Identifying Parasites in the Outlet Sludge of Industrial Wastewater Treatment Plant: A Case Study in Babolsar, Iran

Background and Sewage sludge can supply nutrients and improve soil condition. However, presence of microorganisms, particularly parasites could cause a variety of diseases in humans and animals. This study aimed at identifying parasites in the waste sludge of industrial sewage in Babolsar, north of Iran and comparing their concentration with the EPA standards.
Sampling was conducted in the sludge sewage treatment plant in one industrial town from four sludge depot during six months. Nine samples were taken from each depot. In order to identify the parasites McMaster slide was used according to Bailenger method.
This study showed that the average numbers of helminth eggs in pallets 1, 2, 3, and 4 were 4.42, 17.52, 7.65, and 7.3 per 4 grams dried sludge, respectively. The greatest numbers of helminth eggs, was associated with Toxocara and Hymenolepis diminuta.
In current investigation, the number of helminth eggs in the sludge was higher than that suggested by the EPA standards. The sludge studied was industrial, therefore, the possibility of parasitic infection caused by people is low. On the other hand, the numbers of Hymenolepis diminuta and Toxocara were high. As a result, the possibility of secondary pollution due to movement of animals is high.