Assessment of the start-up of tubular reactors on a laboratory scale for the anaerobic digestion of slaughterhouse wastewater

Slaughterhouse wastewater is a source of contamination due to its high content of organic matter, nutrients, and suspended solids. Anaerobic digestion (AD) is a biological treatment that reduces the organic load of liquid effluents and generates biogas. Plug flow reactors (PFR) are a technological alternative to simple design and implementation for continuous treatment. The research aims to compare the removal of chemical oxygen demand (RCOD) in the initial stage of anaerobic treatment of liquid waste in tubular reactors (TR) designed using the data of methane production kinetics. The slaughterhouse wastewater presented a methane yield of 468.21 NmLCH4.gCOD−1 during the methane biochemical potential assay. The volume of the TRs was 4.69 L (effective volume 3.51 L) and built-in PVC. The design of the considered 0, 2, and 4 baffles section to study their influence on the reactor start-up. The hydrodynamic assays indicated that the reactors behaved differently from the PFR regime with a flow rate of 0.234 L/min. However, the TRs start-ups were similar, with RCOD reaching 87% with hydraulic retention times of 11 d. In addition, the research includes a model to simulate the behavior of TR at different HRT. The simulations showed possible advantages in adapting the technology to the treatment of slaughterhouse wastewater.