The most common used methods for water disinfection were chemicals like chlorine, ozonation, ultraviolet radiation, membrane processes, etc. Water disinfection using irradiation techniques is new in water treatment industry which has been developed recently. The aim of the present study was to investigate radio frequency (RF) efficiency for the inactivation of total coliform (TC), fecal coliform, and heterotrophic bacterial count of water pellets. Tap water samples were taken from School of Public Health, Tehran University of Medical Sciences and irradiated using hydropad device, steam KLEAR model S-38 (1.2 W and frequency of 120-200 kHz). Microbial concentration was measured in cycles 1, 5, 10, 15, 20, 25, 30, 35, and 40 in 1 and 2 h contact time. Indicator bacteria were counted using plate count method and multiple fermentation tube technique. According to the microbial results, after 40 cycles and without chlorine residual, TC, fecal coliform, and heterotrophic bacteria were reduced by 86, 90, and 85%, while after 15 cycles and 0.8 mg/L chlorine residual, removal rate was 89, 91, and 89%, respectively. Furthermore, it was observed that after 2 h of contact time, TCs, fecal coliforms, and heterotrophic plate count were reduced by 78.2, 80, and 60%, respectively. Although RF efficiency in water disinfection has not been studied, our findings suggested its possible use due to more than 75% efficiency. From the standpoint of practical use, more studies should be done, especially to find a fine synergist agent, determining power, frequency, and suitable contact time and also the method should be modified.
Payment P, Waite M, Dufour A. Assessing microbial safety of drinking water. In: World Health Organization, Editor. Assessing Microbial Safety of Drinking Water Improving Approaches and Methods: Improving Approaches and Methods. Paris, France: OECD Publishing; 2003.
Bryant EA, Fulton GP, Budd GC. Disinfection alternatives for safe drinking water. New York, NY: Van Nostrand Reinhold; 1992.
Fenwick A. Waterborne infectious diseases--could they be consigned to history? Science 2006; 313(5790): 1077-81.
Mahvi AH. Health and aesthetic aspects of water quality. 1st ed. Tehran, Iran: Bal Gostar Publication; 1996.
Samadi M, Nasseri S, Mesdaghnia A, Alizadeh MR. Comparison study of THMs removal from drinking water using GAC and Air stripping column and nano-filtration. Journal of Water & Wastewater 2006; 17(57): 14-22.
Rutala WA, Weber DJ. New disinfection and sterilization methods. Emerg Infect Dis 2001; 7(2): 348-53.
Biryukov AS, Gavrikov VF, Nikiforova LO, Shcheglov VA. New physical methods of disinfection of water. Journal of Russian Laser Research 2005; 26(1): 13-25.
Geveke DJ, Kozempel M, Scullen OJ, Brunkhorst C. Radio frequency energy effects on microorganisms in foods. Innovative Food Science & Emerging Technologies 2002; 3(2): 133-8.
Rincon, Pulgarin C. Effect of pH, inorganic ions, organic matter and H2O2 on E. coli K12 photocatalytic inactivation by TiO2: Implications in solar water disinfection. Applied Catalysis B: Environmental 2004; 51(4): 283-302.
Burtner RL. Radio-frequency device [Online]. [cited 1951]; Available from: URL:
Kottke FJ, Ellwood PM. Handbook of Physical Medicine and Rehabilitation. Philadelphia, PA: Saunders; 1966.
Valberg PA. Radio frequency radiation (RFR): the nature of exposure and carcinogenic potential. Cancer Causes Control 1997; 8(3): 323-32.
Geveke DJ, Brunkhorst C. Radio frequency electric fields inactivation of Escherichia coli in apple cider. Journal of food engineering 2008; 85(2): 215-321.
Kim SY, Sagong HG, Choi SH, Ryu S, Kang DH. Radio-frequency heating to inactivate Salmonella Typhimurium and Escherichia coli O157:H7 on black and red pepper spice. Int J Food Microbiol 2012; 153(1-2): 171-5.
Awuah GB, Ramaswamy HS, Economides A, Mallikarjunan K. Inactivation of Escherichia coli K-12 and Listeria innocua in milk using radio frequency (RF) heating. Innovative Food Science & Emerging Technologies 2005; 6(4): 396-402.
Tyagi VK, Lo SL. Microwave irradiation: A sustainable way for sludge treatment and resource recovery. Renewable and Sustainable Energy Reviews 2013; 18: 288-305.
Zielinski M, Ciesielski S, Cydzik-Kwiatkowska A, Turek J, D-?bowski M. Influence of microwave radiation on bacterial community structure in biofilm. Process Biochemistry 2007; 42(8): 1250-3.
Nabizadeh R, Alimohammadi M, Aslani H, Mesdaghinia A, Naddafi K, Nemati R, et al. Comparative study of Fenton's reagent performance in disinfection of raw wastewater and activated sludge effluent. Desalination and Water Treatment 2012; 37(1-3): 108-13.
Eaton AD, Franson MA. Standard Methods for the Examination of Water & Wastewater. Washinton, DC: American Public Health Association; 2005.
Ukuku DO, Geveke DJ. A combined treatment of UV-light and radio frequency electric field for the inactivation of Escherichia coli K-12 in apple juice. Int J Food Microbiol 2010; 138(1-2): 50-5.
Edzwald J. Water Quality & Treatment: A Handbook on Drinking Water. New York, NY: McGraw Hill Professional; 2010.
Velizarov S, Raskmark P, Kwee S. The effects of radiofrequency fields on cell proliferation are non-thermal. Bioelectrochem Bioenerg 1999; 48(1): 177-80.
Saadi, S., Alimohammadi, M., Nabizadeh, R., Mesdaghinia, A., Aslani, H., Nazmara, S., Ghani, M., Mahmoodi, B., Asgari, M., & Mousavipour, N. (2014). Evaluating efficiency of radio waves for microbial removal in water samples. Journal of Advances in Environmental Health Research, 2(3), 157-164. doi: 10.22102/jaehr.2014.40158
Sommayeh Saadi; Mahmood Alimohammadi; Ramin Nabizadeh; Alireza Mesdaghinia; Hassan Aslani; Shahrokh Nazmara; Maryam Ghani; Babak Mahmoodi; Masoomeh Asgari; Nejat Mousavipour. "Evaluating efficiency of radio waves for microbial removal in water samples". Journal of Advances in Environmental Health Research, 2, 3, 2014, 157-164. doi: 10.22102/jaehr.2014.40158
Saadi, S., Alimohammadi, M., Nabizadeh, R., Mesdaghinia, A., Aslani, H., Nazmara, S., Ghani, M., Mahmoodi, B., Asgari, M., Mousavipour, N. (2014). 'Evaluating efficiency of radio waves for microbial removal in water samples', Journal of Advances in Environmental Health Research, 2(3), pp. 157-164. doi: 10.22102/jaehr.2014.40158
Saadi, S., Alimohammadi, M., Nabizadeh, R., Mesdaghinia, A., Aslani, H., Nazmara, S., Ghani, M., Mahmoodi, B., Asgari, M., Mousavipour, N. Evaluating efficiency of radio waves for microbial removal in water samples. Journal of Advances in Environmental Health Research, 2014; 2(3): 157-164. doi: 10.22102/jaehr.2014.40158