Removal of dibutyl phthalate from refuse from different phases of landfill in the presence of its dominant bacterial strains

The degradation of dibutyl phthalate (DBP) before and after inoculation with its dominant bacterial strains in refuse collected during the initial, acidic and methanogenic phases of landfill was evaluated. The results showed that the degradation of DBP fit first-order kinetic models for refuse in different phases with rate constants of 0.0140-0.0187 d(-1) and degradation half-lives of 37.1-49.5 d. DBP was degraded fastest in methanogenic phase refuse and slowest in acidic phase refuse, and pH was found to be the key factor influencing DBP biodegradation. The effects of different concentrations of DBP on its degradation were not obvious. Compared with the CK, the removal of DBP from methanogenic phase refuse increased from 60.3% to 74.5%, 72.4% and 87.3% when Enterobacter T1, Enterobacter T5 and mixed bacteria inoculated. The intermediate products including monobutyl phthalate (MBP) and phthalic acid (PA) were detected in the refuse. The degradation phase of a landfill determines the mineralization extent of DBP, and the major removal of DBP occurred under methanogenic condition. (C) 2014 Elsevier B.V. All rights reserved.