Iranian Journal of

Background and Objectives: Conventional methods of leachate treatment are inefficient due to high pollution loads and characteristics of the leachate. In recent years, an integrated method has been developed considerably. The aim of this research was to evaluate the effect of powdered activated carbon on the treatment of landfill leachate of Kermanshah City by a columnar aerobic sequencing batch reactor.

Materials and Methods: This study was carried out in three reactors having a total volume of 2000 mL and each having an effective volume of 600 mL in the bench scale. To the reactors 2 and 3 that were similar from environmental conditions and operation point of view with reactor 1 (with no carbon powder), 5 and 10 g/L of PAC were added, respectively. The effects of different doses of PAC (0, 5, 10 g/L) and hydraulic detention times (HRT = 48, 96, 144 h) were investigated in order to remove the Chemical Oxygen Demand (COD) and ammonia nitrogen (NH₃-N) from the leachate. The efficiency was investigated using two -way ANOVA test in SPSS software (Ver. 16).

Results: The results of two-way ANOVA showed that there was a significant difference (P-value=0.001) between the removal efficiency of COD and NH₃–N at different HRTs with different doses of PAC. The highest removal efficiency achieved at HRT=144 h for COD and NH₃-N was in Reactor 1 were 50.11 ± 4.42 and 19.85 ± 1.49%; in reactor 2: 55.67 ± 1.6 and 25.7 ± 0.89%; and in reactor 3: 58.02 ± 3.99and 25.48 ± 1.7%, respectively.

Conclusion: It can be concluded that the combination of biological - activated carbon compared with the biological process, can remove COD and NH₃–N of strong sewages such as landfill leachate, although achieving standard treatments using this method is not possible.