Removal of Cadmium, Chromium, Lead and Copper from Industrial Wastewater by Aspergillus niger

Aspergillus niger was employed to remove a series of heavy metals (Cd-2, Pb2+, Cr6+, Cu2+) from a industrial wastewater in order to explore the effectiveness of heavy metals removal using Aspergillus niger. By orthogonal experiments, the optimal removal conditions by Aspergillus niger was found to be at stirring speed 150 rad center dot min-1, lml microbial inoculation, culture time 3d, pH 7.0. The microbial inoculation was the most important factor affecting the removal efficiency. The effect of heavy metal concentration was also investigated, and it showed that the removal efficiency of heavy metals by Aspergillus niger had the following order: Cd>Pb>Cr>Cu. The removal efficiencies of Cd2+ and Pb-+(2) in a high concentration were especially higher than those of other metal ions, the average removal rates reached 91.8% and 86.2%, respectively. The removal efficiency of cadmium was found to be in the range of 86.0%-100.0%. The overall effect on the degradation of copper (Cu2+) is not clear. It can be concluded that due to the relatively high adsorption capability, Aspergillus niger has the potential for the practical removal of heavy metals from wastewater.