Abstract
Interest is growing in an advanced disinfection technique for water treatment without disinfection byproducts. This study presents results of using UV radiation and a liquid-film-forming apparatus (LFFA) for disinfection of Escherichia coli in water. The sensitivity of bacteria to the combined UV/LFFA treatment was examined under various conditions of UV dosages, air flow rates, and initial bacterial concentrations. Combined UV/LFFA treatments resulted in greater disinfection efficiency than those for the UV treatment alone. Combined treatment with UV (UV dosage = 41.67 mJ/cm2, and room temperature) and LFFA (air flow rate = 1.5 L/min) resulted in complete inactivation (5.4 log reduction) of E. coli within 60 min. In contrast, when the UV treatment was used at the same UV dosage, only 4.3 log reduction was achieved after 75 min. The findings could provide an effective method for enhanced bactericidal activity of UV radiation, to address recently emerging problems in water disinfection.
References
- Liu W., Yanmei Z., Christopher C., Dongsheng, W. (2011). Formation of disinfection byproducts in typical Chinese drinking water. Journal of Environmental Sciences. 23(6) 897-903.
- Von Gunten U. (2003). Ozonation of drinking water: part II. Disinfection and byproduct formation in presence of bromide, iodide or chlorine. Water Research. 37, 1469–1487.
- Hijnen W., Beerendonk Ef, Gerriet Jan, M. (2006). Inactivation credit of UV radiation for viruses, bacteria and protozoan (oo) cysts in water: a review. Water research. 40(1) 3-22.
- Beck, S.E., Ryu, H., Boczek, L.A., Cashdollar, J.L., Jeanis, K.M., Rosenblum, J.S., Lawal, O.R., Linden, K.G. (2017). Evaluating UV-C LED disinfection performance and investigating potential dual-wavelength synergy. Water Research. 109, 207–216.
- Koivunen, J., Heinonen-Tanski, H. (2005). Inactivation of enteric microorganisms with chemical disinfectants, UV irradiation and combined chemical/UV treatments. Water Research. 39, 1519–1526.
- Catherman R. (2008). Using ultraviolet to disinfect household drinking water, Director of Safe Water Development MEDRIX™.
- Imai T., Zhu H. (2011). Improvement of oxygen transfer efficiency in diffused aeration systems using liquid-film-forming apparatus in Mass Transfer—Advanced Aspects, H. Nakajima, Ed. INTECH 341–370.