عنوان مجله
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International Journal of Environmental Science and Technology
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کلیدواژهها
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Biogenic nanoparticles,Immobilization, Methylene blue , Photocatalysis, Wastewater
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چکیده
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Untreated wastewater discharged from textile units carries toxic dyes making it a carcinogenic and mutagenic hazard. Unlike
traditional remediation techniques, biogenic zinc oxide nanoparticles (ZnONPs) are emerging as a promising alternative due
to the unique physical properties and surface chemistry of nano-photocatalysts. Hence, in the current study we report the
photocatalytic potential of biogenic ZnONPs immobilized on calcium alginate (Ca–Alg) beads to degrade methylene blue
(MB) dye and treat textile effluents. The ZnONPs were synthesized by using the Bacillus cereus strain SZT1. The material
characterizing techniques confirmed the production of stabilized spherical-shaped nanocrystals of ZnONPs with particle size
ranging from 22 to 46 nm. The different concentrations (0, 1.0, 1.5 and 2.0 mg/ml water) of Ca-Alg immobilized ZnONPs
showed promising photocatalytic decolorization potential against varying levels (50, 100 and 150 mg/l water) of MB. Dye
degradation assays indicated that maximum concentration (2 mg/ml) of immobilized ZnONPS decolorized 50, 100 and
150 mg/l of MB up to 96.83%, 93.20%, and 88.47%, respectively, after 5 h of sunlight exposure. The textile effluents treated
with immobilized ZnONPS showed significant reduction in pH, turbidity, chemical oxygen demand (COD), electrical
conductivity (EC) and total suspended solids (TSS) as compared to the non-treated samples after 5 h of solar irradiation.
Overall, this work highlights the photocatalytic function of biogenic ZnONPs coated on Ca–Alg beads for the decolorization of MB and treatment of textile effluents that could become a robust and eco-friendly approach for large-scale treatment
of textile effluents.
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