复合碳源填料深度反硝化脱氮特性研究

发布时间：2018-02-27 05:11

本文关键词： 预处理反硝化复合碳源填料 Miseq高通量测序　出处：《北京工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：为解决低C/N污水厂尾水深度脱氮外加固体纤维素碳源反硝化效率低、出水TOC高、填料层易堵塞等问题,本研究以玉米芯为研究对象,利用1.5%NaOH、1%H2SO4、1.5%H2O2和碱性双氧水(含有1.5%H2O2的Na OH溶液)并联合UV照射对熟的玉米芯进行预处理,通过分析各种预处理方法对玉米芯释碳和脱氮性能的影响,优选出适宜的玉米芯固体碳源预处理方式;将Fe0、玉米芯和活性炭填充到直径为80mm的聚乙烯悬浮球中制成复合碳源填料,通过三因素三水平正交试验确定复合碳源填料中Fe0、玉米芯和活性炭的填充比例;建立复合碳源填料反硝化脱氮-兼氧生物滤柱(DN/AF)组合工艺,考察该工艺运行特性及微生物菌群多样性。主要研究成果如下:对预处理后玉米芯进行静态释碳和静态脱氮试验,考察预处理后玉米芯释碳、反硝化性能及微生物附着情况。结果表明,从单位质量玉米芯硝酸盐去除负荷、硝酸盐去除率及玉米芯表面性状综合考虑,用碱处理后的玉米芯,处理程度最为适宜,有利于反硝化微生物的降解和利用。以碱处理玉米芯、Fe0和活性炭作为复合碳源填料,选取零价铁类型、玉米芯/(Fe0+C)和Fe0/C三因素,进行三因素三水平正交试验确定玉米芯、Fe0和活性炭联合反硝化系统的影响因素。结果表明,以各组硝酸盐去除率、氨氮积累量、亚氮积累量和pH作为正交试验的评价标准,试验最优条件为:铁丝,玉米芯/(Fe0+C)=5:1,Fe0/C=1:2。从宏观和微观的角度研究DN/AF组合工艺稳定运行特性。一方面,对DN柱出水中TN、硝氮、TOC浓度及AF柱中出水TOC等水质指标进行评价,研究DN/AF组合工艺反硝化特性;另一方面,通过Miseq高通量测序技术和扫描电子显微镜,分析观察DN柱中玉米芯上生物膜的微生物群落组成和形态特征。研究结果表明,DN/AF组合工艺能有效去除水中硝酸盐,保证较低出水TOC,并保持良好的感官效果。反硝化滤池运行159d,单位质量碱处理玉米芯硝氮去除量可达1.32kg/kg,出水TOC在10mg/L以下;运行后期碳源相对不足时会出现亚氮的积累;玉米芯表面SEM图中可以看出,未利用前玉米芯表面非常粗糙,有较多的孔洞;微生物利用后玉米芯表面孔洞增加,并附有一层致密的生物膜,生物膜中微生物以球状和杆状菌为主,成簇生长在玉米芯的表面;根据Miseq高通量测序结果,对微生物在属水平进行聚类分析可知,生物膜中与反硝化作用有关的菌属和与纤维素降解有关的菌属,分别占已知菌属的40.35%和29.04%。因此,污泥中反硝化作用菌属和纤维素降解有关的菌属的大量存在,为复合碳源填料高效反硝化作用提供了可能。本研究在玉米芯作为反硝化碳源时预处理方式的对比筛选,新型复合碳源填料制备及微生物测序技术方面具有一定的新颖性,为改善现行再生水厂氮素含量较高现状,推进污水资源化利用,提高再生水水质方面具有积极意义。
[Abstract]:In order to solve the problems such as low denitrification efficiency of deep denitrification and solid cellulose carbon source in tail water of low C / N wastewater treatment plant, high TOC in effluent and easy plugging in packing layer, the corncob was taken as the research object in this study. The corn cob was pretreated with 1.5 NaOH _ 2 / H _ 2SO _ 4 and 1.5 H _ 2O _ 2 and alkaline hydrogen peroxide (NaOH solution containing 1.5 H _ 2O _ 2) and UV irradiation. The effects of various pretreatment methods on the carbon release and denitrification of corn cob were analyzed. A suitable pretreatment method for solid carbon source of corncob was selected, and Fe0, corncob and activated carbon were filled in the suspension ball of polyethylene with diameter of 80mm to make composite carbon source filler. The filling ratio of Fe0, corncob and activated carbon was determined by three factors and three levels orthogonal test, and the combined process of denitrification denitrification with facultative biological filter column (DN / AFF) was established. The main results are as follows: the static carbon release and denitrification experiments were carried out on the corncob after pretreatment, and the carbon release from the corncob after pretreatment was investigated. Denitrification performance and microbial attachment. The results showed that, considering the nitrate removal load, nitrate removal rate and surface characteristics of corncob, the corn cob treated with alkali was the most suitable. It is beneficial to the degradation and utilization of denitrifying microorganism. Using alkaline treatment of corncob Fe0 and activated carbon as composite carbon source filler, zero valence iron type, corncob / cob Fe0C) and Fe0/C were selected. The influence factors of corncob Fe0 and activated carbon combined denitrification system were determined by three factors and three levels orthogonal test. The results showed that nitrate removal rate, ammonia nitrogen accumulation, nitrous nitrogen accumulation and pH were used as the evaluation criteria of orthogonal experiment. The optimum conditions were as follows: iron wire, corncob / corn cob 5: 1 / Fe0 / C-1 / 2.The stable operation characteristics of DN/AF combination process were studied from macroscopic and microscopic angles. On the one hand, the water quality indexes such as TNC concentration in effluent of DN column, TOC concentration of nitrate nitrogen and TOC in AF column were evaluated. The denitrification characteristics of DN/AF combination process were studied. On the other hand, Miseq high-throughput sequencing technology and scanning electron microscope (SEM) were used. The microbial community composition and morphological characteristics of biofilm on corn cob in DN column were analyzed and observed. The results showed that the combined process of DN / AF could effectively remove nitrate in water. When the denitrification filter was run for 159 days, the removal of nitrate nitrogen in corncob could reach 1.32 kg 路kg ~ (-1) 路kg ~ (-1), the TOC of effluent was below 10 mg / L, and nitrogen accumulation would occur in the later stage of operation when carbon source was relatively insufficient. As can be seen from the SEM diagram of the corncob surface, the surface of the unexploited corncob is very rough, and there are many holes in the corncob surface, and the pores in the corncob surface are increased after microbial utilization, and a dense biofilm is attached to the corncob. The microbes in the biofilm were mainly globular and rod-like bacteria, which grew on the surface of corncob in clusters. According to the results of Miseq high-throughput sequencing, the cluster analysis of microbes in genus level showed that, The genera related to denitrification and cellulose degradation in biofilm account for 40.35% and 29.04 of the known genera, respectively. In this study, the pretreatment methods of corn cob as denitrification carbon source were compared and screened, the preparation of new composite carbon source fillers and microbial sequencing techniques were novel. In order to improve the present situation of high nitrogen content in reclaimed water plant, promote the utilization of wastewater resource and improve the water quality of reclaimed water, it is of positive significance.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703.1

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