【作者】 段莎丽；

【导师】 邓仕槐；

【作者基本信息】 四川农业大学 ， 环境工程， 2008， 硕士

【摘要】 亚硝酸细菌催化氨氮氧化的硝化作用是氮循环的关键步骤,也是现代污水处理厂生物处理氨氮废水的重要环节。自然状况下的化能无机自养亚硝酸细菌具有生长速率低、生物量小和对pH、NaCl、氨氮浓度等环境因子敏感等生理特点。其中pH值与废水中的游离氨（FA）和游离亚硝酸（FNA）的浓度相关,是影响脱氮的重要因素。本文在实验室条件下通过控制好氧污泥驯化的pH值,使目的菌株不断增殖,逐渐成为优势菌株,然后对驯化污泥中的亚硝酸细菌进行分离培养和研究。通过定性检测亚硝酸的生成进行筛选,分别在各个pH条件下分离得到了一株亚硝酸细菌。本文对这6株细菌进行了初步鉴定,并研究了其氨氧化特性。研究结果表明:（1）驯化后的活性污泥在相应pH条件下具有氨氧化能力,均有亚硝酸细菌的生长。（2）根据形态及生理生化实验将分离得到6株细菌鉴定为亚硝酸球菌属（Nitrosococcus）。（3）通过对各菌株进一步的研究,表明在pH为5和6条件下筛选出来的菌株AOBpH5和AOBpH6对pH有较为广泛的适应性,在pH条件为9和10条件下筛选出来的菌株AOBpH9和AOBpH10对碱性条件有较强耐受性,而在pH条件为7和8条件下筛选出来的菌株AOBpH7和AOBpH8则只在中性和弱碱性条件下氨氧化能力较好。（4）AOBpH5在NaCl浓度为5g/L时氨氧化能力最强,并且较高氨氮浓度促进细菌的氨氧化能力升高:AOBpH6的最适NaCl浓度为20g/L,最佳氨氮初始浓度为50mg/L;AOBpH7在较高NaCl浓度和NH₄⁺-N起始浓度下有利于细菌的氨氧化能力的提高;AOBpH8其氨氧化能力随NaCl浓度和NH₄⁺-N起始浓度升高而增加;AOBpH9在NaCl浓度为5g/L时氨氧化能力最强,并且较高氨氮浓度促进细菌的氨氧化能力升高;AOBpH10在碱性环境条件下有较为广泛的适应性最佳NaCl浓度和NH₄⁺-N起始浓度分别在10g/L和20mg/L。更多还原

【Abstract】 Nitrification,performed oxidation of ammonia to nitrate by ammonia-oxidizers is a key process in the cycling of nitrogen and an impotent component of modern wastewater treatment.Ammonia-oxidizers have many unfavorable physiological characteristics, namely,slow growth,small biomass and susceptible to environmental factors.Among the total,pH value is correlated with FA and FNA level of wastewater,this make it to be the important factor of denitrogenation.We directly enriched ammonia-oxidizers of activated sludge via controlling pH factors of sludge acclimatization,to increase the biomass of destination bacteria gradually to be the ascendancy strain.By the procedures of primary screening in which ammonium oxidation was measured qualitatively,six strains of ammonia-oxidizers under there corresponding pH conditions.We identified these six bacteria and studied their character of oxidize ammonia.The results are summarized in the following:(1)The acclimated active sludge had capacity of oxidize ammonia under their corresponding pH factors,and they had ammonia-oxidizers.(2)Through analyzing physiological properties,the results showed that the six strains all identified as Nitrosococcus.(3)During the study,the AOBpH5 and AOBpH6 screened from the pH conditions of 5 and 6,showed the had wide pH adaptability.And AOBpH9 and AOBpH10 screened from the pH conditions of 9 and 10 had better toleration of alkalinity.AOBpH7 and AOBpH8 screened from the pH conditions of 7 and 8 only had better ammonium oxidation in neutrality and weak base condition.(4)AOBpH5 had the best capacity of oxidize ammonia when the concentration of NaC1 was 5g/L,and it increased with the rising of concentration of ammonia nitrogen.The best concentration of NaC1 to AOBpH6 was 20g/L,and the concentration of ammonia nitrogen was 50mg/L.The higher concentration of NaC1 and ammonia nitrogen was better to AOBpH7.To AOBpH8,the capacity of oxidize ammonia increased with the rising of concentration of ammonia nitrogen.AOBpH9 had the best capacity of oxidize ammonia when the concentration of NaC1 was 5rag/L,and it increased with the rising of concentration of ammonia nitrogen.The best concentration of NaC1 and ammonia nitrogen to AOBpH10 was 10g/L and 20mg/L.更多还原