To provide a wastewater treatment method capable of putting bubbles formed by photosynthetic bacteria to practical use by the symbiosis with aerobic organic nutrition bacteria by noticing that two large processes, that is, energy consumption by mainly oxidation making inorganic materials, and energy accumulative assimilation, making resources, are pointed out as an element circulating system of elements on the globe, that the latter is important, and that the combination type of the latter and the former is efficient and little environmental load for wastewater disposal.

When wastewater is treated, a bubble zone generated on the surface of water in a photocatalytic bacteria-added aeration tank is used as a bioreactor for a reducible biological treatment.