A method is described for anaerobic biological waste treatment in multiple stages where a relatively high strength wastewater is introduced into a first biological reactor to produce an effluent of reduced strength. The effluent is passed into a second biological reactor for reaction to take place. The passage of the effluent into the second biological reactor is continued until the biological solids in the second reactor enter into a negative growth phase. It becomes relatively stable, where the flow of waste through the reactors is reversed by terminating introduction of the waste into the first reactor and passing the same into the second reactor. This causes microorganisms in the second reactor to enter into a positive growth phase and the solids in the first reactor to enter into a negative growth phase.
Board of Trustees of the University of Arkansas (Little Rock, AR)
Young, James C., "Cyclic, multi-stage biological process for wastewater treatment" (1990). Patents Granted. 256.