Facile green preparation of nano-scale silver particles using Chenopodium botrys water extract for the removal of dyes from aqueous solution

In this study, the silver nanoparticles (AgNPs) as an eco-friendly, efficient and low-cost adsorbent was synthesized from Chenopodium botrys extract. Characteristics of the prepared adsorbent were investigated using scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDAX). According to the particle size distribution, the average size of AgNPs was obtained 11.9 nm. AgNPs were used for methyl blue (MB) and methyl orange (MO) removal from aqueous solution. Maximum removal percentages of 97.50 and 95.00 was obtained under optimum conditions, including contact time of 25 min, pH = 10, adsorbent dosage of 0.9 g, and dye concentration of 30 mg/L for MB and MO, respectively. Langmuir isotherm indicated the best results of adsorption related to the MB and MO with the maximum adsorption capacity of (q(max)) 90.09 and 80 mg g(-1) for MB and MO, respectively. The kinetics study showed that the results were fitted to the pseudo-second-order model with the coefficient of determination (R-2) of 0.9984 and 0.9919 for MB and MO, respectively. The process of removal can be also by adsorption of dye molecule on the surface of Ag-NPs and also may be due to the removal of dye molecules by hydroxyl radicals generated by the NPs effect on water molecules in the presence of light. The proposed adsorbent with its great properties can be used to remove contaminants from industrial wastewater before discharge to the environment. [GRAPHICS] .

Automated summary

Silver nanoparticles synthesized from Chenopodium botrys extract showed great potential as an eco-friendly and efficient adsorbent for the removal of dyes from wastewater, with high removal percentages and adsorption capacity. The adsorption process may involve both surface adsorption and generation of hydroxyl radicals for dye removal.