A2N双污泥反硝化除磷系统微生物的先间歇后连续培养及快速启动

以实际生活污水为对象,研究了反硝化聚磷菌(DPB)的驯化培养以及A2N双污泥反硝化除磷系统的快速启动.采用先独立培养反硝化聚磷菌和好氧硝化生物膜再连续运行的方式成功地快速启动了A2N系统.采用污水处理厂除磷工艺中的活性污泥为种泥,在SBR系统中以先A/O(厌氧/好氧)后A/A(厌氧/缺氧)的方式运行,32 d成功地使反硝化聚磷菌成为优势菌属.在SBR反应器中,采用硝化效果较好的活性污泥为种泥,好氧硝化生物膜30 d挂膜成功,氨氮去除率稳定在99%以上.然后,A2N系统连续运行,11 d后系统反硝化除磷效果进入稳定状态,出水氨氮和正磷酸盐浓度均为0,硝态氮为10.26 mg/L,出水COD为19.56 mg/L,COD、氨氮、总氮和磷去除率分别为91%、100%、77%和100%,说明A2N系统具有很好的脱氮除磷效果,认为系统启动成功.

双污泥反硝化除磷系统中氨氮容积负荷的优化

农村生活污水具有处理量小,分散,日变化系数大等特点,分散处理成为农村污水处理的首要选择。该研究采用AAO工艺与BAF组成的双污泥反硝化除磷系统（anaerobic anoxic oxic-biological aerated filter,AAO-BAF）处理农村生活污水,探讨了氨氮容积负荷对该系统BAF单元硝化性能及出水悬浮物（SS）的影响。通过改变水力负荷和有效滤料容积（即方式1和方式）2种方式,氨氮容积负荷在0.43-1.21 kg/（m3·d）之间变化。试验结果表明,随着氨氮容积负荷的增加,氨氮去除率呈现先缓慢降低后急剧减小的趋势,不同的是,出水SS对方式1（即水力负荷的变化）更敏感。当氨氮容积负荷在0.43-1.12 kg/（m3·d）时,氨氮去除率大于81%;当氨氮容积负荷大于1.12 kg/（m3·d）,氨氮去除率急剧降低,氨氮容积负荷为1.21 kg/（m3·d）,2种运行方式的氨氮去除率分别为65%和68%。当氨氮容积负荷小于0.74 kg/（m3·d）时,出水SS小于10 mg/L;当氨氮容积负荷大于0.74 kg/（m3·d）时,出水SS急剧增加,但方式1增加得更快,氨氮容积负荷增加到1.21 kg/（m3·d）时,方式1和方式2的出水SS分别为21.8和14.2 mg/L。所以,为保证BAF出水水质达到国家一级A排放标准,其氨氮容积负荷应小于0.74 kg/（m3·d）。

反硝化除磷系统的驯化及反硝化聚磷菌的筛选

利用城市河道底泥,通过厌氧/缺氧/好氧(A2O)工艺驯化反硝化除磷系统,采用BTB培养基、异染粒及PHB(聚β-羟基丁酸)染色等方法,从反硝化除磷系统中分离筛选出反硝化聚磷菌,并通过16S rDNA序列测定分析其遗传背景。在该试验条件下,反硝化除磷系统的氮磷的去除率超过80%。从反硝化除磷系统中分离筛选出DPB-A511、DPB-A9和DPB-A10 3株反硝化聚磷菌,其氮、磷去除率均超过50%。这3株菌中DPB-A511、DPB-A9分别与Dechloromonas aromatica、Candidatus accumulibacter phosphatis的相似性均达到97%,DPB-A10与Bacillus pumilus的相似性达到99%。

Factors affecting biological denitrifying dephosphatation in anaerobic/anoxic/aerobic sequencing batch reactor

This study was conducted to verify and discuss the denitrifying dephosphatation under different levels of nitrate concentration and retention time of anoxic/aerobic process in a Sequencing Batch Reactor (SBR). The results of tests demonstrated that there were two kinds of phosphorus-accumulating organisms (PAOs) in the biological excess phosphorus removal (BEPR) system. One was non-DNPAOs that could only use oxygen as terminal electron acceptors, the other was denitrifying PAOs (DNPAOs) that could use both nitrate and oxygen as terminal electron acceptors. Phosphorus uptake efficiency could be attained under anoxic period ranging from 28.7%-96.7% in an anaerobic/anoxic/aerobic system. Experimental results showed that nitrate concentration and retention time of anoxic/aerobic process were the key factors affecting the course of denitrifying dephosphatation.