EXTRACTION OF HEAVY-METALS USING MICROORGANISMS AND HIGH-GRADIENT MAGNETIC SEPARATION

A large number of microorganisms have an affinity to ingest or precipitate ion species onto their surfaces. In the case of magnetic ionic species, magnetic separation methods could be applied to remove the ion-loaded organisms from the surroundings. A wide range of metal ions were studied. The results show that the microorganisms developed an appreciable magnetic moment which lends their removal by magnetic separation. In most cases, starting metal concentration of the order of 10 ppm were reduced to the 1 ppb level. This process will have applications in the mineral processing industry inaddition to the treatment of effluents from the nuclear industry, in the recovery of precious metals and other industrial plants.