title: Anaerobic digestion of slaughterhouse waste with UF-membrane separation and recycling of permeate after free ammonia stripping.
abstract: Anaerobic digestion can adapt to free ammonia to a certain extent. During the anaerobic digestion of slaughterhouse waste, however, an ammonia concentration of up to 15 g Nl(-1) can be reached in the sludge liquid and this will even inhibit adapted sludge. To lower this concentration, a fraction of the digester liquid must therefore be continuously separated from the digested sludge and the free ammonia stripped before the liquid is recycled to the digester. A mesophilic laboratory digester was successfully operated with an ammonium concentration of 4-5g l(-1) and a pH of 8.0-8.4. After free ammonia stripping, the excess liquid was treated in a laboratory SBR for nitrogen and phosphorus removal before being added to the receiving water. The effluent had no toxic effect on daphnia and algae.
authors.affiliation: EAWAG, Swiss Federal Institute for Environmental Science and Technology, Dübendorf, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Siegrist
authors.forename: W
authors.initials: W
authors.lastname: Hunziker
authors.forename: H
authors.initials: H
authors.lastname: Hofer
mesh_terms: D000003:Abattoirs; D000641:Ammonia / Q000378:metabolism; D001421:Bacteria, Anaerobic / Q000378:metabolism; D019149:Bioreactors; D005232:Fatty Acids, Volatile / Q000378:metabolism; D007220:Industrial Waste; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage; D014462:Ultrafiltration; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D005232:Fatty Acids, Volatile; D007220:Industrial Waste; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D000641:Ammonia