Abstract
Combined anaerobic digestion of olive oil mill effluent (OME) with swine manure, was
investigated. In batch experiments was shown that for anaerobic degradation of OME alone nitrogen
addition was needed. A COD:N ratio in the range of 65:1 to 126:1 was necessary for the optimal
degradation process. Furthermore, it was found that methane productions rates during digestion of either
swine manure alone or OME alone were much lower than the rates achieved when OME and manure were
digested together. Admixing OME with manure at a concentration of 5 to 10% OME resulted in the highest
methane production rates. Using upflow anaerobic sludge blanket (UASB) reactors, it was shown that
codigestion of OME with swine manure (up to 50% OME) was successful with a COD reduction up to 75%.
The process was adapted for degradation of OME with stepwise increase of the OME load to the UASB
reactor. The results showed that the high content of ammonia in swine manure, together with content of
other nutrients, make it possible to degrade OME without addition of external alkalinity and without addition
of external nitrogen source. Anaerobic treatment of OME in UASB reactors resulted in reduction of simple
phenolic compounds such as mequinol, phenyl ethyl alcohol and ethyl methyl phenol. After anaerobic
treatment the concentration of these compounds was reduced between 75 and 100%. However, the
concentration of some degradation products such as methyl phenol and ethyl phenol were detected in
significantly higher concentrations after treatment, indicating that the process has to be further optimised to
achieve satisfactory removal of all xenobiotic compounds.
Original language | English |
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Journal | Water Science and Technology |
Volume | 45 |
Issue number | 10 |
Pages (from-to) | 213-218 |
ISSN | 0273-1223 |
Publication status | Published - 2002 |
Keywords
- olive oil mill effluent
- codigestion
- UASB reactor
- Anaerobic digestion