Nickel oxide and carboxymethyl cellulose composite beads as catalyst for the pollutant degradation

Plant-assisted synthesis and characterization of MnO2 nanoparticles for removal of crystal violet dye: an environmental remedial approach

The current study is focused on the use of the Caryota mitis Lour. (Fishtail palm) flower extract as a reducing agent for the preparation of manganese dioxide (MnO₂) nanoparticles. Scanning electron microscopy (SEM), four-phase infrared analysis (FT-IR), and x-ray diffraction (XRD) methods were used to characterize the MnO₂ nanoparticles. The nature of MnO₂ nanoparticles was revealed by an absorption peak at 590 nm in a spectrophotometer (A1000). Then, these MnO₂ nanoparticles were applied to decolorize the crystal violet dye. At 0.004% dye concentration, pH 4, and concentration of MnO₂ nanoparticles of 0.005 g/L at temperatures of 50 °C, the target dye was decolorized by 91.3%. Percent reductions in COD and TOC were found to be 92.1% and 90.6%, respectively. Finally, the dye decolorization pathway was proposed based on the experimental findings.

Biologically Synthesized Copper Nanoparticles Show Considerable Degradation of Reactive Red 81 Dye: An Eco-Friendly Sustainable Approach

Diospyros kaki leaf extract was used in this study as a favorable basis for the synthesis of copper nanoparticles (Cu NPs). X-ray diffraction (XRD) and UV-visible spectroscopy approaches were used to characterize the biologically synthesized copper nanoparticles. The XRD analysis showed that copper nanoparticles were face-centered cubic structure. Various experimental levels like conc. of dye, concentration of Cu NPs, pH, reaction time, and temperature were optimized to decolorize reactive red 81 dye using the synthesized Cu NPs. Reactive red 81 dye was decolorized maximum using Cu NPs of 0.005 mg/L. Additionally, reactive red 81 dye was decolorized at its maximum at pH = 6, temperature = 50°C. Our study reported that chemical oxidation demand (COD) and total organic carbon (TOC) deduction efficacies were 74.56% and 73.24%. Further degradation study of reactive red 81 dye was also carried out. Cu NPs have the ability and promising potential to decolorize and degrade reactive red 81 dye found in wastewater.