Research on the Effect and Kinetics Mechanism of Biological Iron-Removal from Groundwater

In the present article, the treatment of groundwater containing Fe(II) has been investigated. The oxidation processes were mediated by specific bacteria, namely the Leptothrix ochracea and Gallionella ferruginea, which belong to the general category of iron oxidizing bacteria. This work was focused on the characterization of the products of biological oxidation and to the examination of the kinetics of Fe(II) removal from groundwaters. When pH5.6~6.0, 0.5~1.5 mg/l DO, 8 m/h velocity of filtration ,it has achieved good effluent quality with trace amount of total iron. By the sterilizing test and the bacterial count,the filter indicates that the effect of iron removal by biological oxidation is significant. And through the bed analysis method we test the iron concentration of the effluent to study the kinetics rule of biological removal of iron . The kinetic results indicated that the rates of iron oxidation were several orders of magnitude greater than the abiotic oxidation. The oxidation state of iron in the precipitates was found to be mainly in the form of amorphous ferrihydrite.