Dual return activated sludge process in a flow-equalized wastewater treatment system

A process for treating wastewater or sewage comprising:

• receiving a wastewater inflow or a sewage inflow in a first carbonaceous biological oxygen demand (BOD) removal reactor;
• receiving an outflow from the first carbonaceous BOD removal reactor to one or more second carbonaceous BOD removal reactors;
• receiving an outflow from the one or more second carbonaceous BOD removal reactors in a nitritation reactor;
• receiving an overflow of partially treated wastewater or partially treated sewage from the nitritation reactor in an anammox reactor;
• receiving a bypass flow from the first carbonaceous BOD removal reactor and/or the one or more second carbonaceous BOD removal reactors in the anammox reactor;
• receiving a mixed liquor flow from the anammox reactor in a clarifier;
• providing a first return activated sludge flow from the clarifier to the first flow carbonaceous BOD removal reactor;
• providing a second return activated sludge from the clarifier to the nitritation reactor;
• and, providing a third return activated sludge flow from the clarifier to the anammox reactor,
• wherein the first carbonaceous BOD removal reactor and the one or more second carbonaceous BOD removal reactors are each separated by a partition wall, and
• wherein the partition wall(s) comprise one or more openings providing fluid communication therethrough.