NOVELTY - Method for processing wastewater involves providing wastewater for processing; reducing oxygen (O2) content of wastewater by unactivated aerobic digestion; eliminating all O2 from wastewater by anaerobic digestion; transferring wastewater to photobioreactor (26); and maintaining wastewater in photobioreactor in conditions favorable for algal photosynthesis, thus allowing algae to grow in photobioreactor.    USE - For treating wastewater including domestic and commercial sewage, industrial wastewater, surface runoff and carbon-containing aqueous waste.    ADVANTAGE - Method achieves purification of wastewater together with production of biofuel using bacterial digestion to covert wastewater to a fertile environment for algae growth, and then growing algae in the resulting fertile environment. The device is configured for processing industrial wastewater having relatively high organic content such as household sewage having organic content about 400 mg/L, where the greater amount of wastewater is produced during evening and night time when there is no sunlight. The device provides several modular units, which can be easily transported to target location, and assembled on site; reduces greenhouse gas emissions by preventing carbon dioxide (CO2) and water vapor emission during sludge decomposition stages, and by fixing CO2 during algae photosynthesis; also provides economic benefits by sustainably supplying reclaimed water, production of biofuels and trade in greenhouse gas emissions.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) device (10) suitable for processing wastewater comprising unactivated aerobic digester (14a) having inlet and outlet; anaerobic digester (20a) having inlet (22) which is connected with outlet of unactivated aerobic digester through anaerobic digester inlet conduit; and photobioreactor having inlet which is connected with outlet of anaerobic digester through photobioreactor inlet conduit; and    (2) method for growing algae involving exposing algae in growth medium to sunlight, where growth medium includes nutrients suitable for algal growth, carbon dioxide (CO2) and devoid of viable aerobic bacteria; maintaining density of algae at about 25 wt.% of growth medium; replenishing nutrients and CO2; and alternatingly moving algae together with growth medium at first speed for at least one continuous minute and at second speed being slower that first speed for at least one continuous minute, where moving at first speed occurs for about 5-40% of period of time.    DESCRIPTION OF DRAWING(S) - The figure shows schematic diagram of wastewater processing device.    Device (10)    Unactivated aerobic digester (14a)    Anaerobic digester (20a)    Anaerobic digester inlet (22)    Photobioreactor (26)    Sludge remover (42)    Carbon dioxide inlet (56)    Algae separating unit (78)