Effect of ammonia on the anaerobic hydrolysis of cellulose and tributyrin

• Published in: Biomass & bioenergy Vol. 47; pp. 316 - 323
• Main Authors: Fernandes, Tânia V., Keesman, Karel J., Zeeman, Grietje, van Lier, Jules B.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-12-2012; Elsevier
• Subjects: Ammonia; ammonium nitrogen; anaerobic digestion; Anaerobic hydrolysis; animal manures; Applied sciences; bioenergy; Biomass; bounded noise; Cellulose; cow manure; Exact sciences and technology; gastronomy; hydrolysis; identification; inhibition; kinetics; Lipids; Manure; methane production; methanogenic sludge; nitrogen; oils; organic matter; Pollution; thermophilic digestion; tributyrin; waste; Wastes; Ammonia; Manure; Lipids; Biomass; Cellulose; Anaerobic hydrolysis; Organic waste; Glycerol(tri-O-butyryl); Theoretical study; Modeling; Glyceride; Hydrolysis; Triacylglycerol; Anaerobe; Concentration effect; Mathematical model
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2012.09.029

Ammonia nitrogen is one of the most common inhibitors in the anaerobic digestion of complex wastes containing high concentrations of ammonia like animal manures, blackwater and waste oil from gastronomy. The inhibiting effect of ammonia on methanogenesis has been well established. In contrast, the knowledge on the effect of ammonia on organic matter hydrolysis is rather limited. This study focuses on evaluating the effect of ammonia on the hydrolysis of carbohydrates and lipids, which are commonly found in biomass. Batch digestion of tributyrin and cellulose at varying ammonia concentrations were performed, using biomass adapted to 4.9 g NH4+–N.l−1. From this experimental study it was concluded that total ammonia nitrogen in the range of 2.4–7.8 g NH4+–N.l−1 (283–957 mg NH3–N.l−1) does not inhibit the hydrolysis of tributyrin or cellulose. This result is further confirmed by mathematical analysis of the estimated variation of the first-order hydrolysis constant as a function of the total ammonia concentration.
► Ammonia inhibition on hydrolysis has been overlooked up to now. ► Ammonia nitrogen does not affect hydrolysis of lipids (tributyrin). ► Ammonia nitrogen does not affect hydrolysis of carbohydrates (cellulose). ► Both conclusions were verified by mathematical analysis.