Study of the ibuprofen impact on wastewater treatment mini-plants with bioaugmented sludge

The determination of the peak volumetric removal rate of ibuprofen in batch culture was used to select a microbial community utilizable for augmentation. For a continuous removal process, this rate, particularly the peak value of the volumetric removal rate is an essential factor reflecting the catabolic behavior (metabolic quotient q_S) and the physiological state of a microbial community which depends on environmental conditions. Thus, if stable environmental conditions are maintained in a homogeneous continuous regime, a high metabolic quotient and volumetric removal rate could be maintained for the selected microbial community. Using equations derived from the material balance of ibuprofen in a wastewater treatment mini-plant (WTMP) operating in a homogeneous condition, the beginning and end of an acclimatization period after an IBP toxic shock were estimated by comparison of the experimental values of IBP accumulated to its theoretical accumulation. Using the experimental values of IBP accumulated within the WTMP, the actual transient change in the volumetric removal rate along the acclimatization period was calculated from another derived equation. This procedure allows to measure the change in the volumetric removal rate, showing the kinetic response of the system and the acclimatization time of a microbial consortium after a toxic shock.