Comparison of two biological treatment processes using attached-growth biomass for sanitary landfill leachate treatment

The objective of this investigation was to compare two biological systems u sing attached-growth biomass, for treatment of leachates generated in a typ ical municipal solid waste sanitary landfill. A moving-bed biofilm process, which is a relatively new type of biological treatment system, has been ex amined. It is based on the use of small, free-floating polymeric (polyureth ane) elements, while biomass is being grown and attached as biofilm on the surface of these porous carriers. A granular activated carbon (GAC) moving- bed biofilm process was also tested. This method combines both physico-chem ical and biological removal. mechanisms for the removal of pollutants. The presence of GAC offers a suitable porous media, which is able to adsorb bot h organic matter and ammonia, as well as to provide an appropriate surface onto which biomass can be attached and grown. A laboratory-scale sequencing batch reactor (SBR) was used for the examination of both carriers. The eff ects of different operation strategies on the efficiency of these biologica l treatment processes were studied in order to optimize their performance, especially for the removal of nitrogen compounds and of biodegradable organ ic matter. It has been found that these processes were able to remove nitro gen content almost completely and simultaneously, the removal of organic ma tter (expressed as BOD5 and GOD), color and turbidity were sufficiently ach ieved. (C) 2000 Elsevier Science Ltd. All rights reserved.