05022993 is referenced by 47 patents and cites 11 patents.

The present invention entails a process for treating wastewater utilizing a return activated sludge process. Primary sludge is separated from the wastewater stream and conveyed into a fermentation tank and held a sufficient time to permit hydrolysis of suspended solids so as to produce soluble substrates. Part of the soluble substrates are mixed with nutrified return activated sludge and held for a selected time period to form conditioned return activated sludge. Thereafter, the conditioned return activated sludge is mixed in an initial aerobic treatment zone with pretreated wastewater. Thereafter, the mixed conditioned return activated sludge and pretreatd wastewater is conveyed through a series of treatment zones, which includes at least one anoxic treatment zone, to which part of the soluble substrates are added, where nitrogen and other pollutants are removed from the wastewater.

Title
Process for treating wastewater
Application Number
201185
Publication Number
5022993
Application Date
August 4, 1989
Publication Date
June 11, 1991
Inventor
Ronald E Williamson
Hillsborough
NC, US
Agent
Rhodes Coats & Bennett
Assignee
Orange Water and Sewer Authority
NC, US
IPC
B01D 3/30
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