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In this study, a pilot-scale plug flow reactor has been operated at a hydraulic retention time of 30 d with substrate concentration of total solids (7-10 %) under room temperature ranging from 25-38 °C with a working volume of 1.44*10-3 m³ during 186 days. The average chemical oxygen demand (COD) removal was 66.9 % operating at 1.7 kgVS/m³d. Moreover, the alkalinity to total inorganic carbon rated 0.31 being considered a proper value for the operational control of the reactor. In addition, 65.1 % of Total Volatile Solids removal was attained. The specific biogas and methane yields were up to 0.22 m³/kg VS, 0.25 m³/kg VS, respectively. Longterm operation in a pilot scale demonstrated the technological potential and industrial application of cattle manure treatment for biogas production as a circular economy contribution. [ABSTRACT FROM AUTHOR]

Large pig farms generate enormous volumes of wastewater without proper treatment before discharge. High-rate anaerobic reactors as the expanded granular sludge bed (EGSB) are rarely reported for that purpose. In this study, an EGSB reactor with Cuban natural zeolite addition was evaluated for treating piggery wastewaters at lab scale. This study was conducted at different organic loading rate (OLR) ranging from 0.32 to 6.13 gCOD/Ld with a constant hydraulic retention time (HRT) of 12 h. The evolution of several control and operational parameters as the soluble chemical oxygen demand (COD) demonstrated a proper bioreactor performance to treat piggery wastewater. The results showed that the addition of natural zeolite at 40 gzeo/Lreactor in EGSB reactor results in COD efficiencies over 70%, despite of the fluctuations of fed wastewater characteristics. The kinetic study demonstrates that, the modified Stover-Kincannon model was found to be appropriate for EGSB reactor. The effluent soluble COD was predicted with high determination coefficient. The maximum removal rate constant (Umax) and saturation value constant (KB) were reported for a first time for the EGSB reactor with values of 10.2 and 11.8 gCOD/Ld, respectively. Methane yield for both, batch and continues experiments, were in the range from 214.5 to 299.8 mLCH4/gCOD. [ABSTRACT FROM AUTHOR]