溶解氧浓度对石英砂滤料表面铁、锰氧化膜同步去除地下水氨氮和锰的影响

Effect of DO concentration on removal of ammonium and manganese ion in groundwater by Fe/Mn co-oxides film coating on quartz sands

在实验室放大装置中,考察了溶解氧(DO)浓度对石英砂滤料表面铁锰复合氧化膜同步去除氨氮(NH_4^+-N)和锰(Mn^(2+))的影响。结果表明,DO是同步去除NH_4^+-N和Mn^(2+)的必要条件,当进水DO浓度大于(4.4±0.2)mg·L^(-1),低浓度NH_4^+-N和Mn^(2+)的去除率均可达94%以上。控制进水DO浓度相同,分别从滤柱顶端进水和滤柱底端进水并监测NH_4^+-N和Mn^(2+)浓度随滤层厚度的变化。结果表明,上下滤层对Mn^(2+)的去除效果一致,但上层对NH_4^+-N的去除速率略快于下层。对于含有较高浓度NH_4^+-N(3.2 mg·L^(-1))的进水,进行二次补氧是使出水NH_4^+-N达标的有效方法。

We herein report studies into the simultaneous removal of ammonium（ NH_4~＋-N） and manganese ions（ Mn^（2＋）） by Fe /Mn co-oxide film coatings on quartz sands under different dissolved oxygen（ DO） concentrations using an amplifying filter column. Optimization of the DO concentration was essential for the efficient removal of both NH_4~＋-N and Mn^（2＋）. With DO concentrations （ 4. 4 ± 0. 2） mg·L-1,the removal rates of NH_4~＋-N and Mn^（2＋）exceeded 94%. Under equal DO concentrations,NH_4~＋-N and Mn^（2＋）solutions were pumped into the filter column from either the top or the bottom to determine if the feed direction had an effect on removal rates.The removal rates of Mn^（2＋）were comparable using both water feeding modes,while the removal rate of NH_4~＋-N was slightly faster when fed from the top. Finally,we expect that a second aeration stage could be effective for high concentration NH_4~＋-N（ 3. 2 mg·L^（-1）） removal.