二氧化硅包覆型纳米零价铁/厌氧污泥协同降解2,4,6-三氯苯酚

摘要

利用二氧化硅包覆型纳米零价铁/厌氧污泥体系实现制浆造纸废水中的大量氯代芳香族难降解毒性物质的脱氯降解.通过透射电子显微镜(TEM)、X射线衍射仪(XRD)、红外光谱仪(FTIR)对二氧化硅包覆型纳米零价铁性能表征可知,制备的二氧化硅包覆型纳米零价铁呈球形,平均粒径在50 nm左右,为核壳结构；将二氧化硅包覆型纳米零价铁与厌氧污泥相结合,进行了两者之间相互影响研究,结果表明,体系pH值与氧化还原电位(ORP)呈现先下降后逐渐趋于平缓的趋势,并最终稳定在7.0和-400 mV左右,同时体系的电子传递体系(ETS)活性呈现先下降后稳定一段时间后再上升的趋势；2,4,6-三氯苯酚的降解效率从高到低依次为:二氧化硅包覆型纳米零价铁/厌氧污泥＞厌氧污泥＞二氧化硅包覆型纳米零价铁,最终降解率依次分别为96.7％、93.7％、73.2％.二氧化硅包覆型纳米零价铁与厌氧污泥之间存在明显的协同降解作用.%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.