低溶氧下长期运行的沼液亚硝化工艺的特性  

Characteristics of Anaerobic Digestion Solution Nitrification Process Under Low Dissolved Oxygen for a Long Time

作　　者：雷陈澳 杨懿 姜德平 李向群 王媛媛[1] LEI Chenao;YANG Yi;JIANG Deping;LI Xiangqun;WANG Yuanyuan(College of Engineering,Huazhong Agricultural University,Wuhan 430070,China;Rural Energy Office of Hubei Province,Wuhan 430070,China)

机构地区：[1]华中农业大学工学院,武汉430070 [2]湖北省农村能源办公室,武汉430070

出　　处：《中国沼气》2022年第4期8-17,共10页China Biogas

基　　金：2021湖北省农村能源自主创新技术研发项目(46452103401)。

摘　　要：亚硝化-厌氧氨氧化工艺在处理沼液上有着良好的应用前景,其中亚硝化阶段的稳定实现是工艺的前置关键阶段。以实际沼气工程沼液为原料,以极低的溶氧(DO)配合高NH_(4)^(+)-N为控制手段,研究曝气量、游离氨(FA)、温度、曝气模式等条件对序批式反应器的亚硝化性能的影响。研究发现,反应器启动时使用原沼液会存在FA抑制,可通过调控温度、pH值等参数降低FA解除抑制以实现启动。曝气量高于150 mL·min^(-1)时,亚硝化活性随曝气量上升而上升,在600 mL·min^(-1)时污泥亚硝化活性可达8.680 mgN·g^(-1) h^(-1)。在低溶氧的条件下,30℃时的污泥活性比25℃高25%左右,而35℃下与30℃区别不大。与间歇曝气模式相比,AOAO模式在低溶氧环境有更高的亚硝化转化率且更好地控制污泥的膨胀。通过微生物群落分析发现亚硝化单胞菌仅约占总数量的7.38%,但有着强大的亚硝化能力。试验证明:长期低DO条件可以在沼液中可以实现稳定的亚硝化过程,亚硝酸盐积累率始终大于90%。Nitrification anaerobic ammonia oxidation process has a good application prospect in the treatment of biogas slurry,in which the stable realization of nitrification stage is the pre key stage of the process.Using the actual biogas engineering biogas slurry as raw material,using very low dissolved oxygen(do)and high NH_(4)^(+)-N as control means,the aeration rate and free ammonia were studied(FA),temperature,aeration mode and other conditions affect the nitrification performance of sequencing batch reactor.It is found that there will be fa inhibition when using raw biogas slurry during reactor start-up,and the inhibition can be relieved by adjusting temperature,pH and other parameters.When the aeration rate is higher than 150 mL·min^(-1),the nitrification activity increases with the increase of aeration rate,and the sludge nitrification activity can reach 8.5% at 600 mL·min^(-1) 680 mgN·g^(-1) h^(-1).Under the condition of low dissolved oxygen,the sludge activity at 30℃ is about 25% higher than that at 25℃,but there is little difference between 35℃ and 30℃.Compared with intermittent aeration mode,AOAO mode has higher nitrosation conversion and better control of sludge bulking in low dissolved oxygen environment.Through microbial community analysis,it was found that nitromonas accounted for only 7.38% of the total number,but had strong nitrosation ability.The experiment shows that the stable nitrosation process can b e realized in biogas slurry under long-term low do conditions,and the nitrite accumulation rate is always greater than 90%.

关 键 词：沼液 AOAO 亚硝化 FA 曝气量 氨氮 

分 类 号：S216.4[农业科学—农业机械化工程] X705[农业科学—农业工程]