Search

The anaerobic digestion of pig slurry samples collected from different points of a farm and raw pig slurry pretreated by centrifugation and decantation was first studied. The specific methane production of raw pig slurry and after centrifugation and decantation pretreatment was 158, 24 and 42.34 L kgVS−1, respectively. Second, the anaerobic digestion of the mixture of raw pig slurry and decanted solid fraction at different organic loading rate (1.364–3.41 gVS·L−1·d−1) results in a specific methane production of 249 ± 37·L kgVS −1. The concentration of ammonium ion in the digester increased to 2500 mg L−1 without inhibition. Lastly, the co‐digestion of pear waste and raw pig slurry was also analysed, which enhanced the specific methane production (243 L kgVS−1). This work deals with the integral management of pig slurry and points out the possibility of revalorization of other wastes in the same digester. [ABSTRACT FROM AUTHOR]

This study was undertaken to determine the possible changes in the digester yield and performance for the anaerobic co-digestion under mesophilic conditions of strawberry residues (SRs) together with pig manure (PM). The first part of this paper deals with the digestion of SR as a single substrate. For organic loading rates (OLRs) of 4.4 (g L−1d−1) or less, the experimental specific biogas and methane productions are 0.588 and 0.231 L g−1, respectively. When higher OLRs (5.5 g L−1d−1) are used the digester fails due to acidification. In the second part, the co-digestion of both residues is explored using a wide variety of SR:PM ratios and OLRs of 5.5 g L−1d−1with good stability. Therefore, it is demonstrated that co-digestion allows the improvement of the treatment capacity as compared with SR as a single residue. The methane and biogas productions increase as the SR:PM ratio increases. It may be concluded that, when a digester works with a certain OLR, the performance for co-digestion is always better than for single substrates because the presence of PM provides a better stability and the presence of SR improves the biogas and methane production. [ABSTRACT FROM PUBLISHER]