photocatalytic treatment and kinetic study of dye wastewater by synthesized zno nanoparticles

The increase in the number of factories, the industrialization of human life, and the increasing use of industrial paints have caused an increase in dye wastewater and consequent environmental pollution. discharging wastewater containing the dyes mentioned above, which are often carcinogenic, is a severe threat to living organisms. in this research, a photocatalytic method (as an advanced oxidation method) using zinc oxide nanoparticles was investigated to treat the colored wastewater containing methylene blue. this type of nanoparticle is cheap (based on the used synthesis method), abundant and readily available, and low in toxicity. for this purpose, an evaluation of the optimal ratio between zinc acetate and polyvinylpyrrolidone for the synthesis of zinc oxide nanoparticles was carried out. furthermore, the simultaneous decreasing and increasing effects of independent parameters (ph, irradiation time, methylene blue concentration, zinc acetate to pvp ratio) on the efficiency of the photocatalytic process and kinetic model were evaluated. the results showed that the best pollutant removal efficiency (91.7%) was obtained using the ratio of zinc acetate and polyvinylpyrrolidone equal to 33.67 in 60 minutes of irradiation time. this result shows that the lower ratio of zinc acetate to polyvinylpyrrolidone indicates higher dye removal.