ABSTRACT
Anaerobic digestion of solids or semi solids produces a semi-solid co-product, referred to as digestate. The solid content of the digestate will depend on the level of biodegradability of the solids in the original feedstock, and the effectiveness of any pretreatment that the feedstock may have been subjected to prior digestion. Disinfection reduces the level of enteric pathogenic organisms in the digestate. Digestates from anaerobic digested biosolids, agricultural, and food and drinks residues have generally been found suitable for land or soil application, as organic fertilizer, preferably following posttreatment operations notably dewatering and aerobic digestion. The potential dangers associated with the operation of anaerobic treatment plants from feedstock and wastewater collection, system operation and to the management of co-/by-products are numerous. Depending on the sources of the original wastes or wastewaters and the management options for treated effluents, posttreatment may be required.
