Abstract: A system and method are provided for aerobic treatment of waste, such as animal or human waste. The method includes the continual introduction of microalgae. The high amounts of oxygen produced by the microalgae satisfies the biochemical oxygen demand in the treatment process and also allows oxidation of undesirable contaminants. Delivery of the microalgae at a desired rate is achieved by incorporation of a series of electrical and mechanical devices housed within a greenhouse type structure which optimizes growth conditions for the microalgae, and also allows the system to be automated.