Effects of different valence forms of iron on 2,4,6-trichlorophenol degradation by anaerobic microorganism

Abstract:

[Objective] In the condition of initial pH ranging from 5.0?10.0, the influence of different valence forms of iron (Fe0, Fe2+ and Fe3+) on 2,4,6-trichlorophenol (2,4,6-TCP) degradation by anaerobic microorganism was studied. [Methods] A batch test in the laboratory was conducted by the addition of Fe0, Fe2+ or Fe3+ in the anaerobic system, through inoculating the anaerobic mixed microorganism acclimated for three months. 2,4,6-TCP concentration, pH value, iron ion concentration and microbial dehydrogenase activity was measured. [Results] When the initial pH value is neutral or acidic, the Fe2+-microorganism system could exert an accelerative effect on the 2,4,6-TCP degradation than the others, while the initial pH value is alkalic, the “Fe0-microorganism” system has better performances on the 2,4,6-TCP degradation than the others; each of the “Fe0/Fe2+/Fe3+-microorganism” system has the ability to adjust pH, furthermore, the “Fe0-microorganism” system performs better; in the condition of different initial pH values, the influence of different valence iron on anaerobic microbial activity and 2,4,6-TCP degradation are the same. [Conclusion] The influence of different valence forms of iron on 2,4,6-TCP degradation by anaerobic microorganism is related to the factors such as initial pH value, real-time pH value, iron valence and its concentration.