Sukmilin, A.; Boonchom, B.; Jarusutthirak, C. Catalytic Ozonation using Iron-Doped Water Treatment Sludge as a Catalyst for Treatment of Phenol in Synthetic Wastewater: DOI: 10.32526/ennrj.17.2.2019.15. Environ. Nat. Resour. J. 2019, 17, 87-95.