Elimination of Nematode Cysts and Ova from Hospital Sewage by Activated Sludge Process

Although medical wastewaters are considered as hazardous, little attention is paid to their proper management and disposal. This study conducted on two typical educational hospitals with 300 and 220 beds capacity for parasite cysts and Ova reduction by the hospital wastewater treatment plants. Samples were collected from influents and effluents of the treatment systems by grab and composite methods. Three samples were taken per week in three months by Bailenger method with concentration-flotation on 33 percent zinc sulphate was applied. Slide was prepared and observed under a microscope. Cyst count was done by Mac Master Slide. The average parasites in influent and effluent samples of Imam Hospital was 8.53 and 13.83 per liter, respectively. The Nematode larva with the highest number of 4.78 per liter from the influent and Oocyst with 7.81 per liter of the effluent of the system were determined. Similarly, in Boali Hospital the Nematode larva in influent and Oocyst in effluent were 9.06 and 10.97 per liter, respectively. Nematode larva with 5.97 and of Entamoeba histolytica with 4.12 ranked the highest number. Presence of Nematode in the wastewater influent in both hospitals under study did not match the Engelberg Guideline (less than one per liter).