脱硫脱氮细菌的分离筛选及其生物强化效能研究

发布时间：2018-08-26 11:32

【摘要】：高效脱硫脱氮细菌的分离筛选对于提高同步反硝化脱硫工艺的效能具有重要意义。本课题从稳定运行的同步反硝化脱硫工艺的膨胀颗粒污泥床(Expanded Granular Sludge Bed-Denitrifying Sulfide Removal,EGSB)反应器污泥中成功地分离出1株自养脱硫脱氮菌,经16S r RNA基因同源性分析初步鉴定为硫杆菌属(Thiobacillus sp.)和4株异养脱硫脱氮菌:HDD1、HDD2、HDD3、HDD4,分别被鉴定为索氏菌属(Thauera sp.)、产碱杆菌属(Alkaliflexus sp.)、固氮弧菌属(Azoarcu sp.)和假单胞菌属(Pseudomonas sp.)。通过对5株细菌脱硫脱氮性能的研究发现,当硫化钠、硝酸钾和乙酸钠的初始浓度分别为1.5、0.75和1.0 g/L时,菌株HDD1在16 h内对各底物的平均去除速率均高于其他菌株,24 h后硫化钠、硝酸钾、乙酸钠的最终去除率均达到95%以上,高于其他所分离菌株的最终去除率。选取去除效能最高的异养菌株HDD1作为生物强化实验的投加菌,探究了不同碳氮摩尔比和初始硫离子浓度对菌株HDD1脱硫脱氮过程的影响。当培养基中碳氮摩尔比为1.26:1时,菌株HDD1对硫化钠、硝酸钾和乙酸钠的去除效果较好,15 h内对各底物的去除率可达90%以上,对各底物的去除速率均高于碳氮摩尔比为0.75:1时的去除速率。当培养基中初始硫离子的浓度低于200 mg/L时,菌株HDD1对各底物的最终去除率均在95%以上,较初始硫离子的浓度大于200 mg/L时各底物的最终去除率高约30%。通过生物强化实验,考察了菌株HDD1的投加对反应器模拟体系对硫化钠、硝酸钾和乙酸钠等目标去除物去除效能的影响。当模拟体系中投加菌株HDD1的菌体细胞数量约为4.92×1010个时,生物强化的效果明显,在6-7 h内各目标去除物的降解率达到99%左右,降解时间较未生物强化的对照组缩短了1 h。本课题所分离筛选的高效脱硫脱氮菌将为生物脱硫脱氮工艺的研究提供重要的微生物资源,研究高效脱硫脱氮菌生物强化效能对同步反硝化脱硫工艺的优化调控将起到重要的指导作用。
[Abstract]:The separation and screening of high efficiency desulphurization and denitrification bacteria is of great significance for improving the efficiency of simultaneous denitrification desulfurization process. In this paper, a strain of autotrophic desulphurization and denitrification bacteria was successfully isolated from the sludge of the expanded granular sludge bed (Expanded Granular Sludge Bed-Denitrifying Sulfide Removal,EGSB) reactor with stable running simultaneous denitrification and desulphurization process. The homology analysis of 16s r RNA gene was preliminarily identified as (Thiobacillus sp.) belonging to Thiobacillus sp. And 4 strains of heterotrophic desulphurization and denitrogenation bacteria, 1: HDD1, HDD2, HDD3, HDD4, were identified as (Thauera sp.), Alcaligenes, (Alkaliflexus sp.), Azovibrio, (Azoarcu sp.), respectively. And Pseudomonas (Pseudomonas sp.). The results showed that when the initial concentrations of sodium sulphide, potassium nitrate and sodium acetate were 1.5 渭 g / L and 1.0 g / L, respectively, the average removal rate of each substrate in 16 h by strain HDD1 was higher than that of other strains after 24 h. The final removal rate of potassium nitrate and sodium acetate were over 95%, which was higher than that of other isolates. A heterotrophic strain HDD1 with the highest removal efficiency was selected as adding bacteria in the biointensification experiment. The effects of different molar ratio of carbon to nitrogen and initial sulfur ion concentration on the desulfurization and denitrification process of strain HDD1 were investigated. When the molar ratio of carbon to nitrogen was 1.26: 1, the removal efficiency of sodium sulfide, potassium nitrate and sodium acetate by strain HDD1 was better than 90% in 15 h. The removal rate of the substrates was higher than that of the carbon-nitrogen molar ratio of 0.75: 1. When the initial concentration of sulfur ion in the medium was lower than 200 mg/L, the final removal rate of each substrate by strain HDD1 was over 95%, which was about 30% higher than that of the substrate when the initial concentration of sulfur ion was more than 200 mg/L. The effects of HDD1 addition on the removal efficiency of sodium sulfide, potassium nitrate and sodium acetate were investigated by biological intensification experiments. When the number of bacterial cells added with strain HDD1 was about 4.92 脳 1010, the bioenhancement effect was obvious, and the degradation rate of each target in 6-7 h was about 99%, and the degradation time was 1 hour shorter than that of the control group without bioenhancement. The high efficiency desulphurization and denitrification bacteria isolated and screened in this paper will provide important microbial resources for the study of biological desulfurization and denitrification process. The study of biological enhancement effect of high efficiency desulfurization and denitrification bacteria will play an important role in optimizing and regulating the simultaneous denitrification desulfurization process.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;X172

【参考文献】