N-doped biomass-derived carbon catayst (NBC) : preparation, characterization, and its application in removal of aqueous antibiotics

• Main Author: Loh, Yun Ler
• Other Authors: Lim Teik Thye
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Environmental engineering
• Online Access: http://hdl.handle.net/10356/78428
• Institution: Nanyang Technological University

Due to the widespread distribution of antibiotics pollutants in the aquatic environment and has caused serious pollution problems, such as the evolution of antibiotic resistant pathogenic bacteria and threatens human health, so it is imperative that environmentally friendly solution to degrade antibiotics pollutants should be studied and implemented. This report studied the preparation method, characterization and evaluation of adsorption and catalytic performance of N-doped biomass-derived carbon catalyst (NBC) in degrading sulfacetamide (SAM) via activation of peroxymonosulfate (PMS). NBC were prepared from renewable biomass, which was chitosan, the derivative of chitin. NBC-Chi800 was synthesized by chitosan that underwent pyrolysis to form NBC-Chi800 under temperature of 800oC in the presence of N2 atmosphere. In addition, NBC-CNU600, NBC-CNU700, NBC-CNU800 and NBC-CNU900 were carbon catalysts that synthesized by pyrolysis of chitosan with urea and NaHCO3 in the temperature range of 600oC, 700oC, 800oC and 900oC, respectively. The NBCs were characterized via FESEM, TGA, XRD, XPS, Raman spectra and FTIR then their catalytic and adsorption performance were monitored. Kinetic studies showed that NBC-CNU900 had the most excellent adsorption ability of SAM in pH6.5±0.5 under room temperature due to its highly porous structure that can be observed in FESEM imaging. On the other hand, NBC-CNU800 excelled its catalytic performance due to the porous structure and the presence of graphitic N that created active sites to activate PMS. Experiment result of using different catalytic loading NBC-CNU800 to activate PMS for removing SAM was done. An increase of catalytic loading can enhance SAM removal due to the higher availability of active sites for PMS activation. The quenching experiment revealed that non-radical process was the dominant pathway of PMS activation for SAM removal over the radical pathway due to the presence of graphitic N in NBC-CNU which had higher electronegativity, created active sites for PMS activation through non-radical pathway. Both NBC-CNU800 and NBC-CNU900 can be applied as a green biomass derived carbon catalyst for antibiotic removal by non-radical oxidation process and adsorption process respectively because the method of preparing NBCs, which is through the pyrolysis of chitosan, urea and NaHCO3, is green and cost-effective.