Co-treatment of fruit and vegetable waste in sludge digesters. An analysis of the relationship among bio-methane generation, process stability and digestate phytotoxicity

Greenhouse Gas Emissions and Environmental Impact from Recycling the Organic Fraction of Solid Waste: Comparison of Different Treatment Schemes from a Life Cycle Perspective

“…The pilot-scale apparatus used in analyzing the SADB was the same as that reported in References [2,14]. Briefly, it consisted of a 100-L gas-tight anaerobic reactor with a removable top (Figure 1a).…”

“…The amount of liquid digestate generated spontaneously during SADB is usually <10% w/w of the amount of OFMSW processed [2], whereas the solid digestate is directly treatable in the successive post-composting (PC) phase. As reported by several authors, the PC treatment is a mandatory step for reducing the residual phytotoxicity of the digestate and for achieving a high quality and stabilized soil amendment [13][14][15][16]. Among the different properties required for high quality organic fertilizer, the organic carbon concentration [17][18][19] is of particular interest given its importance in carbon sink (Csink) restoration in soils [20] and CO 2 storage [21].…”

Anaerobic co-digestion of sewage sludge and fruit wastes: Evaluation of the transitory states when the co-substrate is changed

“…Due to the high amounts of easily biodegradable organic matter, FW are ideal co-substrates for SS, substrate which is characterized by relatively low carbon-to-nitrogen ratios and high buffer capacity [10]. Moreover, operational data have indicated some non-used capacity in SS anaerobic digesters, sometimes up to 30% [13][14][15]. Therefore, it would be profitable to use these extra capacities by introducing additional substrates to conduct the co-digestion in the existing anaerobic systems.…”

“…Gómez et al [16], who co-digested primary sludge and FVW, observed some fluctuations in the specific gas production (0.3-0.6 L biogas g À1 VS) when changing the mixing conditions and the OLR. Di Maria et al [15] obtained good specific methane productions (0.25 L CH 4 g À1 VS) when co-digesting sewage sludge and fruit wastes at a short hydraulic retention time (10 days). However, digestate stability was severely affected, likely due to the presence of easy biodegradable organic matter.…”

Changes in Acrylamide Monomer Content During Composting of Dairy Processing Sludge

“…Available literature sources focus primarily on analyzing the problem of acrylamide in foods subjected to intense heat treatment. Studies have also been conducted to analyze this threat from a different perspective, and these studies are therefore related to the application of polyacrylamides in the soil environment as hydrogels or as components of organic fertilizers (Lee and Shoda, 2008;Wan et al, 2011;Dai et al, 2013, Dai et al, 2014Uma Rani et al, 2013Di Maria et al, 2014. Despite the strict legal requirements in this area, the practice of sourcing plant materials, especially vegetables, from soil fertilized with stabilized sewage sludge, and thus the food use of such materials still cannot be clearly excluded (Class et al, 2007).…”