摘要：In consideration of the high concentration of ammonia and refractory organics, co-metabolic biotreatmentsystem of old landfill leachate after bio-nitrification was constructed in ASBBRs with nitrate-N asgrowth substrate. Under the conditions of 0.25 kg COD/(m3·d) and 0.20 kg NO3--N/(m3·d), the degradationrates of chemical oxygen demand (COD), total organic carbon (TOC), NO3--N and colour index, afterthe operation for 67 d were 67.60%, 53.78%, 45.54% and 53.57%, respectively, while the BOD5/CODvalue of old landfill leachate was 0.068. Analyses of molecular weight cut off (MWCO) showed thatmicro-molecular refractory organics of 5~10 KDa in inflow were effectively degraded, of which partsof organics became more difficult to be biodegraded with smaller molecular weight. Fourier transformsinfrared spectroscopy (FTIR) analysis demonstrated that aldehydes, aliphatics, phenols and alcohols,etc. decreased and O-H functional group increased in the effluent. A majority of bacteria in the cometabolic system were discovered to be globular and short-bar-shaped, with a few disc-shapedbacteria by scanning electric microscopy (SEM) testing. Moreover, benzene and toluene, as particularpollutants in old landfill leachate, were researched in different co-metabolic systems with nitrate-N.The result showed that the dehydrogenase concentration might accelerate the degradation of refractoryorganics.
