BIOLOGICAL SEWAGE TREATMENT APPARATUS OF THE ROTARY DISC TYPE

摘要

Sewage treatment apparatus is disclosed. The apparatus comprises a rotary shaft carrying spaced rotary plates adapted to be rotated while being dipped into sewage in a treatment tank. The rotary plates are secured to the shaft by pairs of holding members fixed to the shaft. This provides simple assembly while ensuring a strong connection. More firm fixing of the rotary plates can be achieved by providing the pairs of holding members with projecting portions in one member and complementary recesses in the other. The rotary plates may each be formed of several fan-shaped plates in which case the fan-shaped plates can be fixed easily in position by holding them between the complementary projections and recesses.