Two-phase anaerobic co-digestion of used vegetable oils' wastes and pig manure

作者：Hidalgo D^*; Gomez M; Martin Marroquin J M; Aguado A; Sastre E

来源：International Journal of Environmental Science and Technology, 2015, 12(5): 1727-1736.

DOI：10.1007/s13762-014-0560-9

• Co-digestion
• Hydraulic retention time
• Oily waste
• Pig manure
• Two-phase anaerobic reactor
• Used vegetable oil

The purpose of this work was to study the anaerobic co-digestion of all the by-products generated during the processing of used vegetable oils (UVO) with the objective of proposing a solution for the treatment of these wastes. More specifically, this study investigates the advantages of two-phase anaerobic digestion for treating a mixture (1/5 v/v) of UVO processing wastes (OW) and pig manure (PM) using two semi-continuous digesters operated at mesophilic temperature (37 +/- A 1 A degrees C). The experiments were conducted at hydraulic retention time (HRT) of 0.5, 1, 2 and 4 days in the first stage (acidifier) and at HRT of 11.5, 15, 18 and 20 days in the second stage (methaniser). The results revealed that the HRT had a high influence on the soluble chemical oxygen demand (sCOD) and total dissolved solids (TDS) removal. The maximum total sCOD removal efficiency of 86.4 % and TDS removal efficiency of 81.9 % was achieved at 20 days of global HRT. The maximum biogas production of 0.65 m(3) per kilogramme of volatile dissolved solids (VDS) was removed, corresponding to a methane production of 0.42 m(3) CH4 kg(-1). VDS removed (65 % CH4) was also achieved at 20 days of HRT. The two-phase digestion system showed good stability, which was mainly attributed to the strong buffering capacity with the two-phase system and the high alkalinity from PM when co-digested with OW. The results obtained from this study provide fundamental information for scaling up a high-performance two-phase anaerobic system in the future.

• 出版日期2015-5