一株异养硝化—好氧反硝化Cupriavidus sp. S1的筛选及降解特性研究

发布时间：2018-04-27 23:15

本文选题：异养硝化-好氧反硝化 + 贪铜菌属　；参考：《太原理工大学》2017年硕士论文

【摘要】：含氮废水的超标排放造成水体富营养化日趋严重,因此经济有效的去除水体中氮素是环境治理的关键。生物脱氮工艺因其高效率、低成本以及二次污染小等特点被认为是最佳的脱氮方法。而异养硝化-好氧反硝化作为一种生物脱氮新工艺,是目前废水脱氮方面的研究热点。含氮废水来源广泛,如焦化、石化、钢铁及钒、钨钼、镍钴、稀土等有色行业排出的废水,此类废水中同时含有高浓度的氨氮和大量的金属离子,而金属离子对微生物有毒害作用,因而影响脱氮效率。本文报道了一株从山西省晋中市益兴焦化股份有限公司的焦化废水中筛得的高效异养硝化-好氧反硝化细菌,并深入考察了菌株的异养硝化和好氧反硝化性能,此外,探讨了菌株应用于焦化废水的降解效果,以期为今后的实际工程应用提供技术指导。研究结论如下:1.分离出一株异养硝化-好氧反硝化细菌,通过形态学观察、生理生化实验并结合16S rDNA基因序列分析,鉴定该菌株为贪铜菌(Cupriavidus sp.),命名为S1。2.菌株S1的异养硝化特性实验表明,24 h内NH4+-N的降解率高达99.68%,最大去除速率为10.43 mg/L/h,TN的降解率为98.69%,在硝化过程中几乎无硝氮和亚硝氮的积累。s1的好氧反硝化特性研究表明,24h内no3--n和no2--n的去除率分别为98.03%和99.81%,最大转化速率分别为8.64mg/l/h和8.36mg/l/h,tn的去除率分别为97.4%和96.51%。气体检测结果表明,以nh4+-n、no3--n和no2--n为氮源时,n2是主要的异养硝化好氧反硝化产物,证明s1确实具有异养硝化好氧反硝化的能力。s1可以直接利用有机氮进行生长代谢。3.同步硝化反硝化研究表明,当(nh4)2so4和nano3或者(nh4)2so4和nano2同时作为氮源时,菌株s1都能将体系内的氮完全脱除。三种氮源中,s1会优先降解nh4+-n。4.菌株s1的最适脱氮条件为:温度28.67oc,初始ph7.44,摇床转速133.3rpm,碳源丙酮酸钠。较高的c/n比有利于nh4+-n的去除,且菌株对于高浓度氨氮和苯酚具有较强的耐受能力。5.考察了cu~(2+)、zn~(2+)、ni~(2+)和cr~(6+)对s1氨氮降解性能的影响,研究表明:zn~(2+)和ni~(2+)在一定浓度范围内对脱氮性能无抑制作用,而cu~(2+)对s1的脱氮性能的毒害作用随浓度增加而增大,cr~(6+)对细菌的毒害作用最大。浓度为10mg/l时四种金属离子对s1异养脱氮性能抑制程度强弱顺序为cr~(6+)cu~(2+)ni~(2+)zn~(2+)。与一般的异养硝化细菌相比,s1对金属有一定耐受性。6.利用菌株组合构建异养硝化好氧反硝化功能菌ncb(s1+y1+w4),处理稀释后的焦化废水,发现复合菌具有高效的氨氮去除能力。复合菌对nh4+-n、苯酚和cod降解率在144h后分别达到50%、40%和50%左右。利用菌丝球对复合菌进行固定,固定化微生物的降解性能显著提高,NH4+-N、苯酚和COD去除率较固定化前提高了24.69%、60%和10.56%左右。说明将复合固定化微生物应用于焦化废水的处理具有潜在的研究价值。
[Abstract]:The eutrophication of water body is becoming more and more serious due to the excessive discharge of nitrogen-containing wastewater, so the key to environmental treatment is to remove nitrogen from water body economically and effectively. Biological denitrification process is considered to be the best method for denitrification because of its high efficiency, low cost and low secondary pollution. As a new biological denitrification process, heterotrophic nitrification-aerobic denitrification is a hot spot in wastewater denitrification. Wastewater containing nitrogen is from a wide range of sources, such as coking, petrochemical, iron and steel, vanadium, tungsten, molybdenum, nickel, cobalt, rare earth and other non-ferrous industries, such as wastewater containing high concentrations of ammonia nitrogen and a large number of metal ions, Metal ions have toxic effects on microbes, thus affecting denitrification efficiency. This paper reports a high efficiency heterotrophic nitrification-aerobic denitrifying bacteria isolated from coking wastewater of Yixing Coking Co., Ltd., Jinzhong City, Shanxi Province. The heterotrophic nitrification and aerobic denitrification properties of the strains were also investigated. The degradation effect of the strain applied to coking wastewater was discussed in order to provide technical guidance for practical engineering application in the future. The conclusion of the study is as follows: 1. A heterotrophic nitrification-aerobic denitrifying bacterium was isolated. The strain was identified as Cupriavidus sp. sp., S1.2 by morphological observation, physiological and biochemical experiments and sequence analysis of 16s rDNA gene. The experimental results of heterotrophic nitrification of strain S1 showed that the degradation rate of NH4 -N was 99.68% and the maximum removal rate was 10.43 mg / L / L ~ (-1) TN in 24 h. The aerobic denitrification characteristics of nitrite nitrogen and nitrite accumulation during nitrification were almost zero. The results showed that the removal rates of no3--n and no2--n were 98.03% and 99.81%, respectively, and the maximum conversion rates were 97.4% and 96.51% for 8.64mg/l/h and 8.36 mg / L ~ (-1 / H) H ~ (2 +) n, respectively. The results of gas detection showed that when nh4 -nnno _ 3 n and no2--n were used as nitrogen sources, n _ 2 was the main product of heterotrophic nitrification and aerobic denitrification. It was proved that S1 had the ability of heterotrophic nitrification and aerobic denitrification. S1 could directly utilize organic nitrogen for growth and metabolism. Simultaneous nitrification and denitrification showed that strain S1 could completely remove nitrogen from the system when nh4k2so4 and nano3 or nh4n2so4 and nano2 were used as nitrogen sources. In the three nitrogen sources, nh4 -n.4. The optimum denitrification conditions of strain S1 were as follows: temperature 28.67oc, initial ph7.44, shaking speed 133.3 rpm, carbon source sodium pyruvate. The higher c- / n ratio was favorable to the removal of nh4-n, and the strain had strong tolerance to high concentration of ammonia nitrogen and phenol. The effects of cu~(2 and cr~(6 on the degradation of S _ 1 ammonia nitrogen were investigated. The results showed that cu~(2 _ ZN _ 2) and ni~(2) had no inhibitory effect on denitrification performance in a certain concentration range. The toxic effect of cu~(2 on the denitrification of S1 increased with the increase of concentration. When the concentration of 10mg/l is 10mg/l, the inhibition degree of four metal ions on S1 heterotrophic denitrification is in the order of cr~(6. Compared with the normal heterotrophic nitrifying bacteria, it has a certain tolerance to metal. 6. Heterotrophic nitrifying aerobic denitrification functional bacteria ncb(s1 y1 w4W were constructed by using strain combination to treat the diluted coking wastewater. It was found that the compound bacteria had high ammonia nitrogen removal ability. The degradation rates of nh4-n, phenol and cod reached 40% and 50% respectively after 144h. When the composite bacteria were immobilized with hyphal spheres, the degradation performance of the immobilized microorganisms was significantly improved, and the removal rates of phenol and COD were increased by about 24.6969% and 10.56% compared with those before immobilization. The application of composite immobilized microorganisms in coking wastewater treatment has potential research value.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X172;X703

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