Abstract:
The main causes of pollution in all the mediums are the industries. According to estimates, 10–20% of colors used in typical dyeing processes end up in wastewater and the environment. It is not ideal to have these dyes in water, even at minute concentrations. Before being released into the environment, these effluents need to be treated. Nanoparticles are increasingly important elements in many different kinds of applications. In the present study, 4g of zinc acetate dihydrate was dissolved in 100 ml of mulberry leaf extract. The solution was then stirred using a magnetic stirrer at 60℃ until yellowish precipitates appeared. The mixture was then left at room temperature for 24 hours. After 24 hours zinc oxide nanoparticles settled at the bottom of the beaker in the form of brownish precipitates. The supernatant was removed, and the remaining solution was boiled at 105℃ until all the liquid evaporated leaving dry shiny nanoparticles. The dried zinc oxide nanoparticles were then ground to attain a homogeneous size. Biosynthesized ZnO nanoparticles were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray diffraction (XRD). The dye used for the study was Tartrazine azo dye. For the preparation of 500ppm solution, 0.5g of dye (tartrazine) was added to 1000ml of distilled water. For the preparation of 1000ppm solution, 0.5g of dye (tartrazine) was added to 500ml of distilled water. Different pH dye solutions including pH 3, 5, 7, 9, and 11 were prepared. For acidic conditions concentrated HCl was used and for basic conditions concentrated NaOH was used. The results of characterization of synthesized nanoparticles show vibrations between 610 cm-1 and 1540 cm-1 in FTIR, SEM image showed the nanoparticles are irregular in shape and are clumped together, and XRD pattern analysis showed characteristic peaks at 2θ of 31.789, 34.4568, 36.2567, 56.7006. After the treatment of dyes with nanoparticles, the experiment showed the decolorization and change in pH towards the neutral phase.
