Anaerobic co-digestion of coffee waste and sewage sludge

Abstract

The feasibility of the anaerobic co-digestion of coffee solid waste and sewage sludge was assessed. Five different solid wastes with different chemical properties were studied in mesophilic batch assays, providing basic data on the methane production, reduction of total and volatile solids and hydrolysis rate constant. Most of the wastes had a methane yield of 0.24-0.28 m3 CH4(STP)/kg VS(initial) and 76-89% of the theoretical methane yield was achieved. Reduction of 50-73% in total solids and 75-80% in volatile solids were obtained and the hydrolysis rate constants were in the range of 0.035-0.063 d(-1). One of the solid wastes, composed of 100% barley, achieved a methane yield of 0.02 m3 CH4(STP)/kg VS(initial), reductions of 31% in total solids, 40% in volatile solids and achieved only 11% of the theoretical methane yield. However, this waste presented the highest hydrolysis rate constant. Considering all the wastes, an inverse linear correlation was obtained between methane yield and the hydrolysis rate constant, suggesting that hydrolysis was not the limiting factor in the anaerobic biodegradability of this type of waste.

Anaerobic Co-Digestion of Waste Wafers from Confectionery Production with Sewage Sludge

“…According to literature reports, the AD process is most typically applied to food waste from restaurants [6][7], either individually or after mixing it with other substrates. Moreover, experiments are carried out with food waste arising in the food processing industry such as sugar beet pulp [8], molasses [9], cheese whey [10], fat [11], coffee waste [12], fruit and vegetable waste [13], and dumpling waste [14]. Those with the use of waste arising in confectionery production are carried only very rarely, even though the material -which is usually highly concentrated and rich in carbohydrates -is a promising substrate for the production of biogas, including methane.…”

“…Sewage sludge is one more example of organic waste, used as a substrate for making biogas [7,8,[10][11][12][13][14][15][17][18][19][20]. Among biological methods, which include also aerobic digestion and composting, anaerobic digestion is perceived to be the most environmentally friendly and cost-effective method for neutralization and disposal of sewage sludge [1].…”

Potential of Streptomyces sp. and Trichoderma sp. as compost microbiota for coffee husk

“…Coffee husk is rich in lignocelluloses materials, which makes it an ideal substrate for microbial processes. Among the attempts for coffee husk utilization are: production of biogas, enzymes, mushroom and compost (Pandey et al, 2000;Neves et al, 2006;Dias et al, 2010).…”

Bioenergy Production from Anaerobic Co-Digestion of Sewage Sludge and Abattoir Wastes

“…Nowadays many successful efforts have been reported in co-digestion of sewage sludge with several other substrates, such as the source-sorted organic fraction of municipal solid waste [9]- [11], confectionery waste [12], sludges from the pulp and paper industry [13], coffee waste [14] and grease-trap sludge from meat processing plants [15] [ 16], have been reported. The use of co-substrates usually improves the biogas yields from anaerobic digester due to positive synergisms established in the digestion medium and the supply of missing nutrients by the co-substrates [17].…”