METALBIORDUCTION Development of technologies using the activity of sulphate and metal reducing bacteria (SMRB) to remove heavy metals and metalloids from ground waters and soils
Country: EU Projects
Start Date:   30/6/2000         Duration: 36 months         Project Type: RTD
Contract Number: EVK1-CT-1999-00033
Organisation Type:  EC Project
Topics: 
Contaminated land-->Remediation options-->In situ treatment technologies
Project objectives: 
The presence of toxic Heavy Metals and Metalloids (HMM) in the environment greatly affects the quality of water and chain-food. The aim of the project is to develop 
a number of bioprocesses, based on the activity of sulfate- and metal-reducing bacteria (SMRB), to prevent HMM pollution in water bodies by assessing and minimizing 
HMM pollution originating from contaminated sites. More precisely, the proposal objectives are (1) to obtain improved biological tools (bacteria and enzymes), 
and (2) to develop new, cost-effective and reliable technological alternatives for removing HMM from ground waters and soils.
Project Summary: 
Heavy Metals and Metalloids (HMM) greatly affect the quality of water and chainfood. In contrast to most organic pollutants, HMM are never degraded. The main 
ambition of the  project is to develop new bioprocesses based on the sulfate - and metal - reducing ability of bacteria to prevent HMM pollution in water bodies, 
and to assess and minimise HMM pollution  originating from contaminated sites. More precisely, the objectives are to obtain an improved fundamental understanding 
of the efficiency of biological processes for HMM remedy, and to  develop new, cost-effective and reliable technological alternatives for removing HMM from 
ground waters and soils. The treatements will be done aither on site through pump-and-treat  or bioleaching, or in-situ through biobarriers. The expected 
results are strains and enzymes that could have industrial market, tools for monitoring bioavailable metal content, and  technologically assesse processes 
for HMM remedy.
Achieved Objectives: 
The projects objectives were to obtain improved biological tools (bacteria and enzymes) and to develop effective and reliable technological alternatives 
for removing Heavy Metals and Metalloids (HMM) from ground waters and soils.    
    
Several sulphate reducing bacteria (SRB) from various environments such as mining sites, contaminated soils, or deep sea hydrothermal vents were isolated. 
Lactate, ethanol, methanol, acetate and H2 were used as electron acceptor to isolate these micro-organisms. After isolation using anaerobic techniques, 
some of these strains were characterised phenotypically, genotypically and phylogenetically.    
The physiological factors underlying Cr(VI) precipitation were investigated and the results demonstrate that Cr(VI) reduction can be catalysed by cytochrome 
c3 coupled to hydrogenase with both proteins being localised in the periplasm of the bacteria.    
    
In order to determine the optimum growth for SO42- and metal reduction, continous column test were carried out with different carbon sources, different 
N and P content and types of bioreactors    
    
After selection of a SRB (De. norvegicum) and purification of chromate-reducing cytochromes, the first type of biosensor constructed was an enzymatic 
amperometric biosensor.    
    
At laboratory scale experiments were performed with H2 provided as low-cost substrate. The direct enzymatic reduction of Cr(VI) by a fixed film of SRB was 
evaluated by eliminating SO42- and H2S in the medium.    
Experiments with U(VI) have shown that this contaminant can be removed from water only by direct biological reduction using SRB. SRB are responsible for 
the uranium reduction.    
    
The direct reduction of HMM by SMRB was applied to soils after excavation, pulping or heaping and inoculation. The metal addressed was As.    
Furthermore the technical feasability of the treatment of HMM in ground waters and soils was addressed by using technical data from pilot experiments.
Product Descriptions: 
The aim of the project was to obtain improved biological tools (bacteria and enzymes) and to develop effective and reliable technological alternatives for 
removing Heavy Metals and Metalloids (HMM) from ground waters and soils.    
    
A detailed publication list is available from the project website.
Additional Information:
Project Resources:

Development of technologies using the activity of sulphate- and metal-reducing bacteria (SMRB) to remove heavy metals and metalloids from ground waters and soils (Metalbioreduction): Detailed project abstract

Metalbioreduction Publications
Weblink:
http://metalbioreduction.brgm.fr/default.htm
Funding Programme(s): 
EC Framework Programme 5
Link to Organisations:

BRGM - Geosciences pour une Terre durable (Geosciences for a sustainable Earth)
Submitted by: EUGRIS Team Prof Paul Bardos  Who does what?  03/07/2003 17:48:00
Updated by: EUGRIS Team Professor Paul Bardos  Who does what?  03/10/2006 12:48:00