Efficient methane production from lipid-rich wastewater in high-rate anaerobic ...

• Author(s): Cavaleiro, A. J. ; Salvador, A. F. ; Alves, M. M.
• Date: 2008
• Persistent ID: http://hdl.handle.net/1822/9279
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Methane yield; Sludge acclimation; Sodium oleate; Organic loading rate; Anaerobic bioreactors
• Document Type: Conference Object
• Language: English

Description

In this work, high rate anaerobic mineralization of a synthetic dairy effluent containing 50% COD as oleic acid was accomplished in two reactors operated in parallel. The anaerobic reactors were able to accommodate organic loading rates up to 21 kg COD m-3 day-1, HRT of 9 hours, attaining 99% of soluble COD removal efficiency and methane yield higher than 70%. Long chain fatty acids (LCFA) accumulated inside the reactor only during the last two phases of operation and palmitic acid was the main LCFA quantified, representing 40–100% of the total LCFA detected. High specific methanogenic activity was determined at the end of the operation, in the presence of acetate (1346±87 mg COD-CH4 gVS-1 day-1) and H2/CO2 (3582±309 mg COD-CH4 gVS-1 day-1). The specific activity of the anaerobic consortia present in the reactors during the operation was also determined, and a maximum value of 1170±170 mg COD-CH4 gVS-1 day-1 was obtained. The high performance accomplished in the reactors was a consequence of the discontinuous acclimation strategy applied, that produced an anaerobic microbial community specialized in the efficient mineralization of LCFA.