NOVELTY - Wastewater treatment system comprises inlet flow path (33) and secondary treatment system (30) comprising tank and media wheel(s) (40), and an effluent flow path (34). The tank receives wastewater through inlet flow path, and the media wheel configured for algae growth rotates within the tank. Thus, the portion of media wheel is immersed into the wastewater and rest of the media wheel portion is above the wastewater and rotates for exposing to sunlight for algae growth. The effluent flow path discharges the treated wastewater from secondary treatment system.    USE - System for treating wastewater (claimed) and generating bio-diesel fuel.    ADVANTAGE - The wastewater treatment system effectively and economically treats wastewater and generates non-toxic byproduct such as algae for generating hydrogen gas, bio-fuel, fertilizer and animal feed additives.    DETAILED DESCRIPTION - Wastewater treatment system comprises inlet flow path and secondary treatment system comprising a wastewater-containing tank and media wheel(s), and an effluent flow path. The inlet flow path receives wastewater from source outside the treatment system, and connected to the secondary treatment apparatus. The tank receives wastewater through inlet flow path, and the media wheel configured for algae growth rotates within the tank. Thus, the portion of media wheel is immersed into the wastewater and rest of the media wheel portion is above the wastewater and rotates for alternately exposing to sunlight for algae growth. The effluent flow path which is connected to the tank discharges the treated wastewater from secondary treatment system. The effluent flow path includes chlorine disinfection chamber. The wastewater treatment process includes separate system such as methane digester, bio-fuel production system, ethanol production system and power generation plant. The system receives waste carbon dioxide for contributing algae growth.    DESCRIPTION OF DRAWING(S) - The drawing shows the enlarged sectional view of secondary treatment system.    Secondary treatment system (30)    Tank (32)    Inlet flow path (33)    Effluent flow path (34)    Media wheel (40)    Biological filter media (45)