Further treatment of landfill leachate by nanofiltration and microfiltration–PAC hybrid process

Biological treatment is a commonly used process for the treatment of landfill leachate. However, with this treatment process, the permitted discharge limits cannot be consistently met, due to the recalcitrant characteristics of organic carbon in leachate. Therefore, some physico-chemical treatment technologies should be applied for the removal of inert substances, as a refining step. In this study, the main aim was to reduce the Chemical Oxygen Demand (COD) concentration of the jet-loop membrane bioreactor effluent further to meet the COD discharge limit value (700 mg COD/L) determined by the Ministry of Environment and Forestry of Turkey (MoEF). For this purpose, two different systems were used after the jet-loop membrane reactor, namely nanofiltration (NF) unit and microfiltration–powdered activated carbon (MF–PAC) hybrid system. The membranes used in the NF unit were not able to reduce the COD concentration to the desired levels. However, the MF–PAC system achieved to meet the COD discharge limit value, when 8 g PAC/L concentration was used.