Degradation of 1,2,3-trichloropropane in aqueous solution by ZVI-enhanced Fenton system: Performances and mechanisms

In this research, zero-valent iron (ZVI) was chosen as a reductant in the classic Fenton system to accelerate the generation of Fe(II). The removal of 1,2,3-trichloropropane (TCP) was only 65.3% in classic Fenton system, while with the addition of ZVI its removal could be enhanced to 95.4% in 120 min. Hydroxyl radicals (HO center dot) was confirmed to be the major radical during TCP degradation by electron paramagnetic resonance (EPR) detection and radical quenching tests. Moreover, the mechanism of TCP degradation in H2O2/Fe(II)/ZVI system was proposed. In the presence of ZVI, Fe(III) was reduced to Fe(II), further reacted with H2O2 and produced more HO center dot for TCP removal. 2,3-Dichloro-1-propene and 2-chloro-2-propen-1-ol were the main intermediates in TCP degradation and two possible pathways were proposed. Finally, TCP removal in different solution matrixes and for other chlorinated contaminants removal were tested, revealing the broad-spectrum reactivity and excellent performance of ZVI-enhanced Fenton system in the remediation of chlorinated organic compounds.