Co-digestion of grease trap sludge and sewage sludge.
Redirection of organic waste, from landfilling or incineration, to biological treatment such as anaerobic digestion is of current interest in the Malmö-Copenhagen region. One type of waste that is expected to be suitable for anaerobic digestion is sludge from grease traps. Separate anaerobic digestion of this waste type and co-digestion with sewage sludge were evaluated. The methane potential was measured in batch laboratory tests, and the methane yield was determined in continuous pilot-scale digestion. Co-digestion of sludge from grease traps and sewage sludge was successfully performed both in laboratory batch and continuous pilot-scale digestion tests. The addition of grease trap sludge to sewage sludge digesters was seen to increase the methane yield of 9-27% when 10-30% of sludge from grease traps (on VS-basis) was added. It was also seen that the grease trap sludge increases the methane yield without increasing the sludge production. Single-substrate digestion of grease trap sludge gave high methane potentials in batch tests, but could not reach stable methane production in continuous digestion.
Davidsson
A
A
Department of Chemical Engineering, Water and Environmental Engineering, Center for Chemistry and Chemical Engineering, Lund University, Lund, Sweden. asa.davidsson@vateknik.lth.se
Lövstedt
C
C
Jansen
J la Cour
Jl
Gruvberger
C
C
Aspegren
H
H
D000693:Anaerobiosis; D019149:Bioreactors; D003247:Conservation of Natural Resources; D004787:Environmental Pollution / Q000517:prevention & control; D005223:Fats; D008697:Methane / Q000378:metabolism; D012722:Sewage / Q000737:chemistry*; D013997:Time Factors
D005223:Fats; D012722:Sewage; D008697:Methane