【作者】 董俐；

【导师】 郭劲松；

【作者基本信息】 重庆大学 ， 环境工程， 2010， 硕士

【摘要】 对于传统硝化反硝化脱氮工艺来说,当C/N<3时,如无外加有机碳源,反硝化过程就无法有效地进行,因此传统的生物脱氮工艺己不能满足低碳氮比高氨氮废水的处理要求,寻求一种适合低碳氮比高氨氮废水的处理工艺势在必行。自养脱氮工艺是通过自养微生物的代谢实现氮从NH4+-N至N2的转化,整个过程不消耗有机碳源,尤其适合处理高氨氮、低碳氮比的废水。目前关于自养脱氮工艺的研究大多是在不含有机碳源的无机废水条件下进行的,而实际废水中几乎不存在不含有机碳源的情况,采用自养脱氮系统在有机碳源环境下的运行适应性和稳定性还需要进一步研究。本研究采用自养脱氮工艺处理低碳氮比高氨氮废水,在前期建立的以不含有机碳配水为反应基质的单级自养脱氮系统的基础上,改用低C/N废水为反应基质,对反应器进行二次启动,研究了DO、C/N对系统脱氮性能的影响;进一步对系统内悬浮污泥和生物膜的微生物活性与微生物群落结构进行了研究。采用A、B两个生物膜SBR反应器启动低碳氮比高氨氮废水的自养脱氮系统,两个反应器进水水质和制条件完全一致。启动过程中逐步提高进水COD和NH4+-N浓度对污泥进行驯化,启动结束时COD和NH4+-N浓度分别为240~255mg/L、290~300mg/L,启动过程历经91d。启动初期(1~24d)控制系统pH为7.8～8.5、水温为30±2℃、DO为2.0～2.5(曝气)/0.2～0.4(停曝气)、曝/停比为2h:2h,系统TN去除率仅为60%左右,且出水NO3--N浓度较高。从第25d开始,降低系统DO浓度至1.4～1.7(曝气)/0.2～0.4(停曝气),其他条件不变,运行一段时间后,系统脱氮性能大幅提高,出水NO3--N浓度也大大降低,到启动结束时A、B两个系统的TN去除率均达到90%以上,理论推得,随着进水C/N的升高,系统内自养脱氮脱氮途径对TN去除率的贡献约由90%下降到60%,传统硝化反硝化途径对TN去除率的贡献约由10%上升到40%,自养脱氮仍占主导地位。稳定运行期的B系统内悬浮污泥的亚硝化活性、硝化活性、反硝化活性、厌氧氨氧化活性分别为0.07gN/gVSS·d、0.043gN/gVSS·d、0.017gN/gVSS·d、0.015gN/gVSS·d;生物膜的亚硝化活性、硝化活性、反硝化活性、厌氧氨氧化活性分别为0.112gN/gVSS·d、0.077gN/gVSS·d、0.15gN/gVSS·d、0.19gN/gVSS·d。生物膜各活性均高于悬浮污泥,尤其是反硝化和厌氧氨氧化活性,分别为悬浮污泥的9倍和13倍。表明生物膜更有利于形成好氧菌和厌氧菌共存的微环境,悬浮污泥和生物膜同时表现出了一定的反硝化活性,证明系统内也存在传统硝化反硝化脱氮途径。采用PCR-DGGE技术,对A、B系统以及前期以无机废水为反应基质的C系统内的悬浮污泥和生物膜的总微生物群落结构以及功能菌亚硝化菌(AOB)和厌氧氨氧化菌(ANAMMOX)的群落结构进行测定。结果表明:生物膜与悬浮污泥中的AOB群落结构差别不大,但生物膜样品的总微生物和ANAMMOX的种类和数量远多于悬浮污泥。与以无机废水为反应基质的系统内各微生物群落结构相比,加入有机碳源后,除AOB的群落结构没有发生较大改变外,系统内总微生物群落结构较无机系统更为复杂,其丰富度值有所提高,ANAMMOX的种类也发生了较大改变。本文的研究结果以期为自养脱氮工艺应用于实际工程提供参考和理论依据。更多还原

【Abstract】 For traditional nitrification and denitrification denitrification, Denitrification process cannot effectively when C/N<3 if no plus organic carbon sources,So, The traditional biological denitrification cannot satisfy the requirements of low carbon and high ammonia nitrogen wastewater treatment, Looking for a suitable for low carbon and high ammonia nitrogen wastewater treatment process is imperative. Autotrophic nitrogen removal process could realize the conversion of ammonium to denitrogen gas by autotrophic bacteria, and it particularly suitable to treat high Ammonium and low C/N ratio wastewaters. At present, Most researches of autotrophic nitrogen removal process on condition of inorganicwastewater,but it is not exist in practical wastewater,It need to research the adaptability and stability of autotrophic nitrogen removal process on condition of organic wastes. This study adopts autotrophic nitrogen removal process treatment low carbon and high ammonia nitrogen wastewater, On the basis of one-stage completely autotrophic nitrogen removal process which is established by our group early, With low C/N wastewater as matrix.This paper studied DO&C/N impact on the performance of system denitrification during the start-up process system;it also studied microbial activity and microbial community structure of the different sludge forms in the system during stable operation stage. Main conclusions are as follows:Using two biofilm SBR reactor (A and B) to startup autotrophic nitrogen systems for low C/N ratio and high ammonia nitrogen wastewater,Inflow water quality and exercise macro-control condition of the two reactor are conformity.Domestication the sludge by gradually improve the concentration of COD and NH4+-N in the process of start, Eventually COD and NH4+-N concentration of inflow water are 240~255mg/L and 245~295mg/L, start-up process go through 91d. control condition of initial stage(1~24d) are pH:7.8～8.5,water temperature:30±2℃,DO:2.0～2.5(aeration)/0.2～0.4(not aeration), TN removing rate is 60% in system,and NO3--N concentration of effluent water is high. At 25d, Reduce the concentration of DO to 1.4～1.7(aeration)/0.2～0.4(not aeration), Other conditions remain unchanged, nitrogen removal in system is greatly improved and NO3--N concentration is reduced after a period of time, TN removal rate reached more than 90% in both of A and B system at the startup end. With the increase of the inlet C/N ,Theoretical calculation that autotrophic nitrogen removal pathway by 90% decline to 60% and traditional nitrification and denitrification pathway by 10% to 40%, autotrophic nitrogen removal pathway is still dominant.Taking the suspended sludge and biofilm in autotrophic nitrogen removal system as the research objects, Results showed that nitrosification activity, nitrification activity, ANAMMOX activity and denitrification activity of suspended sludge were 0.07gN/g VSS·d,.043gN/gVSS·d,0.17gN/gVSS·d and 0.015gN/gVSS·d, nitrosification activity, nitrification activity, ANAMMOX activity and denitrification activity of biofilm were0.112gN/ gVSS·d,077g N/gVSS·d, 0.15gN/g VSS·d and 0.19gN/gVSS·d, Microbial activity of biofilm is higher than suspended sludge, especially ANAMMOX activity and denitrification activity, which for the suspended sludge were 9 times and 13 times. which indicate that biofilm is more beneficial for the formation of aerobic-anaerobic micro-environment to make nitrification and ANAMMOX reaction perform well, and biofilm played dominant parts in autotrophic nitrogen removal system. Both of the suspended sludge and biofilm showing the denitrification activity and ANAMMOX activity,which proof that traditional nitrification and denitrification pathway and autotrophic nitrogen removal pathway existence in the system at the same time.Using PCR-DGGE to study total microbial community structure and functional bacteria community structure (AOB and ANAMMOX) in A,B and C system, Experimental results that AOB community structure of suspended sludge and biofilm are basically the same,but The number and variety of the total microbial community structure and ANAMMOX community structure in biofilm are more than in suspended sludge, Compared with microbial community structure of the system which With inorganic wastewater as matrix, After joining the organic carbon source, Besides the community structure of AOB not changed,the total microbial community is more complex, The variety of ANAMMOX have great change.The research results of this topic could provide reference and theoretical basis for autotrophic nitrogen removal process applied to practical engineering.更多还原