Effect of flow rate on heavy metal accumulation by rotating biological contactor (RBC) biofilms

摘要

Immobilized biofilms are effective in heavy metal removal. The current studies investigated the use of rotating biological contactor (RBC) biofilms in treatment of a wastewater containing cadmium, copper and zinc, each at a con- centration of 100 mig L~(-1). In particular, the influence of hydraulic retention time (HRT) on metal accumulation was studied. Longer HRTs (>12 h) were associated with greater metal removal than short ARTs, particularly with regard to cadmium and zinc. The system was also shown to operate successfully over an extended period of time, at an HRT of 24 h, with removal efficiencies of approximately 34%, 85% and 57% for Cd~(2+), Cu~(2+) and Zn~(2+) respectively after 5-8 weeks contact.