Performance and bacterial compositions of aged refuse reactors treating mature landfill leachate

► First attempt to use microbial pyrosequencing technology to study microorganism communities in aged refuse bioreactor. ► Medium and temperature were the main determinants of bacterial community structure in the bioreactors. ► Sequential treatment with aged refuse biofilter and slag biofilter could remove pollutants from mature leachate efficiently. ► Effluent recirculation can stabilize microbes in biofilters, and alleviate the low temperature effect on pollutant removal.