Systems and methods for water treatment

A wastewater treatment method, the method comprising:

• providing wastewater to a membrane bioreactor (MBR);
• providing normal air or pure oxygen to the MBR;
• aerating the wastewater, thereby incorporating the air or pure oxygen into the wastewater;
• producing an output effluent, the output effluent comprising sludge solids, partially treated wastewater and gaseous carbon dioxide from the MBR;
• providing the partially treated wastewater to an ultrafiltration/microfiltration algal membrane photobioreactor (algal-MPBR);
• cultivating algal biomass in the algal-MPBR;
• providing the sludge solids to an anaerobic digester;
• providing the algal biomass to the anaerobic digester;
• producing fertilizer and biogas from the sludge solids and algal biomass by the anaerobic digester.

A wastewater treatment system, the system comprising:

• a staged membrane bioreactor (MBR), the MBR having at least two stages in fluid communication, each stage configured to:
• intake influent wastewater and air or high-purity oxygen;
• aerate the influent wastewater with the air or high-purity oxygen;
• and
• output effluent comprising sludge solids, carbon dioxide and partially treated water;
• a membrane algal photobioreactor (algal-MPBR) in fluid communication with the staged MBR, the algal-MPBR configured to:
• intake the carbon dioxide and the partially treated water;
• and
• output reuse water and an algal biomass;
• an anaerobic digester, the anaerobic digester in fluid communication with the MBR and the algal-MPBR, the anaerobic digester configured to:
• intake the sludge solids and the algal biomass;
• and
• output at least one of fertilizer, biogas and indirect potable water.