Patent ID: 8308944

Claim:
A wastewater treatment and biomass cultivation method, the method comprising the steps of: providing an aerated bioreactor supporting a population of a phototactic heterotrophic microorganism; supplying to the aerated bioreactor a wastewater influent having nutrients and an organic carbon substrate for growth of the phototactic heterotrophic microorganism population; cultivating the phototactic heterotrophic microorganism population to convert at least a portion of the nutrients and the organic carbon substrate into the phototactic heterotrophic microorganism population, the wastewater influent and the phototactic heterotrophic microorganism population together forming a bioreactor effluent; transferring the bioreactor effluent from the bioreactor to a light clarifier; concentrating the bioreactor effluent in the light clarifier to form a low-solids effluent and a high-solids effluent, the concentration performed by inducing the phototactic heterotrophic microorganism population to phototactically self concentrate by exposing the phototactic heterotrophic microorganism population to a source of light having at least one of an intensity and a wavelength sufficient to cause the phototactic heterotrophic microorganism population to migrate away from the source of light, wherein the phototactic heterotrophic microorganism population is concentrated to form the high-solids effluent; dewatering the high-solids effluent to form a concentrated biomass paste; and processing the low-solids effluent to form a treated water stream.