Internal enhancement mechanism of biochar with graphene structure in anaerobic digestion: The bioavailability of trace elements and potential direct interspecies electron transfer

Prediction of Biomass Pyrolysis Mechanisms and Kinetics: Application of the Kalman Filter

“…The solid residue from the pyrolysis of the biomasses is generally described as ''bio-char'', having a high carbon content with a color ranging from brown to black. The char also consists of ash and trace amounts of metals such as Na, K, Hg, Cd, Be, Se, Sb, As, Pb, Zn, Cr, Co, Ni [49][50][51], which may catalyze the pyrolysis reaction with an additional cracking reaction [52][53][54], supporting a serial reaction from bio-oil to gases as suggested in Models 1, 2, 4, and 5. On the other hand, free radicals may polymerize and produce high-molecular-weight products [28,29,55], as suggested in the reversible steps in Models 2 and 5.…”

Improvement of Direct Interspecies Electron Transfer via Adding Conductive Materials in Anaerobic Digestion: Mechanisms, Performances, and Challenges

“…Furthermore, conductive carbon materials have large specific surface areas and porosities ( Figueiredo et al, 1999 ; Chen et al, 2014b ; Zhao et al, 2016a ), which play a vital role in the adsorption, fixation, and enrichment of microorganisms involved in DIET ( Qi et al, 2021 ). Meanwhile, the redox groups on the surface of conductive carbon materials, such as quinone or quinone hydrogen, may be closely related to DIET ( Wang et al, 2020b ).…”

“…Currently, Geobacter species has been proven to be able to establish DIET-based syntrophic associations with methanogens via conductive pili (e-pili) and c-type cytochrome (OmcS), in which methanogens accept electrons and reduce CO 2 to methane ( Rotaru et al, 2014a , b ). Studies have shown that various bacteria that cannot produce e-pili or OmcS can also build DIET-based syntrophic partnerships through adding conductive materials, such as granular activated carbon (GAC) ( Zhang et al, 2020 ), biochar ( Qi et al, 2021 ), carbon cloth ( Jia et al, 2020 ), carbon nanotube ( Shen et al, 2020 ), graphene ( Igarashi et al, 2019 ), and magnetite ( Cheng et al, 2020 ). It is generally agreed that non-biological conductive materials act as an electrical conduit to replace the function of e-pili or OmcS ( Chen et al, 2014a ; Xu et al, 2020 ).…”

Enhancing thermophilic anaerobic co-digestion of sewage sludge and food waste with biogas residue biochar

“…Anaerobic digestion is a classical process allowing to produce biomethane by biodegradation of organic materials [1]. Strategies to enhance anaerobic digestion performance and achieve more energy production include the optimization of operating parameters, pre-treatment of feedstock, co-digestion and supplementation [2]. Anaerobic co-digestion of sewage sludge and food waste provides a more balanced nutritional diet, which alleviates the negative effects of mono-digestion [3].…”