This study evaluated the performance of swim-bed reactors combined with a novel acrylic fiber carrier biofringe conventional activated sludge (AS + BF) and the only conventional activated sludge (AS) reactors for the treatment of semi-aerobic landfill leachate. Partially stabilized leachate was characterized and termed as resistant to biodegradation due to high concentration of refractory compounds. Experiments were conducted using two 10 L laboratory-scale swim-bed reactors in parallel at room temperature (25 degrees C) and pH 7.0 +/- 0.5. The removal performance of AS + BF and AS alone in treating leachate was compared in terms of chemical oxygen demand (COD), biological oxygen demand (BOD5), total kjehldahl nitrogen (TKN), ammonia nitrogen (NH4-N), nitrite, nitrate, PO43-, colour and suspended solids (SS). Sludge reduction was achieved in AS + BF reactor. Swim bed BF efficiently removed nitrite, nitrate and phosphorus from leachate; however, the removal performance was not significant for COD and ammonia nitrogen. (C) 2011 Elsevier B.V. All rights reserved.