title: The challenges of anaerobic digestion and the role of biochar in optimizing anaerobic digestion.
abstract: Biochar, like most other adsorbents, is a carbonaceous material, which is formed from the combustion of plant materials, in low-zero oxygen conditions and results in a material, which has the capacity to sorb chemicals onto its surfaces. Currently, research is being carried out to investigate the relevance of biochar in improving the soil ecosystem, digestate quality and most recently the anaerobic digestion process. Anaerobic digestion (AD) of organic substrates provides both a sustainable source of energy and a digestate with the potential to enhance plant growth and soil health. In order to ensure that these benefits are realised, the anaerobic digestion system must be optimized for process stability and high nutrient retention capacity in the digestate produced. Substrate-induced inhibition is a major issue, which can disrupt the stable functioning of the AD system reducing microbial breakdown of the organic waste and formation of methane, which in turn reduces energy output. Likewise, the spreading of digestate on land can often result in nutrient loss, surface runoff and leaching. This review will examine substrate inhibition and their impact on anaerobic digestion, nutrient leaching and their environmental implications, the properties and functionality of biochar material in counteracting these challenges.
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom. Electronic address: m.fagbohungbe@lancaster.ac.uk.
authors.forename: Michael O
authors.initials: MO
authors.lastname: Fagbohungbe
authors.affiliation: Stopford Energy and Environment, Merseyton Road, Ellesmere Port, Chester CH65 3AD, United Kingdom.
authors.forename: Ben M J
authors.initials: BM
authors.lastname: Herbert
authors.affiliation: Stopford Energy and Environment, Merseyton Road, Ellesmere Port, Chester CH65 3AD, United Kingdom.
authors.forename: Lois
authors.initials: L
authors.lastname: Hurst
authors.affiliation: National Centre for Energy Research and Development, University of Nigeria Nsukka, Enugu State, Nigeria.
authors.forename: Cynthia N
authors.initials: CN
authors.lastname: Ibeto
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: Ariva Technology, The Heath Business and Technical Park, Runcorn, Cheshire WA7 4EB, United Kingdom.
authors.forename: Shams Q
authors.initials: SQ
authors.lastname: Usmani
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom.
authors.forename: Kirk T
authors.initials: KT
authors.lastname: Semple
mesh_terms: D000693:Anaerobiosis; D002606:Charcoal; D005308:Fertilizers; D006863:Hydrogen-Ion Concentration; D059013:Microbial Consortia / Q000502:physiology; D012987:Soil; D018505:Waste Management / Q000379:methods*
chemical_list: D005308:Fertilizers; D012987:Soil; C540010:biochar; D002606:Charcoal
keywords: Anaerobic digestion; Biochar; Digestate; Inhibition; Nutrient leaching