The use of sewage sludge as fertilizer in agriculture is a convenient and economic solution, but it is
essential to monitor presence of parasitic contamination. This study investigated parasites in sewage sludge of wastewater
treatment plant in Gorgan, Iran. This descriptive-analytical study was performed on 18 sewage sludge samples collected
from wastewater treatment plant of Gorgan within 6 months with three repeatitions per month. The samples were analyzed
in the laboratory of School of Public Health at Golestan University of Medical Sciences. Analysis of parasites was done
using Bailenger method of counting parasites in chamber of McMaster slides with volume of 0.3 ml. The results showed
that majority of parasite eggs in the sewage sludge was related to nematodes. The dominant nematode eggs detected were
related to
Ancylostoma duodenale,
Necator americanus
and
Enterobious vermicolaris. However, no parasite was found
in dried sewage sludge. Considering the amount of parasite eggs in the returned sludge, it is necessary to modify the
treatment process. However, it is permissible to use dried sewage sludge as agricultural fertilizer.
