The utility model discloses a small ecological filter device which comprises a shell, at least one
filter material layer is arranged in the shell, a water supplementing pipeline is arranged above the
filter material layer, a water collecting area is arranged below the
filter material layer, a water outlet
pipe is arranged in the water collecting area, a rainproof top cover is arranged above the shell, a ventilation pipeline is further arranged in the shell, and the ventilation pipeline is communicated with the water collecting area. The ventilating pipeline vertically penetrates through the filter material layer and extends out of the rainproof top cover; the water replenishing pipeline is connected with a water inlet
pipe and consists of a water distribution main
pipe and a plurality of water distribution
branch pipes, a water distribution sleeve is arranged at a water outlet of each water distribution
branch pipe, and at least one layer of water distribution holes is formed in each water distribution sleeve. According to the utility model, the
aeration oxygenation effect in the filter tank can be improved under the condition that an additional
aeration device is not added, so that the
treatment effect of the filter tank is improved; the
sewage treatment device is used for treating domestic
sewage, and is particularly suitable for treating pretreated small-scale rural domestic
sewage.