Valorization of sugarcane bagasse cellulose to synthesize novel graphene oxide-based composite for remediation of atrazine – Optimization studies

Abstract

Atrazine (AZE) is a hazardous herbicide that pollutes drinking water and wastewater at an alarming rate, posturing a somberhazard to the environment and human being. This research is aimed to investigate the valorization of biomass for the synthesis and applicationof novel Sugarcane Bagasse Cellulose (SCBC) - Graphene oxide (GO) nanocomposite for remediation of atrazine. The novel nanocomposite is characterized using Fourier transform infrared spectroscopy (FTIR), Particle size distribution, Raman spectra analysis, X-ray analysis (XRD), Scanning electron microscope analysis (SEM) and Transmission electron microscopy (TEM). The prepared GOSCBC had high surface area of 189 m2/g, pore volume of 0.13 cm3/g, and inter-particle pore width of 17 nm. The impact of operating constraints such as adsorbent dose (50–150 mg), medium pH (4.5–8.5), contact period (3 h), temperature (15–45°C), and atrazine concentration (10–50 mg/L) were varied and optimum conditions were examined with the help of Box-Behnken statistical design (BBD). The optimum conditions identified were: 90.84 mg/L nanocomposite; pH 5.51; time 180 min; temperature 34.64°C and feed concentration 27.77 mg/L. The adsorption statistical analyses were performed and the values were determined using the isotherms and kinetic models; the optimal parameters were evaluated using sum of normalised errors approach. The maximum adsorption capacity of AZE was found to be 143.29 mg/g. The mechanism of sorption is well represented by PSO model. The exothermic nature of removal process was confirmed through thermodynamic parameters. The reusability of the nanocomposite was identified to be efficient for six cycles.