Study on the Efficenciy of Raw Sludge Composting by Aerated Static Pailes
Composting of sewage sludge using aerated static piles is a simple and cheap method for sludge stabilization. The
main purpose of this study was to determine the feasibility of sewage sludge stabilization by aerated static piles composting
designed for Tehran Southern Sewage Treatment Plant in Iran. This research has been completed in four steps through a
bench scale in the environmental health laboratory of Tehran medical sciences university over 12 months. The results of this
research demonstrated that this process has significant ability of sludge stabilization, if mixing of dewatered sludge with
sawdust and wood chips with the volume ratio of 1: 1.8. Microbial quality of producing compost was evaluated as the class
A of USEPA standards for agricultural uses. Initial estimate of capital and annual costs for a 25 years project consisting of
composting and anaerobic digestion units indicated that the present value of composting method is less than half of the
present value of anaerobic digestion method for Southern Tehran Sewage Treatment Plant.
Keywords: Sludge Stabilization, Composting, Tehran Sewage.