC adsorption showed a positive relationship with SSA, and sesquioxides and allophanic minerals provided the largest contributions to the SSA in the SCF. Removal of sesquioxides from the SCF resulted in a decrease in SSA and thus DOC adsorption, whereas removal of native OC increased the SSA and subsequent DOC adsorption. Because this study used pedogenic SCFs which represented soils formed in different environments instead of processed clays from geological deposits, it provided realistic information about the interaction of DOC with SCF in relation to their native OC and sesquioxide contents. It also revealed the importance of Ca2+ in enhancing the carbon adsorption capacities of these SCFs.]]> Sat 24 Mar 2018 07:09:55 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43938 ion exchange (22.67%) > Cd2+-p interaction (3.88%), with negligible contributions from functional group complexation, electrostatic attraction and physical adsorption. The MBC could thus be used as a promising adsorbent for Cd2+ removal from aqueous solutions.]]> Mon 29 Jan 2024 18:49:04 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44805 0.9, p < 0.001), which was affected by plant identity and P levels. The results indicated that an integrated approach involving wild plant species and optimum P amendment, which was determined through experimentation using different plant species, was an efficient way to remediate soil contaminated with TPH.]]> Mon 24 Oct 2022 09:24:40 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52720 Mon 23 Oct 2023 16:25:51 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 ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38496 Mon 11 Oct 2021 15:51:00 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36467 Mon 11 Mar 2024 17:44:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34652 max) and SSA. The Q_max value also showed a moderately strong relationship (R² = 0.55, p < 0.05) with zeta potential (at pH 7). Q_max was only poorly correlated with CEC and native OC content. Therefore, along with SSA, the surface charge and functional groups of SCFs played the key role in determining the adsorption affinity and hence retention of DOC in soils.]]> Mon 08 Apr 2019 13:03:30 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46864 Mon 05 Dec 2022 08:29:59 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32949 −1) 2,4-D sorption capacity, which was attributed to the high specific surface area (576 m² g⁻¹). The mechanism of 2,4-D removal from aqueous solution by biochar is mainly attributed to the formation of heterogeneous sorption sites due to the steam activation.]]> Fri 30 Aug 2019 13:07:53 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46355 Fri 18 Nov 2022 10:08:39 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39712 Fri 17 Jun 2022 17:10:04 AEST ]]>