活性碳纤维电极-生物膜反应器对废水的强化脱氮性能

利用自制的活性碳纤维电极-生物膜反应器对低碳氮比(碳元素与氮元素的质量比)废水进行了脱氮实验.实验结果表明:当进水COD和碳氮比较低时,碳氮比和电流密度均对反应器的脱氮性能有很大影响;当碳氮比小于3.0时,出水的ρ(NO3--N)随进水碳氮比的增大而减小;当进水COD为70 mg/L,ρ( NO3--N)为35 mg/L、碳氮比为2.0、电流密度为0.025 mA/cm2、反应时间为8h时,出水的ρ(NO3--N)达到最低值11.2 mg/L,NO3--N去除率为68.0％.在适宜的碳氮比条件下,电极-生物膜反应器具有显著的强化脱氮作用,其对NO3--N的去除率与单纯生物膜反应器相比可提高6.0～15.0个百分点.保持碳氮比不变,提高进水COD会导致所需电流密度的提高和脱氮能力的下降.

Enhanced Denitrogenation Capability of Activated Carbon Fiber Electrode-Biofilm Reactor

The experiments on denitrogenation of the wastewater with low C-N ratio(the mass ratio of C to N) were carried out using the self-made activated carbon fiber electrode-biofilm reactor(EBR).The experimental results show that: When the influent COD and the C-N ratio are low,the C-N ratio and the current density both have great influent on the denitrogenation capability of the EBR;When the C-N ratio is less than 3.0,the effluent ρ(NO3——N) decreases with the increase of the influent C-N ratio;When the influent COD,ρ(NO3——N) and C-N ratio are 70 mg/L,35 mg/L and 2.0 respectively,the current density is 0.025 mA/cm2 and the reaction time is 8 h,the lowest effluent ρ(NO3——N) is 11.2 mg/L,and the NO3——N removal rate is 68.0%.Under the suitable C-N ratio,the NO3——N removal rate by EBR is 6.0-15.0 percent higher than that by biofilm reactor,which indicates that the denitrogenation effect can be enhanced by EBR significantly.With the invariable influent C-N ratio,the increase of the influent COD will result in the increase of needed current density and the decrease of denitrogenation capability.