Anaerobic digesters were first widely constructed in the United States during the 1970’s energy crisis. Within the anaerobic environment inside a digester, methanogenic microorganisms, utilize organic matter, carbon dioxide, and hydrogen to produce methane, resulting in the creation of renewable energy with decreases in greenhouse gas emissions, organic pollutants, pathogens, and odor (Martin, ...

Meat industry waste waters are 5 to 10 times as strong (BOD)as domestic sewage and contain much higher nitrogen, phosphorus and grease concentrations. Conservation measures and pretreatment facilities are aimed principally at blood (or blood water), casing slimes, wet rendering (tank water), paunch manure, yard drainage and hog hair. The answers available are: dry rendering of blood and grease,...

BACKGROUND Anaerobic digestion has been widely applied to treat the waste activated sludge from biological wastewater treatment and produce methane for biofuel, which has been one of the most efficient solutions to both energy crisis and environmental pollution challenges. Anaerobic digestion sludge contains highly complex microbial communities, which play crucial roles in sludge treatment. How...

The results presented in this paper are part of a project aimed at designing an original solution for the treatment of used disposable diapers permitting the recycling of materials and the recovery of energy. Diapers must be collected separately at source and transported to an industrial facility to undergo special treatment which makes it possible to separate plastics and to recover a biodegra...

Inadequate design and improper mixing operation in anaerobic digesters often lead to poor mixing and digester failures due to the presence of dead zones formed in the digester. More research is required to understand the mixing phenomena in anaerobic digesters and thus improve their efficiency. This paper investigates the efficiency of mixing of digester sludge in a mechanically agitated vessel...

A novel co-digestion approach was evaluated to determine if agricultural and industrial waste residues could efficiently degrade straw without pretreatment. Untreated rice straw was co-digested with pig wastewater and anaerobic sludge from the pulp and paper mill treatment process in a pilot-scale digester (1 m) operated in dry, mesophilic conditions. The total weight ratio of dry straw to pig ...

Digester acclimatization can improve the efficiency of anaerobic digestion (AD), a potentially sustainable process for generating biogas from biological decomposition organic byproducts biodiesel production. This study examined impact rate on production and conversion in laboratory digesters using inocula wastewater treatment plant digester an agro-industrial waste digester. The results showed ...

Modelling anaerobic digestion processes is a key aspect of studying and optimizing digesters and related waste streams. However, for the satisfactory prediction of biogas production and effluent characteristics, some parameters have to be calibrated according to the characteristics of the substrates. This article describes a calibration procedure for the IWA 'Anaerobic Digestion Model no. 1' ap...

Anaerobic digestion (AD) has been recently introduced as a promising technology for producing bioenergy around the world. Due to its especial characteristics, solid waste could be considered as a proper feedstock in the digester. Retention time (RT) and rate of biogas production are two major parameters affecting the efficiency of the process. The AD procedure of biogas production consists of h...

Source segregated food waste was collected from domestic properties and its composition determined together with the average weight produced per household, which was 2.91 kg per week. The waste was fed over a trial period lasting 58 weeks to an identical pair of 1.5 m(3) anaerobic digesters, one at a mesophilic (36.5 degrees C) and the other at a thermophilic temperature (56 degrees C). The dig...