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With the growing concern of biofilm-associated infections and drug-resistant bacteria, an increasing interest in developing novel antibacterial agents is an urgent priority. Metal oxide-based polymeric materials are able to distinguish mammalian cells from bacterial cells and thus provide long-term antibacterial growth inhibition. Herein, we report the preparation of MgO, NiO and chitosan-coated metal oxide (CS–MO) nanocomposites via a simple in situ chemistry approach. Fourier transform infrared spectroscopy, X-ray diffraction patterns and X-ray photoelectron spectra results proved the formation of CS–MgO and CS–NiO nanocomposites. Also, the particle sizes were observed to be 18.3 and 25.5 nm for CS–NiO and CS–MgO, respectively. All the samples exhibited antibacterial activities against the Escherichia coli and Staphylococcus aureus strains; however, more effective against S. aureus compared to E. coli. Noticeably, 5 μg/mL CS–NiO comparatively exhibited highest bactericidal capability where E. coli and S. aureus viabilities were reduced to 25–47% after 12 h incubation. After treatment with 15 μg/mL of CS–NiO, ∼98% of S. aureus and 92.3% of E. coli cells were inhibited. [ABSTRACT FROM AUTHOR]

Pyrochar–AgBr (DCG–AgBr) produced from discarded chewing gum for the decontamination of trichlorophenol (2,4,5-TCP) is reported. The DCG–AgBr specific surface area (249.5 m2/g), the pore volume of 0.998 cm3/g, surface functional groups and thermal analysis were established. The 2,4,5-TCP removal efficiency at 10 mg/L was estimated to be ∼96% and the dynamic behavior was successfully described by the Thomas and Yoon–Nelson models. Based on the economic analysis, the total cost for treatment of 2,4,5-TCP simulated wastewater was 14.39 US$/m3. For the first time, commonly discarded chewing gum was employed as a precursor for fabrication of adsorbents for wastewater treatment. [ABSTRACT FROM AUTHOR]

Magnetic biocomposite (MB) was fabricated by co-precipitation of palm seed-based biochar in the presence of Fe3O4particles. The MB sorption behaviour was investigated using nickel as the target pollutant. The MB characterisation revealed that its maintained micro-mesoporous character and high saturation magnetisation (65.8 Am2/kg) enable it to be separated from a solution using a magnet. The nickel removal efficiency of MB, 87% (28 mg/g), was achieved at pH 3; however, this was reduced to 45–75% (15–24 mg/g) in the presence of competing ions. The isotherms and kinetics studies revealed a monolayer interaction via a two-stepped sorption mechanism. [ABSTRACT FROM AUTHOR]

High-performance activated carbon-zinc oxide (Ac–ZnO) nanocatalyst was fabricated via the microwave-assisted technique. Ac–ZnO was characterized and the results indicated that Ac–ZnO is stable, had a band gap of 3.26 eV and a surface area of 603.5 m2g−1, and exhibited excellent adsorptive and degrading potentials. About 93% phenol was adsorbed within 550 min of reaction by Ac–ZnO. Impressively, a complete degradation was achieved in 90 min via a photo-Fenton/Ac–ZnO system under optimum conditions. An artificial neural network (ANN) model was developed and applied to study the relative significance of input variables affecting the degradation of phenol in a photo-Fenton process. The ANN results indicate that increases in both H2O2 and Ac–ZnO dosage enhanced the rate of phenol degradation. The highest rate constant at the optimum conditions was 0.093 min−1 and it was found to be consistent with the ANN-predicted rate constant (0.095 min−1). [ABSTRACT FROM AUTHOR]

Alginate encapsulated nano-hydroxyapatite beads were synthesized and characterized by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface analysis, and X-ray diffraction. Their adsorptive potential for Ni2+and rhodamine B was explored in batch mode and by fixed-bed column passage. In the batch system, maximum uptake capacity for Ni2+was 360 mg g−1and 480 mg g−1for rhodamine B. In the presence of humic acid, sorption was enhanced. For the continuous-flow system, adsorption was effective at low flow rate. For both pollutants, mass transport resistance increased during adsorption. The overall rates of rhodamine B and Ni2+uptake were found to be controlled by external mass transfer. [ABSTRACT FROM AUTHOR]

Pomegranate seed powder (PS) was functionalized with polyvinyl alcohol (PVA) and utilized for boron removal from the aqueous system. Results of Brunauer--Emmett--Teller (BET) surface area analysis and Boehm titration indicated notable decrease in total surface area and increase in acidic surface functional groups of PS after PVA modification. Enhanced sorption is indicative of complex formation between diol groups of the pomegranate seed powder--polyvinyl alcohol (PS–PVA) and borate ions. Under column test, the saturated sorption capacity of boron was noted to be dependent on flow rate and bed height. The developed central composite design (CCD) was adequate to elucidate the sorption mechanism. Mathematical modeling of the column data was conducted, and a modified-dose-response model was the most suitable to describe the breakthrough curve and observed to be consistent with CCD analysis. This is further supported by extensive error analyses conducted between the model predicted and experimental data. [ABSTRACT FROM PUBLISHER]

Here, human genomic DNA (hDNA) was encapsulated into supermacroporous alginate beads (SMPA) fabricated via microinjection and freeze-thawing cryogelation protocol. The scanning electron microscopy of the SMPA beads demonstrated smooth and centred burgled morphologies, while the encapsulated hDNA showed brilliant green fluorescence when visualised by fluorescence microscopy. The encapsulation efficiency of 89.1 − 96.7% was achieved when the concentration of hDNA and alginate varied within 0.05 − 0.075% and 0.5 − 0.75 wt%, respectively in the presence of 0.1 M CaCl2 crosslinking agent. ~80% hDNA was released over an extended period of 80 h when SMPA was immersed in a 0.5 M Na2HPO solution diluted with 10 mM Tris buffer (pH 7). Results and trends here demonstrated that SMPA beads have great potential to be used as a biocompatible vehicle for transporting biomacromolecules. [ABSTRACT FROM AUTHOR]