Enhancement of Cr(VI) reduction by indigenous bacterial consortia using natural pyrite: A detailed study to elucidate the mechanisms involved in the highly efficient and possible sustainable system.

Pyrite was applied to Cr(VI) bioremediation as an inorganic electron donor due to the ability to provide electrons, while the role of pyrite in Cr(VI) bioremediation where organics as electron donors remains unknown. Herein a pyrite-based Cr(VI) bioreduction process in the sediment system containing lactate was demonstrated to be effective to detoxify Cr(VI): over 2200 mg L Cr(VI) was continuously removed within 210 h with high reactivity (10.5 mg/(L·h)) all along.

Conductive property of secondary minerals triggered Cr(VI) bioreduction by dissimilatory iron reducing bacteria.

Although secondary minerals have great potential for heavy metal removal, their impact on chromium biogeochemistry in subsurface environments associated with dissimilatory iron reducing bacteria (DIRB) remains poorly characterized. Here, we have investigated the mechanisms of biogenic secondary minerals on the rate of Cr(VI) bioreduction with shewanella oneidensis MR-1. Batch results showed that the biogenic secondary minerals, schwertmannite and jarosite, appreciably increased the Cr(VI) bioreduction rate.