APPARATUS FOR PURIFYING CONC. FILTHY WATER OF HEAVY RAINFALL BY CAPILLARY INFILTRATED TRENCH

摘要

PURPOSE:To obtain the titled purifying apparatus which can efficiently purify a large amount of rainfall or highly-concentrated filthy water, by packing a trench provided between a surface soil layer and a low-permeable lower soil layer with fillers such as pebbles in a crown-shaped state, and then pouring and arranging covering soil through a net made of synthetic resin or the like stretched over the surface of the fillers. CONSTITUTION:A trench 3 is formed by perforating sedimentary soil comprising the surface soil layer 1 in which granulated structure is grown to enable to retain a large amount of water and a lower soil layer 2 having small porosity and low water-permeability under the surface soil layer 1. Said trench 3 has the cross section of about 60cm in height and about 30cm in width for instance. A saucer 4 composed of a water-impermeable membrane is laid at the lower part of the trench 3, i.e. the inner surface part where the layer 2 is exposed, to inhibit the pollution of underground water by the gravity penetration of filthy water and to obtain the effect to continually supply a large amount of filthy water such as rainwater. The trench 3 is packed with fillers 5 such as pebbles in a crown-shaped state, a trench net 6 made of synthetic resin is sretched over the outer surface of the fillers 5, and an upper part above the net 6 is packe again with returned soil 7, to constitute the objective apparatus for treating highly-concentrated filthy water of heavy rainfall in the capillary infiltrated trench.