The effect of humic acids on the reverse osmosis treatment of hazardous landfill leachate

► We studied treatment of leachate from landfill placed in former open-cast coal mine. ► The leachate was treated by reverse osmosis with emphasis to humic acids content. ► Removal of total dissolved solids from landfill leachate was 99.3% on average. ► Permeate flux and rejection decreased with increasing concentration of humic acids.