An excess of phosphorus (P) is the most common cause of eutrophication of freshwater bodies. Thus, it is imperative to reduce the concentration of P to prevent harmful algal blooms. Moreover, recovery of P has been gaining importance because its natural source will be exhausted in the near future. Therefore, the present work investigated the removal and recovery of phosphate from water using a newly developed hybrid nanocomposite containing aluminium nanoparticles (HPN). The HPN-Pr removes 0.80 ± 0.01 mg P/g in a pH interval between 2.0 and 6.5. The adsorption mechanism was described by a Freundlich adsorption model. The material presented good selectivity for phosphate and can be regenerated using an HCl dilute solution. The factors that contribute most to the attractiveness of HPN-Pr as a phosphate sorbent are its moderate removal capacity, feasible production at industrial scale, reuse after regeneration and recovery of phosphate.

A series of aluminum oxyhydroxide-incorporated titania composites were prepared by a one-pot synthetic procedure using aluminum tri-sec-butoxide as a precursor. The as-synthesized samples were characterized by Fourier transform infrared spectrophotometer, X-ray diffraction, thermogravimetry and differential scanning calorimetry, nitrogen physisorption, and scanning electron microscopy. It was identified that aluminum oxyhydroxide (γ-AlOOH, or boehmite) was produced as aluminum matrix into which titania, commercially available P25, was incorporated. Photocatalytic activity of all nanocomposites was evaluated with respect to the photodecolorization of methyl orange under UV irradiation and almost complete decolorization was eventually achieved under optimum experimental conditions.

Nanocomposite of CeO₂–SnO₂ containing different CeO₂ contents was prepared by coprecipitation process. The material obtained was characterized by X-ray diffraction and N₂ adsorption–desorption isotherms. Its photocatalytic activity was tested in the degradation of azo dye of leather, Direct Black 38, in aqueous solution under sunlight. The photocatalytic activity of the coupled CeO₂–SnO₂ oxide ranged depending on the CeO₂ contents. The optimum amount of CeO₂ for the synthesis of CeO₂–SnO₂ was 7 wt.% since the nanoparticles showed high photocatalytic activity in the degradation of the dye, similar to that of the TiO₂–P25 photocatalyst. The kinetics of photocatalytic degradation and total organic carbon removal under sunlight were found to follow a first-order rate law. The results indicated that CeO₂–SnO₂ can be used for the removal of dyes from wastewater.

INTRODUCTION: Efficient immobilization of TiO2 nanoparticles on the surface of Mg2Al-LDH nanosheets was performed by delamination/restacking process. EXPERIMENTAL PART: The structural and textural properties of as-prepared nanocomposite were deeply analyzed using different solid-state characterization techniques such as: X-ray powder diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopies, chemical analysis, X-ray photoelecton spectroscopy, N2 adsorption–desorption, and electronic microscopy. RESULTS AND DISCUSSION: The photocatalytic properties of immobilized TiO2 nanoparticles on Mg2Al were investigated using the photodegradation of two model pollutants: Orange II and 4-chlorophenol, and compared with pure colloidal TiO2 solution. CONCLUSION: It appears that Orange II photodegradation was systematically faster and more efficient than 4-chlorophenol photodegradation regardless of the medium pH. Moreover under slightly basic conditions, even if the TiO2 photocatalytic efficiency decreases, photodegradation performed in presence of easily recovered TiO2/Mg2Al1.5 nanocomposite gives rise to comparable or better results than pure TiO2.

PURPOSE: The present research aims to optimize the removal of ibuprofen (IBP), a non-steroidal anti-inflammatory, analgesic, and antipyretic drug from the aqueous solution using a synthesized magnetic carbon–iron nanocomposite, and to investigate the individual and combined effects of the independent process variables. METHOD: Combining the adsorptive capability of carbon and magnetic property of iron, a carbon–iron nanocomposite was synthesized. A four-factor Box–Behnken experimental design-based optimization modeling was performed for maximizing the removal of IBP from water by the nanocomposite using the batch experimental data. A quadratic model was built to predict the responses. Significance of the process variables and their interactions was tested by the analysis of variance and t test statistics. RESULTS: The experimental maximum removals of IBP from the aqueous solution by carbon and magnetic nanocomposite were 14.74% and 60.39%, respectively. The model predicted maximum removal of 65.81% under the optimum conditions of the independent variables (IBP concentration 80 mg/l; temperature 48°C; pH 2.50; dose 0.6 g/l) was very close to the experimental value (65.12 ± 0.92%). pH of the solution exhibited most significant effect on IBP adsorption. CONCLUSION: The developed magnetic nanocomposite was found superior than its precursor carbon exhibiting higher removal of IBP from the water and can be easily separated from the aqueous phase under temporary external magnetic field. The developed magnetic nanocomposite may be used for an efficient removal of IBP from the water.

PURPOSE AND METHOD: ZnO/polyaniline nanocomposite in core–shell structure was prepared by the synthesis and adsorption of polyaniline chains on the structure of ZnO nanoparticles. Fourier transform infrared and ultraviolet–visible (UV–Vis) spectroscopy, X-ray diffraction patterns, field emission scanning electron microscopy, and transmission electron microscopy were used to characterize the composition and structure of the nanocomposite. The nanocomposite was used as an active photocatalyst for photodegradation and removal of ampicillin in aqueous solution. RESULTS: UV–Vis spectroscopy studies showed that ZnO/polyaniline nanocomposite absorbs visible light irradiation as well as ultraviolet spectrum, and therefore, it can be photoactivated under visible and ultraviolet lights. The photocatalytic activity of ZnO/polyaniline nanocomposite in degradation of ampicillin molecules in aqueous solution under natural sunlight irradiation was evaluated and compared with that of ZnO nanoparticles and pristine polyaniline. The ZnO/polyaniline core–shell nanocomposite exhibited higher photocatalytic activity compared to ZnO nanoparticles and pristine polyaniline. The effect of operating conditions (pH, ZnO/polyaniline nanocomposite dosage, and ampicillin concentration) in the photocatalytic degradation of ampicillin using ZnO/polyaniline nanocomposite was investigated. The optimum conditions for maximum efficiency of ampicillin degradation under 120 min sunlight irradiation were found as 10 mg L−1 dosage of ZnO/polyaniline nanocomposite, ampicillin concentration of 4.5 mg L−1, and solution pH = 5. Under optimum operating conditions, degradation efficiency was reached to 41% after 120 min of exposure to the sunlight irradiation.

PURPOSE: Removal of malathion from agricultural runoff was studied using novel copper-coated chitosan nanocomposite (CuCH)—a biopolymeric waste obtained from marine industry. METHODS: Synthesis and characterization of the adsorbent using different spectral techniques like Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer, Emmett, and Teller surface analyzer have been carried out. Equilibrium studies have been carried out to optimize the dose rate, pH, and the reaction time. Parathion and methyl parathion removal were also evaluated by CuCH in the batch mode. Using gas chromatography–mass spectrometry (GC–MS) and FTIR studies suitable mechanism for adsorption has been suggested. RESULTS: The particle size of the adsorbent ranged from 700 to 750 nm. The surface area was found to be 20 m2 g-1 with a pore volume of 0.11 cc g-1. The maximum adsorption capacity of malathion by CuCH was found to be 322.6 ± 3.5 mg g-1 at an optimum pH of 2.0. Presence of copper ions enhanced the adsorption capacity of the adsorbent. The reaction was found to follow pseudo second-order kinetics with a rate constant of 0.53 g mg-1 min-1. Evidence from FTIR indicated that copper ions form a dithionate complex with malathion during the adsorption stage. The adsorbent was found to remove malathion completely from spiked concentration of 2 mg l-1 in the agricultural run-off samples. It was also found that CuCH removed other organophospurous pesticides like methyl parathion and parathion under prevailing conditions. CONCLUSIONS: The results indicated that CuCH could be applied for the removal of organophosphorous pesticides.

BACKGROUND: In this study, manganese dioxide-coated multiwall carbon nanotube (MnO2/CNT) nanocomposite has been successfully synthesized. METHODS: The as-produced nanocomposite was characterized by different characteristic tools, such as X-ray diffraction, SEM, and FTIR. The MnO2/CNT nanocomposite was utilized as a fixed bed in a column system for removal of lead(II) from water. The experimental conditions were investigated and optimized. The pH range between 3 and 7 was studied; the optimum removal was found when the pH was equal to 6 and 7. The thickness of MnO2/CNT nanocomposite compact layer was also changed to find the optimum parameter for higher removal. RESULT: It was observed that the slower the flow rates of the feed solution the higher the removal because of larger contact time.