Study the efficiency of the combined system of coagulation and flocculation/ozonation in treatment of fresh landfill leachates in Tabriz city

Fresh leachate has a low pH and high amounts of BOD and COD which are mainly constituents with low weight molecular such as volatile fatty acids (acetic and propionic acids). Management and treatment of leachate is an important subject in sanitary landfill operation and performance.Th objective of this study is determining the efficiency of the integrated coagulation –flocculation and ozonation processes in fresh leachate treatment of Tabriz city.

Quantitive parameters of pH, BOD5, COD, alkalinity and TSS were studied based on standard methods.The study emphasizes of COD and TSS leachate removal.Alum, ferric chloride and PAC had been used as coagulants.

Results indicated the superiority of Ferric chloride at the dosage of 1 g/l in pH 10, which reduced 34% of COD and 54% of TSS.in the stage of ozonation the leachate sample coagulated by ferric chloride was treated by 3 g/h ozone gas at optimum pH and after 39 hours ozonation about 51% of COD and 18.2 % of TSS were reduced.

This study clearly indicates that there would be need to apply biological treatment (after coagulation – flocculation) and ozonation, various advanced oxidation processes and / or other treatment methods for further reduction of COD in leachate and meeting discharge standards.