Although the anaerobic digestion process is the same whether it is treating sewage sludge or domestic waste, it is unusual for both types of waste to be treated together ..In Denmark there is a more “joined up” approach with a major program for biogas production using anaerobic digestion technology. Kruger, part of Veolia Water Solutions & Technology (VWS), was responsible for developing much of the anaerobic digestion technology currently being used in Denmark and they designed a benchmark plant at Grindsted Kommune, a cooperative in a mainly agricultural area with local food processing industries. It co-digests organic household waste, primary and secondary sewage sludge, food wastes from supermarkets and restaurants and food industry wastewater to produce almost 7,000m3/day of biogas. This generates electricity and district heating. The odourless digested sludge is dewatered and then spread on agricultural land. ...The Danish model clearly works and has demonstrated the ability of current anaerobic digester technology to co-digest household waste, industrial waste and sewage sludge. For rural sewage treatment works in the U.K. there is a valuable lesson to be learned. There is already a culture of sorting and recycling waste, so the Danish approach could be easily adopted, given the political will. Aside from the benefits of electricity generation and district heating, the reduction in the quantity of waste going to landfill is significant and there are clear environmental benefits to be gained. Anaerobic digestion technology is continuing to develop and, along with the latest high efficiency CHP systems, it is possible to maximize the economic benefits of energy from waste, and we think it’s high time it happened here in the U.K. Read on at: http://www.renewableenergyworld.com/rea/blog/post/2011/11/co-digestion-a-sust...
