Fate of 2,4,6-Tribromophenol in Soil Under Different Redox Conditions

Fate of 2,4,6-tribromophenol (TBP) in environmental matrices is obscure. We used 14C-tracer to investigated mineralization, transformation, and non-extractable residue (NER)-formation of TBP in a soil under continuously oxic, continuously anoxic, and anoxic–oxic alteration conditions. In all cases, TBP rapidly dissipated, mineralized to CO2, and formed NERs in the soil. Considerable amounts of transformation products (2–12%) were detected during the incubation. Marked mineralization (13–26%) indicated that soil microorganisms used TBP as their energy source. About 62–70% of the initial radioactivity was transformed into NERs, being mainly attributed to binding to humic and fulvic acid fractions. TBP transformation was significantly faster under oxic conditions than under anoxic conditions, and was boosted when the soil redox changed from anoxic to oxic state. The results provide new insights into fate of TBP in soil and suggest the importance to evaluate the stability of NERs for risk assessment of TBP in soil.