title: Mapping thermomechanical pulp sludge (TMPS) biochar characteristics for greenhouse produce safety.
abstract: This study evaluates the existence of toxic compounds in thermomechanical pulp sludge (TMPS) derived biochars obtained through a slow pyrolysis process and establishes the criteria for manufacturing benign-quality biochar for safe greenhouse-based food production. Accordingly, nine TMPS biochars generated at different temperatures (450, 500, 550 °C) and residence times (30, 60, 120 min) were investigated. Depending on the production conditions, the polycyclic aromatic hydrocarbons (PAHs) sum varied from 0.4 to 236 μg/g biochar. Interestingly, correlations between the PAH content, toxicity, and process conditions were derived in the form of process toxicity relationships (PTRs). On the basis of the learning garnered in this study, it is recommended that TMPS feedstock will yield benign quality biochar when processed at a minimum 500 °C temperature for an optimum residence time of 30 min.
authors.affiliation: Alberta Innovates Technology Futures - Bio-Resource Technologies, Highway 16A and 75 Street, Vegreville, Alberta, Canada T9C 1T4.
authors.forename: Ataullah
authors.initials: A
authors.lastname: Khan
authors.forename: Mohyuddin
authors.initials: M
authors.lastname: Mirza
authors.forename: Brian
authors.initials: B
authors.lastname: Fahlman
authors.forename: Ryan
authors.initials: R
authors.lastname: Rybchuk
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.forename: Don
authors.initials: D
authors.lastname: Harfield
authors.forename: Anthony O
authors.initials: AO
authors.lastname: Anyia
mesh_terms: D000383:Agriculture / Q000295:instrumentation*; D002606:Charcoal / Q000737:chemistry* / Q000633:toxicity; D006358:Hot Temperature; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity; D012722:Sewage / Q000737:chemistry*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012722:Sewage; C540010:biochar; D002606:Charcoal
keywords: PAHs; bio-assay; biochar; greenhouse food safety; pulp sludge; toxicity