Effect of layers composition on leachate property from functional layer embedded landfill

Two functional layers embedded landfills (FLELs), namely LR1 (with Layers 1 and 2) and LR2 (with double Layer 1), were conducted to evaluate their efficiency on the reduction of leachate strength at source and the acceleration of waste biodegradation process. It was found that the cumulative COD, NH3–N, leachate quantity and landfill settlement in LR1 was 63.0%, 34.6%, 94.8% and 80.4% of that in LR2 in the entire test periods, while the leachate effluents from these two reactors presented almost the same concentration at the end of the operation period. It could be concluded that leachate pollutants was removed immediately in Layer 2 through the physical–chemical reaction, while double Layer 1s contributed to the pollutant removal in a long run through the improvement of the micro-organism activities in landfill. The layer composition should be applied according to the landfill types, i.e. plain landfill using Layer 2 and valley landfill using Layer 1.