水钠锰矿改性磁铁矿对带不同电性有机污染物的去除研究

Study on Removal of Organic Pollutants with Different Electrical Properties by Birnessite Modified Magnetite

目前,有机染料的污染已成为当前废水污染的热点,而磁铁矿是比较好的环境友好型材料,但对于高浓度有机废水及电荷性质的不同,去除能力上存在一定的不足。因此,为提高磁铁矿对高浓度不同电荷性质有机污染物的去除能力,本文采用回流法在合成酸性水钠锰矿(Bir)的过程中加入磁铁矿合成复合矿物(Fe_(3)O_(4)@Mn),并通过X射线衍射、化学分析、傅里叶红外光谱、Zeta电位对合成的Fe_(3)O_(4)@Mn进行性质表征。结果表明,成功制备出复合矿物Fe_(3)O_(4)@Mn;在pH=5条件下,随着亚甲基兰浓度的升高,Fe_(3)O_(4)@Mn的去除率保持在97%以上,而Fe_(3)O_(4)的去除率仅在0.3%以下;随着偶氮宝石红浓度的升高,Fe_(3)O_(4)@Mn的去除率保持在85%以上,而Fe_(3)O_(4)的去除率~50%。因此,负载Bir后的Fe_(3)O_(4)能够显著提高其对不同电性染料的去除率,这是由于Fe_(3)O_(4)@Mn有较强的氧化能力,且其去除率要远大于吸附作用,并且消除了由于静电作用导致的Fe_(3)O_(4)选择性去除偶氮宝石红而非亚甲基蓝的性质。上述结果为环境友好型材料的开发及工业污水的处理提供参考。

At present, the pollution of organic dyes has become a hot spot of wastewater pollution. And magnetite is a better environment-friendly material, but for high concentration organic wastewater and different charge properties, there are some deficiencies in the removal capacity. Therefore, in order to improve the removal ability of magnetite for organic pollutants with high concentration and different charge properties, the composite mineral(Fe_(3)O_(4)@Mn) was synthesized by adding magnetite into the synthesis process of acid birnessite(Bir) using reflux method. X-ray diffraction(XRD), chemical analysis, Fourier transform infrared spectroscopy(FTIR) and zeta potential were used to characterize Fe_(3)O_(4)@Mn. The results show that the composite mineral of Fe_(3)O_(4)@Mn was successfully prepared;At pH=5, with the increase of methylene blue concentration, the removal rate of methylene blue by Fe_(3)O_(4)@Mn remained above 97 %, while the removal rate of Fe_(3)O_(4) was only below 0.3 %;the removal rate of brilliant crimson red by Fe_(3)O_(4)@Mn was above 85 %, while the removal rate of Fe_(3)O_(4) was about 50 %. Therefore,the removal efficiency of Fe_(3)O_(4) for different electrical dyes could be significantly improved through Bir loaded. Because Fe_(3)O_(4)@Mn had strong oxidation ability,and the removal rate was much higher than that of adsorption, eliminating the selectivity of only removing brilliant crimson red with negative charge but not methylene blue as Fe_(3)O_(4) with positive charge. These results provide a reference for the development of environment-friendly material and the treatment of industrial wastewater.