内源电子受体产生及其在强化脱氮工艺中的研究

In-stream electron acceptor generation and its application on enhanced nitrogen removal process

将城市污水生物脱氮除磷工艺中剩余活性污泥（EAS）与生产废水（RW）按不同比例混合并进行曝气,利用EAS中所含的硝化细菌转化生产废水中的氨氮,并同步获得内源电子受体（硝酸盐）;随后加入一定量的EAS,利用其胞内碳源进行反硝化脱氮。结果表明：采用EAS处理生产废水并用于产生内源电子受体时,生产废水中氨氮浓度由119.94-171.31 mg/L下降为0.24-0.37mg/L,氨氮去除率可达87.65%-99.72%,最佳硝化时间为8h或12h。当硝化生产废水与不同比例EAS进行混合,采用好氧硝化（12h）、重力浓缩（24h）工艺时,最佳混合比为55%（EAS）∶15%（RW）∶30%（EAS）,总氮去除率最高可达68%;采用硝化（12h）、反硝化（24h）、重力浓缩（24h）工艺时,最佳混合比为65%（EAS）∶15%（RW）∶20%（EAS）,总氮去除率最高达75.16%。

The excess activated sludge（EAS）,which was generated from the municipal wastewater treatment plant,was employed as the nitrifier by mixing the EAS with the reject water（RW）under different mixing ratios and different aeration times.This could lead to ammonia removal from RW and cause in-stream electron acceptor（nitrate）generation simultaneously.The nitrified RW was further mixed with the EAS to achieve denitrification through the use of intracellular carbon in EAS.The results showed that the ammonia nitrogen in RW decreased from 119.94-171.31mg/L to 0.24-0.37mg/L.The ammonia nitrogen removal efficiency ranged from 87.65%to 99.72%.The optimal nitrification time was determined as 8hand/or 12 h.When a 12-hour aeration nitrification and 12-hour gravity thickening was carried out and EAS was mixed with the nitrified RW,approximately 68% of total nitrogen（TN）removal was achieved at the optimal mixing ratio of 55%∶15%∶30%（EAS∶RW∶EAS）.When a combined process of 12-hour nitrification,24-hour denitrification,and 24-hour gravity thickening was taken,the optimal mixing ratio might be65%∶15%∶20%（EAS∶RW∶EAS）and approximately 75.16% of TN removal was achieved.