Fabrication and Evaluation of anaerobic baffle reactor for leachate treatment of Sari province

Landfill leachate has been identified as a potential source of ground and surface waters contamination due to the generation of leachate. Further, landfill leachate may percolate through soils and cause the large pollution of streams, creeks and water. Hence, the aim of this study is to evaluate the performance of a laboratory-scale ABR in different COD concentrations and hydraulic retention time for COD removal.
In this research, an anaerobic baffle reactor (ABR) was used for biological landfill leachate treatment. The ABR was 10 cm wide, 60 cm long, and 10 cm depth and was constructed from Perspex with an effective volume of 6 L. The ABR was seeded with anaerobically digested sewage sludge taken from an anaerobic digester of a wastewater treatment plant in Qaemshahr city. Landfill leachate used in this study was collected from a landfill leachate waste municipal site located in Kiasar, Sari. The experiments used in this study were chemical oxygen demand (COD), pH, suspended solids (SS) and alkalinity.
Findings: The anaerobic baffle reactor (ABR) has been have an appropriate performance for COD removal of landfill leachate. Also, the results showed that this reactor presented an acceptable capability of pH control and acidogenic microorganism separation from others. On the other hands, the results demonstrated that an alkalinity remained at the desirable level in the reactor and it is not necessary to add chemical materials to control it. Moreover, the suspended solids were significantly removed in this reactor.
Discussion and The obtained results indicated that the highest COD removal (86%) was achieved at the HRT of 2 days where the COD concentration of 2700 mg/L was reduced to 380 mg/L. Furthermore, the system performance at lower hydraulic retention time was decreased. At the COD concentration of 2700 mg/L, 70% decrement of the reactor efficiency was observed by decreasing hydraulic retention time to 12 hr.