高铁锰氨氮地下水净化试验及氧化动力学

摘要

在水厂,以中试模拟滤柱开展了高铁锰氨氮(8~10℃,TFe 6~14mg/L,Mn 0.8~1.5mg/L,NH4+-N 2.0~3.0mg/L)地下水净化试验及氧化动力学分析.结果表明,一级曝气+一级过滤、一级曝气+两级过滤工艺均由于溶解氧(DO)不足,对高铁锰氨氮地下水净化失败;曝气生物滤池由于曝气对水流造成紊动,净化效果最差;曝气生物滤池+两级过滤工艺可实现高铁锰氨氮地下水净化,但是运行滤速仅有6.0m/h;两级曝气+两级过滤工艺净化效果最优,可实现高铁锰、氨氮地下水(8~10℃,TFe 17.66mg/L,Mn 1.71mg/L,NH4+-N 3.37mg/L)净化,一级和二级滤速分别可达13.25m/h和12.75m/h,且在低温下亦适用,可实现低温高铁高锰高氨氮(5~6℃,TFe 9.72mg/L,Mn 3.29mg/L,NH4+-N 3.44mg/L)地下水的净化,一级和二级极限滤速分别为10.0m/h 和8.0m/h.氧化动力学分析表明,铁氧化去除遵循一级化学氧化动力学规律,其氧化动力学常数为(1.02~1.18)×10.氨氮和锰的去除均遵循零级酶促反应动力学规律,其氧化动力学常数分别为(0.15~0.83)×10-1和(0.31~1.20)×10-1.除铁除锰生物滤池中,铁的氧化去除速率最快,优先完成去除,锰和氨氮完成氧化去除的先后顺序受基质浓度大小影响较大.%Pilot-scale bio-filters were constructed to removal of high-iron, manganese and ammonia nitrogen (8~10℃, TFe 6~14mg/L, Mn 0.8~1.5mg/L, NH4+-N 2.0~3.0mg/L) from groundwater and the oxidation kinetics was analyzed. The results showed that Aeration and Filter process and Aeration and Double Filtration process failed due to lack of dissolved oxygen (DO). Biological Aerated Filter was the worst process due to aeration on the water flow turbulence; Biological Aerated Filter and Filtration process was successful, However, the filter rate was only 6.0m/h; Double Aeration and Double Filtration (DADF) was the best process, which was successful to removal of high-iron manganese and ammonia nitrogen from groundwater (8~10℃, TFe 17.66mg/L, Mn 1.71mg/L, NH4+-N 3.37mg/L), and the maximum filter rate of the first stage and the second stage were 13.25m/h and 12.75m/h. Moreover, which also could be applied to the purification of low-temperature groundwater (5~6℃, TFe 9.72mg/L, Mn 3.29mg/L, NH4+-N 3.44mg/L), and the maximum filter rate of the first stage and the second stage were 10.0m/h and 8.0m/h. The Oxidation kinetics demonstrated that, iron was oxidized and removed followed the first-order chemical oxidation kinetics, and the oxidation kinetics constant was (1.02~1.18)×10, and the removal of manganese and ammonia nitrogen followed the kinetic law of zero-order enzymatic reaction, and the oxidation kinetics constant were (0.15~0.83)×10-1 and (0.31~1.20)×10-1 . The oxidation rate of iron was the fastest and was first removed. The order of oxidation and removal of manganese and ammonia nitrogen was greatly affected by substrate concentration.