Comparison of Various Reducing Agents for Methane Production by .

Biological methanation is driven by anaerobic methanogenic archaea, cultivated in different media, which consist of multiple macro and micro nutrients. In addition, a reducing agent is needed to lower the oxidation-reduction potential (ORP) and enable the growth of oxygen-sensitive organisms. Until now, sodium sulfide (NaS) has been used mainly for this purpose based on earlier published articles at the beginning of anaerobic microbiology research.