Anaerobic Digestion
Anaerobic digestion is a sequence of processes by which microorganisms break down biodegradable material in the absence of oxygen.[1] The process is used for industrial or domestic purposes to manage waste or to produce fuels. Much of the fermentation used industrially to produce food and drink products, as well as home fermentation, uses anaerobic digestion.
Anaerobic digestion occurs naturally in some soils and in lake and oceanic basin sediments, where it is usually referred to as "anaerobic activity".[2][3] This is the source of marsh gas methane as discovered by Alessandro Volta in 1776.[4][5]
The digestion process begins with bacterial hydrolysis of the input materials. Insoluble organic polymers, such as carbohydrates, are broken down to soluble derivatives that become available for other bacteria. Acidogenic bacteria then convert the sugars and amino acids into carbon dioxide, hydrogen, ammonia, and organic acids. In acetogenesis, bacteria convert these resulting organic acids into acetic acid, along with additional ammonia, hydrogen, and carbon dioxide amongst other compounds. Finally, methanogens convert these products to methane and carbon dioxide.[6] The methanogenic archaea populations play an indispensable role in anaerobic wastewater treatments.[7]
Anaerobic digestion is used as part of the process to treat biodegradable waste and sewage sludge. As part of an integrated waste management system, anaerobic digestion reduces the emission of landfill gas into the atmosphere. Anaerobic digesters can also be fed with purpose-grown energy crops, such as maize.[8]
Anaerobic digestion is widely used as a source of renewable energy. The process produces a biogas, consisting of methane, carbon dioxide, and traces of other 'contaminant' gases.[1] This biogas can be used directly as fuel, in combined heat and power gas engines[9] or upgraded to natural gas-quality biomethane. The nutrient-rich digestate also produced can be used as fertilizer.
With the re-use of waste as a resource and new technological approaches that have lowered capital costs, anaerobic digestion has in recent years received increased attention among governments in a number of countries, among these the United Kingdom (2011),[10] Germany,[citation needed] Denmark (2011),[11] and the United States.[12]
Tamworth (/ˈtæmwərθ/) is a large market town and borough in Staffordshire, England, 14 miles (23 km) north-east of Birmingham and on the West Coast Main Line. The town adjoins Warwickshire to the south and east, Lichfield to the north and west and local junctions of the M6 Toll motorway. It takes its name from the River Tame, which flows through it. Its resident population (mid-2019 est.) was 76,696.
Tamworth was historically divided between Warwickshire and Staffordshire until 1889, when the town was placed entirely in Staffordshire.[1]
Tamworth hosts a simple but elevated 12th century castle, a well-preserved medieval church (the Church of St Editha) and a Moat House. Tamworth was the capital of the Anglo-Saxon Kingdom of Mercia during the Heptarchy of seven kingdoms and throughout its later, greater, form.
The town's industries include logistics, engineering, clothing, brick, tile and paper manufacture. Until 2001 one of its factories was Reliant, which produced the Reliant Robin three-wheeler car and the Reliant Scimitar sports car.
The Snowdome, a prototype real-snow indoor ski slope is in Tamworth and 1.7 miles (2.7 km) south is Drayton Manor Theme Park and one of the many marinas serving the Coventry Canal and Birmingham and Fazeley Canal which combine south of the town.