The combination of Fenton process and Phanerochaete chrysosporium for the removal of bisphenol A in river sediments: Mechanism related to extracellular enzyme, organic acid and iron

In this study, Fenton process combined with bioremediation technology, as a novel treatment technology, was applied for the removal of bisphenol A (BPA) from river sediments. The removal rate of BPA reached 58.23% after 24 days of combined treatment, which was higher than those in the treatment with Phanerochaete chrysosporium (P. chrysosporium) alone (21.59%) or the Fenton treatment alone (14.48%). The degradation mechanism of BPA in treatment process was investigated. According to the analyses of pH, iron, enzyme activities and organic acids, it was found that there was a synergetic effect between Fenton process and P. chrysosporium treatment. The organic acids generated by P. chrysosporium created a better acid environment for Fenton reaction, and the ferrous iron introduced by Fenton reagents might stimulate the development of P. chrysosporium. In addition, beta-cyclodextrin (beta-CD) is a good chelating agent together with excellent bioavailability, so we investigated the influence of beta-CD on the combination treatment. Results showed that beta-CD was able to promote the combination treatment. We also obtained that the optimal dosage of FeSO4 (270 mmol/L), ratio of Fe2+ to H2O2 and dosage of beta-CD (13 mmol/L) were 0.5 mL, 1: 14 (mol/mol), 1 mL, respectively. The combined treatment under mild reaction conditions provides a new way for the removal of BPA from polluted river sediments.