title: Continuous, self-sustaining smouldering destruction of simulated faeces.
abstract: A new approach for the rapid destruction of human waste using smouldering combustion is presented. Recently, self-sustaining smouldering combustion was shown to destroy the organic component of simulated human solid waste and dog faeces resulting in the sanitization of all pathogens using a batch process (Yermán et al., 2015). Here, a continuous smouldering process is demonstrated for the first time, allowing for a much smaller reactor size and much less energy input per mass of waste treated. The self-sustained smouldering of simulated human faeces mixed with sand is evaluated over long periods (more than 16 h) based on a single ignition. The key process of intermittent self-sustained smouldering, in which the reaction is terminated and restarted by only turning the air off and on, is demonstrated. Experiments examine the influence of two key operator controls: airflow rate and set elevation of the quasi-steady-state smouldering front in a 37 cm high reactor. Quasi-steady-state fuel destruction rates from 93 g/h to 12 g/h were achieved by varying the superficial flow velocity from 7.4 cm/s to 0.11 cm/s, the latter with a velocity approximately an order of magnitude lower than possible for a self-sustaining reaction in an equivalent batch system. Excess energy of up to 140 J/g of sand was recovered from the clean sand produced in each cycle, which could be used to further increase the energy efficiency of this novel waste treatment system.
authors.affiliation: Department of Civil and Environmental Engineering, University of Western Ontario, London, Ontario N6A 5B9, Canada.
authors.forename: Ivo
authors.initials: I
authors.lastname: Fabris
authors.affiliation: Department of Civil and Environmental Engineering, University of Western Ontario, London, Ontario N6A 5B9, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cormier
authors.affiliation: Department of Civil and Environmental Engineering, University of Western Ontario, London, Ontario N6A 5B9, Canada.
authors.forename: Jason I
authors.initials: JI
authors.lastname: Gerhard
authors.affiliation: Centre for Global Engineering and Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada.
authors.forename: Tomek
authors.initials: T
authors.lastname: Bartczak
authors.affiliation: School of Civil Engineering, The University of Queensland, Brisbane 4072, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Kortschot
authors.affiliation: School of Civil Engineering, The University of Queensland, Brisbane 4072, Australia.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Torero
authors.affiliation: School of Civil Engineering, The University of Queensland, Brisbane 4072, Australia.
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Cheng
keywords: Faeces; Remediation; Smouldering combustion; Waste management