Problems to be solved
The presence of toxic Heavy Metals and Metalloids (HMM) in the environment greatly affects the quality of water and chain-food. In contrast to most organic pollutants, HMM are never degraded. The aim of the present proposal is to develop a number of bioprocesses, based on the activity of sulphate- and metal-reducing bacteria (SMRB), to prevent HMM pollution in water bodies by assessing and minimizing HMM pollution originating from contaminated sites. The possibility to treat efficiently and economically the metal-contaminated waters will contribute to meet one of the major demands of European citizens, namely the provision of affordable high quality water, while maintaining the integrity of ecosystems.
Scientific objectives and approach
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. In order to achieve the above-mentioned project objectives, the technical work consists of the following four main tasks:
· Improved biological tools for metal and sulphate reduction. This work will include the selection of sulphate- and metal-reducing bacterial stains (SMRB), and the improvement of the cytochrome efficiency.
· Monitoring of biological processes. New bio captors with whole cells or enzymes (cytochromes) will be built and used to monitor bio available metal content, and new methods will be developed to analyse the bacterial communities.
· Development of methods for the treatment of HMM pollutants in ground waters and soils. Direct and indirect reduction of the HMM with the SMRB will be exploited at laboratory scale in order to propose specific remedial strategies for each particular and actual contamination problem. The direct reduction of HMM by SMRB will be applied to ground waters using bioreactors (pump and treat) and also to soils after excavation, pulping or heaping, and inoculation (on site leaching). The indirect reduction of HMM by sulphate-reducing bacteria will be applied to ground waters using bioreactors (pump and treat). In site active barriers will be used for soil pore waters.
· Technical feasibility and economic assessment of the treatment of HMM in ground waters and soils. Modelling and simulation of the retained processes will follow setting up in-site and on site pilot operations.
The present project proposes the development of processes more efficient and less expensive than classical methods to remove metals from contaminated water and soil. This purpose converges with the trends of the new Water Framework Directive, setting the objectives for water protection well into the next century. Direct and indirect mechanisms of metal reduction by SMRB should produce high quality water. For an economical point of view, the development of better methods to treat waters and polluted soils will help to reinforce the technological independence of Europe. For the companies and particularly SMEs specialized in soil and water treatment, the project will introduce new products and open new markets.
Funding SchemeCSC - Cost-sharing contracts