What are the possibilities of using microbes for heavy metal removal from waste water?

I recently visited a small scale foundry for environmental inspection.  They have a small waste water treatment unit also. My job was to conduct chemical analysis of the treated water. In the process we measured some of the factors like pH, temperature, electrical conductivity, concentration of iron and total organic carbon – TOC. And we found out that there is still heavy metal that is Iron (Fe) in the treated water. The existing treatmnet procedures require a lot of expenditure to upgrade and modify.  I was reading that some of the microbes could do this job very easily. Can anyone guide me if we want to treat waste water containing iron, can microbes be used for this purpose? What are the different microbes to be used? I hear that F. thioxidans will remove Fe from waste water. Has anyone used this? Your experience much appreciated and will guide us.