Enhancing anaerobic digestion of poultry blood using activated carbon

Abstract

Graphical abstract

Mitigation of Volatile Fatty Acid Build-Up by the Use of Soft Carbon Felt Electrodes: Evaluation of Anaerobic Digestion in Acidic Conditions

“…When fed with the acidic substrate, all reactors underwent rapid acidification, and negligible amounts of CH 4 were produced. Moreover, the AD reactor recovered partially after 60 h, whereas the electrode-integrated digesters did not resume CH 4 production.…”

“…When fed with the acidic substrate, all reactors underwent rapid acidification, and negligible amounts of CH 4 were produced. Moreover, the AD reactor recovered partially after 60 h, whereas the electrode-integrated digesters did not resume CH 4 production. This led to the hypothesis that the poor performance observed in the combined AD-BES reactors could be attributed to improper or insufficient adaptation of the anodic microorganisms to the operating conditions within the anaerobic digesters; the anodes used in this first test were grown with a synthetic effluent, using acetate as substrate and no digested sludge.…”

“…The AD reactor had an initial methane production rate of 0.14 L CH 4 kg VS −1 h −1 , while this value was, on average, 0.56 L CH 4 kg VS −1 h −1 for the OC reactors during the first 40 h. The electrodes adapted to acetate as a carbon source had the highest values of specific methane production within their homologous systems. This is probably because they contained greater microbial populations capable of metabolizing acetate.…”

“…The great demand of energy and the associated impact of fossil fuel consumption on the environment have elicited extensive research on alternative sources of traditional petroleum-derived products [2]. The use of wastes allows the recycling of nutrients, in addition to the production of energy, and offers a solution for the disposal of organic materials that are otherwise difficult to reuse (e.g., weeds, animal blood, manure) [3,4].…”

“…In MECs, exoelectrogenic microorganisms such as Geobacter or Shewanella degrade organic matter. The microorganisms are immersed in an anaerobic environment and, using a small electrical input, convert organic materials into valuable products (e.g., H 2 or CH 4 ). MECs can work with a wide range of substrates, with VFA-rich streams representing the ideal, since most organic acids can be readily converted to electricity by electrogens.…”