Nanofiltration applied to the landfill leachate treatment and preliminary cost estimation

The leachate treatment by nanofiltration (NF) process has received much attention over the last two decades. Previous studies focused on the investigation of the technical feasibility of NF. However, there are a limited number of works that examined leachate treatment costs. On the other hand, in a landfill management system, the economic component is an imperative factor for the decisions of all operations. Thereby, this work aimed to investigate the technical feasibility and economic parameters involved in a full-scale NF plant for the treatment of leachate previously treated by the physicochemical process. The average quality of the pre-treated leachate was 2258 ± 230 mg L^-1 chemical oxygen demand (COD) and 821 ± 86 mg L^-1 humic substances (HS). NF was performed using a bench-scale filtration module with commercial polymeric membranes SR100 and NP030. At the end of each filtration, a cleaning protocol was applied to recover the initial membrane permeability. The concentration of recalcitrant compounds, expressed as HS, was reduced to 84 ± 8 mg L^-1 in the permeate, and COD complies with the wastewater discharge standards imposed by local legislation. The capital costs for a full-scale NF was estimated at MUS$ 0.772, and specific total cost, treated leachate per volume unit, has been estimated at US$ 8.26 m^-3.