Enhancing Methane Production in a Two-Stage Anaerobic Digestion of Spent Mushroom Substrate and Chicken Manure via Activation of Sludge, Optimization of Temperature, and C/N Ratio

Abstract

Management of spent mushroom substrate (SMS) is causing a global environmental concern due to tremendous increase in mushroom production globally. Therefore, in this research, the performance of a two-stage anaerobic co-digestion (TS-AD) of spent mushroom substrate and chicken manure was evaluated in terms of methane and biogas production and process stability with respect to single stage anaerobic digestion (SS-AD). Activation of anaerobic sludge using aeration or heat treatment in the first stage at mesophilic temperature followed by thermophilic co-digestion with chicken manure in the second stage was investigated. TS-AD exhibited better performance and enhanced methane generation over SS-AD. The optimal temperatures were determined as 35°C and 50°C for the first and the second stage of TS-AD, respectively. C/N ratio of 10 was the most suitable for biogas and methane production. TS-AD with C/N ratio of 10 and mesophilic digestion of SMS and sludge for 3 days at 35°C followed by co-digestion of the first stage effluent with chicken manure at 50°C was the optimized state producing 1359 mL of biogas of which 614.42 mL was methane, showing an increment by 59.44% in methane production as compared to SS-AD. TS-AD might be promising approach for utilization of SMS as feed stocks for biogas and methane production.

Effects of Stepwise Temperature Shifts in Anaerobic Digestion for Treating Municipal Wastewater Sludge: A Genomic Study

“…In AD processes, temperature has a significant influence on biogas production and microbial ecology [60,61]. There has been a number of research that examined the effects of temperature in mesophilic and thermophilic conditions [18,62,63]. However, to the best of our knowledge, the assessment of biogas production (especially CH 4 ) and microbial community adaptation under multiple rising temperature conditions in a fed-batch reactor has not been widely studied.…”

Unlocking the Potential of Spent Mushroom Substrate (SMS) for Enhanced Agricultural Sustainability: From Environmental Benefits to Poultry Nutrition

“…Turning to the domain of energy recovery, Shu et al [62] undertook a study focused on the two-stage anaerobic digestion of SMS and CM, with the aim of optimizing methane production. The outcomes demonstrated a notable increase in methane production, showcasing the substantial potential of SMS and poultry waste in facilitating energy recovery within poultry farming operations.…”

Spent Mushroom Substrate Hydrolysis and Utilization as Potential Alternative Feedstock for Anaerobic Co-Digestion

“…[ 22 ]. Considering that for 1 kg of oyster mushrooms about 4–5 kg of residues, called Spent Mushroom Substrate—SMS, are discarded [ 23 , 24 , 25 ], one realizes the huge amount of biowaste generated by the mushroom agroindustry. The SMS as a composted organic medium consists of fungal mycelial residues and renewable agricultural residues such as wheat or rice straw, sawdust, sugarcane bagasse, etc., supplemented with manure and gypsum, and is therefore rich in cellulose, hemicellulose and lignin [ 26 , 27 ].…”

“…Anaerobic digestion (AD) of lignocellulosic biomass to produce biomethane involves a chain of chemical reactions and the presence of a microbial consortium. Practically, polymeric substances are biodegraded through a sequence of metabolic steps consisting of hydrolysis, fermentation (acidogenesis), acetogenesis and methanogenesis [ 9 , 25 , 61 , 65 , 66 ]. The anaerobic digestion process (viz.…”

“…The choice and the utilization of the appropriate substrate represents a very important factor affecting the AD process. Biogas production has been studied for both mono-digestion and co-digestion of SMS, but scientific research mainly focuses on co-digestion of SMS with manure and/or other organic wastes to optimize production [ 25 , 58 , 71 , 72 , 73 , 74 , 75 , 76 ].…”