ENHANCED BISPHENOL A BIODEGRADATION BY Pseudomonas sp. IN THE SURFICIAL SEDIMENTS EXTRACTED WITH (NH_4)_2C_2O_4

摘要

Biodegradation experiment of bisphenol A (BPA) by Pseudomonas sp. in the surficial sediments (SSs) before and after treatment with (NH_4)_2C_2O_4 was carried out. Degradation kinetics and reaction rate constants for BPA were calculated and discussed, and BPA-degrading characteristics of Pseudomonas sp. under different BPA levels, different amounts of SSs and inoculum size were also investigated in detail. The results indicated that BPA-degrading activity and cell growth were inhibited by the increased initial BPA concentration, while the degradation rate of BPA was significantly elevated with the rise of concentrations of SSs, as well as inoculum size. Under the conditions of 10 mg/L of BPA, 40 ml/g of the SSs and 8.0% of inoculum size, ca. 54.6% of BPA were biodegraded in the systems of SSs-water. In addition, the effects of main components of SSs on BPA biodegradation were compared. The comparative results showed that only the SSs treated by (NH_4)_2C_2O_4 reagent, which notably removed Fe oxides and Mn oxides, had positive effects on the degradation rate of BPA during the BPA biodegradation process, and the amount of BPA biodegradation was 65.1%. Therefore, Fe/Mn oxides were likely to have adverse effects on Pseudomonas sp. activity in the biodegradation of BPA.