Green Synthesis of ZnO/αFe2O3 Nano-photocatalyst for Efficient Removal of Carbamate Pesticides in Wastewater: Optimization, Mineralization, and Financial Analysis

다국어 초록 (Multilingual Abstract)

As emerging organic agricultural pollutants, carbamate pesticides can react with other contaminants in aquatic environments to produce new toxic compounds threatening aquatic life and ecosystems. This study introduces a novel, nonhazardous, and greener method to synthesize a cross-linked ZnO/αFe 2 O 3 nano-photocatalyst to treat carbamate pesticides via ball milling.
ZnO/αFe 2 O 3 was characterized through various methods, including XRD, EDX, XRF, DRS, BET, FE-SEM, PL, and FTIR analyses. Using the Response Surface Methodology (RSM), the ability of ZnO/αFe 2 O 3 nano-photocatalyst to remove carbamate from synthesized wastewater was assessed. The BET result indicated a decrease in the diameter of the nanocomposite size after the synthesis. At the same time, the BET surface area and total pores increased from 4.9871 m 2 .g −1 and 0.02806 cm 3 .g −1 to 6.8524 m 2 .g −1 and 0.069497 cm 3 .g −1 , respectively. In addition, the band-gap energy decreased from 3.179 eV for ZnO to 1.907 eV for ZnO/αFe 2 O 3 and eventually reached 1.878 eV for heat-treated ZnO/αFe 2 O 3 nanocomposite. The catalyst concentrations used in the experiments were 0.5, 1, and 1.5 g/L. The solution pH was set to 5, 8, and 11, and three diff erent residence times of 1, 2, and 3 h were used. The model’s results indicated a strong agreement between the experimental and predicted data (R 2 = 0.99). When the nanocomposite’s concentration, pH, and retention time were set at 1 g/L ZnO/αFe 2 O 3 , 8.51, and 3 h respectively, the optimized conditions predicted a removal effi ciency of 89%. In addition, the cost of COD removal was reduced by 50% using ball milling and heat-treatment synthesis. The photocatalyst’s reusability was tested in three stages, and the outcomes demonstrated its stability throughout these three stages.