Peak flow management in wastewater treatment using direct membrane filtration

A process for treating sewage wastewater, using non-biological treatment of an overflow side stream only during peak flow periods, comprising the steps of:

• receiving sewage wastewater,
• sending a defined first portion of said received sewage wastewater to biological treatment and to a submerged membrane filter for membrane bioreactor (MBR) filtration, and when in a peak flow period the quantity of said received sewage wastewater exceeds said defined first portion,
• forming a second portion of sewage wastewater from the received sewage wastewater that exceeds said defined first portion, and sending said second portion to a non-MBR ultra filtration process,
• adding a flocculating agent to the second portion entering the non-MBR ultra filtration process,
• filtering said second portion, thereby producing retentive waste including flocculated material and producing a permeate,
• sending said retentive waste to said biological treatment and submerged membrane filter for MBR filtration,
• treating said permeate to remove biochemical oxygen demand,
• treating said permeate to remove ammonia, and
• combining the resulting filtered, treated side stream with output from the MBR filtration to produce a combined stream to meet a required standard for treated wastewater without further treatment.