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The chief source of water pollution is industrial wastewater containing dyes. In current study, the optimum conditions for removal of Red-XGRL dye by green metal oxide polymeric nanocomposites were determined via batch and column study. The synthesized materials were characterized via SEM, FTIR and thermal analysis. The optimum pH for attaining maximum adsorption capacity of WD, WD-ZnO-PTh, WD-ZnO-PAN and WD-ZnO-PPY was found to be 8 (12.9 mg/g), 10 (30.2 mg/g), 11 (35.8 mg/g) and 11 (40 mg/g), respectively, and optimum dose was found to be 0.05 g/50 mL. The highest adsorption potential for all composite materials was attained within 90 min and maximum adsorption potential for WD (40.8 mg/g), WD-ZnO-PTh (60.7 mg/g), WD-ZnO-PAN (70.4 mg/g) and WD-ZnO-PPY (86.3 mg/g) was obtained using 200 mg/L dye concentration at 30 °C. The adsorption data showed better fitness to pseudo-second-order kinetics and Langmuir sorption isotherm giving significant R2 values of 0.95–0.99 and 0.97–0.99, respectively. Thermodynamic study showed exothermic nature of sorption. During column study, optimum adsorbent bed height, dye flow rate and inlet initial dye concentration to attain highest adsorption (35 mgg−1) were determined to be 3 cm, 1.8 mL min−1 and 70 mg/L, respectively. Hence, the present study aimed to remove Red-XGRL dye proved that these green metal oxide polymeric nanocomposites could efficiently be synthesized and utilized for efficient removal of Red-XGRL dye from aqueous solution both in batch and in column mode. [ABSTRACT FROM AUTHOR]

This study explores the efficient removal of the synthetic anionic dye-reactive red Me4BL (RRMe4BL) from an aqueous medium which is a significant contributor to environmental pollution. The present study investigates the synthesis of zinc oxide, nickel oxide, cobalt oxide and copper oxide nano adsorbents (ZnO (II), NiO (II), CoO (II), CuO (II)) through the co-precipitation method and their effectiveness in eliminating the reactive red dye Me4BL(RRMe4BL). Maximum adsorption capacities were achieved at pH 2 for ZnO (96.1 mg/g), NiO (86.9 mg/g), CoO (93.4 mg/g) and at pH 6 for CuO (76.3 mg/g) under a 0.05 g/50 mL nano-adsorbent dose, 50 mg/L dye initial concentration and 25°C T and 90 min of contact time. The fitness of the pseudo-2nd-order model explained the kinetics, while Langmuir and Temkin adsorption isotherm highlighted the efficiency of the dye adsorption. Thermodynamic studies revealed the spontaneous and exothermic nature of adsorption. The influence of electrolytes, surfactants and desorption was also analysed. Characterisation of the nanoparticles was done through SEM, XRD and FTIR which revealed the morphology and functional groups of nano-adsorbents. The adsorption method used for eliminating this anionic red dye shows several benefits, including affordability, simplicity of use and the presence of intelligent adsorbents for environment-friendly removal of industrial dyes from wastewater. [ABSTRACT FROM AUTHOR]

Hybrid Layered Double Hydroxides (HLDH) are promising adsorption materials for water treatment due to their excellent anion exchange capacities, abundance of active sites, and eco-friendliness. HLDH was synthesized utilizing the co-precipitation technique in this work to demonstrate its applicability for the removal of direct sky-blue dye via an adsorption procedure. The effects of pH, dose, contact time, initial dye concentration, and temperature on the direct sky-blue dye adsorption efficiency were thoroughly investigated. The adsorbents were analyzed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), energy dispersive X-ray (EDX), and Brunauer–Emmett–Teller (BET). Under the best conditions, the maximum adsorption capacity has been achieved for Mg–Cr–Cl (42.95 mg/g) > Zn–Al–CO3 (39.76 mg/g) > Mg–Fe–Cl (38.08 mg/g). The adsorption of dyes on Mg–Cr–Cl, Zn–Al–CO3, and Mg–Fe–Cl followed a pseudo-second-order kinetic model and exhibited Langmuir-type monolayer adsorption. The influence of temperature was studied to determine the thermodynamic parameters. The estimated results showed spontaneous and exothermic adsorption processes. Electrolyte enhances the adsorption capacity to some extent, while surfactants block the sites, thus reducing the adsorption capacity. The maximum desorption of dye was influenced by the sodium hydroxide solution. The research described here might be utilized to create novel adsorbents with improved adsorption capacities for preserving the aquatic environment. [ABSTRACT FROM AUTHOR]