Enhancing the biodegradation of ibuprofen through factor analysis and kinetic modeling

Abstract

Ibuprofen ranks as one of the most frequently detected pharmaceutical pollutants in water across many countries. Previous studies identified conditions for actinobacterial degradation of ibuprofen and developed a chromatographic analysis technique, enabling the measurement of residual ibuprofen levels during biodegradation. However, the impact of a complex interplay of factors on the dynamics of ibuprofen biodegradation remains insufficiently explored. The objective of this study was to enhance the biodegradation process of ibuprofen through a multifactorial experiment that controled key parameters and to predict changes in substance content and the time needed for process optimization using kinetic modeling. As a result of this study, varying the concentrations of glucose, n-hexadecane, inoculum, and pH values has enabled a remarkable reduction in the biodegradation process duration for ibuprofen (0.1 g/L), from 10 days to just 2 days when employing cosubstrates in quantities of 1.0 g/L, 10.0 ml/l, and adhering to the turbidity standard NTU-5, along with pH stabilization at 6.5. By applying the kinetic equation of the first-order derivative, dx/dt = –k x-1, we determined the parameter ‘k’ for the ibuprofen biodegradation rate to be 138.88÷146.84%2/h. The half-life (t1/2) was calculated as 25.54÷27.00 hours, and the process’s endpoint, t1/100, was refined to 34.05÷36.00 hours under the optimized conditions.