Investigation the effectiveness different coagulants in the country for the treatment of sewage sludge

Background and Aim: In order to reduce investment and operating expenses Stabilization sludge treatment plant is necessary, sludge in wastewater treatment plants is reduced as much as possible. . The modified sludge is easily concentration, thus preparing sludge is important . The aim of this study was to evaluate the effectiveness of different coagulants in the country's for condense municipal sludge. Materials and Method: In this project plant south of Tehran, were selected for sampling and. samples consisting of a mixture of primary and secondary sludge settling pond and with the container at 4 ° C in the laboratory, Faculty of Health Sciences it was the transfer of medical shahid beheshti. Materials sludge coagulants that were tested include aluminum sulfate (alum), ferric chloride, poly aluminum chloride and ferric sulfate. Results: The results showed that the ferric iron had highest efficiency in the sludge dewatering. Aluminum sulfate was least effective in the sludge dewatering. The mean of PH was 7.66 and the mean of TSS was 3405.5. the mean of solid materials sedimentation was 1343 ml per liter and the mean of VS sludge was equal to 56.5. Cnclusion: Among the various methods of sludge dewatering using chemicals because of the low cost of materials is a good option for treatment. But chemicals in the production of sludge can increase the production of sludge that is required to select the best material to reduce the sludge. But as the results show that the iron sulfate sludge reduction is the best female performance.