Introduction: The presence of pathogenic microbial agents and pathogens in organic fertilizers causes health problems and disease transmission. The aim of this study was to evaluate the efficiency of vermicomposting process in improve the microbial quality of the compost produced.
Materials and Methods: This experimental study was conducted as a pilot-scale one, in the laboratory of school of Health. In order to produce vermicompost, some perishable domestic waste were mixed whit sludge of wastewater treatment plant in a reactor. Tests to determine the microbial quality of the product were carried out at an early stage, during the process of production, and on the final product. The worms used for the production of vermicompost were Eiseniafotida worms.
Results: According to the results of this study, a significant decrease was observed in the number of fecal coliforms in Sludge- domestic waste; as the number of fecal coliforms reduced from 7500000 (MPN/g), in the raw sample, to 1500 (MPN/g), eight weeks after the outset. Removal efficiency of fecal coliforms was 99.98 percent. Moreover, according to the obtained results, the mixture of Sludge and domestic waste had some parasite eggs (22 number/gr) in the raw samples. This amount was fully removed by the process of vermicomposting, during the forth week.
Conclusion: The results showed that earthworms are a great ability to remove pathogens but to reach the standard set in mixed microbial treatment sludge - waste can not be sure.