Optimizing treatment of alcohol vinasse using a combination of advanced oxidation with porous α-Fe2O3 nanoparticles and coagulation-flocculation
Zohal Safaei Mahmoudabadi, Alimorad Rashidi, Davood Mohammady Maklavany
Abstract
This study utilizes a novel method, namely the combination of advanced oxidation processes with synthesized highly porous α-Fe2O3 nanoparticles and coagulation-flocculation with polyacrylamide, to investigate the effects on COD removal in alcohol vinasse. Highly porous α-Fe2O3 nanoparticles were prepared via a chemical precipitation technique. The characteristic of the synthesized α-Fe2O3 nanoparticles were determined by FT-IR, Raman spectroscopy, XRD, SEM, and N2 adsorption-desorption isotherms. The effect of different α-Fe2O3 nanoparticles loading for chemical oxygen demand (COD) removal efficiency was investigated. The results revealed that at α-Fe2O3 nanoparticle dose of 3000 ppm had the highest COD removal for vinasse. Then, central composite design (CCD) was used to optimize the operating variables such as pH, time, oxidant dosage, and coagulant dosage, and their optimum values were determined to be pH:7.36, 90 min, 17.89 wt% oxidant dosage, and 1.6 wt% coagulant dosage, to achieve a high COD removal efficiency in 70 ℃ for alcohol vinasse (98.64%). Based on optimal conditions, the porous α-Fe2O3 nanoparticles possess superior catalytic activity in the advanced oxidation process compared to other treating methods. Also, the mechanism of the catalytic oxidation reaction is evaluated.