Solar Photocatalytic Efficiency of Zinc Oxide for Water Decontamination
DOI:
https://doi.org/10.46754/umtjur.v1i1.55Keywords:
Zinc oxide, photocatalyst, solar thermal, water purificationAbstract
Solar photocatalysis is a green technology that takes advantage of sustainable solar energy for enhancing oxidation process of numerous harmful water contaminants. In this study, a custom solar driven zinc oxide (ZnO)-mediated photocatalytic system was developed and its efficiency to remove organic contaminants as well as to disinfect selected bacteria was investigated. Methylene blue (MB) dye was used as the model organic contaminant, while Escherichia coli (E.coli) was used as the model fecal coliform bacteria in contaminated water. A series of photodegradation experiments were conducted on water contaminated with either 10 mg/L of MB or ~1010 CFU/ml of E.coli. The experiments were completed under sunlight irradiation in the presence of 1 g/L of nano ZnO photocatalyst for up to 6 hours. Using a solar thermal collector, the photoreactor operated in the temperature range of 25 to 50 oC. The findings revealed that the combination of solar thermal with solar photocatalysis using ZnO intensified the degradation of MB and disinfection of E.coli. 98.08% of MB dye and 99.99% of E.coli were successfully removed from the water within the first 3 hours of treatment. Almost complete removal was eventually achieved after 6 hours of treatment. It is therefore suggested that ZnO-based solar photocatalytic system developed in this study is highly efficient at enhancing water decontamination process.
References
Aziz, P. A., Wahid, S. S. A., Arief, Y. Z., & Aziz, N. A. (2016). Evaluation of Solar Energy Potential in Malaysia. Trends in Bioinformatics, 9(2), 35-43.
Behnajady, M. A., Modirshahla, N., & Hamzavi, R. (2006). Kinetic study on photocatalytic degradation of CI Acid Yellow 23 by ZnO photocatalyst. Journal of Hazardous Materials, 133(1): 226-232.
Byrne, J. A., Fernandez-Ibañez, P. A., Dunlop, P. S., Alrousan, D. M., Hamilton, J. W., & Abdel-Mottaleb, M. S. (2010). Photocatalytic enhancement for solar disinfection of water: A review. International Journal of Photoenergy, 2011: 77.
Das, S., Ranjana, N., Misra, A. J., Suar, M., Mishra, A., Tamhankar, A. J., Lundborg, C.S. & Tripathy, S. K. (2017). Disinfection of the water borne pathogens Escherichia coli and Staphylococcus aureus by Solar Photocatalysis using sonochemically synthesized reusable Ag@ZnO core-shell nanoparticles. International Journal of Environmental Research and Public Health, 14(7), 747.
Hussein, F. H. (2012). Photochemical treatments of textile industries wastewater. Asian Journal of Chemistry, 24(12), 5427.
Kondrakov, A. O., Ignatev, A. N., Lunin, V. V., Frimmel, F. H., Bräse, S., & Horn, H. (2016). Roles of water and dissolved oxygen in photocatalytic generation of free OH radicals in aqueous TiO2 suspensions: An isotope labeling study. Applied Catalysis B: Environmental 182, 424-430.
Lee, K. M., Lai, C. W., Ngai, K. S., & Juan, J. C. (2016). Recent developments of zinc oxide based photocatalyst in water treatment technology: A review. Water Research, 88: 428-448.
Ljubas, D. 2005. Solar photocatalysis - A possible step in drinking water treatment. Energy, 30(10), 1699-1710.
Mac Mahon, J., Pillai, S. C., Kelly, J. M., & Gill, L. W. (2017). Solar photocatalytic disinfection of E. coli and bacteriophages MS2, ΦX174 and PR772 using TiO2, ZnO and ruthenium based complexes in a continuous flow system. Journal of Photochemistry and Photobiology B: Biology, 170, 79-90.
Mahalakshmi, M., Arabindoo, B., Palanichamy, M., & Murugesan, V. (2007). Photocatalytic degradation of carbofuran using semiconductor oxides. Journal of Hazardous Materials, 143(1): 240-245.
Mai-Prochnow, A., Clauson, M., Hong, J., & Murphy, A. B. (2016). Gram positive and Gram negative bacteria differ in their sensitivity to cold plasma. Scientific Reports, 6: 38610.
Malato, S., Fernández-Ibáñez, P., Maldonado, M. I., Blanco, J., & Gernjak, W. (2009). Decontamination and disinfection of water by solar photocatalysis: recent overview and trends. Catalysis Today, 147(1): 1-59.
Malato, S., Maldonado, M. I., Fernandez-Ibanez, P., Oller, I., Polo, I., & Sanchez- Moreno, R. (2016). Decontamination and disinfection of water by solar photocatalysis: The pilot plants of the Plataforma Solar de Almeria. Materials Science in Semiconductor Processing, 42, 15-23.
Mondal, K. & Sharma, A. (2014). Photocatalytic oxidation of pollutant dyes in wastewater by TiO2 and ZnO nano-materials—A mini-review. Nanoscience & Technology for Mankind; The Academy of Sciences India (NASI): Allahabad, India, 36-72.
Palmer, F. L., Eggins, B. R., & Coleman, H. M. (2002). The effect of operational parameters on the photocatalytic degradation of humic acid. Journal of Photochemistry and Photobiology A: Chemistry, 148(1-3), 137-143.
Rajendran, S., Khan, M. M., Gracia, F., Qin, J., Gupta, V. K., & Arumainathan, S. (2016). Ce3+-ion-induced visible-light photocatalytic degradation and electrochemical activity of ZnO/CeO2 nanocomposite. Scientific Reports, 6, 31641.
Rodrigues-Silva, C., Miranda, S. M., Lopes, F. V., Silva, M., Dezotti, M., Silva, A. M., Faria, J. L., Boaventura, R. A. R., Vilar, V. J. P. & Pinto, E. (2017). Bacteria and fungi inactivation by photocatalysis under UVA irradiation: liquid and gas phase. Environmental Science and Pollution Research, 24(7), 6372-6381.
Seven, O., Dindar, B., Aydemir, S., Metin, D., Ozinel, M. A., & Icli, S. (2004). Solar photocatalytic disinfection of a group of bacteria and fungi aqueous suspensions with TiO2, ZnO and Sahara desert dust. Journal of Photochemistry and Photobiology A: Chemistry, 165(1-3), 103-107
Umar, M., & Aziz, H. A. (2013). Photocatalytic degradation of organic pollutants in water. Inorganic Pollutants-Monitoring, Risk and Treatment. 195-208.
