Media type: E-Article Title: Anaerobic digestion of aerobic granular biomass: effects of thermal pre‐treatment and addition of primary sludge Contributor: Val Del Río, Ángeles; Palmeiro‐Sanchez, Tania; Figueroa, Mónica; Mosquera‐Corral, Anuska; Campos, José L; Méndez, Ramón imprint: Wiley, 2014 Published in: Journal of Chemical Technology & Biotechnology Language: English DOI: 10.1002/jctb.4171 ISSN: 0268-2575; 1097-4660 Keywords: Inorganic Chemistry ; Organic Chemistry ; Pollution ; Waste Management and Disposal ; Fuel Technology ; Renewable Energy, Sustainability and the Environment ; General Chemical Engineering ; Biotechnology Origination: Footnote: Description: <jats:title>Abstract</jats:title><jats:sec><jats:title>BACKGROUND</jats:title><jats:p><jats:bold>Management of the sludge generated in the wastewater treatment plants accounts for more than 50% of their operational costs. To minimise these costs, technologies capable of reducing the production of sludge in the plant need to be developed, such as aerobic granular systems. The aggregation state of aerobic granular sludge (<jats:styled-content style="fixed-case">AGS</jats:styled-content>) could be a limiting factor for its further anaerobic digestion. Therefore in this work the feasibility of anaerobic digestion of <jats:styled-content style="fixed-case">AGS</jats:styled-content> has been studied under three conditions: (1) raw <jats:styled-content style="fixed-case">AGS</jats:styled-content>, (2) thermal pre‐treated <jats:styled-content style="fixed-case">AGS</jats:styled-content> and (3) a mixture of thermal pre‐treated <jats:styled-content style="fixed-case">AGS</jats:styled-content> with primary sludge.</jats:bold></jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p><jats:bold>The values obtained for anaerobic biodegradability and reduction of solids in the case of raw <jats:styled-content style="fixed-case">AGS</jats:styled-content> were 44% and 32%, respectively. Thermal pre‐treatment of <jats:styled-content style="fixed-case">AGS</jats:styled-content> at 133 °C enhanced the anaerobic digester performance, in terms of solids reduction, by approximately 47%. The mixture of thermal pre‐treated <jats:styled-content style="fixed-case">AGS</jats:styled-content> with primary sludge provided better results for solids removal than in the case with only thermal pre‐treated <jats:styled-content style="fixed-case">AGS</jats:styled-content>.</jats:bold></jats:p></jats:sec><jats:sec><jats:title>CONCLUSION</jats:title><jats:p><jats:bold>Anaerobic digestion of <jats:styled-content style="fixed-case">AGS</jats:styled-content> has a similar performance as that reported for waste activated sludge, which indicates that the aggregation of the biomass into granules does not seem to limit the anaerobic process. © 2013 Society of Chemical Industry</jats:bold></jats:p></jats:sec>