Publication: Sugarcane bagasse as a co-substrate with oil-refinery biological sludge for biogas production using batch mesophilic anaerobic co-digestion technology: Effect of carbon/nitrogen ratio
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Date
2021
Authors
Ghaleb A.A.S.
Kutty S.R.M.
Salih G.H.A.
Jagaba A.H.
Noor A.
Kumar V.
Almahbashi N.M.Y.
Saeed A.A.H.
Saleh Al-dhawi B.N.
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI AG
Abstract
Man-made organic waste leads to the rapid proliferation of pollution around the globe. Effective bio-waste management can help to reduce the adverse effects of organic waste while contributing to the circular economy at the same time. The toxic oily-biological sludge generated from oil refineries� wastewater treatment plants is a potential source for biogas energy recovery via anaerobic digestion. However, the oily-biological sludge�s carbon/nitrogen (C/N) ratio is lower than the ideal 20-30 ratio required by anaerobic digestion technology for biogas production. Sugarcane bagasse can be digested as a high C/N co-substrate while the oily-biological sludge acts as a substrate and inoculum to improve biogas production. In this study, the best C/N with co-substrate volatile solids (VS)/inoculum VS ratios for the co-digestion process of mixtures were determined empirically through batch experiments at temperatures of 35-37 �C, pH (6-8) and 60 rpm mixing. The raw materials were pre-treated mechanically and thermo-chemically to further enhance the digestibility. The best condition for the sugarcane bagasse delignification process was 1% (w/v) sodium hydroxide, 1:10 solid-liquid ratio, at 100 �C, and 150 rpm for 1 h. The results from a 33-day batch anaerobic digestion experiment indicate that the production of biogas and methane yield were concurrent with the increasing C/N and co-substrate VS/inoculum VS ratios. The total biogas yields from C/N 20.0 with co-substrate VS/inoculum VS 0.06 and C/N 30.0 with co-substrate VS/inoculum VS 0.18 ratios were 2777.0 and 9268.0 mL, respectively, including a methane yield of 980.0 and 3009.3 mL, respectively. The biogas and methane yield from C/N 30.0 were higher than the biogas and methane yields from C/N 20.0 by 70.04 and 67.44%, respectively. The highest biogas and methane yields corresponded with the highest C/N with co-substrate VS/inoculum VS ratios (30.0 and 0.18), being 200.6 mL/g VSremoved and 65.1 mL CH4/g VSremoved, respectively. � 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Description
Bagasse; Biogas; Biological water treatment; Carbon; Delignification; Liquid methane; Methane; Petroleum refineries; Sewage treatment plants; Sludge digestion; Sodium hydroxide; Substrates; Wastes; Wastewater treatment; Anaerobic co-digestion; Anaerobic digestion technology; Batch experiments; Biogas and methanes; Biological sludge; Solid-liquid ratio; Sugar-cane bagasse; Wastewater treatment plants; Anaerobic digestion; activated sludge; anaerobic digestion; biogas; biotechnology; carbon isotope ratio; crop residue; experimental study; industrial production; nitrogen isotope; organic pollutant; substrate