| High arsenic groundwater has always been a major environmental geological problem in international hydrogeological circles.Reductive dissolution of arsenic-bearing iron oxide minerals has been recognized as the main cause of high arsenic groundwater.Arsenic-bearing iron oxides in high-arsenic groundwater aquifers are usually a mixture of various iron oxide minerals.It is of great significance to study the reduction and arsenic release characteristics of arsenic-bearing iron oxide minerals in situ groundwater arsenic enrichment mechanism.Therefore,this study used different kinds of iron reducing bacteria（only iron reduction ability of Shewanella oneidensis MR-1 and Inner Mongolia high arsenic groundwater sediments with arsenic iron reduction ability of separation of Clostridium sp.anHT01）reduction of different proportions of mixed arsenic oxide of iron mineral,explore microbial-carrying arsenic oxide iron interaction system’s influence on the migration behavior of arsenic.Gain the following knowledge:（1）In the reduction process mediated by iron reducing bacteria MR-1,the maximum reduction rate of aqueous iron ore from the phosphoric acid reaction system was 291 g·L-1·h-1,the reduction volume was 3501 M,the maximum release rate of arsenic was 276 g/L,the maximum reduction rate of aqueous iron ore from the carbonate system was 366 M/h,the reduction rate of aqueous iron ore was 3023 M,the maximum release rate of arsenic was 25 g/L.The reduction rate of aqueous iron ore in carbonate system was higher than that in phosphate system,but the total reduction was lower than that in phosphate medium.In the phosphoric acid system,arsenic is released first and then iron oxide is reduced.In the carbonic acid system,arsenic is reduced first and then released.The arsenic released in the phosphate system is greater than that in the carbonate system.（2）The reduction rate of MR-1 strain was 260 M h-1,the reduction rate of MR-1strain was 3023 M,the release rate of arsenic was 25 g·L-1·h-1,and only 201 M goethite was reduced.The maximum reduction of the mixed minerals was 2241 M,which was more than half of the sum of the two systems.Clostridium sp.anHT01reduced 3980 M hydrite in carbonate medium with arsenic release of 332 g·L-1·h-1,maximum reduction rate of mixed ore of 57 M·h-11 and maximum arsenic release of283 g·L-1·h-1.Finally,59.90%of the hydrated ore was reduced,only 167 M goethite was reduced,and the mixed system reduced 39.10%.Mineral mixture not only increases the reduction rate,but also increases the reduction degree of minerals,which increases from 27.10%to 30.6%.Clostridium sp.anHT01 promotes the migration of arsenic,and mineral mixing only affects the rate of arsenic release but not the total amount of arsenic release.（3）Shewanella oneidensis MR-1 reduced abiogenic iron ore at a rate of 70 M/h with a maximum reduction of 2104 M,but no arsenic in the solution was detected.The reduction rate was 126 M/h,the maximum reduction was 4229 M,the arsenic release rate was 16 g·L-1·h-1,the maximum arsenic release was 403 g/L,and the final release was 264 g/L.Clostridium sp.anHT01 reduced biogenic iron ore at a maximum rate of 84 M/h,at a maximum reduction rate of 4132 M,and released arsenic of 1325 g/L.The biogenic iron ore was not reduced,and the biogenic iron ore was reduced faster and at a higher degree than the non-biogenic mineral.As is more effectively fixed in the formation of the resulting secondary iron mineral（cyanite,siderite）. |
PDF Full Text Request