Digestion of cattle manure under mesophilic and thermophilic conditions: characterization of organic matter applying thermal analysis and 1H NMR

Abstract

Digestion of cattle manure collected from a livestock farm together with bedding material (straw) has been studied under mesophilic and thermophilic conditions in batch reactors. The digestion was carried out for a prolonged period with the aim of evaluating the changes undergone by the organic matter. The mesophilic digestion carried out revealed a greater capacity to produce gas and transform organic matter, while a higher conversion rate, but a lower gas yield, was obtained under thermophilic conditions. Degradation of the organic matter was evaluated by means of thermal analysis and (1)H NMR. Stabilisation through anaerobic digestion (either mesophilic or thermophilic) resulted in an increase in the quality of the organic matter, as characterised by an enrichment in thermostable compounds, and an accumulation of long chain aliphatic materials. The experiments performed demonstrated the transformation of organic matter into complex materials under anaerobic conditions with an accumulation of aliphatic components under both types of conditions tested. Degradation through mesophilic digestion, in comparison to the thermophilic process, resulted in a greater destruction of straw particles.

The Effects of Microwave Pretreatment of Dairy Manure on Methane Production

“…Therefore, both methane potential and rate decreased for the sets of MW pretreatment. Studying kinetics of biogas production from cattle manure, Budiyono et al [31] [33]. The results of the untreated manure sets in this study were comparable to their findings.…”

Transformation of organic matters in animal wastes during composting

“…A c c e p t e d M a n u s c r i p t 11 illustrated that the cow manure had the highest content of cellulose and lignin components among the three manures, which was in according to the previous articles [11,42].…”

Comparison of the mesophilic and thermophilic anaerobic digestion of spent cow bedding in leach-bed reactors

“…In this regard the use of thermophilic conditions in LBRs treating spent cow bedding could represent an effective solution to enhance the process performance. Indeed, when comparing the influence of mesophilic and thermophilic temperatures, several authors agreed on the faster degradation kinetics when using thermophilic conditions to treat different substrates such as: spent horse bedding (Böske et al, 2015), the organic fraction of municipal solid waste (Fernández-Rodríguez et al, 2013), spent cow bedding (Gómez et al, 2011), wood chips (Hegde and Pullammanappallil, 2007) and cow dung (Jha et al, 2013).…”

“…In the literature, few data comparing mesophilic and thermophilic treatment are available on spent animal bedding consisting of faeces and straw. Böske et al (2015) used a continuous upflow anaerobic solid-state (UASS) reactor to treat spent horse bedding, whereas Gómez et al (2011) used a dry unmixed batch system to digest spent cow bedding. In thermophilic conditions, the first authors observed higher kinetics and methane yield than at mesophilic temperature, while the second reported higher kinetics and a lower methane yield.…”