Multi-zone process and apparatus for treating wastewater

An apparatus for treating wastewater comprising:

• a first zone adapted to receive a mixed stream comprising previous, anaerobically treated wastewater from a second zone, wherein the previous, anaerobically treated wastewater facilitates direct transport and passage of one or more second microbes from the second zone to the first zone, said first zone comprising a first bioreaction zone, wherein the first bioreaction zone is configured with one or more retaining or facilitating structures that retain or facilitate growth of one or more first biological microbes and convert organic matter in the mixed stream into at least volatile fatty acids (VFAs) to produce treated wastewater;
• and
• the second zone adapted to receive the treated wastewater from the first zone, said second zone comprising a second bioreaction zone comprising a plurality of anaerobically facilitating structures configured to anaerobically facilitate growth of one or more second biological microbes, and
• means for mixing contents of the second zone, and
• wherein said plurality of anaerobically facilitating structures comprise a pair of electrodes comprising both an anode and a cathode configured to further treat for further treating the wastewater and at least convert the VFAs into methane.