Trace metal dynamics in methanol fed anaerobic granular sludge bed reactors

Trace metals are essential for anaerobic microorganisms, because they are present as cofactor in many of their enzymes. Therefore anaerobic wastewater treatment systems using these microorganisms to perform biological conversions are dependent on these metals for their (optimal) performance. In practice these metals are supplied to the influent when they are absent or insufficiently present in the wastewater. This supply is generally not very rational. However, such a rational metal supply is desired in order to reduce the costs, to minimize the introduction into the environment and to maximize the biological activity. To achieve this insight, in the trace metal dynamics in anaerobic granular sludge bed reactors is required. This thesis therefore focuses on the retention, accumulation and release of trace metals in anaerobic granular sludge and the factors affecting these processes. Further the impact of metal presence/absence and dosing on the anaerobic conversion of methanol was addressed