直流电对硝化细菌活性的影响

研究外加直流电分别对悬浮和固定膜二种存在状态的硝化细菌代谢活性和硝化效率的影响 .小于 2 5A·m-2 的直流电对游离细菌硝化氨氮没有影响 ,5A·m-2 以上的电流开始抑制细菌的硝化作用 .生物膜具有较强的抗电能力 ,15A·m-2 的直流电仅使氨氮的硝化速率降低 2 0 % .另外 ,电流对生物膜的持菌量影响差异较大 .当电流密度为 15A·m-2 时 ,负极的持菌量减少 90 %以上 ,正极减少 5 8% ,而电极中间填料的持菌量仅减少 8% .测量生物膜中磷脂含量发现 ,正极表面生物膜中活细菌比重最小 ,正极其次 ,填料表面生物膜中活细菌含量最高

The effects of direct electric current on the metabolism of nitrifying bacteria

The nitrification efficiency and population dynamic of nitrifying bacteria in liquid culture and biofilm under series of direct electric current were experimentally investigated.The results indicated that the electric current less than 2.5A·m^-2 had no effect on the cells in liquid,but if the electric current was more than 5A·m^-2 the nitrification efficiency decreased.Biofilm could stand even higher current,when the current increased up to 15A·m^-2 ,the nitrification efficiency only decreased 20%.In addition,the current also greatly affected the population dynamics of nitrifying biofilm.When the current was 15A·m^-2 ,the biomass on the cathode,anode and packing decreased about 90%,58% and 8% respectively.The LP/dry biofilm weight increased when the current was high.