While studies on the potential of many biosorbents for heavy metal uptake have been reported, the results on scale-up are relatively scanty. Even in those papers where there is a report of reactor performance, more emphasis is given to the metal uptake part and the critical issue of headloss development in columns is not touched upon. This paper presents the results of a scale-up study conducted with an established biosorbent. Ganoderma lucidum, for uptake of rare earth elements. The uptake as well as the reactor characteristics are discussed. © 1994.