Taguchi L9 (34) Orthogonal Array Design for Photocatalytic Degradation of Methylene Blue Dye by Green ZnO Particles Biosynthesized by Chrysanthemum spp. Flower Extract

• Published in: Water (Basel) 2023-06, Vol.15 (12), p.2186
• Main Authors: Tran, Thuan Van, Alsaiari, Mabkhoot, Harraz, Farid A., Nabgan, Walid, Nguyen, Dinh Tien Dung, Nguyen, Chi Van
• Format: Article
• Language: English
• Subjects: biosynthesis; Chrysanthemum; Clean energy; Degradation; Design; Design optimization; Dyes; Efficiency; energy; experimental design; Flavonoids; flower extracts; Flowers & plants; human health; Irradiation; Methods; Methylene blue; Nanoparticles; Optimization; Orthogonal arrays; Photocatalysis; Photodegradation; Pollutants; pollution; Polyphenols; Radiation; Reaction mechanisms; reactive oxygen species; solar radiation; Spectrum analysis; Taguchi methods; Ultrasonic imaging; Wastewater; Wastewater pollution; water; Zinc oxide; Zinc oxides
• ISSN: 2073-4441; 2073-4441
• DOI: 10.3390/w15122186

The pollution of synthetic dyes in wastewater exerts many negative impacts on the environment and human health. There is an increasing demand for the degradation of dyes, with an emphasis on photocatalysis. Here, we investigated the bio-mediated synthesis of ZnO using Chrysanthemum spp. flower extract and its utilization for the removal of methylene blue dye under sunlight irradiation. The bandgap energy of green ZnO nanoparticles was determined to be 3.0. The Taguchi L9 (34) orthogonal array design was applied to optimize the photocatalytic degradation of methylene blue dye by green ZnO particles. Four parameters, including the initial concentration (10–50 mg/L), ZnO dosage (0.33–1.0 mg), contact time (30–120 min), and pH (4–10) of the solution, were surveyed based on the Taguchi design. We found that the test result (99.0%) at 10 mg/L was almost equivalent to the predicted value (99.5%) of degradation efficiency. The reaction mechanisms shed light on the major role of reactive oxygen species (•O2−, •OH). More importantly, the green ZnO particles could be reused for at least five cycles and demonstrated high stability.