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In this work, a novel nanoadsorbent is reported for the surface grafting of poly[(N, N- dimethylacrylamide)-co-(allyl acetoacetate)] onto zinc oxide nanoparticles by free radical polymerization method for removal of Pb(II) in water and biological samples. The obtained nanoadsorbent was characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. The calibration curve was linear in the concentration range of 2–100 mg L−1 with a removal efficiency in the range of 70–98%. Under the optimal conditions, the nanoadsorbent offered high adsorption capacity (56.20 mg g−1), low limit of detection (S/N = 3) of 11 ng mL−1 and the limit of quantification (S/N = 10) of 37 ng mL−1 with a relative standard deviation of <2% (n = 3). The results indicate that the Freundlich isotherm model and pseudo-second-order kinetic model are the best models that describe the sorption system. [ABSTRACT FROM AUTHOR]

We developed a novel three-dimensional graphene oxide/allylamine/allyl glycidyl ether, and evaluated its adsorption performance for humic acid removal in an aqueous solution. The effective parameters were optimized by the Taguchi design method. Effective parameters on the removal of humic acid, including adsorbent dosage, solution pH, contact time, and temperature were evaluated using an L9 orthogonal array. The optimum parameters were adsorbent dosage of 0.02 g, pH of 6, contact time of 120 min, temperature of 25°C, and the removal efficiency of humic acid was 58%. Also, analysis of variance showed the most significant factors were adsorbent dosage and contact time with 33.58% and 51.62% contribution, respectively. The prepared nanoadsorbent was characterized by Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy with energy-dispersive X-ray analysis, and thermogravimetric analysis. The equilibrium data were evaluated by different isotherm models, where the data followed a Langmuir model with a maximum sorption capacity of 25.97 mg/g. Also, the kinetic adsorption data were well evaluated by the pseudo-secondorder model. The thermodynamic data shown that the sorption of humic acid onto the nanoadsorbent was an exothermic, favorable, and spontaneous process. The regeneration test indicated that the nanoadsorbent could be reused in the water treatment application. This study concluded that nanoadsorbent is a very hopeful nanoadsorbent for the remediation of water polluted by humic acid. [ABSTRACT FROM AUTHOR]

A novel of ZnO and CoS2/ZnO nanomaterials were prosperously synthesised by using the wet chemical-ultrasonic method. The optical and morphological properties of the synthesized nanomaterials were characterised by X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, surface-active area and field emission scanning electron microscopy. The average diameters of ZnO and CoS2/ZnO were distinguished to be 39.19 and 50.73 nm, respectively. The photocatalysis proficiency were investigated by using the degradation of rhodamine B under ultraviolet light irradiation. Results depicted that CoS2/ZnO nanocomposites illustrated a great photo-degradation efficiency (99.36% in 60 min) than the other nanomaterials. The photocatalysis process was optimised via the response surface methodology and Box–Behnken design. The prepared photocatalyst can be preserved a stable degradation proficiency for 5thcycle times. [ABSTRACT FROM AUTHOR]

The current research was accomplished to study the application of graphene oxide functionalised with cyanuric chloride and allylamine (GO/Fe3O4/CC/AA) for the removal of pyrene from tap water, river water, seawater and sewage as real samples. The properties of the synthesised adsorbent were emphasised using various analytical techniques such as X-ray diffraction (XRD) spectrometry, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA). In the batch test, the adsorption factors, including the contact time, pH of solution, temperature and adsorbent dose were studied. The optimum dose, pH, temperature and contact time were obtained to be 0.01 g, 5.0, 35°C and 30 min, respectively. The experimental adsorption data were well modelled using Freundlich and pseudo-second-order models. Furthermore, pyrene loaded on the adsorbent could be easily desorbed with methanol and the adsorbent showed good reusability for the adsorption of the PAHs compounds. [ABSTRACT FROM AUTHOR]

This novel method, called layer by layer, is composed of alternate layers of graphene oxide and bismuth telluride nanoparticles, and to enhance the adsorption capacity the surface of nanoparticles was modified by 4-aminoantipyrine. A high-performance liquid chromatography with fluorescence detector technique was validated and used for analysis of nonylphenol extracted from environment water samples. Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray, thermogravimetric analysis, and X-ray diffraction spectroscopy were applied to characterize the nanoadsorbent. Under the optimum conditions (pH = 5, contact time = 15 min, temperature = 30°C, and initial nonylphenol concentration = 20 mg L–1), the developed technique shown the excellent reusability. Within the 5th cycle, the adsorption potential of recycled nanoadsorbent was restored by nearly 90% and this percentage decreased to 60% in the 8th cycle. The adsorption data fitted well with the Langmuir isotherm model (R2 = 0.9927) and pseudo-second-order kinetic model (R² = 1). The obtained nanoadsorbent possess the highest sorption capacity (43.47 mg g–1). Recoveries, at 1 µg mL–1 concentration level, ranged from 89% to 98% with relative standard deviations lower than 5% (n = 3). The results of nonylphenol removal from the environment samples shown the great applicability of nanoadsorbent for the removal of nonylphenol. [ABSTRACT FROM AUTHOR]