Chromium removal from a real tanning effluent by autochthonous and allochthonous fungi

Heavy metals represent an important ecological and health hazard due to their toxic effects and their accumulation throughout the food chain. Conventional techniques commonly applied to recover chromium from tanning wastewaters have several disadvantages whereas biosorption has good metal removal performance from large volume of effluents. To date most studies about chromium biosorption have been performed on simulated effluents bypassing the problems due to organic or inorganic ligands present in real industrial wastewaters that may sequestrate the Cr(III) ions. In the present study a tanning effluent was characterized from a mycological point of view and different fungal biomasses were tested for the removal of Cr(III) from the same tanning effluent in which, after the conventional treatments, Cr(III) amount was very low but not enough to guarantee the good quality of the receptor water river. The experiments gave rise to promising results with a percentage of removed Cr(III) up to 40%. Moreover, to elucidate the mechanisms involved in biosorption process, the same biomasses were tested for Cr(III) removal from synthetic aqueous solutions at different Cr(III) concentrations.