New and Broader Applications of Anaerobic Digestion

The general performance of anaerobic digesters and the diversity of wastes that these can treat have been increasing steadily during the last decade as a result of new reactor designs, operating conditions, or the use of specialized microbial consortia. This article illustrates a few examples of new or broader applications of anaerobic digestion to the treatment of sewage, slurries, industrial wastewater, and solid wastes. In the case of domestic sewage, the sustainability of the overall process is much improved by the adoption of an anaerobic pretreatment step, for example, an upflow sludge blanket (USB) reactor. New methods for nutrient removal need to be coupled with anaerobic digestion. These may include, for example, anaerobic ammonium oxidation (anammox) and chemical P precipitation. In terms of industrial wastewaters, new additives are being developed that help the anaerobic sludge deal with unbalanced or toxic wastewaters. Engineering of anaerobic sludge granules is a new area of research that ser...