Full Length ArticleKinetic study of the effect of bisphenol A on the rates of organic matter removal, decay and biomass generation in a membrane bioreactor

- Effect of bisphenol A on heterotrophic biomass of MBR was analyzed by respirometry.
- Rates of organic matter removal and heterotrophic growth increased with bisphenol A.
- Shock additions of bisphenol A reduced decay rate for heterotrophic biomass.
- No inhibitory effect was detected on heterotrophic biomass in presence of bisphenol A.
- Temperature was the variable with the highest influence on the heterotrophic kinetics.

This study analyzed the effect of bisphenol A (BPA) on the kinetic behavior of the heterotrophic biomass of a membrane bioreactor (MBR) treating municipal wastewater in order to determine possible variations in the rates of organic matter removal, decay and biomass generation. Four operation phases were analyzed in the steady state at different values of hydraulic retention time (6-10 h), mixed liquor suspended solids (4000-7000 mg L−1), temperature (12.1-31.1 °C), and sludge retention time (9.81-21.67 day). A respirometric procedure was used to model the kinetic behavior of heterotrophic biomass contained in the MBR in absence and presence of BPA, and a multivariable statistical analysis was applied to determine the effect of the variables on the substrate degradation rate for organic matter removal (rsu,H), decay coefficient for heterotrophic biomass (bH), and net heterotrophic biomass growth rate (ŕx,H). The results showed that there was no inhibitory effect of BPA on heterotrophic biomass, with higher values of rsu,H and ŕx,H, and lower values of bH in presence of BPA. Heterotrophic biomass from phase 2 showed the highest values of rsu,H (190.22 mgO2 L−1 h−1), bH (0.1304 day−1) and ŕx,H (170.68 mgVSS L−1 h−1) in presence of BPA due to its higher temperature (31.1 °C).