A PRELIMINARY-STUDY OF PIGGERY WASTE TREATMENT BY AN UPFLOW SLUDGE BED ANAEROBIC REACTOR AND A PACKED-BED ANAEROBIC REACTOR

Piggery waste is one of the most important sources of environmental pollution in Cuba and Mexico. Anaerobic digestion by high rate processes such as the upflow anaerobic sludge bed (UASB) and the anaerobic packed bed (APE) is a possible treatment for this waste to reduce the pollution potential. Both processes were studied using laboratory scale models under the same range of organic volumetric loadings. The high efficiency of the UASB and the APE was demonstrated. However, the APE showed better performance under changes of organic loadings than the UASB. COD removals in the range of 85 to 65% were obtained in the APE while in the UASB values of 80 to 58% were obtained at organic loading rates in the range of 1.3 to 11.0 kg COD/m(3) reactor d. In consequence, methane yield was slightly higher in the APE (0.4 to 2.0 m(3)/m(3) reactor d) than in the UASB (0.4 to 1.7 m(3)/m(3) reactor d). (C) 1995 Silsoe Research Institute