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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]

The studies about the viability of the employment of anaerobic combined system for the vinasse treatment, have increased in the last years. Therefore, the objective of present work was to evaluate the anaerobic digestion process of raw vinasse using a combined system of upflow packed reactors (UPR) in series. Organic loading rate (OLR) was evaluated in the range of 2 to 10 kgCOD/m³d. The 10 kgCOD/m³d was selected as the stable operating load, obtaining average values of 90% and 1.03 N LCH/Ld for the combined system in terms of elimination of COD and productivity of methane, respectively. The above represents average increases of 18 and 15% for these same parameters with respect to the use of a single anaerobic configuration. [ABSTRACT FROM AUTHOR]

The application of anaerobic digestion, from waste streams that currently have no use, can be utilized for bioenergy production. The present work objective was to evaluate the mixing effect in the biodegradability of residues from the Cuban sugar industry such as bagasse, press mud and vinasse using a mixture design. Methane yield and kinetic process were also evaluated using two different kinetic models: first order model and Gompertz model. The results showed that press mud had the higher methane yield (252 mLCH4/gVS) mean while bagasse had the lowest value (170 mLCH4/gVS). All substrates mix resulted an increase in methane yield up to 23% compared to the expected yield calculated as individual fractions potential methane. This behavior demonstrate a significant synergistic effect. The kinetic results showed that vinasse had the best results. [ABSTRACT FROM AUTHOR]

This paper examines the use of membrane bioreactor technology (MBRs) in the treatment of wastewater generated in the dairy industry. These wastewaters have physicochemical and microbiological characteristics that require specialized treatments; biological processes are the most recommended because of their costeffectiveness, efficiency of elimination and high environmental friendliness. MBRs combine the biological degradation process with membrane filtration, obtaining a high quality effluent. They can be aerobic or anaerobic, highlighting that when the process occurs anaerobically, by-products such as biogas and biofertilizers are generated, in addition to the possibility of direct reuse of the effluent in secondary processes of the industry, which constitutes an approach to the biorefinery concept. Different investigations have shown organic matter and total suspended solids (TSS) removal values in the ranges of 90 - 99 % and 85 - 100 %, respectively, compared to conventional biological treatment processes, which only reach up to 80 %. Emphasis is placed on the type of membranes used and their particularities due to their impact on the quality of the final effluent, being microfiltration (MF) and ultrafiltration (UF) the most commonly used to treat dairy wastewater. These premises make membrane bioreactor technology a viable option for the treatment of wastewater generated in the dairy industry in Cuba. [ABSTRACT FROM AUTHOR]