A Comparison of the Efficiency of Natural Wastewater Treatment Plants in Removal of Protozoan Cysts and Parasitic Eggs

Document Type : Research Paper



One of the most important quality characteristics associated with wastewater reuse in agriculture, which takes into consideration, is the microbial quality. The aim of this study is determination of efficiency of wastewater treatment plants in removal of protozoan cysts and parasitic eggs of Ghasreshirin (constructed wetland), Islamabadgharb and Gilangharb (stabilization ponds). This study was accomplished during six months and sampling was done from inlet and outlet of wastewater Plants, as weekly. Totally, 144 samples were investigated for parasitic analysis with Bailenger method by Mac Master Slide (with a hole size 0.3 ml). The findings showed that mean of removal efficiency in constructed wetland for  parasitic eggs and protozoan cysts are %99.7±0.23 and %100  respectively, but, any parasitic eggs and protozoan cysts in outlet effluent of  both of wastewater  stabilization ponds were not observed, so removal efficiency of these two parameters in these systems was %100 obtained. Ascaris lumbricoides eggs had most number of parasitic eggs in inlet wastewater   and outlet effluent of all three wastewater treatment plants. According to the results, the efficiency of all three wastewater treatment plants  in terms of removal of cysts and parasitic eggs are desirable and there was no significant difference between them (Pvalue>0.05). The outlet effluent quality of them in terms of nematode eggs rate is consistent with Engelberg index (number of nematode eggs: 1 ≥ number per liter).


1- Tchobanoglus, G., and Burton, F.L. (2003). Wastewater engineering, 4th Ed., McGraw Hill, Metcalf and Eddy, New York.
2- Donald, R., and Rowem, I. (1995). Handbook of wastewater reclamation and reuse, 1th Ed., CRC Press, Boca Raton.
3- Weizhen, L.u., and Andrew, A.Y. (2003). “A Preliminary study on potential of developing shower/aundry wastewater reclamation and reuse system.” Chemosphere, 52, 1451-1459.
4- Papaiacovou, I. (2001). “Case study-wastewater reuse in Limassol as an alternative water source.” Desalination, 138, 55-59.
5- Kalavrouziotis, I.K., and Apostolopoulos, C.A. (2007). “An integrated environmental plan for the reuse of treated wastewater effluents from WWTP in urban areas.” Building and Environmental, 42, 1862-1868.
6- Carr, R. (2005). Guideline for safe wastewater use –more than just numbers, irrigation and drainage, WHO., California, America.
7- Bitton, G. (2005). Wastewater microbiology, 3th Ed., John Wiley and Sons, Inc., Hoboken, New Jersey.
8- Palese, A.M. (2009). “Irrigation of olive groves in Southern Italy with treated municipal wastewater: Effect on microbiological quality of soil and fruits.” Agriculture,Ecosystems and Environment, 129, 43-51.
9- Lubello, C. (2004). “Municipal-treated wastewater ruse for plant nurseries irrigation.” Water Research, 38, 2939-2947.
10- Gupta, N., Khan, D.K., and Santra, S.C. (2009). “Prevalence of intestinal helminth eggs on vegetables grown in wastewater-irrigated areas of Titagarh, west Bengal, India.” Food Control, 20, 942-945.
11- Miranzadeh, M.B., and Mahmoudi, S. (2002). “Investigation into the removal of nematodes eggs in influent and effluent of shoosh wastewater treatment plant.” J. of Water and Wastewater, 42, 32-36. (In Persian)
12- Patricia, M., Ivan, B., Gemma, A., and Estanislao, D. L. (2008). “Removal of wastewater pathogen indicators in a constructed wetland in Leon, Spain.” Ecological Engineering, 33, 252-257.
13- Matteus, F.A. (2000). Water management and conservation in arid climates, Technomic Publishing, USA.
14- Molleda, P., Blanco, I., Ansola, G., and  Luis, D.E. (2003). “Removal of wastewater pathogen indicators in a constructed wetland in Leon, Spain.” Ecological Engineering, 33, 252-257.
15- Rachei, M., and Mara, D. (1996). Analysis of wastewater for use in agriculture-A laboratory manual of parasitological and bacteriological techniques, WHO, USA.
16- Mahvi, A.H., and Kia, E.B. (2006). “Helminthes eggs in raw and treated wastewater in the Islamic Republic of Iran.” Eastern Mediterranean Health, 12, 137-143.
17- Arbabi, M., and Zahedi, M. R. (1998). “Performance evaluation of stabilization ponds in urban wastewater treatment (in cooling climate).” Second Congress of Environmental Health, University of Medical Sciences, Kerman, Iran. (In Persian)
18- Jimenez, B. (2007). “Helminthes (worms) eggs control in wastewater and sludge.” International Symposium on New Directions in Urban Water Management, UNESCO, Paris.
19- Zamo, A.C., Belghyti, D., Lyagoubi, M., and Elkharrim, K. (2003). “Parasitological analysis of the untreated wastewater of the Ville Haute’ urban emissary (Maamora district, Kenitra, Morocco).” U.S. National Library of Medicine National Institutes of Health, 13(4), 269-272.
20- Amahmid, O., Asmama, S., and Bouhoum, K. (2001). “Urban wastewater treatment in stabilization ponds: Occurrence and removal of pathogens.” Urban Water, 4(3), 252-262.
21- Grimason, A.M., Wiandt, S., Baleux, B., Thitai, W.N., Bontoux, J., and Smith, H.V. (1996). “Occurrence and removal of Giardia sp. cysts by Kenyan and French waste stabilization pond systems.” Water Sci. Technol., 33 (7), 83-89.
22- Ellis, K. V., Rodrigues, P. C. C., and Gomez, C. L. (1993). “Parasite ova and cysts in waste stabilization ponds.” Water Research, 27 (9), 1455-1460.
23- Ben Ayed, L., Schijven, J. A., Jemli, Z., and Sabbahi, S. M. (2009). “Presence of parasitic protozoa and helminth in sewage and efficiency of treatment in Tunisia.” Parasitol Res., 105, 393-406.
24- Reinoso, R., Alexandra Torres, L., and Bécares, E. (2008). “Efficiency of natural systems for removal of bacteria and pathogenic parasites from wastewater.” Science of Total Environmental, 34, 80-86.