Synergistically improved methane production from anaerobic wastewater treatment by iron/polyaniline composite

The methane (CH4) production could be enhanced effectively by adding iron oxides and polyaniline (PANI) composite in anaerobic wastewater treatment. Synergic improvement on the methane production was observed in anaerobic system which was amended by the iron oxides/PANI composite. A total of ~530 mL of methane was produced from the anaerobic bio-system added composite, which was ~1.5 times of the sum of the systems added with the iron oxides and PANI. Then, the effect of the addition of the iron oxides/PANI composite on the degradation of organics, metabolism of the acetic acid, and the bio-electron transfer at the interface of composite was also investigated. The results showed that the iron oxide component in composite increases the activity of PTA enzymes to improve the production of acetic acid, thereby increase the methanogenesis by the acetoclastic methanogens. The PANI layer of the composites has a high bio-affinity, which makes the bio-electron transfer between the interface of electron-carrier and the material easier. Generally, the addition of iron oxides/PANI composite improved methanogenesis by the acetoclastic methanogens as well as improve the microbial extracellular electrons transfer at the interface of material.