Strengthen “the sustainable farm” concept via efficacious conversion of farm wastes into methane

• DOI: 10.1016/j.biortech.2021.125838
• Publication Date: 2021-08-27T01:36:23Z
• Authors: Ahmed Tawfik; Gamal K. Hassan; Hanem Awad; Marwa Hassan; Patricia Rojas; Jose L. Sanz; Mohamed Elsamadony; Deepak Pant; Manabu Fujii
• Keywords: 2. Zero hunger; Farms; 330; Sewage; 15. Life on land; Waste Disposal, Fluid; 01 natural sciences; 7. Clean energy; 630; 6. Clean water; 12. Responsible consumption; Bioreactors; 13. Climate action; Anaerobiosis; Methane; 0105 earth and related environmental sciences

With escalating global demand for renewable energy, exploitation of farm wastes (i.e., agriculture straw wastes (ASWs), livestock wastewater (LW) and sewage sludge (SS)) has been considered to attain maximum methane yield (MY) via anaerobic digestion (AD). Results pointed that mixture of SS and LW as anaerobes' source with 20 g of ASWs/300 mL of working volume achieved maximum MY and volatile solid (VS) removal efficiency of 0.44 (±0.05) L/gVS and 51.4 (±4.1)%, respectively. This was mainly because of emerging heavy duty bacterial species (i.e., Syntrophorhabdaceae and Synergistaceae) and archaeal community (i.e, Methanosarcina and Methanoculleus) after 70 days of anaerobic incubation. This was acquired along with boosting enzymatic activity, especially xylanase, cellulase and protease up to 71.5(±7.9), 179.3(±14.3) and 207.2(±16.2) U/100 mL, respectively. Furthermore, the digestate contained high concentrations of NH4+ (960.1±(76.8) mg/L), phosphorus (126.3±(10.1) mg/L) and trace metals, making it a good candidate as organic fertilizer.