Abstract
In this study, we investigated the concentration of
trace elements in the digestates in a laboratory batch anaerobic
digester. Many of these trace elements are important macro
and micro nutrients. The availability of these nutrients for
microbes responsible for anaerobic digestion and substrate
toxicity have to be controlled in biogas production. The
analyzed substrates were characterized at various
concentrations in the following trace elements; potassium,
phosphorus, manganese, copper, calcium, molybdenum, zinc,
cobalt, iron, aluminum, silver, nickel and cadmium. Trace
elements like copper, silver, nickel, cadmium, zinc have been
reported to be inhibitory and toxic under certain conditions in
biochemical reaction depending on their concentrations. These
trace elements lower biogas production above threshold
concentration due to accumulation of organic acid as a result
of methanogenic bacterial inhibition. There was no deficit of
nutrients detected in the anaerobic digesters analysis.