Microbial Removal Efficiency of UV in Tehran Shahid Mahallati Wastewater Treatment Plant

Document Type : Research Paper


Assistant Professor, Nuclear Science and Technology Research Institute


Shahid Mahallati Wastewater Treatment Plant was selected for installing a UV disinfection unit to investigate its germicidal effect on microbial removal. Low pressure mercury lamps were used to generate germicidal ultraviolet radiation (UV-C). The UV system was operated over a period of 6 months that included both warm and cold seasons. A maximum UV disinfection efficiency of 14.4m3/h was recorded for the system on the basis of design criteria within turbidity ranges of 9 to 32 NTU. The minimum UV dose applied in the UV unit was 40000 µW.s/cm2 and the highest bacterial density in the UV unit influent was 5.6*107. Effluent total coliform or fecal coliform enumeration after exposure to UV ray showed the microbial density decreasing from four logs, or 99.99%, to as high as six logs, or 99.9999% removal efficiency, under different conditions. Effluent microbial densities in terms of total and fecal coliforms were below 1000MPN/100mL and 400MPN/100mL, respectively. These values comply with wastewater discharge or agricultural irrigation standards according to Iran Department of Environment. From our results, it is concluded that UV disinfection may be an effective technique for wastewater disinfection in Iranian wastewater treatment plants.


1- Black, G.J. (2002). Microbiology: principal and explorations, 5th Ed., John Wiley  and Sons Inc.
2- Tchobanoglous, G., Burton, F.L., Stensel, H.D. (2002). Wastewater engineering: treatment and reuse, 4th Ed., McGraw-Hill, Metcalf and Eddy Inc.,USA.
3- Lorch, W. (1987). Handbook of water purification, 2nd  Ed., Ellis Hor Wood Ltd,England.
4- Dizer, H., Bartocha, W., Bartel, H., and Seidel, K. (1993). “Use of ultraviolet radiation for inactivation of bacteria and coliphages in pretreated wastewater.” Water Research, 27(3), 397-403.
5- Bourrouet, A., Garcia, J., Mujeriego,R., and Peñuelas, G.(2001). “Fecal bacteria and bacteriophage inactivation in a full-scale UV disinfection system used for wastewater reclamation.” 43(10),187-194.
6- Nasser, A.M., Paulman, H. Sela, O., Ktaitzer, T., Cikurel, H., ZuckermanI., Meir, A., Aharoni, A., and Adin, A.  (2006). “UV disinfection of wastewater effluents for unrestricted irrigation.” Water Science and Technology, 54(3), 83-88. 
7- Tessele, F. , Monteggia, L.O., Rubio, J.(2005). “Treatment of municipal wastewater UASB reactor effluent by unconventional flotation and UV disinfection.” Water Science and Technology, 52(1-2), 315-322.
8- Eiichi, I.(1999). “Application of UV disinfection for wastewater treatment plant discharges.” Japan J. of ultraviolet rays, 18(1),17-20. 
9- Kang, S.J., Allbaugh, T.A., Reynhout J.W., Erickson, T.L., Olmstead, K.P., Thomas, L., and Thomas, P.(2004). “Selection of an ultraviolet disinfection system for a municipal wastewater treatment plant.” Water Science and Technology, 50(7),163-169.
10- White, G.C. (1992). The handbook of chlorination and alternative disinfectants, 3rd Ed., VanNostrand Reinhold,New York,USA.
11- Reynolds, T. D., and Richards, P.A. (1982). Unit operations and processes of environmental engineering, 2nd Ed., PWS publishers,Boston,USA.
12- Wolf, R.L. (1990). “Ultraviolet disinfection of Potable Water.” Environmental Science and Technology, 24(6), 768-773.
13- Dingman, J.D.(1990). “Public pool disinfection.” J. of Environmental Health, 52(6), 341-343.
14- Johnson, I.D. (1975). Disinfection water and waste water, Annarbor science pub Inc,USA.
15- Cheremisinoff P. N., and young, R.A. (1975). Pollution engineering practice handbook, Annarbor Science pub. Inc,USA.
16- Crandall, R.A. (1986). “The use of ultraviolet light in the treatment of water in public spas and hot tubs.” J. of Environmental Health, 49 (1), 16-23
17- دباغ،ر.(1378). کاربرد پرتوهای فرابنفش در گندزدایی آب. پایان‌نامه کارشناسی ارشد، دانشکده محیط زیست، دانشگاه تهران.
18- غفوریان، ح.،دباغ، ر.، نبی، غ.، و مهردادی، ن.( 1379). کاربرد پرتوهای فرابنفش در گندزدایی آب. م. آب و فاضلاب، 36، 39-47.
19- واعظی، ف.(1373). کاربرد پرتوهای فرابنفش برای گندزدایی فاضلاب و بررسی اثر آن بر تخم کرم آسکاریس. رساله دکترا، دانشکده بهداشت، دانشگاه علوم پزشکی تهران.
20- واعظی ، فمصداقی‌نیا ، ع.ر.، و ایماندل، ک.(1373). استفاده از پرتو فرابنفش برای گندزدایی فاضلابها، طرح پژوهشی، دانشگاه علوم‌پزشکی و خدمات بهداشتی درمانی تهران، دانشکده‌بهداشت و انستیتو تحقیقات بهداشتی، شماره 18714، پژوهشگاه اطلاعات و مدارک علمی ایران.
21- موبدی،ا.،  شریعت ، م.، منشی، ح.، واعظی، ف.، مصداقی‌نیا، ع.، و ایماندل، ک. (1373). استفاده از پرتو فرابنفش برای گندزدایی فاضلاب، طرح پژوهشی، دانشگاه علوم‌پزشکی و خدمات بهداشتی درمانی تهران، دانشکده‌بهداشت و انستیتو تحقیقات بهداشتی، شماره 28863، پژوهشگاه اطلاعات و مدارک علمی ایران.
22- Ellis, K.V.(1991). “Water disinfection, a review with some consideration of the requirements of third world ultraviolet radiation.” Critical Reviews in Environmental Control, 20 (5-6), 370- 376.
23- De Robbertis, E.D.P., De Robbertis, E.M.F. (1980). Cell and molecular biology, 7th  Ed., Holt-Sanders Japan Ltd,Japan.
24- WPCF. (1986). Wastewater disinfection manual of practice-FD-10,Virginia,USA.
25- Qualls, R.G., and Johnson, I.D. (1985). “Modeling and efficiency of ultraviolet disinfection systems.” Water Res., 19 (8), 1039-1046.
26- Weber. W.J. (1972). Physico chemical processes for water quality control, John Willey Inc,New York,USA.
27- McGraw-Hill Encyclopedia of Science and Technology. (1982). V.9, p.551.
28- دباغ،ر.، غفوریان، ح.، چهره‌ای، م.، و طاهرخانی، ع.(1384).تأثیر وجود آهن و کدورت بر گندزدایی آب به کمک پرتوهای فرابنفش. خلاصه مقالات هشتمین همایش ملی بهداشت محیط، دانشگاه علوم پزشکی تهران، 16.
29- APHA, AWWA, WPCF. (1989). Standard methods for the examination of water and wastewater, 17th Ed., Section 9221B, 9221C and 9221D, USA.
30- Quek, P.H., and Hu, J. (2008). “Indicators for photoreactivation and dark repair studies following ultraviolet disinfection.” J. of Industrial Microbiology and Biotechnology, 35, 533-541.
31- http://www.trojanuv.com/en/pdf/UV%20papers/CryptoGiardia.pdf, Trojan Technical Bulletin #51, (Dec. 20, 2008).