Amir Hossein Mahvi, Ghasem Kiani feizabadi, Mohammad Hadi Dehghani, Sajad Mazloomi
School of Public Health and Center for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran
Department of Environmental Health, Faculty of Health, Semnan University of Medical Sciences, Semnan, Iran
Key words: Leachate, Compost, Coagulant, Pretreatment.
Leachate is an important pollution factor resulting from composting plant. The method applied to treat leachate is highly dependent on the characteristics of the leachate. One of the most common and simplest methods is using coagulation process. This study was aimed to compare the efficiencies of different coagulants which include ferrous sulfate, ferric chloride, poly ferric sulfate, alum and poly aluminum chloride along with two anionic and cationic commercial co-coagulants (K350CF and LT25) in removing chemical oxygen demand (COD) and total suspended solid (TSS) from the leachate generated in a composting plant. Leachate samples were collected from the Isfahan composting leachate´s collection ponds. In this study, jar-test experiments were carried out to determine the optimum conditions for the removal of COD and TSS, effective dosage, optimum pH and the most convenient coagulant. According to the results, poly ferric sulfate resulted in the highest COD and TSS removal at pH= 11, with 2 g /L of coagulant. At this experimental condition, COD and TSS removal efficiencies were obtained 49% and 51% respectively. Results also showed that using K350CF and LT25 along with coagulants can improve COD and TSS removal and PFS along with K350CF had the highest removal efficiency. Based on obtained results, it may be stated that Coagulation-flocculation can be used as a simple and efficient pretreatment in which composting leachate is processed for better and more convenient treatments during the following stages.
Get the original articles: http://www.innspub.net/volume-6-number-6-june-2015-jbes/