Anaerobic mesophilic and thermophilic treatability of vegetable oil refining wastewater

Three anaerobic filters, two mesophilic (35oC) and one termophilic (55 oC), were operated with a vegetable oil refining wastewater at varying organic loadings. The organic loadings rate (OLR) applied were 1, 2, 4, 6, 8, 10, and 15 g COD/L d with a constant hydraulic retention time (HRT) of 24 hours. The chemical oxygen demand (COD) removal rates were % 26-86 and % 37-97 for the mesophilic reactors. The methane yields were 0,377-0,0132 L CH4/g CODremoved and 0,391-0,016 L CH4/g CODremoved, respectively. The thermophilic reactor, however, were able to remove % 26-97 of the COD with a methane yield of 0,461-0,0839 L CH4/g CODremoved. The data obtained for both mesophilic and thermophilic reactors were then applied to the Stover-Kincannon model and Umax and KB values were determined.