Landfill leachate treatment - towards an integrated approach

Abstract

Full-scale results during two years operation in a controlled activated sludge system with
nitrogen removal show that nitrification can be managed around the year, even long periods at
low temperature ( 4 - 5 °C), which is a new feature in landfill leachate management. The total
nitrogen removal was 46 - 57 % as annual averages and was limited seasonally by the low
carbon content of leachate, Addition of external carbon was also tested. The removal of
heavy metals was reasonable (45 - 90 %), but organohalogen compounds was removed only
partially (around 20 %). The biological step suits for the first phase of local treatment and
rather low costs can be achieved. If more stringent effluent standards are required, a post
treatment system can be added - some of the most suitable alternatives and their costs are
discussed. From environmental point of view more comprehensive alternatives should be
considered, which means the integration of processes inside the landfill body to the whole
treatment system.