Kinetics of Acetate Metabolism during Sludge Digestion

Kinetics of primary sludge digestion at various temperatures

Anaerobic digestion is now commonly used for sludge treatment. Most industrial digesters operate under mesophilic (37°C) or thermophilic (55°C) conditions. These two regimes are considered as optimal for methane production. In this work, continuous sludge digestion has been operated at labscale at 5 different temperatures comprised between 28° and 55°C. The reactors were first inoculated with a...

Methanosarcinaceae and acetate-oxidizing pathways dominate in high-rate thermophilic anaerobic digestion of waste-activated sludge.

This study investigated the process of high-rate, high-temperature methanogenesis to enable very-high-volume loading during anaerobic digestion of waste-activated sludge. Reducing the hydraulic retention time (HRT) from 15 to 20 days in mesophilic digestion down to 3 days was achievable at a thermophilic temperature (55°C) with stable digester performance and methanogenic activity. A volatile s...

Multistaged Anaerobic Sludge Digestion Processes

Two multistaged anaerobic digestion systems, a four-stage thermophilic anaerobic digestion (4TAD), all at 55°C, and a four-stage anaerobic digestion with a tapered temperature configuration (4ADT) at 55, 49, 43, and 37°C, respectively, were studied to evaluate their solids, volatile organic sulfur compounds, and indicator organism (E. coli and fecal coliform) reduction potentials. The 4TAD syst...

Chemical Studies on Sludge Digestion

Digestion kinetics of carbohydrate fractions of citrus by-products

The present experiment was carried out to determine the digestion kinetics of carbohydrate fractions of citrus by-products. Grapefruit pulp (GP), lemon pulp (LE), lime pulp (LI) and orange pulp (OP) were the test feed. Digestion kinetic of whole citrus by-products and neutral detergent fiber (NDF) fraction and acid detergent fiber (ADF) fractions of citrus by-products were measured using the <e...