Evaluating inhibition conditions in high-solids anaerobic digestion of organic fraction of municipal solid waste

Abstract

a b s t r a c tHigh-solids anaerobic digestion (HSAD) processes, when applied to different types of organic fractions of municipal solid waste (OFMSW), may easily be subjected to inhibition due to organic overloading. In this study, a new approach for predicting these phenomena was proposed based on the estimation of the putrescibility (oxygen consumption in 20 h biodegradation, OD 20 ) of the organic mixtures undergoing the HSAD process. Different wastes exhibiting different putrescibility were subjected to lab-scale batch-HSAD. Measuring the organic loading (OL) as volatile solids (VS) was found unsuitable for predicting overload inhibition, because similar VS contents corresponded to both inhibited and successful trials. Instead, the OL calculated as OD 20 was a very good indicator of the inhibiting conditions (inhibition started for OD 20 > 17-18 g O 2 kg À1). This new method of predicting inhibition in the HSAD process of diverse OFMSW may be useful for developing a correct approach to the technology in very different contexts.

Greenhouse Gas Emissions and Environmental Impact from Recycling the Organic Fraction of Solid Waste: Comparison of Different Treatment Schemes from a Life Cycle Perspective

“…The lower biogas production for test 6 was a consequence of the higher TS concentration (Table 4), generating an increase in mass transfer resistance through the media [42]. Both biogas yield and its relation to TS content and process inoculation were in accordance with the data reported by other authors [4,12,[43][44][45].…”

Improved ADM1 model for anaerobic digestion process considering physico-chemical reactions

“…The disintegration, hydrolysis and bacterial decay steps are represented by first order kinetics, while all the other steps are represented by Monod-type kinetics. Besides, ADM1 includes several inhibition factors such as LCFAs, dissolved hydrogen and ammonia (Angelidaki et al, 1993;Chen et al, 2008; Schievano et al, 2010;Zonta et al, 2013). In conjunction with the rate equations, 24 dynamic state concentration variables are set for the components involved in anaerobic digestion.…”

Influence of temperature on the anaerobic stabilization of organic solid residues

“…The stability of the anaerobic process is crucial in maintaining the balance between the various microbial populations that are responsible for the conversion of complex organic compounds into simple substances; such as methane, carbon dioxide, nitrogen, ammonia, hydrogen sulfide and other products of low molecular weight (Lay et al, 1998;Raposo et al, 2011). By virtue of the greater proportion of cellulose and lignocellulosic polymers present in solid degradable materials compared with liquid wastes, the time required to attain stabilization during anaerobic digestion of the former is much longer (Schievano et al, 2010).…”