Background Wales has a long history of base metal mining and this has left a legacy of highly contaminated spoil tips and drainage waters. Galena, and later sphalerite, were the main minerals exploited in the ore bodies that, in this area, have a low pyrite content and typically no carbonate in the gangue. These drainage waters are circum-neutral, but still highly contaminated and cause significant water quality failures in the receiving water courses (e.g. the Freshwater Fish Directive 78/659/EEC) and ultimately to the pollution of the sea. Of particular concern are cadmium, lead and nickel, which have been identified as ‘Priority hazardous substances’ (ENV/191000/01); along with the ubiquitous zinc. In 2000 nearly 200km of river systems in England and Wales failed water quality standards as a result of metal pollution from abandoned mines. Traditional methods of cleaning these drainage waters are usually costly and require large areas of land, such as removing the iron by decreasing the acidity of the water and then further treatment to remove the remaining metals. This is undertaken through "active" chemical treatment or "passive" treatment such as allowing the acidic water to flow over the limestone to reduce the acidity, and then through reed beds to slow down the flow and allow the iron to precipitate. Objectives The BIOMAN project was to demonstrate a combined water treatment process to remove hazardous/toxic metals (such as cadmium, nickel, zinc and lead) from waters draining from abandoned mines at sites in Wales and Italy using a novel bioabsorber. Dealginated seaweed (a waste product from the alginate industry) was to be used as a bioabsorber. This project was to be conducted in 3 phases: Phase I Define the absorption characteristics of the dealginated seaweed in a series of laboratory based experiments Develop a method to pre-treat the drainage waters to raise the pH and remove the iron from solution Determine the stability of the precipitated iron Evaluate the performance of the dealginated seaweed (without any chemical pre-treatment) in the field using a dealginated seaweed only trial plant Phase II Incorporate the results from phase I into the design and construction of 2 Pilot Treatment Plants (PTP) which were to be deployed and operated at mine sites of differing chemical and climatic characteristics in Wales and Italy. Phase III Redeploy the PTPs to extend the range of climatic coverage and metal mine drainage compositions Operational parameters of the PTPs were to be incorporated into the design and build of a Large Scale Treatment Plant (LSDP). Results The Bioman LIFE project was set up to deal with the problem of mine drainage from abandoned metal mines. This drainage is often contaminated with potentially harmful elements which enter local water courses. Abandoned metal mines exist throughout Europe and continue to contaminate surface water long after they are abandoned. The technological approach adopted during this project was to produce a filter system which used the waste product from the processing of brown seaweed. Brown seaweed is used as a source of alginates which are additives for the food/cosmetic/pharmaceutical industries. The waste product from this industry, dealginated seaweed, has been shown to act as an adsorber of potentially harmful elements (PHEs) which are contained in water. Dealginated seaweed is, therefore, a bioadsorber. This project has shown that the technology works and that dealginated seaweed is capable of removing potentially harmful elements from mine water in a low technology, transferable and sustainable system. The systems designed during this project do not require any source of energy and simply work on gravity filtering. Small scale tests were completed in the laboratory. These tests defined the ‘best’ conditions for the bioadsorber to remove metals from the water. The conditions are that the water must be in contact with the adsorber for 10 minutes and the pH of the solution must be close to neutral. The results of the small scale tests were used to produce the first field-based system which has successfully treated 1 litre per minute of contaminated mine water. The test system removes more than 90% of the zinc, cadmium and lead from the mine water in the initial stages. As the adsorber becomes saturated the zinc and cadmium are less strongly retained but the lead continues to be removed from the water. Test results have been compiled from three different mine sites in Wales and one mine site in Italy. A second system, capable of treating 10 litres per minute of contaminated mine water was tested at one of the mine sites in Wales, but the design required some modification. This was to be completed in 2007. There were problems encountered in the project such as the difficulty to obtain a supply of dealginated seaweed. This meant that the project did not manage to build a large scale development plant. However, at the end of the project, the BIOMAN team were investigating the possibility of applying for funds to take the work further so that a large scale plant could be built. The project has demonstrated that the process of Bioadsorption can be applied to different mine waters in different geographical and hydrogeological settings. Long term trials were completed at 3 different mine sites in Wales treating between 1 and 2 L min-1 of contaminated mine water. The BIOMAN team were encouraged by the performance of the systems and intended to continue with the trials of a modified larger system. Project dissemination was also very well done, with a large number of articles in the press, exhibitions and presentations at conferences. The beneficiary was pro-active, e.g. inviting the press to the installation of the treatment system which led to TV coverage. A Canadian television channel, The Discovery Channel, broadcast a report about the project in their science series "Daily Planet". Finally, the project won the UK category of the Energy Globe Awards 2006.