Abstract: This invention provides an activated sludge process for treating wastewater containing ammonia as a contaminant and further for treating wastewater containing ammonia as a contaminant and other contaminants which may possibly be present including cyanide, thiocyanate, sulfide and/or organics, wherein the process involves treating wastewater in the presence of an appropriate microorganism population acclimated to the wastewater contaminants and their levels in the wastewater, this microorganism population including (1) nitrifying microorganisms capable of converting ammonia to nitrite, (2) optionally, nitrifying microorganisms capable of converting nitrite to nitrate, and (3) facultative microorganisms capable of denitrifying nitrite and/or nitrate by oxidizing organic material and converting nitrite and/or nitrate to free nitrogen, with the process being operated under a series of controlled conditions to ultimately achieve in the activated sludge process a microbial conversion of ammonia to nitrite and/or ni

Abstract: The process embodying the discovery of the effects of large lime dosages on sewage sludge character consists of: adding lime to raw, sanitary sewage in amounts to exceed a 1:1 weight ratio of lime to COD, or at least 500 ppm lime; immediately treating with carbon dioxide to reduce the pH of the limed sewage mixture to about pH 11; providing a brief period for settling of sludge from the aqueous phase; further adjustment of effluent pH with carbon dioxode to a pH below about 8; discharge of treated effluent water; burning of the sludge to incinerate the organic matter and calcine the calcium carbonate to lime for reuse in the process. This process permits treatment of sanitary sewage in about 30 minutes total as compared to several hours, e.g., 4-8 hours, for other methods of sewage treatment.