Continuous flow fermentation to purify waste water by the removal of cadmium

Abstract

Fungi have been isolated that can tolerate and absorb high levels of heavy metals, especially Cd, when grown in a continuous flow air-lift fermenter with up to 10 throughputs per day. This allows the recovery of metals or the purification of industrial effluent streams. An average of over 97% of the Cd was removed from the simulated effluent during passage through the fermenter, reducing the Cd concentration from over 6 mg L−1 to less than 0.2 mg L−1. The biomass recovered contained up to 2.9% Cd (on a dry weight basis) and can either be disposed of or returned for smelting to recover the metal.