[Transformation of dibutyl phthalate in bioreactor landfill]

Considering the refuse and leachate as one whole system, a conventional landfill (CL) was set as a control, transformation of dibutyl phthalate (DBP) in recirculated landfill (RL) and bioreactor landfill (BL) was studied. Results showed that DBP was detected in both leachate and refuse from CL, RL and BL. The initial DBP amount was 18.5 microg x g(-1) in the landfill refuse. In addition, the stabilization process of landfill, with sequences of BL > RL > CL, played an important role on the biodegradation of DBP in refuse. Compared to the acidic environment, the methanogenic environment was beneficial for DBP degradation. At the day of 310, refuse sedimentation rates were 7.0%, 11.9% and 24.3% in CL, RL and BL, respectively. DBP residual amounts were 2.1, 1.3 and 0.8 microg x g(-1), and its removal rates were 89.5%, 93.9% and 96.6% in the refuse from CL, RL and BL, respectively. The residual amounts of DBP with significant differences well fitted exponential decay models in CL, RL and BL. Finally, DBP biodegradation was obviously accelerated with the operation of leachate recirculation compared to the conventional operation, and it was further promoted with the introduction of methanogenic reactor.