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

Abstract 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 (r su,H ), decay coefficient for heterotrophic biomass (b H ), and net heterotrophic biomass growth rate (ŕ x,H ). The results showed that there was no inhibitory effect of BPA on heterotrophic biomass, with higher values of r su,H and ŕ x,H , and lower values of b H in presence of BPA. Heterotrophic biomass from phase 2 showed the highest values of r su,H (190.22 mgO 2  L −1  h −1 ), b H (0.1304 day −1 ) and ŕ x,H (170.68 mgVSS L −1  h −1 ) in presence of BPA due to its higher temperature (31.1 °C).