Growth and Detachment of Periphyton in an Effluent from the Secondary Treatment Plant of Wastewaters

Growth, followed by detachment of periphyton was observed in an artificial stream receiving effluent from a secondary wastewater treatment plant. The cycle of growth and detachment was more conspicuous in summer (water temperature ranged nearly from 24 to 26°C) than in winter (water temperature from 12 to 19°C). This cycle was accompanied by a succession of dominant species of microorganisms in the periphyton. In the light of this work, the considerable pollution caused by periphyton in the Tama River, a shallow stream, running through metropolitan Tokyo, was discussed.