Investigation and Comparison of physicochemical and microbiological parameters between compost and vermicompost producing through windrow method from aerobic digestion sludge of Hamedan wastewater treatment plant

Background & Objective: Compost production is a biological treatment process of organic solid wastes that are used to recovering and volume reducing waste and stabilization programs. The aim of this study was to compare physicochemical and microbiological parameters between compost and vermicompost producing through windrow method from aerobic digestion sludge of Hamedan wastewater treatment plant. Materials & Methods: By using the Windrow method, act to produce compost from the sludge of excreted bed of dryer sludge (lagoon) of Hamedan wastewater treatment plant and mixing with bulk materials. At the same time with this activity, vermicompost production from excreted sludge carried out by using Eisenia fetida for 15 weeks. All statistical analyses were done by SPSS software. Results: There is no significant difference in C/N ratio, pH, moisture, ash, organic matter and sodium parameters between compost and vermicompost, but there is a significant difference in Cu, Cd, Ni, Pb, Zn and temperature, carbon, nitrogen, phosphorus, magnesium, calcium, total and fecal coliform parameters between compost and vermicompost producing from aerobic digestion sludge. Also, the average concentrations of heavy metals in both compost and vermicompost produced from aerobic digestion sludge were lower than the MPC established by EPA. Conclusion: Concentrations showed that Ni and Pb, C, N, P, Mg values and microbial population of fecal coliform in producing compost is more from vermicompost and Ni and Cu, Cd, Zn amounts and microbial population of total coliform in producing vermicompost is more from compost producing. Therefore, it is concluded that both compost fertilizers could be appropriate quality for agricultural and horticultural uses