Two pilot scale simulated columns,with and without leachate recirculation,were erected to study impacts of leachate recirculation of traditional anaerobic bioreactor landfill on leachate ultimate treatment methods.The results indicate that recirculation can remove organic pollutants visibly,but it isn't effective to inbiodegradable components,nitrogen(N) and phosphorus(P) pollutants.After recircualted for 44 weeks,test column has a BOD_5 removal ratio of 98.5%.BOD_5/COD value of outflow is only 0.07.BOD_5/T...