Characteristics of preponderant bacteria enhancing the nitrate removal from wastewater with low ratio of carbon to nitrogen at low temperature
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.
NETL
NSTL
万方数据
维普
