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The mechanical properties of polymeric membranes are critical factors for a successful and durable application in water treatment technologies. Fabricating membranes with optimal mechanical properties require delicate balancing between material, additives, processing conditions, porosity, and many other variables. Several variables to be optimized demands detailed experimental and computational investigations. The design of experiments (DOEs) technique using a validated framework with a computational model for the prediction of the elastic behavior can lower the number of conducted experiments for optimal membrane fabrication conditions. In this study, optimization of the elastic modulus of polymeric membranes is performed using DOE with computational modeling and validated with experiments. The optimum storage modulus of polymeric nano‐filled membranes is determined at an operating temperature of 35°C. DOE is employed with a three‐factor–three‐level problem. The Taguchi DOE is utilized to obtain the experiments scheme, followed by the prediction of the storage modulus and fabrication of the polymeric nano‐filled membrane with the optimum modulus. Predicted results demonstrate that the modulus of polyether sulfone (PES) reinforced with 0.3 wt.% halloysite nanotubes (HNTs) is the optimum combination. The fabricated PES/0.3 wt.% HNT membrane is in good agreement with the predicted modulus with a percentage error of 3%. [ABSTRACT FROM AUTHOR]

In the present work, the removal of Mo from aqueous solutions and real groundwater by using the novel high-surface-area adsorbent carbide-derived carbon (CDC) was performed. The adsorbent was characterized using X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), Brunauer, Emmett, and Teller (BET) surface area analysis, and Fourier-transform infrared spectroscopy (FTIR). The effect of the operational parameters (contact time, CDC loading, Mo concentration, and pH) on the adsorptive performance of the sorbent in the batch adsorption mode was studied. The experimental work revealed that the adsorption of Mo onto CDC is a very fast process and provides 99% Mo removal in less than 30 min. The adsorption process was pH-dependent, achieving the maximum adsorptive removal at a pH range of 3–5. The highest adsorption capacity corresponded to 16.24 mg/g at a Mo concentration of 10 ppm, adsorbent loading of 0.6 g/L, and pH 3. Four models were used to analyze the adsorption isotherms of Mo onto CDC, which were Freundlich, Langmuir, Temkin, and Sips. The obtained adsorption results were also processed using four adsorption kinetic models: intra-particle diffusion, Elovich, second-order, and pseudo-first-order. The adsorption of Mo onto CDC was found to fit the Freundlich isotherm model, as confirmed by the highest R2 values (0.9118) and lowest SSE (0.4777), indicating the heterogeneous multilayer adsorption of Mo onto CDC. Likewise, the experimental adsorption data were found to be more consistent with the pseudo-second-order model. The main adsorption mechanisms contributing to Mo adsorption were found to be electrostatic interactions and ligand–ligand exchange, in addition to surface complexation or ion exchange between Mo ions and oxygen-containing groups on the CDC's surface. Moreover, the removal efficiency under acidic conditions (pH: 3) was found to be stable and high (>99%), regardless of the Mo concentration (0.5–10 ppm) due to the characteristic PZC corresponding to CDC (pH 9.9). A performance test of the CDC using both real groundwater and GW spiked with 570 µg/L Mo showed an almost complete removal of Mo from GW. The regeneration tests confirmed that adsorbed Mo can be recovered from CDC by pH adjustment and the regenerated CDC can be reused. [ABSTRACT FROM AUTHOR]

MXene as a new type of metal carbide was used as a nanoadsorbent for the removal of toxic arsenic species from water. It was prepared by etching the Ti3C2Al powders in HF solution. The final product was (2D) titanium carbide nanosheet. The prepared MXene exhibited high sorption capacities and fast kinetics for As(III) removal from water. It provided an efficient removal performance for As(III) with a capacity of 2.8 mg/g, higher than most of the commercial adsorbents. The residual concentration of As in water is far below the standard limit set by World Health Organization for drinking water at 10 µg/L. Using steered molecular dynamics simulation, the global minimum energy between arsenic and MXene surface was found to be of 7.1 kJ/mol. The arsenic adsorption data with MXene fits very well the pseudo-second-order model with a coefficient of determination being close to unity. The second-order rate constant was (k2) found to be 25.38 g/mgh and adsorption capacity was found to be 0.241 mg/g. Furthermore, MXene nanosheets were also discovered to remove other contaminants, such as Cr(VI), Ba(II) and Pb(II) from water. These significantly expand the potential applications of 2D Ti3C2Tx nanosheets in water treatment due to their well-defined morphology, which holds promising industrial advantages. [ABSTRACT FROM AUTHOR]