不同SRT条件下厌氧污泥中氮元素的变化规律研究

氮素是衡量污泥性能的重要指标之一,在污泥厌氧消化过程中,污泥中所含的四种氮素形态之间可相互转化,研究其过程中的氮素变化规律对于优化厌氧消化工艺具有重要的指导意义。通过对5 d和10 d两种不同污泥停留时间(SRT)的污泥厌氧消化系统的研究,分析氮元素的变化规律。研究结果表明,SRT为5 d天和10 d的两个系统中,均无亚硝态氮的累积,实验前期,10 d的系统中硝态氮的产生速率比5 d的快,但系统运行10 d后10 d系统的硝态氮的含量低于5 d系统。在两反应系统中,氨氮的变化规律十分接近,10 d的系统中氨氮含量一直高于5 d的系统。总氮含量的变化与氨氮含量变化一致,四种形态氮素中,对总氮贡献最大的是氨氮。实验过程中,两系统中均并无明显产气现象,在SRT小于等于10 d的厌氧反应器中,虽然有发生反硝化反应,但通过该反应去除的氮素极少。

CHANGING RULE OF NITROGEN RELEASED BY ANAEROBIC SLUDGE UNDER DIFFERENT SLUDGE RETENTION TIME

Abstract： Nitrogen is one of the most important indices that shown the properties of sludge. There are a series of reactions among these four forms of nitrogen under anaerobic condition. It is important to optimize the anaerobic digestion that studying the changing of nitrogen. To analyze the changing rules of nitrogen under different anaerobic sludge retention time （SRT）, this is 5 days and 10 days. The experimental result shown that there was no the accumulationof nitrite in the two systems. At the oegmnmg of experiment, the producing rate of nitrate in 10 days of SRT system was faster than that in the 5 days SRT system, but the concentration of nitrate in 10 days SRT system was lowerthan that in 5 days SRT system after 10 days operating. The changing rule of ammonia nitrogen was similar in the two systems, the concentration of ammonia nitrogen in the 10 days of SRT system was higher than that in 5 days of SRT. The changing rule of total nitrogen was same in the two system, the ammonia nitrogen was the great contribution to the total nitrogen among the four types of nitrogen. There was no obviously gas produced by the systems during the experiment, that shown nitrogen was rarely removed through Denitrifying reaction, when the SRT was less than 10 days.