Modelling hydrolysis: Simultaneous versus sequential biodegradation of the hydrolysable fractions. (1st January 2020)

• Record Type: Journal Article
• Authors: Jimenez, Julie; Charnier, Cyrille; Kouas, Mokhles; Latrille, Eric; Torrijos, Michel; Harmand, Jérôme; Patureau, Dominique; Spérandio, Mathieu; Morgenroth, Eberhard; Béline, Fabrice; Ekama, George; Vanrolleghem, Peter A.; Robles, Angel; Seco, Aurora; Batstone, Damien J.; Steyer, Jean-Philippe
• Is Part Of: Waste management. Volume 101(2020)
• Page Start: 150
• Page End: 160
• Publication Date: 2020-01-01
• Subjects: ADM1 -- Fractionation -- Hydrolysis -- Modelling -- Model selection -- Organic matter; ADM1 anaerobic digestion model number one -- ASM activated sludge model -- BMP biochemical methane potential (NmL CH4.gVS−1) -- BMP 2.0 biochemical methane potential number 2 after acclimation phase (NmL CH4.gVS−1) -- DOM dissolved organic matter -- COD chemical oxygen demand (g O2.g TS−1) -- Faccessibilityi switching function -- f_XRC_xI inert fraction of XRC (% COD) -- f_XRC_ch carbohydrate fraction of XRC (% COD) -- f_XRC_pr protein fraction of XRC (% COD) -- f_XRC_li lipid fraction of XRC (% COD) -- f_XMC_xI inert fraction of XMC (% COD) -- f_XMC_ch carbohydrate fraction of XMC (% COD) -- f_XMC_pr protein fraction of XMC (% COD) -- f_XMC_li lipid fraction of XMC (% COD) -- f_XSC_xI inert fraction of XSC (% COD) -- f_XSC_ch carbohydrate fraction of XSC (% COD) -- f_XSC_pr protein fraction of XSC (% COD) -- f_XSC_li lipid fraction of XSC (% COD) -- f_XNE_xI inert fraction of XNE (% COD) -- f_XNE_ch carbohydrate fraction of XNE (% COD) -- f_XNE_pr protein fraction of XNE (% COD) -- f_XNE_li lipid fraction of XNE (% COD) -- f_xch_xc ADM1 default parameters for disintegration of particular COD into carbohydrates (%COD) -- f_xli_xc ADM1 default parameters for disintegration of particular COD into lipids (%COD) -- f_xpr_xc ADM1 default parameters for disintegration of particular COD into proteins (%COD) -- f_xi_xc ADM1 default parameters for disintegration of particular COD into inerts (%COD) -- Khyd_XRC contois hydrolytic biomass growth rate for XRC hydrolysis (d−1) -- Khyd_XMC contois hydrolytic biomass growth rate for XMC hydrolysis (d−1) -- Khyd_XSC contois hydrolytic biomass growth rate for XSC hydrolysis (d−1) -- Khyd_XNE contois hydrolytic biomass growth rate for XNE hydrolysis (d−1) -- KI_XRC switching function inhibition parameter for XMC hydrolysis (kg COD. m−3) -- KI_XMC switching function inhibition parameter for XSC hydrolysis (kg COD. m−3) -- KI_XSC switching function inhibition parameter for XNE hydrolysis (kg COD. m−3) -- NIRS near infra-red spectroscopy -- VFA volatile fatty acids -- VS volatile solids (% dried matter) -- XD dead biomass variable (kg COD. m−3) -- XRC readily biodegradable fraction (kg COD. m−3) -- XMC moderately biodegradable fraction (kg COD. m−3) -- XSC slowly biodegradable fraction (kg COD. m−3) -- XNE non-extractible fraction (kg COD. m−3); Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2019.10.004
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Classical hydrolysis modelling by simultaneous approach was challenged. Accessibility fractionation revealed sequential hydrolysis. ADM1 model was modified and a switching function was introduced. Sequential model fits better than simultaneous model in all the studied cases. Abstract: Hydrolysis is considered the limiting step during solid waste anaerobic digestion (including co-digestion of sludge and biosolids). Mechanisms of hydrolysis are mechanistically not well understood with detrimental impact on model predictive capability. The common approach to multiple substrates is to consider simultaneous degradation of the substrates. This may not have the capacity to separate the different kinetics. Sequential degradation of substrates is theoretically supported by microbial capacity and the composite nature of substrates (bioaccessibility concept). However, this has not been experimentally assessed. Sequential chemical fractionation has been successfully used to define inputs for an anaerobic digestion model. In this paper, sequential extractions of organic substrates were evaluated in order to compare both models. By removing each fraction (from the most accessible to the least accessible fraction) from three different substrates, anaerobic incubation tests showed that for physically structured substrates, such as activated sludge and wheat straw, sequential approach could better describe experimental results, while this was less important for homogeneous materials such as pulped fruit. Following this, anaerobic incubation tests were performed on five substrates. Cumulative methane production was modelled by the simultaneous and sequential approaches. Results showed that the sequential model could fit the experimental data for all the substrates whereas simultaneous model did not work for some substrates.