aim of this study was to evaluate the effect of copper and iron on acidogenic
biomass immobilized on clinoptilolite in an anaerobic packed bed reactor.
Copper and iron were fed to the reactor at concentrations of 100 and 300 mg·L-1, respectively. Both metal ions had
insignificant inhibitory effect over the metabolism of the biomass,
specifically, on substrate consumption and production of volatile fatty acids
(VFAs). The microstructural characterization of the biofilm by Scanning Electron
Microscopy showed no effect on the morphology of the microorganisms after the
metals treatment. Copper and iron removal was also measured in the reactor,
achieving a breakthrough time of 3 days, during which removal efficiencies were
higher than 90%. It was also observed that the biomass had a greater affinity
for copper. The results indicate that acidogenic biomass can be used
effectively as a sorbent agent. The pollution of river-streams with heavy
metals—mainly copper and iron—was one of the most compelling
motivations for conducting this investigation. The San Pedro River Basin, a
trans-boundary river that originates near the mining town of Cananea, Sonora,
México, and flows to Arizona, USA, exemplifies this environmental issue.