Roles of iron and/or arsenic reducing bacteria in controlling the mobilization of arsenic in high arsenic groundwater aquifer

摘要

To investigate microbial mediated As release and mobilization in the high arsenic groundwater,indigenus iron/As reducing bacteria were isolated from high arsenic groundwater in the Hetao Basin of Inner Mongolia in China.These isolates were identified to be Fe(III) and As(V) reducing (IAR) Shewanella putrefaciens IAR-S1,Fe(III) reducing (IR) S.xiamenensis IR-S2 and Klebsiella oxytoca IR-ZA,and As(V) reducing (AR) Cit-robacter freundii AR-C1,Paralostridium bifermentans AR-P1,Klebsiella pneumoniae AR-K1 and Aeromonas hydrophila AR-A1-The incubation results showed that strains IAR-S1,IR-S2 and the control S.oneidensis MR-1 reduced ferrihydrite quickly and re-immobilized As.Strains AR-C1,AR-P1,AR-K1 and AR-A1 reduces As(V) to As(III).and arsenic (As(-tot)) was released into the aqueous phase with strain IR-ZA and strain AR-C1.