This study investigates the photoassisted processes, namely direct photolysis (DP), heterogeneous photocatalysis (HP) and photoelectrolysis (PEC), in 2,4,6-Tribromophenol (TBP) abatement, mineralization and debromination. Electric energy per order (E-EO), degradation kinetic (k'), half-life time (t(1/2)) and toxicity were also evaluated. The results showed that the direct photolysis process is an important TBP debromination and oxidation pathway. However, the DP process leads to higher by-product formation, presenting phytotoxicity and genotoxicity. The hydroxyl radical based processes (HP and PEC) showed higher mineralization and also decreased toxicity. This indicates that hydroxyl radicals based processes represent a chief route for diminishing the overall environmental impact of TBP. (C) 2017 Elsevier Inc. All rights reserved.