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Empirical Kinetic Models have been used to describe and establish the Anaerobic Digestion kinetics of pig slurry’s (8% TS) Biochemical Chemical Potential. A wide selection of Empirical Kinetic Models were fitted to the experimental data collected in batch assays of different Substrate to Inoculum ratios, 0.65 (BMP1) and 1 (BMP2). For the selection of the most suitable model for each BMP assay, the statistical tools R2 and the RMSE, along with the Information Criterion AIC and BIC, were taken into consideration. From all the studied models, the Weibull model proved to be the most suitable for kinetic parameter prediction for both BMP1 and BMP2 assays. This model presented the lowest values of AIC and BIC, along with the highest value of R2 and the lowest RMSE. In this regard, a R2=0.998, and a RMSE=0.004, was obtained for BMP1, and a R2=0.999 and a RMSE=0.008 for BMP2.

This study assesses the methane production potential for the Anaerobic Digestion of Pig Slurry, using two different Substrate to Inoculum Ratios, 0.65, and 1, and its comparison with the theoretical prediction. The Specific Biogas Production, the Specific Methane Production, and the average methane content were determined for both experiments and adjusted to Standard Temperature (273.15 K) and Pressure (1 atm). The results reached in this study show that the experience conducted with a SIR of 1 produced more volume of biogas, with higher methane content than the one with the lower SIR. With a SIR of 1.0, it was achieved a SMP of 0.568 NL CH4/g VS with an average methane content of 83%. The Technical Digestion Time was found to be 12 days. By comparing the experimental BMP with the estimated value of 0.623 NL CH4/g VS, it was possible to conclude that the estimated value presented a deviation of just 2.96 % during the assay with a SIR of 1.

The authors conducted a study on treating synthetic dairy wastewater using aerobic granular sludge (AGS) in a laboratory-scale continuous flow reactor (CFR) system. The system consisted of an anaerobic reactor, an aerobic reactor, and a settling sedimentation tank, with different hydraulic retention times tested over a 90-day period. The study monitored sludge characteristics and effluent treatment performance and found that the system achieved excellent removal rates for chemical oxygen demand and total carbon, exceeding 90%. As a result, the effluent met Portuguese laws for direct release into the water environment. Moreover, the study found that the AGS system improved the sludge sedimentation capacity from 272 to 80 mL/g, demonstrating its effectiveness as a viable treatment alternative for this type of effluent.

The Moving Bed Biofilm Reactor (MBBR) system is considered an Advanced Wastewater Treatment (AWT), which combines the best of Conventional Activated Sludge (CAS) and biofilter processes, making use of suspended biomass and attached biomass. This system requires less space than CAS to process the same amount of wastewater and can be adapted to the existing structures of CAS. The dairy wastewater obtained during the milk transformation and cleaning operations is a residue characterized by a high content of organic matter and hydrocarbon compounds which contribute to its biodegradability, normally allowing the use of biological processes for the treatment of these effluents. In this study, the performance of the MBBR at a lab-scale during batch and continuous operations was addressed while changing the Organic Load (OL), the Filling Ratio (FR) and the Hydraulic Retention Time (HRT). The MBBR shows to be more stable when a FR of 40% is used, which allows a reduction of the HRT from 8 to 4 h, reaching a COD removal of 95%, allowing a reduction on the energy consumption, compared to the conventional processes.