Evaluation of methylparaben removal and microbial behavior using a SBR system/Remocion de methilparabeno y comportamiento microbiano de un sistema SBR

We evaluated the variation in microbial populations and the behavior of an SBR system in the removal of methylparaben (MePB). The experimentation was carried out for 14 weeks, in three operational stages as follows: stabilization (Stage I), (Stage II = 300 [micro]gMePB/L and Stage III = 600 [micro]gMePB/L). The variation of the microorganisms was analyzed over the experimentation time along with the contact with the pollutant to be degraded, and the removal percentage of COD and MePB, with results of 88 [+ or -] 5,5% and 92 [+ or -] 7,7% respectively. Kinetic of MePB removal was evaluated to obtain the rate constant of biological degradation, [K.sub.biol]. Using these kinetic results, the effect of different concentrations of MePB and biomass on biodegradation behavior was evaluated. [K.sub.biol] ([LgSS.sup.-1][d.sup.-1]) values were obtained of 42.8 and 79 respectively; and 472 [+ or -] 38.0 [micro]gMePB/L, at biomass contents of 1466.7 and 2666.7 mgSSV/L, where [K.sub.biol] ([LgSS.sup.-1] [d.sup.-1]) values were obtained of 11.0 and 32.6 respectively.