Evaluating input parameter effects on the overall anaerobic co-digestion performance of abattoir and winery solid wastes

Impact of Thermal Pretreatment on the Physicochemical Characteristics and Biomethane Yield Potential of Solid Slaughter Waste from High-Throughput Red Meat Abattoirs Valorized as a Potential Feedstock for Biogas Production

“…According to Otero et al [53], Ortner et al [59], and Obileke et al [60], reduction in COD in feedstock occurs due to the degradation of complex organic compounds, which in turn increases the stability of the AD process by reducing organic acid production during digestion that will cause pH drop, thus enhancing microbial metabolism during AD. The results in this study were higher than those reported by Khumalo [54], Budiyono et al [46], and Otero et al [53], and were observed to be lower than those reported by Ortner et al [59]; this is owing to the difference in feedstock composition. The organic carbon produced during AD of red meat abattoir waste is mostly produced during the degradation of carbohydrates by microorganisms [57,58].…”

“…Although results in previous studies suggest that the efficiency of AD increases as feedstock moisture levels increase [46,54,56], there is no information on optimum moisture levels reported. In support of the studies by Zamri et al [55], Cvetković et al [54], and Kabeyi and Olanrewaju [57], a study by Khumalo [54] reported that activated sludge with 95% moisture content had a hydrolysis phase of six days, while sludge with 88% moisture content had a hydrolysis phase of 30 days. Similar observations were also observed in this study in sterilized cattle and pig abattoir slaughter samples (Table 3), as the moisture contents were observed to be 63.09 ± 2.07% and 69.95 ± 0.98%, respectively, and the hydrolysis phase was observed to be slower compared to pasteurized and untreated samples during AD.…”

“…Feedstock moisture content is one of the most important factors affecting the efficiency of AD, more especially the hydrolysis phase [54,55]. Although results in previous studies suggest that the efficiency of AD increases as feedstock moisture levels increase [46,54,56], there is no information on optimum moisture levels reported.…”

“…Feedstock moisture content is one of the most important factors affecting the efficiency of AD, more especially the hydrolysis phase [54,55]. Although results in previous studies suggest that the efficiency of AD increases as feedstock moisture levels increase [46,54,56], there is no information on optimum moisture levels reported. In support of the studies by Zamri et al [55], Cvetković et al [54], and Kabeyi and Olanrewaju [57], a study by Khumalo [54] reported that activated sludge with 95% moisture content had a hydrolysis phase of six days, while sludge with 88% moisture content had a hydrolysis phase of 30 days.…”

“…The organic carbon produced during AD of red meat abattoir waste is mostly produced during the degradation of carbohydrates by microorganisms [57,58]. Carbon as well as nitrogen are essential nutrients for regeneration and growth of methanogens during the AD process [54,59]. The results for carbon concentrations are presented in Table 4.…”