New challenges to protect health and food quality when managing manures from intensive animal production

摘要

Modern livestock require the proper handling of the large volumes of manure produced. The main concerns are nutrients which are often in excess of the capacity of the local environment resulting in air and water pollution. Treatment can play a key role in the removal of these surpluses either by their breakdown or by exporting as useful products - a wide range of technologies is already well established. However it is the hygienic aspect of manure handling that may pose the greater challenge as concerns grow over the spread of disease and the potential contamination of water and food crops. In exceptional cases, treatment by chemicals is used but storage and biological treatments can also substantially reduce pathogen numbers. However, it is thermaltreatment that is potentially the most comprehensive and reliable treatment for animal wastes where specific disease risks must be regularly removed. Although an effective and versatile option, it is often overlooked due to the anticipated expense in energy consumption. Heat recovery may yet make this approach accessible to the farming systems especially if the process is coupled to an anaerobic digester which can potentially produce an energy neutral process.