ANAEROBIC DEGRADATIONd OF TWO TYPES OF WHEY UASB REACTORS

Abstract

The aim of this study was evaluated the anaerobic degradation of acid whey and the whey obtained from the elaboration of cottage cheese, for the methane production with UASB reactors operated to 1 day of HRT. Two reactors of 2,5 L were inoculated with sludge from a wastewater treatment plant of a cheeses factory. The reactors were operated during 84 days (whey of cottage cheese) and 95 days (acid whey), to a concentration of 1.0 and 2,5 g COD/L. The reactors fed with whey of cottage
cheese and acid whey to 1 g COD/L had an average removal efficiency of 76,0 and 77,3 % and maximum of 90,7 and 100 %, with an average methane production of 0,30 and 0,43 L/day,
respectively. To 2,5 g COD/L the average removal efficiencies were of 33,7 and 56,0 %, with a maximum of 44 y 69 %, respectively, and it not showed an increase of methane production. In a third stage, the reactors were operated to the initial conditions and presented removal efficiencies lower
(59,0 and 62,0 %) than the reached in the first conditions. It was found that the inoculum and the temperature had influence marked in the degradation process.