Diversity Analysis And Optimization Of Bacteria In Biological Treatment Of Coalbed Methane Produced Water In The Eastern Margin Of Ordos Basin

The eastern margin of Ordos Basin is the key block of coalbed methane exploration and development in China.The produced water in this block has the characteristics of high mineralization and high concentration of COD and ammonia nitrogen in some areas.The direct discharge of produced water will cause environmental pollution and other problems.Therefore,the produced water must be treated stably and discharged to the standard.According to the characteristics of the water quality of the coalbed methane produced water in the eastern edge of Ordos Basin,the biological aerated filter(BAF)was used to treat the coal bed methane produced water.Finally,an efficient bacterial mixture matching the water quality was selected,and the bacterial community structure and microbial diversity in the device were analyzed by using Illumina miseq high-throughput sequencing technology and achieved the following results:(1)The laboratory experiment shows that the 1~#bacteria agent is the most effective for the removal of COD and ammonia nitrogen from the coalbed methane produced water of a station in the eastern edge of Ordos Basin,the removal rates are63.5%and 51%,respectively,and the microbial survival and reproduction ability is strong and the stability is good.(2)The field test shows that the average removal rates of COD and ammonia nitrogen are 72%and 99%,respectively,the effluent can meet the discharge standard continuously,and the treatment effect of the produced water is good.(3)In the study of microbial diversity,the biological abundance and diversity of aerobic filter are higher than that of anaerobic filter,but the microbial functions of the two filters tend to be stable and complete.The dominant microbial population in the 1~#bacteria agent is Fimicutes,which can degrade COD and lactic acid,and Proteobacteria,which can remove nitrogen and phosphorus.