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:
Project Type: RTD
| Contract Number: EVK1-CT-1999-00033
| Organisation Type:
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.
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
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
| Funding Programme(s):
EC Framework Programme 5
| Link to Organisations:
BRGM - Geosciences pour une Terre durable (Geosciences for a sustainable Earth)
Prof Paul Bardos
Who does what?
Professor Paul Bardos
Who does what?