Removal of Bisphenol A and Methylene Blue by α-MnO2 Nanorods: Impact of Ultrasonication, Mechanism, Isotherm, and Kinetic Models

This study will investigate the applicability of alpha-MnO2 nanorods, green synthesized using sugarcane juice for the treatment of toxicants in wastewater; Bisphenol A (BPA) and methylene blue (MB). Analysis of parameters that influence adsorption, such as pH, adsorbent dose, concentration of pollutant, contact time, temperature, humic acid (HA), ionic strength, ultrasound frequency, and power will be performed. Treatment results for silent (86.1%, 97.54%) and ultrasonic assisted (36.52%, 94.98%) adsorption of BPA and MB respectively, will be obtained at optimum conditions. The impact of ultrasonication and mechanisms that control adsorption will be assessed. Improved results (BPA: 36.52% to 81.2%) under ultrasonic assisted coadsorption might be due to hydrophobic interactions. Among various isotherms and kinetic models, the Langmuir isotherm and pseudo-second-order kinetic model showed the best correlation for both water contaminants. The growth mechanism of alpha-MnO2 nanorods is explained using LaMer's theory. The adsorbent characterization will be performed using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunaeur-Emmet-Teller (BET), X-ray photoelectron spectroscopy (XPS), and Fourier Transform Infrared (FTIR) spectroscopy. The results suggest alpha-MnO2 nanorods are a potential nanomaterial for the adsorption of persistent micropollutants and dyes. (c) 2021 American Society of Civil Engineers.

Automated summary

This study investigates the applicability of alpha-MnO2 nanorods for treating toxicants in wastewater, achieving optimal treatment results for BPA and MB under different conditions. The impact of ultrasonication on adsorption and the growth mechanism of alpha-MnO2 nanorods are assessed.Various techniques are used for adsorbent characterization, confirming the potential of alpha-MnO2 nanorods for removing micropollutants and dyes.