Effect of pretreatment and co-substrate addition on biogas production from pig slurry

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 center dot L-1 center dot d(-1)) results in a specific methane production of 249 +/- 37 center dot 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.