US EPA. National Emission Standards for Hazardous Air Pollutants: Miscellaneous organic chemical, 2006.
 Manufacturing; Final rule, Federal register part V, 40 CFR Part 63, United States Environmental Protection Agency, 2006.
 K.M. Parida, S. Parija, Photocatalytic degradation of phenol under solar radiation using microwave irradiated zinc oxide, Sol. Energy, 80 (2006) 1048-1054.
 S. Ahmed, M.G. Rasul, W.N. Martens, R. Brown, M.A. Hashib, Heterogeneous photocatalytic degradation of phenols in wastewater: A review on current status and developments, Desalination, 261 (2010) 3-18.
 J.C. Radcliff, Future directions for water recycling in Australia, Desalination, 187 (2006) 77-87.
 V.G. Mitchell, R.G. Mein, T.A. McMahon, Utilising storm water and wastewater resources in urban areas, Aust. J. Water Resourc. 6 (2002) 31-43.
 Z. Guo, R. Ma, G. Li, Degradation of phenol by nanomaterial TiO2 in wastewater, Chem. Eng. J. 119 (2006) 55-59.
 G.C. Yang, Y.W. Long, Removal and degradation of phenol in a saturated flow by in-situ electrokinetic remediation and Fenton-like process, J. Hazard. Mater. 69 (1999) 259-271.
 V.A. Cooper, J.A. Nicell, Removal of phenols from a foundry wastewater using horseradish peroxidase, Water Resour. 30 (1996) 954-964.
 G.S. Veeresh, P. Kumar, I. Mehrotra, Treatment of phenol and cresols in upflow anaerobic sludge blanket (UASB) process: A review, Water Resour. 39 (2005) 154-170.
 Y. Zhang, D. Ma, Y. Zhang, W. Chen, S. Huang, N-Doped carbon quantum dots for TiO2-based photocatalysts and dye- sensitized solar cells, Nano Energy, 2 (2013) 545-552.
 L. Yang, D. Chu, L. Wang, Porous hexapod CuO nanostructures: precursor-mediated fabrication, characterization, and visible-light induced photocatalytic degradation of phenol, Mater. Lett. 160 (2015) 246-249.
 M. Aslam, I.M.I. Ismail, N. Salah, S. Chandrasekaran, M.T. Qamar, A.Hameed, Evaluation of sunlight induced structural changes and their effect on the photocatalytic activity of V2O5 for the degradation of phenols, J. Hazard. Mater. 286 (2015) 127-135.
 M. Aslam, M.T. Qamar, M. Tahir Soomro, I.M.I. Ismail, N. Salah, T. Almeelbi, M.A. Gondal, A. Hameed, The effect of sunlight induced surface defects on the photocatalytic activity of nanosized CeO2 for the degradation of phenol and its derivatives, Appl. Catal. B: Environ. 180 (2016) 391-402.
 J. Ye, X. Li, J. Hong, J. Chen, Q. Fan, Photocatalytic degradation of phenol over ZnO nanosheets immobilized on montmorillonite, Mat. Sci. Semicon. Proc. 39 (2015) 17-22.
 X. Feng, H. Guo, K. Patel, H. Zhou, X. Lou, High performance, recoverable Fe3O4-ZnO nanoparticles for enhanced photocatalytic degradation of phenol, Chem. Eng. J. 244 (2014) 327-334.
 B. Ozturk, G.S. Pozan Soylu, Synthesis of surfactant-assisted FeVO4 nanostructure: Characterization and photocatalytic degradation of phenol, J. Mol. Catal. A- Chem. 398 (2015) 65-71.
 M. Zare, M. Gashang, A. Saffar-Tei, BaO-ZnO nano-composite efficient catalyst for the photo-catalyti degradation of 4- chlorophenol, Biointerface Res. Appl. Chem. 6 (2016) 1049-1052.
 J. Wrzyszcz, M. Zawadzki, J. Trawczynski, H. Grabowska, W. Mista, Some catalytic properties of hydrothermally synthesized zinc aluminate spinel, Appl. Catal. A. 210 (2001) 263-269.
 H. Grabowska, W. Mista and J. Trawczyski, A method for obtaining thymol by gas phase catalytic alkylation of m-cresol over zinc aluminate spinel, Appl. Catal. A- Gen. 220 (2001) 207-213.
 S. Farhadi, K. Jahanara, ZnAl2O4@SiO2 nanocomposite catalyst for the acetylation of alcohols, phenols and amines with acetic anhydride under solvent-free conditions, Chinese J. Catal. 35 (2014) 368-375.
 T.E Nabarawy, A.A. Attia, M.N. Alaya, Effect of thermal treatment on the structural, textural and catalytic properties of the ZnO-Al2O3 system, Mater. Lett. 24 (1995) 319-325.
 Y. Wang, Q. Liao, H. Lei, X.P. Zhang, X.C. Ai, J.P. Zhang, K. Wu, Interfacial reaction growth: morphology, composition, and structure controls in preparation of crystalline ZnxAlyOz nanonets, Adv. Mater. 18 (2006) 943-947.
 X.Y. Chen, C. Ma, Z.J. Zhang, B.N. Wang, Ultrafine gahnite (ZnAl2O4) nanocrystals: Hydrothermal synthesis and photoluminescent properties, Mater. Sci. Eng.-Adv. 151 (2008) 224-230.
 X. Li, Z. Zhu, Q. Zhao, L. Wang, Photocatalytic degradation of gaseous toluene over ZnAl2O4 prepared by different methods: a comparative study, J. Hazard. Mater. 186 (2011) 2089-2096.
 J. An, L. Zhu, Y. Zhang, H. Tang, Efficient visible light photo-Fenton-like degradation of organic pollutants using in situ surface-modified BiFeO3 as a catalyst, J. Environ. Sci. 25 (2013) 1213-1225.
 W. Luo L. Zhu, N. Wang, H. Tang, M. Cao, Y. She, Efficient removal of organic pollutants with magnetic nanoscaled BiFeO3 as a reusable heterogeneous Fenton-like catalyst, Environ. Sci. Technol. 44 (2010) 1786-1791.
 M. Sajjia, M. Oubaha, M. Hasanuzzaman, M.G. Olabi, Developments of cobalt ferrite nanoparticles prepared by the sol-gel process, Ceram. Int. 40 (2014) 1147-1153.
 V.S. Kirankumar, S. Sumathi, Catalytic activity of bismuth doped zinc aluminate nanoparticles towards environmental remediation, Mater. Res. Bull. 93 (2017) 74-82.
 R. Huo, Y. Kuang, Z. Zhao, F. Zhang, S. Xu, Enhanced photocatalytic performances of hierarchical ZnO/ZnAl2O4 microsphere derived from layered double hydroxide precursor spray-dried microsphere, J. Colloid Interf. Sci. 407 (2013) 17-21.
 Z. Zhu, Q. Zhao, X. Li, H. Li, M. Tade, S. Liu, Photocatalytic performances and activities in Ag-doped ZnAl2O4 nanorods studied by FTIR spectroscopy, Catal. Sci. Technol. 3 (2013) 788-796.
 a) A. Hameed, T. Montini, V. Gombac and P. Fornasiero, Surface phases and photocatalytic activity correlation of Bi2O3/Bi2O4−x nanocomposite, J. Am. Chem. Soc. 130 (2008) 9658-9659.
b) A. Hameed, M. Aslam, I.M.I. Ismail, S. Chandrasekaran, M.W Kadi, M.A. Gondal, Sunlight assisted photocatalytic mineralization of nitrophenol isomers over W6+ impregnated ZnO, Appl. Catal. B- Environ. 160-161 (2014) 227-239.
 M.M. Haque, M. Muneer, Photodegradation of norfloxacin in aqueous suspensions of titanium dioxide, J. Hazard. Mater. 145 (2007) 51-57.
 H. Zhao, Y. Dong, P. Jiang, G. Wang, J. Zhang, C. Zhang, ZnAl2O4 as a novel high-surface-area ozonation catalyst: One-step green synthesis, catalytic performance and mechanism, Chem. Eng. J. 260 (2015) 623-630.
 C.H. Chiou, C.Y. Wu, R.S. Juang, Influence of operating parameters on photocatalytic degradation of phenol in UV/TiO2 process, Chem. Eng. J. 139 (2008) 322-329.
 N. Kashif, F. Ouyang, Parameters effect on heterogeneous photocatalysed degradation of phenol in aqueous dispersion of TiO2, J. Environ. Sci. 21 (2009) 527-533.
 K. Pirkanniemi, S. Metsärinne, M. Sillanpää, Degradation of EDTA and novel complexing agents in pulp and paper mill process and waste waters by Fenton’s reagent, J. Hazard. Mater. 147 (2007) 556-561.
 H.Y. Chen, O. Zahraa, M. Bouchy, Inhibition of the adsorption and photocatalytic degradation of an organic contaminant in an aqueous suspension of TiO2 by inorganic ions, J. Photochem. Photobiol. A. 108 (1997) 37-44.
 U.I. Gaya, A.H. Abdullah, Z. Zainal, M.Z. Hussein, Photocatalytic treatment of 4-chlorophenol in aqueous ZnO suspensions: Intermediates, influence of dosage and inorganic anion, J. Hazard. Mater. 168 (2009) 57-63.
 R. Wang, J.H. Xin, Y. Yang, H. Liu, L. Xu, The characteristics and photocatalytic activities of silver doped ZnO nanocrystallites, J. Appl. Surf. Sci. 227 (2004) 312-317.
 S. Colis, H. Bieber, S. Begin-Colin, G. Schmerber, C. Leuvrey, Magnetic properties of Co-doped ZnO diluted magnetic semiconductors prepared by low-temperature mechanosynthesis, Chem. Phys. Lett. 422 (2006) 529-533.
 R. Ullah, J. Dutta, Photocatalytic degradation of organic dyes with manganese-doped ZnO nanoparticles, J. Hazard. Mater. 156 (2008) 194-200.