Investigation of Biodegradation and Environmental Fate of Tetrabromobisphenol A (TBBPA) in Guelph Municipal Wastewater
Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant that has endocrine disrupting properties. As such, research was completed to evaluate the environmental fate, kinetics and biodegradation of TBBPA in conventional activated sludge (CAS) and membrane bioreactor (MBR) systems at the Guelph municipal wastewater treatment plant. In addition a robust analytical method for measuring TBBPA at environmental levels was developed using gas chromatography-negative ion chemical ionization-mass spectrometry (GC-NCI-MS). The wastewater influent contained TBBPA concentrations in the range of 10 ng/L to 145 ng/L. The removal of TBBPA for CAS and MBR processes were 83% and 76%, respectively, during the study period. The matrix effects were shown to be (79.2±4.5) % (n=10) and (36.5±5.9) (n=10) respectively, for activated sludge mixed liquor and influent wastewater. A novel biodegradation method for quantifying aerobic biodegradation of TBBPA has been established. The degradation rate constants Kbio of CAS and MBR sludge systems were 0.134 d-1 and 0.168 d-1 respectively. A number of partitioning coefficients were experimentally determined to develop a fate model. The experimental data were fitted to multiple isotherm models in order to establish the environmental fate and partitioning and removal of TBBPA from wastewater.