Composition Feature Of Microbial Communities In Acid Mine Drainage From Yangquan Mining Area And Its Impact On Water Quality Downstream

The pollution of acid mine drainage is a serious environmental problems in coal mining area.Since several coals in Yangquan mining area has been forbidden producing,large amount of acid mine drainage turned up in this area,which impact the ecological environment and health of resident seriously.In order to explore the feature of communities composition in acid mine drainage from Yangquan mining area and estimate the impact of acid mine drainage on water quality downstream,Yangquan mining area and basin of Shandi river were chose as research sites.The samples were collected in summer,winter,and spring of 2017-2018 from Yangquan mining area in which AMD1 was from a disused mine at Xiaogou village,AMD2 was from an open pond circled by a surface mine at Xiaogou village.After the physiochemical property were determined,the bacterial community in each sample was analyzed using the high-throughput sequencing technology.The composition feature and seasonal variation of microbial communities in each sample were analyzed by column of communities composition and hierarchical clustering analyze.The association of microbial communities and physicochemical factor was estimated by canonical correspondence analysis.The samples were also collected from Shandi river before and after the acid mine drainage penetrated and the water quality,concentration of heavy metal,chemical composition and bacterial communities were determined.The experimental results is as follows:(1)Bacterial communities were detected in all three seasons in AMD1 and AMD2,while archaea communities was only found in summer of AMD1 and summer and spring of AMD2.Autotrophic iron oxidizing bacteria were dominant lineages of which Acidithiobacillus and Gallionella were the main members of AMD1 in summer and spring and Ferrovum was the main genus of AMD2 in winter and spring.Iron-reducing bacteria was only the dominant genus in summer of which Acidiphilium was the major genus while sulfur-oxidizing bacteria,heterotrophic iron oxidizing and reducing bacteriaand average heterotrophic bacteria were the minor part of community.Archaea found in experiment excluded any iron-oxidizing and sulfur-oxidizing archaea with all members were heterotrophic,the only functional bacteria was a sulfur-reducing genus--Thermoplasma found in AMD1.(2)Hierarchical clustering analyze indicated that microbial community in Acid mine drainage was significantly varied during the sampling seasons and the bacterial communities in summer was especially different from winter.Canonical correspondence analysis suggest that temperature of water was the principle factor causing the variation of microbial communities.The seasonal differences was possible caused by the the susceptibility for temperature of bacteria in watercourse considering phenotype of main dominant genus.(3)After the acid mine drainage infiltrated,the concentration of Fe and Mn dropped dramatically with Fe up to 612.6mg/l and Mn up to 37.4mg/l,the total concentration of ion added around 3.6 times,and composition of ion species varied dramatically with the main iron were Ca2+?Mg2+?Na+?Fe2+ and SO42-.At the same time,the original bacterial communities upstream was seriously destroyed in which the average soil bacteria and floating bacteria disappeared and the anaerobic/ facultative anaerobic bacteria took up in high abundance.Above results indicate that we should pay more attention to Acidithiobacilllus,Gallionella,Ferrovum and Acidiphilium which are the main dominant genus in microbial communities in the management of acid mine drainage in future.The permeating of acid mine drainage had an serious impact on Shandi river,especially caused the pollution of sulfate and heavy metal,which will be a potential threat on the agriculture and safety of water consumption in basin of Shandi river,which also worth concerning in future.