净化铁锰氨生物滤池内氨氮转化途径

为考察净化铁锰氨生物滤池内NH₄+-N的转化途径,利用氮素计量关系和沿程试验研究了净化铁锰氨生物滤池内产生TN_loss(氮损失)的原因和NH₄+-N转化途径. 结果表明,净化铁锰氨生物滤池内DO消耗异常,TN_loss不守恒,当进水ρ(NH₄+-N)平均值分别为1.262、2.296、3.111 mg/L时,NLR(氮损失率)分别能达到7.89%、12.91%、17.73%. 利用硝化反应和CANON(全程自养脱氮)方程式计算得出理论TN_loss和TDOC(理论耗氧量),与实际TN_loss和ADOC(实际耗氧量)的差值分别小于±0.030、±0.10 mg/L,各阶段NH₄+-N 通过CANON途径转化的比例分别为48.58%、60.77%、68.10%,硝化反应和CANON途径共同参与了NH₄+-N转化. 沿程试验结果表明,整个试验阶段,NO₂--N在滤层中均有积累,并在滤层厚度为10~18 cm内出现NO₂--N和NH₄+-N共存的现象,进一步证明CANON途径是净化铁锰氨生物滤池内产生TN_loss的原因. 

Ammonia Conversion Process in a Biofilter for Iron and Manganese Removal

In order to investigate the conversion of ammonia and the cause of nitrogen loss in an iron manganese ammonia biofilter, the stoichiometry and the variation of nitrogen along the filter were explored. The results indicated that an unusual DO consumption and nitrogen loss phenomenon occurred in the filter. When the NH₄+-N concentrations were 1.262,2.296 and 3.111 mg/L, the nitrogen loss rates reached 7.89%, 12.91% and 17.73%, respectively. Moreover, when the nitrification and CANON equations were used to calculate the theoretical nitrogen loss and theoretical oxygen consumption, and then compared with the actual nitrogen loss and the actual oxygen consumption, the values were less than 0.030 and 0.10 mg/L, respectively. The calculation results demonstrated that both the CANON process and nitrification contributed significantly to the removal of NH₄+-N, with the CANON process contribution being about 48.58%, 60.77% and 68.10%, respectively. The variation of nitrogen along the filter showed that throughout the test, NO₂--N accumulated in the filter layer. In addition, a NO₂--N and NH₄+-N coexistence phenomenon appeared in the filter layer of 10-18 cm, which further illustrated that the CANON process was the main cause of the nitrogen loss.