Enhanced tris-(2-chloroisopropyl) phosphate degradation through ultraviolet driven peroxymonosulfate process: Kinetics, mechanism, residual toxicity assessment of intermediates products by proteomics

Highlights: • A well removal performance on TCPP was realized via SO₄⁻ based AOPs treatment. • Degradation products involved in hydroxylation and dechlorination were proposed. • Toxicity of TCPP was weakened via oxidation treatment by proteomics analysis. • Metabolism network of E. coli was interfered by degradation intermediates of TCPP. • An incomplete mineralization is feasible and safe for TCPP elimination. Tris-(2-chloroisopropyl) phosphate (TCPP), one of emerging organic pollutants has aroused a growing concern due to its potential biotoxicity and persistence. Oxidation degradation of using SO₄*⁻ based AOPs was explored. A pseudo-first order kinetics reaction with the degradation rate constant at 0.1789 min⁻¹ fitted the transformation of TCPP. SO₄*⁻ was the predominant oxidation species confirmed by scavenging assay. Five steady intermediates including C₆H₁₃Cl₂O₄P (m/z 251.0002), C₃H₈ClO₄P (m/z 174.9922), C₉H₁₇Cl₂O₅P (m/z 307.0266), C₉H₁₇Cl₂O₆P (m/z 323.0217), C₆H₁₂ClO₆P (m/z 247.0134) were screened by high resolution mass spectroscopy analysis. The influences of vital parameters, i.e., natural anions, pH value, humic acid (HA) and peroxymonosulfate (PMS) dose were tested. HA and alkaline conditions can significantly decreased the photocatalytic rate to inhibit removal efficiency. EE/O evaluation had also proved that a neutral condition and HA pretreatment were conductive to elevating removal efficiency and reducing energy consumption. Based on proteomics and metabolic network analysis, TCPP was effectively detoxified as its further transformation proceeded, which was proved by nucleotide metabolisms, citric acid metabolism, oxidative phosphorylation and amino acid biosynthesis. To summarize, an appropriate degradation of TCPP likewise are effective for its detoxification, indicating the feasibility and security of TCPP elimination using UV/PMS treatment.