Anaerobic co-digestion of cheese whey and the screened liquid fraction of dairy manure in a single continuously stirred tank reactor process: Limits in co-substrate ratios and organic loading rate.
Mesophilic anaerobic co-digestion of cheese whey and the screened liquid fraction of dairy manure was investigated with the aim of determining the treatment limits in terms of the cheese whey fraction in feed and the organic loading rate. The results of a continuous stirred tank reactor that was operated with a hydraulic retention time of 15.6 days showed that the co-digestion process was possible with a cheese whey fraction as high as 85% in the feed. The efficiency of the process was similar within the range of the 15-85% cheese whey fraction. To study the effect of the increasing loading rate, the HRT was progressively shortened with the 65% cheese whey fraction in the feed. The reactor efficiency dropped as the HRT decreased but enabled a stable operation over 8.7 days of HRT. At these operating conditions, a volumetric methane production rate of 1.37 m(3) CH4 m(-3) d(-1) was achieved.
Department of Water and Environmental Science and Technologies, University of Cantabria, Avda. Los Castros, s/n, 39005 Santander, Spain. Electronic address: ricoc@unican.es.
Carlos
C
Rico
Energy Lab (Sustainable Energy Technological Center), Edificio CITEXVI, Local 1 R/Fonte das Abelleiras, s/n, Campus Universitario de Vigo, 36310 Vigo, Spain; Department of Chemical and Process Engineering Resources, University of Cantabria, Avda. Los Castros, s/n, 39005 Santander, Spain.
Noelia
N
Muñoz
Department of Chemical and Process Engineering Resources, University of Cantabria, Avda. Los Castros, s/n, 39005 Santander, Spain.
José Luis
JL
Rico
D000693:Anaerobiosis / Q000187:drug effects; D000818:Animals; D019149:Bioreactors; D002417:Cattle; D002611:Cheese / Q000032:analysis*; D003612:Dairying; D008372:Manure / Q000032:analysis*; D008697:Methane / Q000096:biosynthesis; D009930:Organic Chemicals / Q000494:pharmacology*; D012037:Refuse Disposal / Q000379:methods*; D013997:Time Factors; D014865:Waste Disposal, Fluid; D000067796:Whey / Q000737:chemistry*
D008372:Manure; D009930:Organic Chemicals; D008697:Methane
Biogas; CSTR; Cheese whey; Co-digestion; Organic loading rate