摘要
低温、低碳氮比(BOD5/TN)污水的有效脱氮一直是北方城镇污水处理厂亟待解决的难题.对从哈尔滨地区低温(4～6 ℃)地下水中筛选获得的优势菌Y24-6进行研究,初步鉴定其为假单胞菌属(Pseudomonas),研究发现菌株Y24-6在自养条件下对硝酸盐去除率为(24.00±1.24)％.通过分析Pseudomonas sp.Y24-6对NO3--N的去除过程,发现其在2 h内对硝酸盐的去除速率最高,为25.91 mg·L-1·h-1.基因组(序列号:JACBXG000000000)分析结果表明,菌株Y24-6通过CsrA、GlnL、GlnK和GlnA信号蛋白调控菌株的碳、氮代谢,且其中存在CO2固定的关键酶基因(ppc和icd),在有机碳源不足时可通过固定环境中的CO2来去除NO3--N.将菌株Y24-6固定在S3型填料,24 h后每个填料可形成的菌量为(7.3±3.7)mg.用固定化的菌株Y24-6处理BOD5/TN＜1、4℃的实际污水,TN的去除率平均为(34.55±0.09)％,对低温低碳氮比污水处理效果显著,本研究结果为寒区城镇污水冬季脱氮提供了参考依据.
Abstract
Nitrogen removal became a common problem for municipal wastewater with low organic carbon(BOD5/TN)at low temperature.The predominant strain Y24-6 was isolated from 4～6 ℃ groundwater in Harbin region.The preliminary identification results show that it is related with the genus of Pseudomonas.The strain Y24-6 is found to remove nitrate with the efficiency of(24.00±1.24)％at autotrophic condition.The NO3--N removal process was analyzed and the highest nitrate removal appeared at the primary 2 h with the removal rate of 25.91 mg·L-1·h-1.The genome(Accession No.:JACBXG000000000)analysis results show that the strain Y24-6 regulates carbon and nitrogen metabolism with CsrA,GlnL,GlnK and GlnA signal regulator.Key CO2 fixation genes(ppc and icd)existing in the strain Y24-6 show that it can fix CO2 as carbon source to remove NO3--N as lack of organic carbon.The strain Y24-6 is immobilized on the S3 carriers and(7.3±3.7)mg of bacterial content is developed on carriers after 24 hours'immobilization.The immobilized strain Y24-6 is used to treat real wastewater of BOD5/TN＜1 at 4 ℃.TN removal efficiency is(34.55±0.09)％,which shows significant effect in low BOD5/TN wastewater treatment at low temperature.The results obtained in this study propose references for nitrogen removal from municipal wastewater in winter of cold region.
基金项目
黑龙江省自然科学基金资助项目(LH2019E074)
国家级大学生创新训练计划项目(202010212029)
NETL
NSTL
维普
万方数据