Advances in Tetrabromobisphenol A (TBBPA) degradation: A comprehensive review of physicochemical and biotechnological strategies

Tetrabromobisphenol A (TBBPA), a widely-used brominated flame retardant, poses significant risks to the environment and human health due to its persistence, bioaccumulation, and toxicity. Although numerous remediation strategies have been developed, their comparative effectiveness requires systematic assessment. This review summarizes current physical, chemical, and biological approaches for TBBPA degradation. Adsorption can effectively remove TBBPA from aqueous solutions, yet this approach only achieves pollutant transfer rather than elimination. Pyrolysis and photodegradation can effectively decompose TBBPA, but their practical applications are constrained by the formation of hazardous by-products (e.g., dioxins) and challenges related to photocatalyst recovery. Chemical reduction and oxidation can effectively debrominate or mineralize TBBPA. However, these processes often generate toxic intermediates like bisphenol A (BPA), introducing secondary environmental risks. Compared to physicochemical methods, biological treatments offer a more sustainable and cost-effective alternative for TBBPA remediation. Under anaerobic conditions, TBBPA undergoes reductive debromination, primarily converting to BPA with limited mineralization (<5 %). In contrast, aerobic degradation pathways, including hydroxylation and ring-opening, improve mineralization to approximately 20 % but is constrained by substrate concentration. Sequential anaerobic-aerobic processes combine the advantages of reductive debromination and oxidative mineralization, significantly improving TBBPA degradation efficiency. For physicochemical technologies, future research should prioritize process optimization and the development of high-performance catalysts to improve TBBPA degradation kinetics while reducing the formation of toxic by-products. In parallel, biological treatment efforts should focus on isolating robust microbial strains and identifying effective electron donors that enhance microbial activity and degradation efficiency. The integration of physical, chemical, and biological technologies will be essential for achieving efficient and sustainable TBBPA remediation.