Analysis of anaerobic sludge containing heavy metals: A novel technique

Heavy metal ions are accumulated in anaerobic digesters outside the bacterial cells by precipitation and adsorption reactions, and inside the cells by microbial absorption. In order to gain a better understanding of the mechanisms which are involved in processes removing heavy metal ions from wastewater, and to be able to optimize the overall process, a novel analytical technique has been developed to separate heavy metal ions accumulated inside the bacterial cell from heavy metal ions accumulated outside the cell. This method has major advantages in comparison to existing methods, since it provides accurate and replicable results rapidly and requires only small sample volumes (< 10 ml). An illustration is given of the information gained about the nature of the biomass found in laboratory-scale UASB reactors, removing heavy metals from synthetic wastewater.