| 摘要 |
<p>A filling for a percolating filter for biological purification of waste water includes a plurality of flexible, irregularly touching, randomly arranged plastic strips up to 8 cm in width and several meters in length twisted together and suspended from a support over the height of the filter tank. The strips may have a maximum thickness of 30-100 mu m and a minimum thickness of 10-60 mu m, varying in such thicknesses over their width. The strips may be residue edge portion cuttings severed from the production of continuously produced sheet materials.</p> |
