三维电极生物膜与硫自养耦合工艺脱氮特性

Nitrogen Removal in Three-dimensional Electrode Biofilm Coupled with Sulfur Autotrophic Process:Influence of HRT and Sodium Bicarbonate

采用三维电极生物膜与硫自养耦合工艺去除模拟地下水中的硝酸盐氮,考察了水力停留时间(HRT)和进水NaHCO_(3)浓度对脱氮特性的影响。当温度为20~25℃、进水NO_(3)^(-)-N浓度为70 mg/L左右、电流强度(I)为400 mA、进水pH为7.0~7.5时,反应器的最佳HRT为16.0 h,最佳进水NaHCO_(3)浓度为1.0 g/L。HRT对反应器去除NO_(3)^(-)-N的影响比较显著,NO_(3)^(-)-N去除率随HRT的缩短而下降,但在各种HRT条件下均能保持较稳定的NO_(3)^(-)-N去除负荷。进水NaHCO_(3)浓度对反应器去除NO_(3)^(-)-N影响显著,NO_(3)^(-)-N去除率随进水NaHCO_(3)浓度的减小而急剧下降。HRT与进水NaHCO_(3)浓度均能显著影响反应器中NO2--N的积累程度;SO_(4)^(2-)的积累量随HRT的缩短和进水NaHCO_(3)浓度的减小而下降。HRT能显著影响反应器中氢自养与硫自养各自所占比例,而进水NaHCO_(3)浓度对氢自养与硫自养各自所占比例均无明显影响。

The three-dimensional electrode biofilm coupled with sulfur autotrophic process was used to remove nitrate in simulated groundwater,and the effects of HRT and influent sodium bicarbonate(NaHCO_(3))concentration on the denitrification characteristics were explored.When the temperature was 20-25 ℃,the influent NO_(3)^(-)N concentration was about 70 mg/L,the current intensity was 400 mA,and the influent pH was 7.0-7.5,the optimal HRT and influent NaHCO_(3)concentration of the reactor was 16.0 hours and 1.0 g/L respectively.The impact of HRT on the removal efficiency of NO_(3)^(-)N was significant.The removal rate of NO_(3)^(-)N decreased with the shortening of HRT,but it could maintain a relatively stable NO_(3)^(-)N removal load under various HRTs.The influent NaHCO_(3)concentration had a significant impact on the removal efficiency of NO_(3)^(-)N.The removal rate of NO_(3)^(-)N decreased sharply with the decrease of influent NaHCO_(3)concentration.Both HRT and influent NaHCO_(3)concentration could significantly affect the accumulation of NO_(3)^(-)N in the reactor.The accumulation of SO_(4)^(2-)-decreased with the shortening of HRT or the decreasing of NaHCO_(3)concentration in the influent.HRT could significantly affect the proportion of hydrogen autotrophic and sulfur autotrophic in the reactor,while the concentration of NaHCO_(3)in the influent had no significant effect on their proportions.