高铁酸钾强化铁锰氧化膜过滤去除水中有机物

前期研究发现铁锰氧化膜(MeO_x)对水中氨氮、铁、锰等污染物具有较高的去除率，但对水中有机物(以COD_Mn计)的去除效果较差。为了提高MeO_x对COD_Mn的去除率，本研究采用高铁酸钾强化MeO_x的催化氧化过程，探究其对水中COD_Mn的有效去除及相关影响因素。实验结果表明：仅投加0.1mg/L的高铁酸钾强化MeO_x过滤，对于进水中20mg/L的COD_Mn，去除率可达到约92.5%；滤速对其具有一定的影响，去除率随着滤速的提高呈下降的趋势，在6～10m/h出水滤速中的COD_Mn均能达到3.0mg/L以下，当滤速达到11m/h时去除率下降到81.65%；较低的p H(约6.51)具有一定的不利影响，COD_Mn的去除率随着p H的降低而逐渐下降；进水中NH₄⁺也会影响COD_Mn的去除，NH₄...

Removal of CODMn in water by potassium ferrate enhanced iron-manganese oxide film filtration and its influencing factors

Previous studies have found that the iron-manganese oxide film (MeO _x ) has a high removal efficiency for ammonium, iron and manganese in water, but the removal efficiency of organic matter (in COD_Mn) is poor. To improve the removal efficiency of MeO _x for COD_Mn, the potassium ferrate was used to strengthen the catalytic oxidation process of MeO _x, and its effective removal of COD_Mn and some influencing factors were explored in this study. The experimental results were showed that when only 0.1mg/L of potassium ferrate was added into the influent, the removal efficiency could be about 92.5% for 20mg/L COD_Mn in the influent. The filtration rate (v) had a certain influence on the removal of COD_Mn. The removal efficiency of COD_Mn would gradually decrease with increasing filtration rate, and the concentration of COD_Mn in the effluent could be 3.0mg/L (v=6—10m/h). When the filtration rate reached 11m/h, the removal efficiency of COD_Mn would reduce to 81.65%. The lower pH (about 6.51) had certain adverse effect, and the removal efficiency of COD_Mn would gradually decrease with the decrease of pH. The NH₄⁺ in the influent would also affect the removal of COD_Mn, and the higher the concentration of NH₄⁺, the lower the removal efficiency for COD_Mn. Scanning electron microscope (SEM) results indicated that some brown substances was formed on the surface of MeO _x after ferric acid-base enhanced filtration for about 60 days. The surface of MeO _x was analyzed by electron energy dispersive spectrometer (EDS). It was found that the proportion of C and O elements were increased and that of Mn and Fe elements were decreased significantly, but the reduced Fe and Mn species did not affect the removal of COD_Mn. X-ray photoelectron spectroscopy (XPS) analysis showed that the compounds corresponding to Mn elements were MnO, Mn₂O₃ and Mn₃O₄ before and after enhanced filtration, and the substances on the surface of MeO _x for C and O elements was (CH₂)₄O_n .