Anaerobic photobioreactor and method for biomass cultivation, wastewater treatment, nutrients recovery, energy production and high-value products synthesis

An anaerobic photobioreactor for purple phototrophic bacteria (PPB) biomass cultivation, wastewater treatment, nutrients recovery, energy production and high-value products synthesis, comprising:

• a. a horizontal closed anaerobic ditch;
• b. an inlet and an outlet of wastewater, both connected to an internal space of the anaerobic ditch body;
• c. a covered wastewater circulation system inside the anaerobic ditch;
• d. a lid covering the anaerobic ditch to block light at wavelengths below 750 nm, wherein the covering lid is made of poly(methyl methacrylate) with wavelength shifting compounds, wherein the compounds are cyanine dyes selected from the group consisting of 1,1,2-Trimethylbenzindoleninium 1,3-disulfonate, 5-carboxy-1-(4-sulfobutyl)-2,3,3-trimethyl-3H-indolenine 2, and 1-(4-sulfonatobutyl)-2,3,3-trimethylindoleninium-5-sulfonate, or N-Ethyl-2,3,3-trimethylbenzindoleninium 5,7-Disulfonate;
• e. a cylindrical sampling tube submerged into the anaerobic ditch and stuck to the lid, to perform water and biomass analysis and control the headspace pressure;
• f. a settleable biomass recirculation pipe from a biomass separator to the anaerobic ditch;
• and
• g. a biomass outlet line from the biomass separator.