A method for processing wastewater includes the steps of introducing air and a liquid into a pump, and subjecting the air and liquid to high heat and pressure; delivering the heated and pressurized air and liquid from the pump to a gas and liquid separator to separate the air from the liquid; expanding the air from the gas and liquid separator through a nozzle to accelerate the air as it expands; injecting at least some portion of the wastewater to be processed into the air from the nozzle in an entrainment section downstream from the nozzle to entrain the wastewater into the air; passing the liquid portion from the gas and liquid separator through a valve to lower the pressure of the liquid to achieve flash evaporation of the liquid to produce water and steam; introducing the water and steam produced from the valve into the air and entrained wastewater in the entrainment section, to enhance entrainment of water into the air; and delivering the air and entrained wastewater from the entrainment section to an in line gas and solid separator to separate the air and steam from waste solids.