Assessment and optimization of total ammonia nitrogen adsorption in aqueous phase by sodium functionalized graphene oxide using response surface methodology

• Published in: Environmental progress & sustainable energy Vol. 39; no. 4
• Main Authors: Mirahsani, Arghavan, Sartaj, Majid, Giorgi, Javier B.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.07.2020
• Subjects: ammonia; nanomaterials; optimization; temperature
• ISSN: 1944-7442; 1944-7450
• DOI: 10.1002/ep.13344

Total ammonia nitrogen (TAN) uptake by sodium functionalized graphene oxide as an efficient adsorbent was evaluated and optimized using response surface methodology (RSM). Batch adsorption tests were carried out based on a central composite design experimental plan at 3 pH levels (6, 7, and 8) and 3 temperature levels (5, 25, and 45°C). The equilibrium condition was reached within 5 min. Quadratic models for percent TAN removal (R%) and solid phase TAN concentration (qe) as response were obtained and evaluated by statistical analysis to predict the experimental data. The models were reduced by eliminating insignificant terms. The final reduced models were significant (p < .0001) with R2 values .96 for R% and .97 for qe, respectively. The optimum pH and temperature to reach the maximum values for R% (58.23%) and qe (27.45 mg/g) were predicted by the RSM. The laboratory experiments were in very good agreement with the predicted optimized values for R% and qe by RMS as the error was 1.2 and 0.3%, respectively.