| 摘要 |
<p>Provided is a slow filtration device by which raw water collected from a river or underground can be treated to give drinkable water or the like within a short time after newly assembling. A slow filtration device comprising a sand filter layer, a raw water supply port and a discharge port, which is equipped with a net (15) being provided above the sand filter layer (13) in a filtration tank (11) so as to cover the sand filter layer (13) and serving as a support for the growth of algae; a heater (18) being provided just below the net (15) and maintaining the net (15) at a definite temperature; and an algae-rearing pump (16) being provided above the net (15) in the filtration tank (11) and irradiating light to the net (15) to promoting the growth of the algae.</p> |
