ANAEROBIC CO-DIGESTION OF CHICKEN MANURE – EFFECT OF MATERIAL RELATIONS IN FEED MIXTURE AND HYGIENISATION ON BIOGAS PRODUCTION

摘要

Anaerobic digestion of chicken manure (CM) is challenging due to the high nitrogen content of thematerial. Co-digestion of CM with cattle slurry (CS) and vegetable wastes (VW) from a food industry dilutes the feedmaterial and enhances the buffering capasity towards the pH increase. Anaerobic co-digestion of CM, CS and VWfrom a food industry was studied in the wet weight (W.W.) relations of A) 10:70:20 (hygienised mixture A~*; 70 °C/1hour), B) 13:76:11, C) 15:82:03 and D) 25:50:25 at 33 ±2 °C. The objective of the present study was thecharacterisation and optimisation of anaerobic co-digestion process treating CM with the ultimate aim to enhance themethane (CH_4) production. Highest content of CM in the feed mixture (25%) was tolerated, when it was bufferedwith the adequate amounth of VW. The highest CH_4 production (300 m~3 of CH_4 /t volatile solids; VS) was achievedwith the mixture D. The synergistic effect of co-digestion was achieved, and process produced more CH_4 thancalculated theoretically. Hygienisation enhanced the biological CH_4 potential (BMP) by 43% from A~*, whencompared to the untreated mixture A.