Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Extractive membrane bioreactors for detoxification of chemical industry wastes

The project is aimed at developing a biotechnology for use in cleaning up toxic aqueous wastes generated by the european chemical industry. Many aqueous wastes emanating from the chemical industry have high concentrations of inorganic species (acids, bases, metal, salts) and are contaminated with low levels of highly toxic organic molecules. If the toxic organic molecules can be removed, the wastes can be safely disposed of, or even re-used. The extractive membrane bioreactor (EMB) is an innovative new biotechnology for dealing with these wastes. The EMB places a membrane between the waste and a nutrient medium, which contains micro-organisms able to break down the organics in the waste-water to carbon dioxide and water. The membrane protects the micro-organisms from the effects of the high ionic strength of the wastes but allows the organics to permeate from the waste into the nutrient biomedium. With the support of the Environment of Climate Programme, it has been possible to assemble a consortium of universities, research institutes and companies to develop and apply this technology.

Work at GBF in Braunschweig is addressing the development of stable microbial consortia which are able to break down range the toxic organics which have been targeted for attention in the project. Both batch and continuous enrichment processes have been used to isolate a range of new microbial cultures. At the Universidade Nova in Lisbon, work is concentrating on understanding and controlling growth of microbial biofilms on the surface of the membrane tubes. This is important for controlling biodegradation activity on-line. XFlow, a membrane producer based in Almelo, are applying their expertise to manufacture of improved membranes for use in the EMB, with the specific goals of improved flux for hydrophilic organics and improved chemical resistance. At Imperial College in London, membrane mass transfer is being studied together with on-going improvement of microbial strains. Also at Imperial College, mini-EMB units are being operated using cultures from GBF, membranes from XFlow and operating conditions dictated by the results of work at Universidade Nova. These micro-EMB units (5-10 litres per day) are used as a stepping stone to the operation of larger mini-EMB units at the sites of chemical company partners Hickson and Welch of Castleford and Solvay Deutschland in Hanover. Waste flows of up to 500 litres per day have been treated on site with over 99% removal of the toxic organic species present.

It is anticipated that this successful research project will be followed up by a technology transfer project aimed at a full pilot scale operation of an EMB unit.

Reported by

Imperial College of Science, Technology and Medicine
Prince Consort Road
SW7 2BY London
United Kingdom
See on map