Degradation of 2,4,6-trichlorophenol Treated with Nanoscale Zero-valent Iron/Anaerobic Sludge System

Pulping and papermaking wastewater contains chlorinated aromatic substances,which have serious impact on environment.Chlorinated aromatic substances reduction in nano zero-valent iron/anaerobic microorganism system is recognized as a promising treatment technology in recent years.The silica coated nano zero-valent iron(NZVI) is characterized by TEM,XRD,and FT-IR.Zero-valent iron is sphere,whose average particle size is about 50 nm,and with inuclear-shell structure.The interaction effect between nano zero-valent iron and anaerobic sludge was investigated.The results indicated that pH and ORP in the system declined at first then gradually became leveling-off,and ultimately stabilized at about 7.0 and-400 mV respectively.On the other hand ETS fell at first,stabilized for a while then rose.The degradation effect on 2,4,6-trichlorophenol from high to low were: nano zero-valent iron/anaerobic sludge anaerobic sludge nano zero-valent iron,and the final degradation rates were 96.7%,93.7%,73.2% respectively.The synergetic effect between nano zero-valent iron and anaerobic microorganism was obvious.