Search

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]

Present study focused on the green nanocomposites synthetization to treat textile wastewater and its reusability for agriculture crops. Punica granatum (leaves and peels) and biomass (almond shells, sugar cane bagasse, eggshells) are used for synthesis of zinc oxide nanocomposites (PGL-ZnO), copper nanocomposites (PGP-Cu) and iron nanocomposites (PGL-Fe). It is characterized by scanning electron microscope, Fourier-transform infrared spectroscopy, X-ray powder diffraction and Brunauer–Emmett–Teller. The highest adsorption efficiency of all synthesized nanocomposites was accomplished at pH 2 which is acidic, 0.01 g dose, 50 mg/L initial dye concentration and 90 min contact time at 40 °C temperature. The highest adsorption proficiency Punica granatum = 18 < Zinc Oxide nanocomposites = 78 < Iron nanocomposites = 65 < Copper nanocomposites = 85 mg/g of all synthesized nanocomposites was obtained. The model Freundlich showed good fitness results which indicate complex nanocomposites nature. The 1st order showed best results on fitness of isotherm on kinetic data and rate constants determined the best fitness of model. The negative value of ΔHo and ΔSo of nanocomposites exhibited the exothermic nature and decrease in disorderness of adsorption process for dye exclusion. When values of Δ G o is positive then the reaction is spontaneous. Desorption of acidic dye from maximum efficient nanocomposites was 99 mg/g using eluent. Hence, it was determined that these nanocomposites serve as the novel, feasible, cost-effective, ecofriendly, and bio recyclability for treating acid dye-containing wastewater. [ABSTRACT FROM AUTHOR]

In this study, ZnFe2O4-Polyaniline (PANI), ZnFe2O4-Polystyrene (PST), and ZnFe2O4-Polypyrrole (Ppy) nanocomposites were synthesized by the adsorption method and characterized by field emission scanning electron microscopy and Fourier transform infrared spectrometer. Batch adsorption experiments were conducted for removing two types of hazardous dyes Red X-GRL and Direct Sky Blue 51 from an aqueous solution and the effect of pH, adsorbent dosage, contact time, and initial concentration of dyes were investigated. Meanwhile, kinetic, isotherm, and thermodynamic parameters were also determined. The electrolyte and surfactant effect was also tested for the prepared nanocomposites. To test the reusability desorption study was also conducted. [ABSTRACT FROM AUTHOR]