Use of a Rotating Biological Contactor for
Removal of Ammonium from Mining Effluents
and mill effluents often contain appreciable quantities of ammonia. The discharge of
effluents containing ammonia to aquatic systems can have significant environmental effects
because ammonia is toxic to fish and other organisms. The Rotating Biological Contactor
(RBC) technology has been in use for several years for the treatment of municipal and
industrial wastewater. This study evaluates the application of RBC technology for the
removal of ammonia from mining industry effluents. The research shows that the RBC is very
effective in the removal of ammonium (NH4-N) from simulated mining effluents in
the temperature range of 4.5 to 24 oC and pH values ranging from 7.5 to 8.0.
The RBC was able to remove more than 95% of the influent NH4-N (at a
concentration of 45 mg/L) at a hydraulic retention time (HRT) of 1.7 h and a hydraulic
loading rate (HLR) of 0.04 m3/m2•d at ~ 8 oC. At 4.5 oC
the RBC produced an effluent with NH4-N and NO2-N concentrations of
0.1 and 0.7 mg/L, respectively, at HRT of 3.2 h and HLR of 0.02 m3/m2•d.
The results show that RBC biological treatment systems are capable of treating mine
effluents at cold temperature conditions (4 to 5 oC) for ammonia removal. The
RBC was observed to recover approximately 50% to 75% of normal ammonia removal process
efficiency in about a day after process upsets.